Agricultural Plant Pest Control

Kansas State University Agricultural Experiment Station and Cooperative Extension Service Category 1A

Agricultural Plant Pest Control July 2011 Table of Contents Integrated Pest Management and the Environment Definition of a Pest ...... 6 Definition of a Pesticide ...... 6 Integrated Pest Management ...... 6 Worker Protection Standard...... 7 Pesticide Selection ...... 8

Insect Pest Management in Field Crops Common Insect Groups ...... 11 Sampling ...... 13 Alfalfa Pests ...... 17 Corn Pests ...... 19 Cotton Pests ...... 21 Sorghum Pests ...... 23 Soybean Pests ...... 25 Sunflower Pests ...... 27 Wheat Pests ...... 29 Beneficial Organisms ...... 31

Insect and Mite Pests of Fruit Crops Apple Insect and Mite Pests ...... 33 Peach Insect Pests ...... 35 Management ...... 36

Vegetable Crop Pests Soil Insects ...... 39 Sucking Insects and Mites ...... 41 Chewing Insects ...... 44 Management ...... 49

Crop Plant Diseases Causes and Types ...... 53 Abiotic Disorders ...... 57 Disease Management ...... 58 Cultural Practices...... 60 Disease Diagnosis ...... 64 Sample Submission ...... 65 References ...... 67

4 Table of Contents Weed Management in Field Crops Weed Identification and Biology ...... 70 Weed Life Cycles ...... 71 Types of Herbicides ...... 78 Herbicide Modes of Action ...... 79 Herbicide Resistance ...... 80 Herbicide Application ...... 81 Soil-Applied ...... 81 Foliar-Applied ...... 81 Weed Management Decisions...... 82

Pasture and Rangeland Weed and Brush Control Weeds in Pasture and Rangeland ...... 85

Equipment and Calibration for Commercial Field Crop Applications Nozzle Selection ...... 95 Minimizing Spray Drift ...... 98 Calibration ...... 101 Mixing Pesticide Formulations ...... 111 Maintenance and Cleaning ...... 112 Record Keeping ...... 114

Aerial Application Dispersal Equipment ...... 116 Calibration ...... 118 Drift Reduction ...... 120 Operations ...... 121

Directions for Using this Manual This is a self-teaching manual. At the end of each major section is a list of study questions to check your understanding of the subject matter. These study questions are representative of the type that are on the certification exam. By studying this manual and answering the study questions, you should be able to gain sufficient knowledge to pass the Kansas Commercial Applicators Certification examination. Correct answers appear on page 124.

5 Integrated Pest Definition of a Pest Integrated Pest Management and The first step to managing pests Management the Environment is to identify them. A pest is any Integrated pest management plant, animal, or microbe that is (IPM) is a pest management unwanted, troublesome, annoying strategy that focuses on long- or destructive. This manual covers term prevention through regular three types of pests: monitoring and a combination of • insects and related arthropods, control methods. IPM attempts • plant disease agents, to prevent losses from pests in ways that are effective, economical, • weeds. and available, while maintaining Crop plants can be pests (weeds) safety of the crop, people, and if present where they are not environment. IPM is based on wanted, for example, volunteer a thorough understanding of alfalfa in corn, corn in soybeans, the pest, so cultural, mechanical, or rye in wheat. Plant disease biological, genetic, and chemical agents can be desirable if they techniques can be integrated help control weeds. Where and to optimize control. Pest when the organism occurs plays management tactics commonly an important role in determining used in field crop situations whether it is actually a pest. include the use of resistant varieties, crop rotation, following Definition of a Pesticide recommended tillage practices, and proper soil fertilization. A pesticide is a substance or mixture intended to prevent, The integrated approach is control, destroy, repel, or attract important because of problems a pest. This includes the use of associated with exclusive use plant regulators, defoliants, and of chemical pesticides. Some desiccants. Pesticides can be pest species have no satisfactory grouped by target: pesticide available for control, so other methods are important. • insecticides (kills insects) Adverse weather conditions may • fungicides (kills fungus) prevent application or reduce • her bicides (kills weeds) efficacy of pesticides that are • miticides (kills mites) applied. Safe pesticide application • nematicides (kills nematodes) is impossible in areas close to dwellings, livestock, beehives • rodenticides (kills rodents) or water resources. Inadequate coverage, poor placement, or improper timing can lead to poor control. And pests can develop resistance through the use of a single pesticide. Chemical pesticides can be responsible for destruction of natural enemies, outbreaks of secondary pests, environmental contamination, 6 Integrated Pest and cause health hazards for the • a verbal warning or a sign at a applicator and people who come in treated site if the label requires it. Management and contact with the treated area. The commercial applicator The reason for most pest control business must inform its customer the Environment failures is not understanding the (a producer of agricultural plants) biology of the pest, its effect on the of the following information crop and how a particular control before each pesticide application: method works. • specific locations to be treated, • time and date the pesticide Worker Protection is scheduled to be applied, Standard (WPS) • product name, EPA The Worker Protection Standard registration number, and is a federal regulation intended active ingredient, to reduce the risk of illness or • restricted entry interval injury to pesticide handlers and (REI) for the pesticide, agricultural workers. A pesticide • whether the label requires both handler is a person hired to treated area posting and oral mix, load, transfer, apply, or notification, dispose of pesticides and their containers. Agricultural workers • other safety requirements on are individuals hired to do manual the label for workers and other labor, such as thinning, pruning, persons in the area. weeding, rouging, detasseling, or On the other hand, the customer hand harvesting. must inform the business of any Worker Protection Standard other areas that may be treated requirements should be followed with a pesticide or are under a by individuals handling pesticides restricted entry interval (REI) that for production of agricultural are within ¼ mile on the same plants on farms, forests, nurseries, agricultural establishment. and greenhouses when the product For more information about label refers to WPS, which is Worker Protection Standards for referenced in the “Agricultural Use agricultural pesticides, consult the Requirements” box of the label. manual “How to Comply with Employers who hire handlers and the Worker Protection Standard workers are required to provide: for Agriculture Pesticides: What Employers need to Know,” or visit • EPA approved pesticide safety the agricultural compliance center training, at http://www.epa.gov/agriculture/ • perso nal protective equipment twor.html (PPE), • decontamination supplies, • emergency assistance, • post application and safety information at a central location,

7 Integrated Pest Pesticide Selection • Will the use of this pesticide Management and expose humans to health or The decision to use a pesticide safety risks? should be based on information the Environment obtained from scouting, • Will the use of this pesticide knowledge of economic thresholds, threaten wildlife populations? and an awareness of potential • Will the use of this pesticide benefits and risks associated affect what you plan to plant with treatment. Improperly used, back? pesticides can cause detrimental • Are there any preharvest effects to the applicator, the crop, intervals that could affect or the environment. Pesticides can harvest? provide effective control, but they • Do the pesticides should be used judiciously and in characteristics create potential combination with nonchemical for nontarget injury? methods that can be incorporated into the cropping system. Once a Although the use of pesticides can decision to use a pesticide has been greatly enhance food and fiber made, several questions should be production during pest outbreaks, carefully considered. misuse may create adverse environmental effects. • Is the target pest listed on the pesticide label? Pesticides can negatively impact groundwater, nontarget organisms, • Does the label state that the and threatened and endangered pesticide will control the pest, species if label directions are not or does the word “suppression” followed. A pesticide's potential appear on the label? to move in the environment is • Are you familiar with relevant related to its solubility, persistence, university research and and ability to adsorb to the soil recommendations? or organic matter as well as other • Is the recommended rate of properties. Knowledge about application economical for the specific pesticide allows the your operation? applicator to make an educated • How toxic is the pesticide? decision about which product is Dermally? Orally? best for the situation. • Is the pesticide a restricted use Site conditions also play a role in product? whether a pesticide will stay in • Does the pesticide have the place or move. Field characteristics potential to contaminate such as soil texture, percent slope, groundwater, even when percent organic matter, and label recommendations are presence of cracks, channels, or followed? other large openings in the soil profile combine to give each site a potential for run off or leaching. Agricultural land with coarse, sandy soil is more susceptible to the movement of chemicals into the groundwater than heavy clays. 8 Integrated Pest The threat of contamination is some time, and these intervals higher in areas where the water are set to ensure the crop will Management and table is close to the soil surface. meet established pesticide residue Agricultural land that has coarse, tolerances. the Environment sandy soil, little organic matter, and a high water table requires an Protecting Bees applicator to use a higher degree It is important to recognize of caution to prevent groundwater potential hazards to honeybees contamination. when applying pesticides. Honeybees are important to the Pesticide applicators should be pollination of agricultural crops. aware of laws protecting animal These strategies can be used to and plant species classified as reduce bee losses associated with threatened or endangered under pesticide use. the Endangered Species Act. “Threatened” means the species • Do not apply insecticides is facing endangerment, while while crops are in bloom. “endangered” means the species • Give beekeepers notice. is nearing extinction. New and • Communication among existing pesticides are evaluated growers, applicators, and by the EPA to determine beekeepers is essential. potential harm to these species. • U se less toxic compounds. Product labels warn applicators to be aware of these species and • Use less toxic formulations. potential harm. Pesticide labels • Apply chemicals while bees may instruct applicators to refer to are not actively foraging. a county bulletin for information • Choose application techniques on the protected species, the wisely. pesticide of concern, and specific • Do not contaminate drinking use limitations. Bulletins may water. be accessed six months before pesticide application. For specific information on endangered species protection bulletins, go to www. epa.gov/espp and click on Bulletins Live! It is important the applicator pay attention to preharvest intervals. A preharvest interval is the amount of time needed between the last application of a pesticide and harvest. Consult the pesticide label to determine the amount of time for a specific crop. Do not use the pesticide if harvest is anticipated before this time expires. Pesticide residue can remain in or on a feed or food commodity for 9 Integrated Pest Study Questions 4. Agriculture land with ______Management and soils allows pesticides to move These study questions are designed faster. to help you learn the material on the Environment pages 6 through 9. a. coarse, sandy 1. A pest is ______. b. heavy clay a. destructive c. heavy loam b. beneficial d. high organic matter c. annoying 5. To protect honeybees from pesticides, do not apply insecticides d. both a and c ______. 2. What type of pesticide is used to kill a. during the month of May weeds? b. while crops are in bloom. a. rodenticide c. within six months of harvest. b. herbicide d. when the wind is from the c. insecticide south. d. miticide 6. The potential for a given pesticide 3. Which one of these is a control to contaminate groundwater method promoted in integrated pest depends on: management? a. its ability to move in the soil. a. biological control b. its persistence. b. cultural control c. its solubility. c. chemical control d. all of the above. d. all of the above

10 Insect Pest The key to managing insects is to look for when diagnosing to identify the insect causing plant damage. For example, holes Management the problem and develop an chewed in leaves indicate a pest appropriate management plan. Of with chewing mouthparts and in Field Crops the tens of thousands of insects eliminates those with sucking known to occur in Kansas, only a mouthparts. few dozen are common pests of the state’s major field crops. Of the Common Insect Groups insects considered to be potential Although there are more than pests, most only occasionally two dozen groups or orders of reach levels justifying active insects, common field crop insects management. generally fall into one of five fairly Learning to recognize common easily recognized groups. Along pests and knowing when and with these common insect groups, how they might damage crops a few other arthropods should be is the first step in managing recognized to manage field crop them. If insects are not correctly pests. identified and treatments not properly timed, losses related to Thrips (Order: Thysanoptera) making unnecessary or ineffective Thrips are tiny, slender insects. The insecticide applications can exceed order name means fringed wings. damage related to infestations. Winged adults have two pair of delicate, fringed wings. The group Characteristics commonly used to is unusual in that mouthparts are identify insect groups are wings, asymmetrical. The right mandible legs, and mouthparts. The number, is greatly reduced or lacking, giving shape, and function of wings are them a unique rasping-sucking often used to identify adult insects. feeding style that leads to distinctive For example, bees have two pair scarring of leaf surfaces. of wings, while flies have only one pair. In beetles, the front pair of Thrips undergo gradual wings is often hardened and used metamorphosis with three stages to conceal or protect the more (egg, nymph, and adult). Nymphs delicate second pair of wings. are similar to adults except they are Grasshoppers have leathery front smaller and lack fully developed wings while true bugs have front wings. wings that are part leathery and While many species are considered part membranous. pests because they feed on Legs can be modified for running, plants, a few species can feed on jumping, or digging, and the other insects or mites and can number of leg segments can be be considered beneficial. While used to separate some groups of generally considered weak fliers, insects. Mouthparts also can be under ideal conditions populations useful in recognizing insects. In can explode and lead to swarms that addition, knowing the type of can be carried long distances by the mouthparts various groups of wind. When abundant, they can be insects possess can be critical in considered a nuisance if they enter understanding what type of insects homes and can bite exposed skin. 11 Insect Pest Bugs (Order: Hemiptera) adult. They are generally easy to Management Bug is a common name for a recognize by their large chewing large, diverse group of insects. mouthparts and long, jumping in Field Crops The name Hemiptera refers to hind legs. Species determination is the forewing of many “true” bugs difficult but important because because wings are hardened near different species prefer different the base and membranous at hosts. Some species are general the end, but the wings actually feeders and pose a threat to many vary greatly among the group. crops, while others may be specific The one thing members of the and limit feeding to specific group have in common is sucking noneconomic weeds or grasses. mouthparts. This group of insects Treatments are more effective can be subdivided into three when nymphs are small. smaller, commonly recognized groups: true bugs (stink bugs, plant Moths, Butterflies, and bugs, etc.), hoppers (leafhoppers, Caterpillars (Order: Lepidoptera) treehoppers, planthoppers, etc.), Caterpillars are the larval stages of and aphids. Adults of the true moths and butterflies. They have bugs have the distinctive forewing, chewing mouthparts and generally mentioned above, which are held are the developmental stage flat over the body when at rest. responsible for damage and are Hoppers have two pair of wings susceptible to various management held roof-like over the back, while practices. Moths and butterflies aphids lack wings or have delicate are fairly easy to recognize because membranous wings. True bugs are of the scales on their wings. Scales fairly diverse with some species are particles that rub off easily being plant feeders and others when wings are touched. being predators, but all hoppers Moths and butterflies are the and aphids are plant feeders. adult stage. They have siphoning All Hemiptera have gradual mouthparts that allow them to metamorphosis, but some species, feed on nectar and other liquids. including many of the aphids, bear Moths are active at night and live young rather than laying eggs. have antennae that vary in shape but are never knobbed at the tip. Grasshoppers Butterflies, on the other hand, (Order: Orthoptera) are daytime flyers with slender, Grasshoppers are common knobbed antennae. summertime pests of a variety of crops and have caused much Both moths and butterflies concern throughout the state since undergo complete metamorphosis the 1800s. Newspaper reports (egg, larva, pupa, and adult). The from the 1870s describe “a flood pupal stage is generally considered of grasshoppers that made the sun the inactive stage, but during this dim” and literally ate all foliage, stage the caterpillar transforms even eating the “peaches so that into the adult butterfly or moth. just the stones hung from twigs.” Because eggs, caterpillars, and They experience gradual pupae look nothing like the moths metamorphosis: egg, nymph, and and butterflies they become,

12 Insect Pest observers must learn to recognize determine what pest is most likely multiple stages of these crop pests. to be causing the problem. In Management other cases, damage symptoms can Beetles, Weevils, Grubs, and be distinctive. For example, the in Field Crops Larvae (Order: Coleoptera) rolled up leaves and purple striping Beetles and weevils belong to a caused by the Russian wheat aphid diverse group of insects that vary are often detected first. Leaves greatly in shape, size, and ability to can be unrolled to confirm the damage plants. The adults of this presence of the aphids. group are recognized for having two pair of wings, with the front If timing, host, and damage wings, called elytra, being thick symptoms do not match and stiff and serving as covers for preliminary pest identification, the membranous hind wings. identity should be confirmed. There is always a chance a pest Beetles go through complete has made a host shift or weather metamorphosis. Coleoptera have patterns may have affected when chewing mouthparts in both larval or where a pest occurs. It is also and adult stages. Weevils are a possible that a new pest has subgroup or family of beetles that been introduced into an area. In generally have mouthparts at the this case, prompt submission of end of a long rostrum or snout specimens for official identification as adults. Larvae of beetles vary can reduce the spread and alert greatly, from long and slender other producers of a potential new “wireworms” to short and plump pest. grubs. To correctly identify and manage pest problems it is Sampling important to recognize multiple life stages. The key elements to sound pest management are correct Other Keys to Proper Insect identification and knowing Identification how to sample a particular pest In addition to a basic under- to determine its status relative standing of insect groups and life to established management cycles, other clues can help identify recommendations. To estimate pest problems. Time of year, host pest populations, various sampling preferences, and injury symptoms techniques may be required can confirm a pest’s identity. Some based on the type and life stage pests occur at specific times of the of pest(s), crop type and growth year. For example, army cutworms stage, and established treatment lay eggs in the fall, and larvae thresholds. A sample is a small feed in late winter or early spring. portion that should accurately Fall armyworms are active in late estimate the whole population summer and early fall. Time of from which it was taken. year that feeding injury occurs can When researchers develop narrow the list of possible pests. treatment thresholds they must Some pests are host specific. also develop sampling techniques Knowing the host can help that can be easily followed and provide reproducible results. This 13 Insect Pest is why sampling techniques vary by levels. Some pests tend to have Management pest, crop, and plant stage. fairly even distributions and are Another sampling consideration easy to detect. Sampling a few in Field Crops is where and when to take samples. plants may be all that is required In general, samples should be to determine if populations exceed scattered throughout the field treatment thresholds. Other pests to gain a good representation of may have spotty distributions the pest population across the or low treatment thresholds and entire field. If there are noticeable require more extensive sampling to differences in a field due to determine pest status. soil type, planting dates, plant For some pests, sequential emergence, or moisture levels, then sampling programs have been separate samples from each area developed to simplify the may be justified. management decision-making Many pests migrate into fields, so process. Sequential sampling is an populations are often greater along extensive program that has been field borders. Mostly, sampling developed from intensive research guidelines recommend sampling and is used to make accurate several feet from field edges. treatment decisions. Based on pest This is especially important if the densities as indicated by sampling, management plan calls for treating this program will determine if the whole field. If significant more or less sampling is required populations are only present along relative to the treatment threshold. field borders and samples are only High or low densities may indicate taken from the edge of the field, treatment is needed or not needed, one will not have a true indication but either way, no more samples of populations throughout the field are necessary. If populations are and treatments may be applied near the action threshold, the when they are not really needed. sequential sampling program will indicate more samples are For some pests, sampling field necessary before management borders may be appropriate if decisions can be made. border treatments can be applied to stop pest immigration. For example, A good understanding of the grasshoppers and chinch bugs often pest life cycle is critical to proper move into fields from adjacent sampling. It is often helpful to fields, so sampling and treating know if populations are increasing borders is often all that is needed to or decreasing. Sometimes sampling protect the whole field. for one stage of an insect can help time proper sampling for a The number of samples needed treatable stage. Sampling corn per field varies with field size, pest, borer pupae to determine moth and population levels. Larger fields emergence can help focus, or require more samples to accurately time, egg sampling and give an estimate pest populations. The indication of the percentage of number of samples (or the number moth emergence. This information of plants to be sampled) will vary helps determine if oviposition is by pest and established threshold on the increase or if most of the 14 Insect Pest moths have already emerged and pests are much more difficult to oviposition has peaked. sample and harder to predict such Management In a few cases, the time of day can as spider mites and sunflower greatly affect numbers of pests moths. But the basic principles in Field Crops that may be found. The sunflower are the same. Nothing takes the moth is generally more active at place of getting out in the field night than in the daytime. When and monitoring pest populations. populations are low, samples may In general, the more samples need to be taken in the evening and the more often they are or early morning to determine if collected, the more accurate they treatments are justified. are in determining management decisions. Sampling plans for some pests are well defined and relatively easy to understand, for example, corn borer and alfalfa weevil. Other

15 Insect Pest Study Questions 6. Beetles and weevils belong to a Management large, diverse group of insects that These study questions are designed vary greatly in size and shape. to help you learn the material on This group is called: in Field Crops pages 11 through 15. a. Orthoptera 1. Pests of field crops generally fall into one of how many fairly easily b. Lepidoptera recognized groups? c. Coleoptera a. two d. Hemiptera b. five 7. Even if the pest itself cannot be c. seven found, there are some other keys to help one determine the pest d. twenty-four problem. These include: 2. Characteristics commonly used to a. time of year correctly identify insects include which of the following? b. type of host c. type of damage a. wings d. all of the above b. legs c. mouthparts 8. True or False. When sampling a field for a pest, always concentrate d. all of the above along the field border because pests 3. The key characteristic to will be most numerous there. identifying insects belonging to the a. true order Thysanoptera (thrips) is: b. false a. fringed wings 9. True or false. The number of b. chewing mouthparts samples needed per field varies c. sucking mouthparts with field size, pest, etc. Generally, d. none of the above larger fields require more samples to get an accurate estimate of the 4. All members of the order population. Hemiptera (true bugs) have which one of the following characteristics? a. true a. chewing mouthparts b. false b. sucking mouthparts 10. Sampling plans are relatively c. utilize plants as hosts well-defined and easy to understand for the following d. lack wings pests: 5. The developmental stage generally a. corn borers and alfalfa weevils responsible for plant damage in the order Lepidoptera (butterflies and b. spider mites moths) is: c. sunflower moths a. egg d. all of the above b. larvae c. pupa d. adult 16 Alfalfa Pests Alfalfa provides refuge for many at any one time. As with all arthropods (insects and mites). crops and pests in Kansas, the Most insects found in Kansas key to profitable production is to alfalfa fields are not pests, but know which pests affect forage there may be two to five pest production, how and when to treat, species present in an alfalfa field and whether or not treatment will be cost effective. Insect Pests of Alfalfa Distribution in Insect Importance as Pest Kansas Early season – primarily first Alfalfa Weevil Statewide cutting. No. 1 alfalfa insect pest in Kansas. Statewide, but Occasional pest – eggs laid in fall. Army primarily western Cutworm May be serious in first-year fields two thirds in fall or spring. Rarely damage crop. Main concern is hay infested with blister beetles Blister Beetle Statewide which may be toxic if consumed by horses. Spring to midsummer – rarely occur in sufficient numbers to Cowpea Aphid Statewide cause damage but can produce large quantities of honey dew. Statewide, but Garden more problematic May cause serious defoliation Webworm in eastern especially in mid- to late summer. two-thirds Dry years seem to favor grasshopper survival. Damage Grasshoppers Statewide usually in mid- to late summer starting from field borders. Probably more damaging than Potato Statewide growers realize from second to Leafhopper fourth cutting. Statewide, but Serious damage rarely occurs. May more common be problematic to first year crop if Pea Aphids in south central late spring frost. Kansas Beneficials usually control. Most common after first cutting Spotted Alfalfa Statewide in mid-summer. Non resistant Aphid seedling plants most at risk.

17 Alfalfa Pests Study Questions 3. Dry years seem to favor survival of this pest which can damage the These study questions are designed crop from mid- to late summer: to help you learn the material on page 17. a. alfalfa weevil 1. Considered the number one insect b. grasshopper pest of alfalfa throughout Kansas: c. garden webworm a. grasshopper d. cowpea aphid b. potato leafhopper 4. This insect is often overlooked c. pea aphid by growers but probably causes considerable damage: d. alfalfa weevil a. grasshopper 2. May feed on plants but the main concern is that toxin produced by b. potato leafhopper this insect may be toxic to horses: c. pea aphid a. garden webworm d. alfalfa weevil b. alfalfa weevil c. blister beetle d. cowpea aphid

18 Corn Pests Many pests may attack corn at to lodge or fall over. With the any stage, from seed-infesting all widespread use of seed treatments, the way to physiological maturity. crop rotation, Bt varieties, and Even as growers wait for plants to the understanding of successful dry sufficiently so harvest can be management strategies for most accomplished, yield may still be corn pests, producers can avoid lost due to prior feeding by stalk- major losses and have done so boring insects, which causes plants relatively successfully for years.

Key Pests of Corn Insect Distribution in Kansas Importance as Pest Larvae defoliate from the ground up, often leaving only Armyworm Statewide the midrib of the leaf – usually midsummer to fall. Statewide, but more Damage usually occurs within first two weeks of planting. Black Cutworm common in eastern half Larger larvae may sever plants resulting in reduced plant of Kansas stand. Primarily eastern half Move from maturing wheat fields to seedling plants Chinch Bugs of Kansas sucking plant juice causing wilting and sometimes death. Feeding in whorl-stage corn causes tattered, ragged Corn Earworm Statewide looking leaves. Feeding during silking causes loss of kernels at the tip of the ear. Larval root feeding may cause lodging. Continuous, Corn Rootworms Statewide susceptible varieties most at risk. European Corn Seldom problem prior to whorl stage. Main concern due Statewide Borer to larval tunneling at ear shank causing ear droppage. Larvae eat holes in whorl-stage; more problematic later Fall Armyworm Statewide if feed on ears, ear shank, or stalk. Slowly migrating from east Adult feeding on tassels and silks may reduce grain fill. Japanese Beetle to west across Kansas Seldom problem prior to silking. Main concern due to Southwestern Western two thirds, usually stalk tunneling weakening stalk and consequent girdling, Corn Borer south of I-70. causing lodging. Mite colonies start developing from the ground up. As Spider Mites Statewide: more problematic numbers increase, more leaves turn yellow and start to (Twospotted and in western half of Kansas die. May reduce yield if significant leaf death occurs from Banks Grass) tasseling through soft dough. Western Bean Occasional: Western one Larvae feed on corn ears. Damage can be severe when Cutworm third numbers are significant. Larval feeding on roots in fields recently broken out White Grubs Statewide of CRP or pasture may reduce plant stands. Damage may occur due to larval feeding early on seeds Wireworms Statewide and roots in fields recently broken out of sod or where there is considerable crop residue.

19 Corn Pests Study Questions 3. Damage from this insect usually occurs within the first two weeks These study questions are designed of planting but mainly in eastern to help you learn the material on Kansas. This insect is: page 19. a. corn rootworm 1. The main problem associated with this pest is larval feeding on roots b. black cutworm which may cause lodging. The c. Japanese beetle insect is: d. wireworm a. corn rootworm 4. These insects often migrate from b. black cutworm maturing wheat fields to suck plant juice from seedling corn. c. Japanese beetle The insect is: d. wireworm a. corn rootworm 2. These insects seem to be slowly b. black cutworm migrating from east to west across Kansas. The insect is: c. white grubs d. chinch bugs a. corn rootworm b. black cutworm 5. Which of the following pests are not insects? c. Japanese beetle d. wireworm a. spider mites b. wireworms c. white grubs d. armyworms

20 Cotton Pests Kansas cotton producers do not Information from traditional have a long history, so cotton pests cotton-producing states will guide have not been as problematic as Kansas cotton producers, but in other regions of the Cotton adjustments will need to be made Belt. Pests may become more because of the relatively short common, so monitoring for signs growing season and reduced yield and symptoms is recommended. potential.

Key Insect Pests of Cotton Distribution Insect Importance as Pest in Kansas Larvae feed on all plant parts. Cotton Damage occurs when larvae Bollworm Statewide where feed on squares and bolls, often (Corn cotton is grown destroying one terminal and up Earworm) to eight bolls per larva. Nymph and adult feeding on Cotton Statewide where young squares and flowers Fleahopper cotton is grown cause desiccation and results in “blasted” appearance. Feeding on squares, bolls, anthers Tarnished Statewide where and terminals may cause boll Plant Bug cotton is grown reduction. Damage occurs as thrips move from maturing wheat field Statewide where and feed on young leaves and Thrips cotton is grown terminals (less than six weeks old) delaying maturity and possibly killing terminal.

21 Cotton Pests Study Questions 2. Damage occurs as these insects move from maturing wheat fields. These study questions are designed These insects are: to help you learn the material on page 21. a. chinch bugs 1. Pest information from traditional b. thrips cotton-producing states can help c. fleahoppers guide Kansas cotton producers but adjustments will need to be made d. bollworm because: a. pests are not the same b. Kansas has more pests c. Kansas has fewer pests d. growing season is shorter

22 Sorghum Pests Insects may attack sorghum at any droughty conditions. Sorghum is stage but most frequently after more often planted in dry land germination. Seedling through than other Kansas crops. This plus physiologically mature plants are the stress of insect feeding often all at risk for damaging insect compounds the impact on the infestations, especially under plant’s development.

Key Insect Pests of Sorghum

Insect Distribution in Kansas Importance as Pest

Cattail Highly visible leaf feeding causes concern but very little resultant Eastern two-thirds Caterpillar damage. May be very destructive to young plants as wheat matures and Eastern two-thirds Chinch Bug nymphs move to adjacent sorghum. Often more severe during dry (May–June) springs. Can be very common, especially visible during whorl stage when Statewide dramatic leaf feeding causes large holes in leaves, but rarely results in Fall Armyworm ( July–August) yield reductions.

Often mistaken for chinch bugs. Feed on sorghum as a last resort, False Chinch Bug Statewide but if populations are significant they can reduce yield by feeding on developing grain. May damage sorghum at any growth stage but have not been as problematic in recent years. Seed treatments are very effective for Greenbug Statewide protecting seedlings, and foliar applications work well as rescue treatments. Natural enemies are important in controlling greenbug populations. Sorghum Statewide Sorghum may be infested from bloom through milk stage. Significant Headworm (Corn ( July–September) yield loss can occur quickly because larvae feed directly on the grain. Earworm) Small larvae feed on developing seed. Destroyed seed give “blasted” Sorghum Midges Southeastern half appearance to head. Infestations common but rarely significant. Statewide Sorghum Larvae feed on developing seeds and can cause significant damage (most common in Webworms but rarely infest large areas. Hot, dry conditions are detrimental. southern half ) Adults and larvae feed on seedling plants. May be problematic for Sugarcane Statewide seedlings in dry years, and early season stalk tunneling may cause late Rootstock Weevils season lodging.

23 Sorghum Pests Study Questions 3. Early season stalk tunneling by these insects may cause late season These study questions are designed lodging. These insects are: to help you learn the material on page 23. a. sorghum midges 1. Damage occurs if these insects b. chinch bugs migrate from maturing wheat c. sugarcane rootstock weevils fields to suck juice from seedling d. sorghum headworms plants: These insects are: 4. These insects seem to feed on a. chinch bugs sorghum as a last resort but may b. cattail caterpillars cause yield loss if they feed on c. fall armyworms developing grain. These insects are: d. false chinch bugs a. false chinch bugs 2. Larval feeding by this insect often b. chinch bugs causes a “blasted” appearance to c. sorghum headworms sorghum heads. These insects are: d. greenbugs a. chinch bugs b. sorghum midges c. sorghum webworms d. sorghum headworms

24 Soybean Pests Soybeans seem to be more effects and filling in stand losses tolerant of insect damage than with additional branching. These most other Kansas crops. They plant characteristics need to be are very resilient at replenishing considered in insect management lost foliage with no detrimental decisions.

Key Insect Pests of Soybeans Distribution in Insect Importance as Pest Kansas May feed on leaves early causing round or oval holes. Beetles may feed Bean Leaf Beetles Statewide on pods later in the season causing yield reduction sand may transmit bean pod mottle virus. Adult foliage feeding can be significant but is usually localized. Spot Blister Beetles Statewide treatment is often sufficient. Larvae tunnel within the stalk which may cause yield loss, but the main Dectes Stem Borer Western one half problem is due to late-season stem girdling that may lead to lodging. Larvae web together and skeletonize foliage as they feed. Can be Garden Webworm Statewide devastating to young plants. Larvae chew irregularly shaped holes in leaves from July through Green Cloverworm Statewide September. Cause considerable concern but often are controlled by naturally occurring fungus. Nymphs and adults suck sap from plant causing leaf to wrinkle and Potato Leafhopper Statewide turn yellow (hopper burn). Damage has not been significant in Kansas. Capable of causing severe damage but populations usually are controlled Soybean Aphid Statewide (since 2002) by natural enemies and lack of overwintering hosts (buckthorn). Soybean Podworm Larvae feeding on seeds within pods may cause significant yield loss Statewide (Corn Earworm) quickly. Adult and nymph feeding on young seeds within pods may result in Stink Bugs Statewide shrunken and deformed seeds. Large, highly visible, hairy larvae feed on exposed leaves that quickly Woollybear Statewide become skeletonized but rarely in areas large enough to cause economic Caterpillars damage.

25 Soybean Pests Study Questions 3. These pests were first detected in Kansas in 2002. They are: These study questions are designed to help you learn the material on a. garden webworm page 25. b. green cloverworms 1. These pests may feed on plants c. soybean aphids and may transmit bean pod mottle d. soybean podworms virus. They are: 4. Both adults and nymphs may feed a. blister beetles on beans inside the pod causing b. bean leaf beetles shrunken and deformed beans. c. soybean aphids These are: d. stink bugs a. soybean podworms 2. These pests are very common later b. soybean aphids in the season and their leaf feeding c. bean leaf beetles causes grower concern but they are d. stink bugs often controlled by a white fungus. They are: a. garden webworms b. green cloverworms c. soybean aphids d. soybean podworms

26 Sunflower Pests Kansas is the sunflower state for Likewise, cultivated sunflowers good reason — native sunflowers attract a variety of insects, both and closely related species occur pest and beneficial. Because of the in abundance throughout the potential for damage due to the state. These provide an ideal most common sunflower pests, it is reservoir for many potential quite common to make at least one pests, but they also act as a host insecticide application during the for many beneficial arthropods. growing season.

Key Insect Pests of Sunflowers Distribution in Insect Importance as Pest Kansas Cutworms Larvae feeding during seedling (various Statewide stage may cause stand loss. Planting species) earlier or later helps avoid damage. Adult, shiny black, small weevils Sunflower cause considerable concern to Headclipping Statewide growers by clipping heads along Weevil border rows but rarely enough to result in significant loss. Most consistently serious sunflower pest. Larvae feed on and around Sunflower seeds, quickly causing serious yield Statewide Headmoth loss. Treatment(s) need to be applied early before larvae burrow into or under seeds. Two species of borers that both tunnel in stalk. Significant Sunflower Western half populations may weaken it. Dectes Stem Borers larvae girdle plant, which may result in lodging. Thistle Larvae are active defoliators but Caterpillar Statewide rarely occur in populations sufficient (Painted Lady) to cause economic loss. These hairy caterpillars may defoliate flowers enough to cause Woollybear Statewide economic loss if they are in the Caterpillars reproductive stages and larvae are less than ½ inch long.

27 Sunflower Pests Study Questions 2. Most serious sunflower pest year after year is: These study questions are designed to help you learn the material on a. cutworms page 27. b. sunflower headmoths 1. May cause dramatic damage to c. headclipping weevils plant because of their unique habit d. stem borers of head clipping. These insects are: 3. Highly visible, hairy caterpillars a. cutworms that are often common late season b. sunflower headmoths and may defoliate sunflowers: c. headclipping weevils a. cutworms d. sunflower stem borers b. sunflower headmoths c. stem borers d. woollybears

28 Wheat Pests Wheat is a unique crop because of volunteer wheat. Most wheat it is planted in the fall and pests, including diseases, use this harvested the following summer. “green bridge” between last season’s This presents several management crop and the new crop to survive. challenges that do not apply Planting date is also important to other field crops. Probably because fields planted later have the most important practice a much better chance of avoiding before planting is destruction pest infestations.

Key Pests of Wheat Pest Distribution in Kansas Importance as Pest Larvae may cause “windowpaning” in leaves in fall, but majority of Army Cutworm Western two-thirds damage is in spring. May cause fields to fail to “green-up” due to plant feeding if larvae are numerous. May damage plants by leaf removal before soft dough stage. Armyworm Statewide May clip beards and heads also. Aphids (Bird Rarely damage plant by direct feeding but may transmit virus Cherry-Oat and Statewide diseases. Seed treatments and natural enemies usually work well Greenbugs) to control populations. Larvae usually feed on seed following drilling row. Fields with False Wireworms Western two-thirds substantial residue and continuous wheat are most at risk. Fall infested plants turn dark green and may die. Larvae feeding Hessian Fly Statewide in stems during spring may cause shrunken heads and result in lodging. Oversummer and winter as flaxseeds. Direct feeding damage is usually negligible. But important Statewide (predominately Wheat Curl Mite vector of wheat streak mosaic virus and other viruses that may be in western half ) destructive to plants. Larvae feed on wheat head and may damage kernels. Kernel Wheat Head Statewide damage may be confused with stored product pest damage and Armyworm result in dockage at harvest. Wheat Stem Larval feeding in stem results in conspicuous white heads. Statewide Maggot Rarely exceeds 1 to 2 percent of the field. These tiny mites have a dark-colored body with distinctively Winter Grain Mite Statewide colored reddish-orange legs. May cause yellowing of leaves in cool, dry fall or spring weather. Heavy rain often mitigates mite feeding.

29 Wheat Pests Study Questions 3. Larvae often reduce early season plant stands by feeding on seeds These study questions are designed right down the drill row. These to help you to learn the material insects are: on page 29. a. army cutworms 1. Destruction of volunteer wheat is a very important part of pest b. army worms management for these wheat pests: c. wheat stem maggots a. aphids d. false wireworms b. Hessian flies 4. Larval feeding in stem often c. wheat curl mites results in a 1 to 2 percent field-wide occurrence of white d. all of the above heads. These insects are: 2. Oversummering and over- a. army cutworms wintering stage of these insects is called flaxseed. The insects are: b. wheat head armyworms c. wheat stem maggots a. aphids d. false wireworms b. Hessian flies c. wheat curl mites d. wheat head armyworms

30 Beneficial Beneficial Organisms Parasites (Parasitoids) Many beneficial organisms are Organisms Naturally occurring beneficial commonly referred to as parasites, organisms often are important but the correct term would be in helping regulate crop pests. parasitoid. True parasites live in or These include predators, parasites on a host without preventing the (parasitoids), and pathogens. host from reproducing. Parasitoids kill and often consume their hosts. Predators Predatory insects are found in Pathogens (Fungi, viruses, all crops. Some are generalist bacteria, nematodes, etc.) predators, meaning they will feed Insects are susceptible to many on a wide range of arthropods. diseases resulting from exposure Others concentrate on certain to bacteria, fungi, nematodes, and groups of arthropods as hosts such. In some cases, these may and are considered to be more provide some natural control of beneficial (or highly beneficial) insect pests. because in large enough populations, they are often capable Consult Crop Insects of Kansas, of reducing the pest population S-152, K-State Research below the economic threshold. and Extension, for color images of these insects. See the appropriate crop insect management guide to obtain specific control measures.

31 Beneficial Study Questions 2. True or False. Insects may be Organisms infested with many different types These study questions are designed of pathogens, much like humans. to help you learn the material on However, viruses cannot infect page 31. insects. 1. True or False. Predatory insects a. True are found in all crops. Some are generalist predators and others are b. False more specific for certain groups. The specific feeding predators are considered more beneficial. a. True b. False

32 Insect and Most of the important insect and It takes 16 to 25 days to complete mite pests of fruit trees in Kansas development. When full-grown, Mite Pests feed primarily on the developing the caterpillar exits the apple and fruit. Examples include the codling seeks a place under loose bark on of Fruit Crops moth and plum curculio on apples, the tree trunk or limb to spin a and the oriental fruit moth and cocoon. plum curculio on peaches. Damage Caterpillars pupate, and then is either caused by feeding on emerge as adults in 12 to 21 the surface or tunneling inside days (around early July). There the fruit. This may result in fruit are two to three generations per dropping prematurely or decreased year. Codling moths primarily acceptance by consumers, reducing spend the winter as caterpillars in marketability. There are other cocoons located under bark. The insect and mite pests that feed on first moths of the season usually leaves, twigs, limbs, or trunks of appear as the petals fall from apple fruit trees. Examples include spider blossoms. Peak adult emergence mites, scales, and the peach tree usually occurs four to 12 days later borer. Fruit tree insect and mite depending on weather conditions. pests may be grouped according to crop: apples or peaches. San Jose Scale San Jose scale (Quadraspidiotus Apple Insect perniciosus), overwinters as and Mite Pests a partially-grown scale. As temperatures increase and plant Codling Moth growth begins in the spring, The caterpillar stage of codling scales resume development. Males moth (Cydia pomonella) is the emerge and mate with females in familiar “apple worm.” Codling May. Females eventually die, but moth also attacks pear, crabapple, not before producing offspring. English walnut, quince, and Young crawlers are born alive and occasionally other fruit such as move around before settling down apricot and cherry. Caterpillar to feed. There are two generations tunneling reduces marketability per year, with all life stages present and consumer acceptance. Female during the growing season. San moths lay 50 to 60 eggs on leaves, Jose scale can be detected by twigs, and mature fruit. Young visually inspecting the tree trunk caterpillars crawl around until they and scaffold limbs. Scales are find fruit on which to feed. Early usually found in protected areas in the season, caterpillars enter underneath loose bark. If high at the calyx but later feed on the scale populations are present, side of the apple. Once inside, the they may be observed on the fruit caterpillar usually tunnels toward during harvest. the center, feeding on seeds. As the caterpillar feeds, it pushes out a mass of chewed material, which accumulates around the entrance hole. The caterpillar is whitish- pink in color, with a brown head. 33 Insect and European Red Mite their stylet-like mouthparts. This Mite Pests The European red mite results in symptoms such as leaf (Panonychus ulmi) overwinters bleaching, yellow stippling, and of Fruit Crops in the egg stage on fruit trees. leaf bronzing. Eggs hatch about the time Red Delicious are in the pink-bud Plum Curculio stage, which is usually between Plum curculio (Conotrachelus seven to 10 days. Young mites or nenuphar) is an insect pest that larvae migrate to opened leaves attacks apples, peaches, pears, and and begin feeding. Mites reach cherries. Damage is caused by both maturity (adults) in approximately the adult (snout beetle) and larvae. nine days, then mate, after which In spring, adults feed on buds, females begin laying eggs. There blossoms, leaves, and new fruits. may be eight to 12 generations The major damage occurs when per year, and populations females lay eggs. Early feeding and increase rapidly during warm, egg-laying punctures can cause dry conditions. Females lay eggs, scarring and fruit distortion. This which is the overwintering stage, damage on the surface of peaches around mid-September. often causes severely deformed fruits, which is referred to as To detect the presence of mite “catfacing.” Larvae feed inside the eggs, visually inspect small fruit until full grown then drop to twigs and branches early in the the ground to pupate. On fruits season. Larvae and nymphs may such as apple, the only larvae that be detected by inspecting leaf survive to maturity are those that undersides. However, only the feed in fruit that has dropped adult stage is readily visible to the prematurely from the tree. Feeding naked eye when using a 10X hand and female egg-laying also may lens. The lower portion of the tree cause fruit to drop prematurely. is the best location to search for mites. Leaves can be removed and Adult plum curculio is small, then brushed over a white sheet brownish-black in color, with of paper, and mites counted to white and orange mottling and determine abundance. prominent black bumps on the back. Adults have an extended Adult female mites may be snout with chewing mouthparts. identified with the use of a 10X Plum curculio overwinters as an hand-lens. Females are distinctly adult in debris near and around red in color and rounded with the orchard. Adults first appear in bristles extending from the spring when trees are in the pink back. Each bristle arises from stage. Females initiate egg-laying a conspicuous white spot. The as soon as young fruit forms, immature life stages (larvae and continuing for up to four weeks. nymphs) are usually located on Each female can deposit between the undersides of leaves, while 60 to 150 eggs. There is only one females are located on both upper generation per year. Adults are and lower leaf surfaces. Damage is active in July, feeding mostly on caused by the mites withdrawing apple and plum before hibernating. the contents of the leaf cells with

34 Insect and Their feeding results in irregularly Peachtree Borer shaped holes in the flesh of large Peachtree borer (Synanthedon Mite Pests fruits. exitiosa) is one of the most destructive insect pests of peach of Fruit Crops Twospotted Spider Mite trees. It also attacks plum, cherry and The twospotted spider mite apricot. The caterpillar damages the (Tetranychus urticae) is an tree by tunneling into the inner bark occasional pest of fruit trees in at or just below the soil. Feeding orchards. Twospotted spider may girdle the tree, preventing mite populations may become movement of water and nutrients, more problematic after pesticides and eventually killing it. have been applied to regulate populations of insect pests that are Evidence of an infestation includes natural enemies. Twospotted spider masses of plant fluids, which appear mites have pale green, translucent “gummy” and are mixed with pieces bodies with two dark spots visible of chewed wood and insect feces on both sides of the abdomen. found at or below the soil surface. This species resembles the young Early symptoms of an infestation stages of European red mite, may result in leaf yellowing of one or except eggs are pale green and not more branches and stunted growth, red like European red mite. especially on young trees. Adult peachtree borers are clear- Peach Insect Pests wing moths. Females are wasp-like in appearance, dark, steel blue in Oriental Fruit Moth color, with one or two orange bands Oriental fruit moth (Grapholita on the abdomen. Front wings are molesta) attacks many orchard opaque. Hind ones are clear except fruits, but prefers peaches. The for the margins. Male moths are white to pink colored caterpillar smaller and more slender with all feeds within the fruit and causes four wings clear. severe damage in the summer. Moths appear from late June Damage also may be caused by through mid-August. Egg-laying the caterpillar tunneling into begins about two weeks after adult the rapidly extending terminal emergence with the eggs deposited portions of twigs early in the on the trunk at or near the base season. The ends of infested twigs of plants. A single female can lay wilt and eventually die. After between 500 to 600 eggs, with eggs awhile, the caterpillar enters new hatching in about nine days. fruit often through the stem end. There are four to five generations Caterpillars tunnel into the bark per year. and are 1 to 11 inches long and yellowish-white with a dark-brown Plum Curculio head. Peachtree borer caterpillars Refer to Apple Insect Pests. overwinter under the bark and pupate in the spring. Empty pupal cases may be seen protruding from the bark at the base of the tree. There is one generation per year.

35 Insect and Management A non-pesticidal management Mite Pests strategy for dealing with the Management of insect and mite oriental fruit moth involves pests of fruit trees calls for a removing all fruit at harvest. of Fruit Crops holistic approach that alleviates Collecting and disposing of damage by implementing proper infested fruits may prevent moths cultural, sanitation, mechanical, from emerging. Insecticides must and pesticide practices, and be applied before caterpillars enter preserves natural enemies. the fruit. Use pheromone traps to Most insect and mite pests capture adults, which will help in respond favorably to fruit timing insecticide applications. trees that are overfertilized or Pesticides (insecticides or stressed through overwatering or miticides) may be used when underwatering. Maintain plant necessary to regulate populations health and apply only the amount of the insect and mite pests of fertilizer needed based on plant discussed on pages 33–35. To needs and soil test results. This will protect fruit trees from damage, prevent the buildup of twospotted most pesticides should be applied spider mite populations. early in the season. Insecticides Removal of weeds within the must be applied to trees before fruit orchard and surrounding eggs hatch into young caterpillars. areas will minimize migration of Apply as soon as pests are present insect and mite pests. Many weed or active, or at the first signs of leaf types serve as reservoir for specific or fruit damage. More effective insect populations. Spraying trees regulation occurs when pesticides forcefully with water a couple of are applied when immature times per week may be effective stages (larvae or nymphs) are in quickly removing all life stages present. Young or immature (e.g., eggs, larvae, nymphs, and stages are killed more easily adults) of the twospotted spider than adults. Afterward, regularly mite. monitor fruit trees to determine Pheromone traps can be used to if or when another application detect the presence and activity of may be required. San Jose scale adult codling moths. In general, populations may be managed by eggs hatch within 10 to 16 days applying dormant oil sprays. of adult emergence, but this varies The frequency of pesticide depending on temperature. In applications required for regulation orchards with low codling moth of insect or mite pest populations populations, the initial pheromone depends on several factors, trap catches may not be a reliable including life stages present and indicator of first adult emergence migration of adults from weeds or compared to trap catches in other plants in adjacent fields. orchards with higher populations of codling moth. For both insecticides and miticides, it is important to

36 Insect and thoroughly cover upper and lower when caterpillars are small and leaf surfaces because the life stages before plant damage is evident. Mite Pests (e.g., eggs, larvae, nymphs, pupae, For peachtree borer management, and adults) may be present on insecticides should be applied to of Fruit Crops both, depending on the insect the base of trees before caterpillars or mite pest. Apply insecticides enter.

37 Insect and Study Questions 5. The adult plum curculio Mite Pests overwinters: These study questions are designed to help you learn the material on a. in debris in and around the of Fruit Crops pages 33 through 37. orchard. 1. This caterpillar is the familiar b. in bunch grasses. “apple worm” but also attacks pear, c. in plum trees. crabapple, and English walnut. d. underground around fruit Which insect is it? trees. a. codling moth 6. One of the most destructive pests of b. San Jose scale peach trees is: c. plum curculio a. peach tree borer d. peach tree borer b. plum curculio 2. The San Jose scale is best managed c. diamondback moth by: d. gypsy moth a. spraying all four sides of the 7. This insect pest that attacks most tree. orchard fruits, but prefers peaches b. applying oil. is the : c. picking of the scales. a. plum curculio d. cutting off affected parts of b. codling moth the tree. c. oriental fruit moth 3. San Jose scale are usually found d. gypsy moth ______of the apple tree. 9. ______is important in the a. on leaves management of fruit insect and b. on the roots mite pests. c. beneath loose bark a. plant health d. on fruit b. overwatering 4. Bronzing of apple tree leaves is c. overfertilization caused by the: d. none of the above a. codling moth. b. European red mite. c. San Jose scale. d. plum curculio

38 Vegetable Insect pests pose a perennial threat Soil Insects to vegetable production. Some Crop Pests pests feed on seedlings. Others and Other Pests attack growing plants and consume Soil insects include those whose foliage or fruit. Uncontrolled immature developmental stages insect pest populations are capable are found in the soil. They attack of destroying various crops. ungerminated seeds, reducing Continual monitoring and pest stands, or feed on underground management is a demanding portions of tender young plants. chore. They leave feeding scars or create tunnels in true root crops (carrots, Healthy, vigorously growing beets, turnips, rutabagas, radishes plants are better able to withstand and parsnips) as well as potatoes. insect attacks. Proper irrigation, The two major pests in this group fertilization, and weed removal can are wireworms and white grubs. help minimize insect injury. To manage insect populations, Wireworms vegetable plants should be Wireworms are the larval stages Wireworm inspected frequently. When of click beetles. Click beetles are damage is detected, the proper elongated flattened beetles with pesticide (insecticide or miticide) large movable prothoraxes and should be applied at the labeled pointed posteriors. While there dosage to reduce the pest are more than 800 species of click population to an acceptable level. beetles in North America, few are Thorough coverage of all plant cause for economic concern. Click parts is essential for achieving beetle larvae/wireworms possess control. six short legs, have a hard shiny body, and are slender, cylindrical Because insecticides used on and yellow-to-brown. Larvae are vegetables do not have lasting especially numerous in weedy effects, additional treatments (grassy) fields and gardens or newly may be needed when populations established areas previously in sod. resurge. Excessive insecticide applications should be avoided Wireworms are primarily a to prevent plant injury and too tunneling pest of root and much residue on crops. Minimal tuberous crops, including potatoes. use of insecticides also helps On potato seed pieces, wireworm conserve populations of naturally feeding provides entry sites for occurring beneficial parasitoids soilborne pathogenic organisms, and predators. which cause seed pieces to decay and fail to produce plants. Insect and mite vegetable pests can Those that do develop may be be categorized according to where weakened, resulting in poor yields. they are found and how they feed. Additional wireworm damage may create wounds that allow soft rot organisms to enter, which may reduce storage times.

39 Vegetable Under favorable conditions, end, large larvae in the third and Crop Pests the life cycle of most common final growth stage descend again wireworms requires three to four into the soil to overwinter. In the years to complete. Wireworms spring of the third year, larvae feed overwinter in the soil either as for a short time early in the season partially grown larvae or newly but are not considered a serious formed beetles in earthen cells. pest. They then descend deeper As soil warms in the spring, into the soil where they pupate. beetles move to the surface. Click New beetles emerge from the pupa beetle adults are not a concern. but remain in the soil throughout After emerging from the soil and fall and winter. They emerge from mating, the female burrows back the soil the next spring to mate into the soil and deposits eggs and deposit eggs for the next up to several inches deep. Some generation. females may not lay all the eggs As with wireworms, white grubs in one location. Rather, they fly are numerous in weedy (grassy) to a nearby area, reenter the soil, May Beetle fields or gardens or newly and continue egg laying. This may established fields or gardens result in spotty infestations. previously in sod. Although During the second and third years, capable of stretching out as they wireworm larvae cause severe move, they are most commonly feeding damage. During the third seen as c-shaped larvae with brown or fourth years, mature larvae head capsules. White grub damage transform to fragile pupae in is similar to that described for earthen cells. After approximately wireworms. three to four weeks, pupae change to adults and remain in Slugs earthen cells until the following Slugs are not insects but are spring. Because of their extended classified as mollusks, related to developmental cycle, all wireworm oysters and clams. They are brown stages may be present in the soil and 11 to 2 inches long. But some during the growing season. slugs may be up to 5 inches long. Slugs lay clusters of translucent, White Grubs pearly shaped eggs under debris White grubs are the larvae of or buried beneath the soil surface. May/June beetles, which have a They can lay between 20 to 100 three-year developmental cycle. eggs several times per year. Slugs Adults live a few weeks during may damage some vegetables by which they mate and deposit eggs feeding on tender foliage or leaves, in the soil. Larvae hatch, and and can cause serious damage to grubs remain small and are not a young plants such as lettuce. Slugs concern for the first summer. After feed at night and leave slime trails overwintering as second growth- that glisten during the day. stage larvae, they ascend the next spring and continue development. During the second summer, they grow large and are capable of inflicting damage. By summer’s 40 Vegetable Sowbugs and Pillbugs stems of squash, pumpkin and Sowbugs and pillbugs are not related crops. Winter varieties of Crop Pests insects but are closely related to squash, such as Hubbard, are most crayfish and crabs. Both sowbugs susceptible to squash bugs. Leaves and pillbugs are about 3/8 inch long wilt rapidly, becoming blackened when fully grown. They are grayish and crispy. Early in the growing to black and have seven pairs of season, vine crops are easily killed legs. Sowbugs have two small, tail- by squash bugs. On older plants, like appendages located at the end one or more runners may be of the body. Pillbugs do not have damaged or killed. Young squash these appendages. Sowbugs and bugs or nymphs usually are found pillbugs are distinctly segmented. in clusters feeding on the leaves, Pillbugs are capable of rolling into stems, and fruits. a ball when disturbed, whereas Adult squash bugs are brownish- sowbugs do not. Sowbugs and Squash Bug black insects about 5/8 inch long. pillbugs feed on young, tender When newly hatched, a nymph vegetation or fruit and can cause possesses a dark head, antennae, damage to beans, lettuce, and other thorax and legs. The abdomen is vegetable crops. They primarily green. As nymphs develop, their feed at night. Both sowbugs bodies become distinctly grey. and pillbugs require moisture Both the adults and nymphs emit for survival because they cannot a disagreeable odor when disturbed control water loss from their or crushed. bodies. Adults can live up to two years or more. Squash bugs overwinter as adults in protected places under debris, Sucking Insect piles of boards, and packing crates, and also in buildings. They leave and Mite Pests hibernation sites in late spring Sucking insects include those and fly to fields of squash or with mouthparts modified into related crops, where they feed. needle-like stylets capable of After mating, eggs (1/16-inch long piercing a host plant’s epidermis and light to dark brown) are and withdrawing fluids. At the deposited in clusters, usually on same time, salivary secretions the undersides of leaves, but also injected into plants may clog on stems. Nymphs emerge in one vascular elements or cause to two weeks and remain clustered distorted growth. Introduction of for a short time. They become plant pathogenic organisms may adults in about five weeks. There cause plant decline. These feeding are two generations per year. activities may result in a loss of plant vigor, stunted plant growth Aphids and reduced quantity and quality Aphids are small, soft-bodied of produce. insects that withdraw sap from leaves, stems, blossoms and pods Squash Bug of host plants. Heavily infested The squash bug (Anasa tristis) plants become stunted and may withdraws sap from the leaves and have distorted growth. Aphids are

41 Vegetable notorious for the transmission of Leafhoppers are mobile when Crop Pests several important plant diseases. disturbed. Several species of Found singly or in clusters, aphid leafhoppers also transmit plant species vary in color. Cabbage pathogenic diseases. aphid (Brevicoryne brassicae) is Stink Bugs green to gray or powdery blue. Various species of stink bugs Potato aphid (Macrosiphum are commonly encountered on euphorbiae) pink to green; melon vegetable crops. Some are harmful aphid (Aphis gossypii) green to to plants, such as the green black; pea aphid (Acyrthosiphon stink bug (Acrosternum hilare) pisum) green; and bean aphid and harlequin bug (Murgantia (Aphis fabae) almost black. But histrionica), while the spined stink aphids vary in color depending bug (Anaspis erythrocephala) is on the plant type fed on, so color a beneficial predator of certain should never be used to identify plant pests. Stink bugs feed aphid to species. on the fruit of a wide-range of Aphid Aphids overwinter as either eggs plants, including beets, beans, or adults. Aphids emerge or hatch peas, squash, tomatoes, and corn. in the spring, mature rapidly and Stink bug feeding causes fruit to give birth, without mating, to become shriveled and deformed. living young. Mature aphids may Insecticides should be applied be wingless or winged. Winged when stink bugs are present and aphids migrate to cultivated crops at the first signs of foliage or fruit during the spring and summer damage. where they start new colonies. Only females are produced during Thrips the summer, and due to their rapid Thrips are small (2.0 mm long) reproduction rate, tremendous insects that feed on tender plant populations may develop in a short tissue. They withdraw plant time. Aphids may be a continuous fluids with their piercing-sucking problem throughout the season. mouthparts causing stunted and deformed growth. Thrips are With the approach of cooler usually a problem on seedlings but weather and shorter fall days, may attack plants at any growth both male and female forms are stage. Thrips also feed on certain produced. Mated females deposit weed species around or adjacent to eggs that overwinter. vegetable crops. Leafhoppers Twospotted Spider Mite Leafhoppers are small wedge- The twospotted spider mite shaped insects. Several different (Tetranychus urticae) feeds on a species attack certain vegetable wide variety of plants and is one of crops. In addition to withdrawing the most common mites attacking plant fluids, phytotoxic saliva vegetables, especially tomatoes, injections may cause yellowing, cucurbits, and beans. The adult leaf-curling, and stunting. The female is pale to dark green with nymphs and adults may be conspicuous dark spots on each present on plants simultaneously. 42 Vegetable side of the abdomen, which is the from the plant. Individual mites result of food showing through the drop from the chains and walk or Crop Pests transparent body wall. are carried by wind to other plants. Eggs are spherical, clear, and Feeding usually takes place on colorless when laid. They become lower leaf surfaces, but they opaque and ivory just before occasionally feed on upper leaf hatching. The emerging larva is surfaces. Feeding by light to colorless at first, turning green moderate infestations causes after feeding. Both nymphal stages stippling on upper leaf surfaces. are green to pale yellow in color. As feeding continues and mite Twospotted spider mites usually populations increase, leaves overwinter as adult females in become lighter in color as a nearby debris. Overwintering result of the mites removing the females are pale orange to straw- chlorophyll (green content) from colored and active, although leaf tissue. Heavily damaged leaves they do not produce eggs during turn tan or bronze, dessicate, and the winter. Twospotted spider usually die. Twospotted spider mite mites are typically present on populations may be a problem Twospotted Spider Mite the undersides of plant leaves. throughout the season, especially Webbing is visible to the naked when temperatures are 80°F or eye and all life stages occur in and higher. beneath the webbing. Many female mites may be present on each infested leaf. Infestations usually begin near a leaf vein, spreading rapidly to nearby leaves and plants, depending on environmental conditions such as temperature. The rate of population increase is highly dependent on the weather. Dry, hot weather (80 to 90°F) is most favorable for mite development and reproduction, and may intensify feeding damage to plants. A single female mite produces from two to 20 eggs per day for a total of about 150 to 200 eggs during a two- to three-week lifespan. In general, development from egg to adult takes from five to 15 days. As the host plant becomes seriously damaged, leaves turn yellow and brown, and mites begin to migrate to uninfested plants. Migrating mites occasionally form long chains of individuals hanging 43 Vegetable Chewing Insects Striped and Spotted Crop Pests Cucumber Beetles Chewing insects may cause more Cucumber beetles are chewing damage to vegetables than either insects that attack crops such soil or sucking pests. They feed on as cucumbers, beans, melons, all parts of plants, consuming both squash, and pumpkin. Cucumber foliage and fruit. A wide range beetles are particularly destructive of chewing insects attack plants, to emerging seedlings that are including grasshoppers, leafminers, emerging through the soil surface. beetles, and numerous caterpillars. Later in the season, adults feed on Corn Earworms leaves, blossoms, and fruits. The The corn earworm (Helicoverpa larvae feed on roots and tunnel zea) is considered a serious pest of into underground parts. sweet corn with feeding generally The striped cucumber beetle confined to the tips of the ears. (Acalymma vittatum) is about While the total amount of corn 1/5 inch long and has a black head, consumed is negligible, the yellow thorax and striped yellow Corn Earworm Larvae presence of caterpillars, their wet and black abdomen. Larvae are fecal pellets and associated soft slender, white with brown heads, rots may be repulsive to consumers and measure 3/8 inch fully grown. who expect worm-free ears. The spotted cucumber beetle Corn earworms vary from light (Diabrotica undecimpunctata green, pink to brown, or nearly howardi) is about ¼ inches long black. They are marked with and has a black head and black alternating light and dark stripes legs. Its body is yellowish-green, extending the length of the body. with 12 distinct black spots on the The head capsule is yellow and the wing covers. When fully grown, legs are dark or nearly black. Corn larvae are ½ inch long. earworm also attacks tomatoes Corn Earworm Moths Both striped and spotted and beans, which is why they are cucumber beetles overwinter as called tomato fruitworm and bean adults sheltered around the edges podworm. of fields or woodlots. Only striped Moths vary in color. They are cucumber beetles overwinter in attracted to green silks upon which large numbers in Kansas. Most they deposit eggs mainly at dusk spotted cucumber beetle adults and during the evening hours. Eggs migrate from the south. After hatch in two to 10 days. Young leaving hibernation sites in the larvae immediately move down to spring, beetles feed on nearby the eartips seeking protection under vegetation before appearing in husks. They then begin feeding on large numbers on vine crops. the kernels. Larvae are cannibalistic, Females deposit eggs in the which accounts for finding a ground near the base of plants on single worm per ear. Fully mature which they are feeding. Larvae caterpillars drop to the ground and feed for two to four weeks on the pupate in the soil. There may be two roots of host plants. Depending on or three generations in Kansas. weather conditions, there are one to two generations per year. 44 Vegetable Overwintered striped cucumber Cabbage Looper beetles transmit bacterial wilt The cabbage looper (Trichoplusia Crop Pests disease and mosaic, two serious ni) is green and approximately 11 diseases of vine crops. Either the inches long, with stripes along the diseases or feeding injury can back and sides. They tend to move cause serious damage resulting in in a looping motion. Caterpillars complete crop loss. hibernate in a silken cocoon on old cabbage stalks or debris on Cabbage Caterpillars the ground. The adult is a dark- Extensive populations of certain brown moth that emerges from caterpillars can completely the cocoon in the spring and is defoliate cabbage and other primarily active at night. Females cole crops. They may consume deposit pale yellow to white, round cabbage heads near the base of eggs on the undersides of leaves. the plant, which protects them Caterpillars emerge from eggs in from exposure to insecticide about 10 days and are full grown in Imported Cabbageworm applications. Feeding injury causes two to four weeks. They produce a decay of the head and general up to three generations per year. poor appearance of the cabbage. The presence of the caterpillars Diamondback Moth and their frass may contaminate Diamondback moth (Plutella other cole crops, such as broccoli. xylostella) caterpillars are green, Caterpillars may be a problem very active, and about 1/3 inch long throughout the season. when full grown. They overwinter as adults under old cabbage stalks There are three species of and plant debris. Females deposit Imported Cabbageworm Butterfly caterpillars that primarily small yellowish-white eggs on attack cole crops: the imported leaves. Caterpillars emerge from cabbageworm, the cabbage lopper, eggs and are full grown in about and the diamondback moth. two weeks. Imported Cabbageworm Imported cabbageworm (Artogeia Cutworms rapae) is a velvety greenish Cutworms attack almost every caterpillar reaching 1¼ inches in vegetable crop. Seedlings are length when full grown. Imported particularly susceptible to cabbageworms overwinter as cutworms because the main chrysalids attached by strands stem is slender, tender and easily of silk to old cabbage stalks or severed. Cutworm larvae usually adjacent debris. During warm appear as dingy, grayish-black, periods as early as March, white smooth caterpillars that curl into Cabbage Looper Moth butterflies emerge and can be seen a ball or c-shape when disturbed. flying in search of hosts plants Cutworm moths vary in color and upon which to lay eggs. Elongated wing patterns. yellow eggs are primarily deposited Several species of cutworms on the undersides of leaves. Eggs exist in Kansas. Life cycles vary hatch within a week, followed by considerably, but all involve an rapid larval development in two to egg, larva, and pupa stage before three weeks. In Kansas, there are becoming adults. Female moths three to four generations each year. 45 Vegetable deposit eggs, which hatch into species is the black cutworm Crop Pests small caterpillars. The caterpillars (Agrotis ipsilon). This cutworm cuts have chewing mouthparts and a young plant at the soil surface, damage plants during feeding. As pulls the plant into a tunnel and caterpillars grow they shed their consumes the entire contents. skins periodically until they reach Several generations of this species 1 to 1½ inches long at maturity. develop annually. The greatest They undergo a pupal stage, and damage usually occurs from then adult moths emerge from April through June when the first the pupae. Adult moths have generation is feeding. Outbreaks siphoning mouthparts and feed on of this insect frequently occur in pollen and nectar. areas that are constantly moist. Rainfall and temperature affect The black cutworm overwinters as cutworm survival and abundance. either a caterpillar or pupa. Heavy rains may impair moths’ Colorado Potato Beetle egg laying ability. Flooding may The Colorado potato beetle force caterpillars to the surface, (Leptinotarsa decemlineata) feeds on Variegated Cutworm increasing exposure to natural the leaves and terminal growth of enemies such as parasitoids and plants such as potato, tomato, and predators that can kill them. eggplant. Potatoes are the preferred There are two general categories host plant. Both adult and larvae of cutworms based on habitat and feeding may reduce yield or tuber feeding behavior. Each category size. damages plants differently. One Colorado potato beetle eggs example of each category is are orange-yellow, and found discussed below. in clusters on the undersides of Climbing Cutworms leaves. Larvae are reddish/pinkish Several species of climbing with two rows of black spots on Subterranean Cutworm cutworms feed on the foliage, both sides of the body, about stems, and fruits of many plants. ½ inch long and shaped like a Like other cutworms, they feed semicircle. Beetles are convex, primarily at night and hide in leaf 3/8 inch long and possess yellow litter or under boards or rocks and black stripes extending the during the day. However, feeding length of the wing covers. may occur on cool, cloudy days. Colorado potato beetles produce The variegated cutworm (Peridroma two generations per year. Beetles saucia) is an important climbing overwinter in the soil. They emerge cutworm. In most areas of Kansas, and mate in early spring. Females this cutworm spends the winter deposit about 500 eggs over a as a caterpillar. The number of three- to five-week period on the Colorado Potato Beetle Larvae generations per year varies, but the underside of leaves. Eggs are laid generation that occurs April to July in clusters of approximately 24. accounts for the most damage. Larvae emerge in four to nine days Subterranean Cutworms and immediately begin feeding. These cutworms feed mostly below Larvae undergo four instar stages in the soil surface. One important two to three weeks. They enter the 46 Vegetable soil, form a spherical cell, and then pepper, and potato. Feeding may pupate. Adults emerge in five to 10 be confined to stems, but also in Crop Pests days and the life cycle is repeated a the fruit of pepper and corn ears. second time. Usually only the first Mature caterpillars are ¾ to 1 inch generation is a concern. Insecticides long. The body is flesh-colored, should be applied when larvae first and marked with small faint round appear. spots. There are two generations per year. The damaging second Stem Borers generation, occurs from August Several types of caterpillars through September. Sweet corn bore or tunnel into the stems is a likely host this time of year. of certain vegetables, including Infested plants have signs of tomato, eggplant, pepper, potato, shothole feeding injury on the squash, sweet corn and bean. Plant leaves and caterpillars may be found stunting and wilting, coupled deep within the plant canopy. with the presence of small piles of moist excrement and plant Stalk Borer The stalk borer (Papaipema nebris) material at the point of entry into Colorado Potato Beetle the stem, are usually evidence of an attacks corn, tomato, pepper, and infestation. A description of each potato. Injury is most common borer type and the plants attacked on plants located at the edge of is provided below. fields because the caterpillars migrate in from weeds near field Squash Vine Borer margins. Caterpillars are slender, The squash vine borer (Melittia creamy white, with purple stripes cucurbitae) is the larva of the adult extending lengthwise on the body. squash vine borer clearwing moth. There is a brown or purple band Eggs are deposited primaily at the behind the head. Once caterpillars base of stems of squash, pumpkins, enter the stalks, management with and to a lesser extent, other vine insecticides is very difficult. There Squash Borer Larvae crops. The caterpillar hatches and is one generation per year. immediately bores into the stem and feeds in the stem near the Leafminers base of a runner. Caterpillars are Leafminers are the immature or white, wrinkled, with a brown- larval stages of small flies. The head. Squash vine borer damage larvae feed between the upper resembles bacterial wilt disease, in and lower leaf surfaces, tunneling which the plant exhibits symptoms out plant tissue. They may attack of wilting but without signs of spinach, pepper, and tomato. tunneling in the stems. Once a Leafminers pupate in the soil. The runner wilts, it is too late to save larvae may feed on many weed the plant. types growing around or adjacent Squash Borer Moth European Corn Borer to vegetable crops. While mainly a pest of field Blister Beetles and sweet corn, the European A number of blister beetle species corn borer (Ostrinia nubilalis) attack vegetable crops, and most also attacks tomato, eggplant, of these species vary in size and color. For example, some are black, 47 Vegetable some gray, some spotted, and some Melonworm and Pickleworm Crop Pests are striped with black and yellow. The melonworm (Diaphania Blister beetles move in swarms and hyalinata) and pickleworm consume foliage before they are (Diaphania nitidalis) are insect noticed. They are mostly associated pests with similar habits and feed with alfalfa, soybeans, potatoes on the same plant types. Young tomatoes, eggplant, and beans. caterpillars feed on plant leaves. Blister beetles also secrete a fluid Later they tunnel into the stems that causes blisters when in contact and fruit. They can severely with the skin. These beetles should damage melons and cucumbers be handled carefully. late in the season.

Flea Beetles Webworms Flea beetles are small beetles with The beet webworm (Loxostege enlarged hind legs for jumping. sticticalis) and garden webworm Some are striped, but most are (Achyra rantalis) attack many either black, brown, or green. They different types of vegetable crops. Flea Beetles damage plants by chewing holes in They spin a web on the plant the leaves. Flea beetles attack bean, and consume leaves. The beet pea, cabbage, carrot, eggplant, webworm is a slender, yellowish- turnip, mustard, potato, and green caterpillar with a black stripe tomato. Apply insecticides when on the back. The garden webworm beetles are present on plants. is light green to yellow and has black dots covering the body. Tomato Hornworms The tomato hornworm (Manduca Grasshoppers quinquemaculata) is the most Grasshoppers vary in size, from destructive and widespread insect 3 to 11 inches in length, and in pest of tomato. It is a large green color, depending on the species. Tomato Hornworm caterpillar with a hard, curved Grasshopper females deposit eggs horn on the back of the abdomen. under the soil surface in pod- Only a few large caterpillars are like structures. Each pod may enough to cause significant plant consist of 20 to 120 elongated damage. Apply insecticides when eggs. Female grasshoppers can the caterpillars are small, and produce between eight to 25 egg before plant damage in evident. masses during their lifetime. Most grasshopper species overwinter as eggs, whereas other species may overwinter as nymphs. Eggs hatch into young grasshopper nymphs, which resemble adults. The life cycle from egg to adult takes from 40 to 60 days. But this depends on ambient and soil temperatures. After mating, female grasshoppers feed for about two weeks before they initiate egg-laying. This usually occurs from summer

48 Vegetable through fall. Grasshoppers feed pests discussed previously. Most on many plants, including most soil insects can be controlled or Crop Pests vegetables. Large numbers of both regulated by applying a registered nymphs and adults can consume insecticide to the soil two weeks all portions of a plant. Because of before planting. The insecticide their mobility, grasshoppers can should be applied uniformly to the migrate in from weeds around or soil surface and thoroughly mixed from adjacent fields. or incorporated into the soil at a depth of 4 to 6 inches. Cutworms, Management sowbugs, and pillbugs may be effectively dealt with by using Management of vegetable baits that are impregnated with crop pests calls for a holistic an insecticide and consumed by approach that alleviates damage these pests. Also, insecticides may by implementing proper cultural, be applied directly to soils infested sanitation, mechanical, and with cutworms before seeds or pesticide practices, and preserves transplants are planted. But it is natural enemies. Most insect difficult to manage cutworms in and mite pests respond favorably established vegetable plantings to vegetable crops that are even with insecticides. overfertilized or stressed through overwatering or under-watering. Most pesticides need to be applied Maintain plant health and apply early in the season to protect fertilizer based on plant needs and vegetable plants from damage soil test results. This will prevent from both sucking and chewing buildup of aphid and twospotted insect and mite pests. Apply as spider mite populations. soon as pests are present or at the first signs of leaf or fruit damage. Removal of weeds both within More effective regulation occurs vegetable crops and surrounding if pesticides are applied when areas adjacent to fields will nymphs are present. Young or minimize the migration of certain immature stages are more easily insect pests, including aphids, killed than adults. leafhoppers, flea beetles, thrips and most species of adult moths. Many Afterward, monitor vegetable weed types may serve as reservoir crops to determine if or when for specific insect populations. another application may be Spraying plants with water a required. The number of couple of times per week may applications will depend on be effective in quickly removing several factors, including life all life stages (e.g., eggs, larvae, stages present and migration nymphs, and adults). This practice of adults from weeds or other works best against aphids, thrips, plants in adjacent fields. For and the twospotted spider mite. both insecticides and miticides, thoroughly cover upper and lower Pesticides (insecticides and leaf surfaces. Life stages (e.g., eggs, miticides) may be used when larvae, nymphs, pupae, and adults) necessary to regulate populations may be present on both, depending of the insect and mite, and other

49 Vegetable on the insect or mite pest. Apply early or late-planted sweet corn, Crop Pests insecticides when caterpillars applications may be necessary are small, before plant damage before silking, when adult females is evident. For corn earworm are laying eggs on stalks and flag management, apply insecticides leaves. During pollen shed, apply when silks first appear and treat at insecticides, preferably in the late two- to three-day intervals until afternoon, and avoid spraying silks are dry (brown). On very tassels to reduce bee mortality.

50 Vegetable Study Questions 5. One of the most common mites attacking vegetables, especially Crop Pests These study questions are designed tomatoes, curcubits, and beans is to help you learn the material on the: pages 39 through 50. a. Banks grass mite 1. The three general categories of vegetable insect pests are sucking, b. twospotted spider mite chewing, and: c. brown wheat mite a. flying d. potato mite b. biting 6. This insect group causes more c. stinging damage to vegetables than do the other categories: d. soil a. soil 2. ______are the immature stage of May or June beetles. b. chewing c. sucking a. wireworms d. flying b. white grubs c. cutworms 7. Cucumb er beetle larvae destroy the ______of vegetable d. sowbugs plants. 3. Squash bug nymphs are found in a. fruit clusters feeding on leaves, stems, and fruits of squash and pumpkin b. underground parts plant. They: c. leaves a. damage the plants by chewing d. blossoms and shredding them. 8. The imported cabbageworm b. can give humans a painful caterpillar becomes full-grown in bite. about: c. have a disagreeable odor when a. two weeks crushed. b. four weeks d. ar e a dark gray when newly c. six weeks hatched. d. eight weeks 4. The following is true of aphids on 9. When disturbed, cutworms will: vegetable crops: a. emit a stinking odor. a. heavy infestations stunt plants. b. sting. b. the largest aphids are about c. curl into a ball of c-shape. one inch long. d. burrow quickly into the soil. c. they are usually found on the top sides of the leaves. d. the y cannot transmit disease.

51 Vegetable Study Questions 12. The ______is the most Crop Pests destructive and widespread pest 10. This distinctive yellow and black of tomato. striped beetle is a serious pest in the United States and Eastern a. grasshopper Canada. The female lays orange- b. tomato cutworm yellow eggs on the underside of c. garden webworm leaves. What is this pest? d. tomato hornworm a. Colorado potato beetle b. click beetle c. flea beetle d. Mexican bean beetle 11. These caterpillars are flesh colored with light small round spots and may attack the stems of some vegetables. They commonly feed on fruit of pepper or corn. What pest is this? a. European corn borer b. squash vine borer c. common stalk borer d. southwestern corn borer

52 Crop Plant Plant disease is a broad term that produce their own food through describes almost any abnormal photosynthesis, and most fungi Diseases growth pattern or disruption to obtain food through the decay of normal plant function. Diseases dead plant material. Unfortunately, are caused by pathogens that some fungi also attack living plants, obtain nutrients from the living resulting in disease. plants they infect. Every plant is Fungi can enter plants by susceptible to multiple diseases mechanically forcing their way that are managed in an integrated into their potential host or by fashion. using enzymes that weaken natural This section introduces key defenses. Other fungi enter plants concepts of plant pathology through natural openings such while providing a few examples as stomata, which are small pores of important crop diseases to that allow gas exchange in leaves illustrate those concepts. A list of or stems. This infection process references is included for more is favored by extended periods information about specific diseases of high relative humidity or the of major crops grown in Kansas. presence of dew on plant surfaces. Once inside a susceptible plant, Causes and Types of the fungi begin to feed on and colonize plant tissue. The fungi Plant Disease obtain nutrients by producing Four major groups of plant toxins that damage plant cells, or pathogens — fungi, bacteria, by inserting specialized feeding nematodes, and viruses — are structures directly into the cells. responsible for most of the common crop diseases in Fungi reproduce through the Kansas. All of these organisms production of spores, which are infectious and can be spread function much like the seeds of from plant to plant, causing flowering plants. Many fungi disease outbreaks within plant have the capacity to reproduce populations. Understanding basic with or without the genetic characteristics of these organisms recombination afforded by sex, can provide important insights and can produce thousands of into plant disease management. In spores every day. These spores are the context of plant diseases, plants typically produced by specialized are referred to as hosts. reproductive structures or fruiting bodies of the fungus. Fungi are the most common cause of plant disease in Kansas crops. The spores are spread throughout Fungi consist of groups of cells the environment by wind or the that are typically arranged as tiny splashing produced by raindrops. threadlike filaments. As fungi Insects and farm equipment grow, they produce large numbers can also move fungal spores to of these filaments that form neighboring plants. Many fungi the visual structures commonly that cause disease survive between referred to as molds or mushrooms. growing seasons within colonized Unlike plants, fungi are not able to plant debris or by initiating specialized resting structures. 53 Crop Plant Bacteria are single-celled Viruses are tiny particles Diseases organisms that are much smaller composed of nothing more than than fungi. Most bacteria have a their genetic material (DNA cell wall that determines shape or RNA) surrounded by a coat and may produce a slime coat that made of protein. Viruses depend can improve survival in adverse on the cells of a susceptible plant conditions. Bacteria often have for reproduction. Virus particles tiny whip-like appendages that readily move from cell to cell help the bacteria move short within plants and often spread distances in water or other liquids. through the plant’s vascular Bacteria reproduce by “fission,” system, which brings nutrient rich meaning one cell divides into two sap to the plant’s own cells. identical daughter cells. Bacteria This ability to move with the sap can multiply extremely quickly, is also critical in spreading viruses going from one cell to a colony of to other plants, and contact with a million cells, sometimes in less sap from infected plants can than a day. transmit the virus to a healthy Many bacteria enter plants plant. Contaminated pruning through wounds or natural tools or direct contact of wounded openings in the plants when plant tissues are two ways conditions for infection are infected sap can be spread from favorable. The invasion of the plant to plant. The mechanical plant by bacteria typically requires spreading of viruses is common extended periods of warm, moist in the propagation of woody weather. Once inside the plant, the plants including fruit trees and bacteria often produce enzymes grapevines. The spread of plant or toxins that destroy plant cells. viruses can also result from the Bacteria generally can only move feeding activities of insects, mites. short distances themselves but or other organisms. Any organism are easily moved by splashing that spreads a pathogen is rain, insects, and contaminated generally referred to as a “vector.” tools used in plant propagation These vectors are so important and pruning. Some bacteria can to the spread of plant viruses that survive on plant surfaces for only control of many viral diseases short periods of time, while others depends on managing the vector can survive for months as decay population. organisms in the soil.

54 Crop Plant Plant viruses generally do not Most nematodes do not persist in survive for more than a few days the soil for extended periods of Diseases or weeks without a living host time and are vulnerable to cold and plant. The seasonal break between dry conditions. The population of annual crops that occurs when one plant pathogenic nematodes will crop matures and another has not drop rapidly in the absence of a yet been planted can serve as a susceptible crop. Crop rotation in natural barrier to plant viruses. The annual crops can be an effective effectiveness of this break between means of keeping nematode crops is compromised if the virus populations below damaging is allowed to persist in weedy or levels, but some weeds can reduce volunteer plants. Weeds can also the effectiveness of these rotations. be important reservoirs of virus in Nematodes can move only short new plantings of perennial crops. distances through soil, but can be Nematodes are microscopic, moved long distances by human non-segmented, roundworms. activities. The long distance These tiny worms are common movement of nematodes is often and can be found in nearly every associated with infested soil that environment. In the soil, most can contaminate clothing or field species of nematodes feed on equipment, irrigation water, or bacteria and other small life forms. plant parts used for propagation Approximately 10 percent of (i.e., bulbs, rootstocks, tubers). nematodes are plant pathogens. Recognizing Diseases Nematodes that feed on plants Plant diseases are recognized by have a needle-like feeding visible changes to plant growth structure called a stylet, which that they cause. These visible is used to pierce and ingest the expressions of disease by the contents of plant cells, similar to plant are called symptoms and inserting a straw into a drink and include spots, cankers, galls, wilts, then sucking up the liquid. mosaic patterns, stunting or other Most nematodes have a simple deformities. In some cases, the life cycle. They begin as eggs. This pathogen will produce structures is followed by two juvenile stages that can be seen with an unaided and the adult stage. Reproduction eye. Other pathogens can only occurs when nematodes reach the be seen with a hand lens or adult stage of their life cycle. A microscope. These visible pathogen single female can lay hundreds structures are considered signs of of eggs and the entire life cycle the disease. (egg to adult) can be completed in several weeks. Most nematodes feed on plant roots, and high populations can severely damage a root system.

55 Crop Plant Diseases and Symptoms Powdery mildew and rust diseases Diseases Seed decay and damping- can be readily identified by visual off occur when fungi or other evidence of the pathogens. The pathogens attack a plant shortly fungi that cause powdery mildews after planting. These diseases remain on the upper surfaces of often occur when adverse weather leaves. This superficial growth conditions slow germination or the of the fungus gives the leaves early stages of seedling growth. In a powdery-white appearance. some cases, the seed is destroyed by Rust diseases are named for the the pathogens before germination powdery orange-to-brown spores takes place. This destruction of produced by the fungi that cause seed is generally referred to as seed this type of disease. decay. Seedlings are vulnerable Wilt diseases destroy or reduce to attack by many soilborne a plant’s ability to absorb and pathogens during germination and distribute water. Drought and emergence. Damping-off occurs many other problems also can when pathogens destroy the root cause plants to wilt, and it is often and stem tissues of the seedlings. necessary to examine plants for Preemergent damping-off occurs additional symptoms to make a when seedlings succumb to definitive diagnosis. Discoloration disease shortly after germination of vascular tissues or roots often but before emergence from the helps confirm the cause of wilting. soil. Postemergence damping-off Cankers often inhibit normal occurs when the young plants formation of wood and bark, develop stem lesions at the soil- resulting in sunken or discolored Damping-off level. The destruction of the stem portions of the twigs, branches or tissue causes plants to fall over and trunk. The affected portions of die rapidly. woody plants, such as fruit trees Spots, blotches, and blights or grapevines may die if a canker are commonly associated with enlarges enough to completely fungal and bacterial diseases of encircle a branch or trunk. Stem leaves and fruit. The term “spot” lesions on herbaceous plants are is generally used for lesions that also referred to as cankers. remain confined in a localized area Root rot diseases occur when of the plant. The terms “blotch” healthy roots are invaded by a and “blight” describe lesions that pathogen. Early symptoms are Leaf Spot rapidly expand to destroy large usually hidden below ground. portions of the infected leaves or Adverse environmental conditions fruit. Leaves and fruit may also such as drought, freezing, or poor develop abnormal color patterns drainage can predispose plants to in response to viral disease. These root rots and decay organisms. The color patterns include symptoms feeding activity of nematodes or such as ring-spots and mosaics. insects also increases the risk of some root rot diseases because of the wounds they create. (Photos on page 58.) Leaf Spot 56 Crop Plant Abiotic Disorders Moisture Water is essential for plant growth, Diseases Abiotic plant disorders often but too much or too little can be cause symptoms that resemble damaging. Excess water depletes plant diseases. Abiotic disorders the oxygen supply to roots. As are sometimes referred to as root health deteriorates, the plant physiological disorders or cannot take up enough water environmental stresses. Some of the and nutrients. This condition is most common abiotic disorders in sometimes referred to as “wet Kansas are caused by extremes in feet,” and certain plants are more temperature, moisture, or fertility. vulnerable than others. Wet soils Disorders may also result from poor can also trigger certain root rot site selection, soil compaction, and pathogens that are adapted for chemical toxicities. In addition, dispersal in saturated soil. abiotic disorders can weaken plants and increase their susceptibility Fertility and Soil to diseases caused by pathogens. Plants need the correct amounts Powdery Mildew Understanding the normal growth of essential nutrients such as of various plant types will often nitrogen, phosphorus, potassium, help identify abiotic disorders and and a few minor elements facilitate the differentiation from including iron, sulfur, and zinc. disease. These nutrients can come from the soil or from fertilizers — Temperature manufactured products as well as Each plant species has an optimal natural organic sources such as temperature range, and exposure manures and compost — added to temperatures outside that range to the soil. Fertility imbalances are can be stressful. In Kansas, rapidly damaging, and some fertility issues Rust fluctuating temperatures disrupts can mimic diseases. normal metabolism. For example, a warm spell in winter can cause Chemical Injury a plant to emerge from dormancy While pesticides and fertilizers prematurely, or an early fall frost can enhance plant health and can harm plant tissues that have lead to yield and quality benefits, not adapted to cold temperatures. misapplication can result in injury. Peach trees are frequently damaged Chemical injury to plants is by cold winter temperatures, and referred to as phytotoxicity and it Canker this injury can make trees more can be caused by several sources. prone to cankers. Vegetable plants Herbicide drift, carryover, such as tomato may fail to set and spray tank contamination: fruit if temperatures are too hot Herbicides can drift from a or too cold at flowering. Likewise, neighboring field onto a nontarget grain sorghum will not pollinate crop. They can also persist in the when nighttime temperatures drop soil from one crop to the next below about 55⁰ F. if cropping restrictions are not followed. Crop damage can occur

Canker 57 Crop Plant if the spray tank is not adequately benefit is greater than the loss that Diseases cleaned between use of different will be incurred if they are not products. Herbicides are discussed used. This is commonly known as in depth in another chapter. the economic threshold of damage. Inappropriate rates: Pesticides When organic growing methods can be applied at rates that are are employed, only certain disease toxic to the plants. It is important control materials may be used to read the label and calibrate for pest control. Some “natural” equipment to ensure proper pesticides can be used in organic application rates. growing, and there are lists of Incompatible tank mixes: such products available online. Pesticides that are safe when One source of information is applied alone can be highly www.omri.org (Organic Materials phytotoxic when applied in Review Institute), but growers combination. A classic example interested in organic production should check with their particular Root Rot of this is when the fungicide captan is applied in a tank mix certifier. with oils, compounds that are Foundation commonly used in fruit pest and Understanding the biology of plant disease control. This mixture is so diseases is critical to identifying phytotoxic that these compounds appropriate disease management should not be applied within strategies. Plant pathologists often 14 days of each other, and labels use diagrams to help conceptualize often advise against such mixtures. the critical stages of pathogen Read the label for advice on Root Rot biology or illustrate the interaction incompatibility. between pathogen, plants, and the environment that result in disease. Disease Management The “plant disease triangle” is often Managing plant diseases requires used to identify factors that are an understanding of the plant, important for disease development. the environment, and potential In the plant disease triangle, the pathogens in the area. Integrated three sides of the triangle represent pest management (IPM) should 1) the presence of a viable serve as the foundation for disease pathogen; 2) a susceptible host; management whether in a crop Cold Injury and 3) an environment that favors field, orchard, greenhouse, nursery, disease. All of these factors must or home landscape. be present for disease to occur. IPM has been defined in many When developing management different ways, but the general strategies, it is important to message is that management consider all three parts of the of plant health takes a holistic, disease triangle. For example: common sense approach that • Pathogen: What strategies uses host resistance and cultural can be used to prevent the methods as the foundation of introduction of a pathogen to a disease control. Pesticides should field? How can chemicals be used Nutrient Deficiency be used only when the economic to reduce pathogen growth? 58 Crop Plant • Host: Are resistant varieties or Start with Clean hybrids available? Planting Material Diseases • Environment: Are there cultural Using clean, disease-free seed or practices that can make the propagating materials is the first environment less favorable for step to disease management. This disease? includes using seed from reliable sources such as certified seed Host Plant producers. Hot water treated seed can eliminate bacterial pathogens on some vegetable seeds, but this can reduce germination, increasing seed costs. Fungicide-treated seed can be used to eliminate pathogens Pathogen Environment in or on the seed and to provide a zone of protection around the Diagrams of disease cycles are germinating seed in the soil. For also used to illustrate pathogen example, fungicide seed treatments survival, movement, infection, are an effective means of managing colonization, and reproduction. Herbicide Injury the common bunt of wheat. For Knowledge of these processes vegetatively propagated plants, can provide important insights only use cuttings from reliable into management strategies that sources should be used. Inspect are important for a given disease. transplants carefully for unusual For example, if a pathogen is symptoms on foliage or roots. Use known to survive in the debris of a clean pots and sterile soil because previous crop, debris removal may some pathogens can survive in reduce the risk of severe disease in contaminated soil and pots. subsequent years. Sanitation Pathogen Exclusion Weeds, crop debris, volunteer Quarantines can be an effective plants and previously infected way to eliminate the introduction plants can harbor some plant of a pathogen into a geographical pathogens as well as insects that area. This is particularly useful spread certain plant diseases. for diseases that may be moved Wheat streak mosaic, for example, by human activity such as the is known to persist in volunteer importation of foreign plant wheat and several grassy weeds. materials that may be infected with In greenhouse, garden, or nursery a disease not known to occur in the locations, remove infected plants United States. Often, native plants or plant parts such as foliage, have no resistance to these new fruit, or blossoms that may allow diseases, or there may be no natural pathogens to survive between enemies of disease spreading crops or planting cycles. Do not insect vectors. Some of the worst pile plant debris near the garden plant disease epidemics, including or greenhouse — remove it from Dutch elm disease, chestnut blight, the site, or burn it. Prune out and soybean cyst nematode were infected twigs and branches on introduced from abroad. woody plants such as fruit trees 59 Crop Plant or grapevines. Again, be sure to Cultural Practices Diseases remove pruned tissue from the site so it does not serve as a source of Avoid Problematic Sites new infection. Clean up soil and Avoid planting susceptible other debris in potting areas. varieties into sites with a history of disease problems. For example, Host Resistance if a certain kind of plant is highly Use of disease resistant or tolerant susceptible to root diseases that cultivars, when available, should are favored by saturated soils, do always be one of the first lines not plant it into locations with of defense in developing pest poor drainage. Choose the “right management strategies. Terms plant for the right place” based such as resistance and tolerance on drainage, soil type, shade, etc. are all used to describe a plant’s If preparing a new planting, take reaction to plant pathogens. the time to sketch out a map, Resistance to plant disease among considering shade, slopes, etc. types of plants and varieties of the same crop may also be variable. In In agronomic situations, drainage some cases, resistance is complete: can sometimes be improved to the variety does not become reduce problems from diseases infected. In other cases, resistance such as Phytophthora root rot is not complete and the cultivar of soybeans or downy mildew of can be infected at low levels. The sorghum. Additionally, irrigation term "tolerance" is used to describe can be used to successfully manage a variety that is minimally affected charcoal rot, a disease favored by by the pathogen, even though it hot, droughty soils. develops disease symptoms similar Tillage to plants with low or moderate In agronomic field situations, levels of resistance. infected crop residues can be Seed company and garden brought into contact with the soil catalogs are a good source with varying degrees of tillage when looking for information allowing it to be more quickly about a variety’s resistance to degraded by soil microorganisms. specific diseases. Soybean seed Fire is sometimes used to remove companies for example, indicate crop residues and pathogens that the “field tolerance” of a variety to survive in association with the Phytophthora root rot when listing residue. These tillage or burning the variety’s characteristics. Kansas practices must be balanced with State Research and Extension also needs for soil conservation, which provides this type of information often discourage the destruction of in Extension publications such as crop residues. Wheat Variety Disease and Insect Ratings, MF-991. Manage Moisture and Humidity Frequent rains, wet soils, and high relative humidity can favor many plant diseases. For some fruit and vegetable crops, opening up plant canopies by staking or trellising 60 Crop Plant will change the canopy structure, corn crop is planted. Make sure keep plants off of the ground, and that the rotational crop is NOT Diseases allow for greater air movement. also susceptible to the problematic Similar changes to canopy disease or the rotation will not be structure can be achieved in crop effective. Sclerotinia white mold, plants by adjusting row spacing for example, has a wide host range and planting density. These including tomatoes, asparagus, changes to the crop canopy will sunflowers, and soybeans. reduce drying times following rain or heavy dews and reduce the risk Vector Management of disease. In contrast, planting in Insects or arthropods spread many shady areas may increase drying plant diseases and are considered times following rains and dew, to be disease vectors. Examples of increasing disease risk. Watering in disease spreading pests in Kansas the evening increases the period of include western flower thrips, time that leaves are wet, which can leafhoppers, soybean aphids, and trigger the development of certain the wheat curl mite. In some cases, diseases, especially foliar leaf spots the management of the insect or and blights. Whenever possible, arthropod is the primary means of water in the morning. achieving disease control. This can be done through timely pesticide Rotate Crops to Avoid application or by removing sites Pathogen Buildup where vectors persist between Plant pathogen populations tend cropping seasons. For example, to increase at sites where the same control of volunteer wheat can crop is grown for multiple years. help reduce the risk of severe Crop rotation, whether in a home outbreaks of wheat streak mosaic garden or on a commercial farm, in western Kansas. can be an effective way to manage diseases. The length of rotation Pesticides required to manage a disease Pesticides can be classified in problem varies considerably. a number of different ways. Some soilborne diseases such For instance, plant pathogen as Sclerotinia white mold and controlling pesticides are classified soybean cyst nematode may based on the type of organism require rotations as long as three they control. The three most or four years to reduce pathogen common groups are fungicides, populations below economic bactericides, and nematicides. thresholds. Where no-till farming Likewise, insecticides are used is practiced, rotations to control to control insects, and herbicides residue-borne diseases need to be are used to control weeds. Like long enough so debris from the human pharmaceuticals, pesticides susceptible crop has completely have both a technical name that decomposed. For example, in a identifies the active ingredient and two-year corn-soybean rotation a trade name to identify a specific using no-till practices, gray leaf commercially licensed product. spot infested residue may still be Some products contain a mixture present on the soil when the next of pesticides such as two different 61 Crop Plant fungicides or a fungicide and an move downward through the leaf Diseases insecticide formulated together. to protect the bottom side as well. Fungicides can be classified in a Some fungicides can move from number of different ways. At the the tip to the base of a leaf or largest scale, they can be classified from the base to the tip. Locally as either contact or systemic systemic fungicides generally will materials. This classification is not move from leaf to leaf within based on how they interact with a plant. This is an important the plant. A contact fungicide is concept, particularly for wheat applied to and remains on the growers. Agronomists have calcu- plant surface. Because they work lated that nearly 70 percent of the best when applied before pathogen grain fill in a wheat plant comes spores arrive, they are sometimes from the flag leaf (the last leaf to referred to as “protectants.” emerge). For good disease control There are advantages to using in wheat, the fungicide must contact fungicides. One is that come in contact with the flag leaf. they are usually effective against Applications before the flag leaf a broad range of fungi. A second emerges will not protect it. is that they attack multiple Advantages of systemic fungicides metabolic sites within the fungus include their ability to be rain- simultaneously, making it difficult fast. That is, once they are for a fungus to develop resistance absorbed into the plant, they to this class of fungicide. A cannot be washed off by rain or disadvantage of contact materials irrigation water. Some systemic is that they are often not rain- fungicides can be applied for fast and need to be reapplied curative (sometimes referred to after a rainfall event or overhead as kick-back) purposes. Curative irrigation. They also must be applications are made after the reapplied every five to 14 days infection process has begun. This to keep new growth protected curative action is usually limited and are most effective when to the first 24 to 48 hours of applied to both the upper and the infection process. Curative lower leaf surfaces. This usually fungicides will not be affective requires much larger volumes of against severely diseased plants. water, which increases application Systemic fungicides are typically costs. Some examples of contact effective for 14 to 21 days. Because chemicals are mancozeb, maneb, of this, they can be used effectively chlorothalonil, captan, and copper with disease forecasting models. formulations. This can drastically reduce the Systemic fungicides, as the name number of fungicide applications suggests, are absorbed into the that need to be made in a season. plant. Foliar systemic fungicides The curative activity of a fungicide are usually considered to be locally varies with pathogen sensitivity, systemic, which means they will environment, and type of plant only move short distances within a treated. A disadvantage of systemic leaf. For example, if the product is fungicides is that they have a applied to the top of the leaf, it can narrow mode of action, sometimes 62 Crop Plant targeting a single enzyme within azoxystrobin, pyraclostrobin, and the fungus. The narrow mode trifloxystrobin. Commonly used Diseases of action increases the risk that triazoles include propiconazole a fungal population will become and tebuconazole. resistant to a fungicide. Individuals Bactericides are compounds that within a pathogen population kill or slow the growth of bacteria. may be less susceptible or have They are sometimes referred to as cellular mechanisms that render antibiotics. They generally have a fungicide’s mode of action a minor role in management of ineffective. Resistance is most bacterial plant diseases. This is likely to develop when fungicides because they are very expensive with the same mode of action and repeated use results in the are applied repeatedly in a given same type of antibiotic resistance growing season. Fortunately, that is familiar in humans and different systemic fungicide groups animals. target different metabolic processes in the fungus. Nematicides are used to manage nematodes, small plant pathogenic Two of the most common classes worms found in soil and in plant of systemic fungicides used in roots. Nematicides generally agriculture are the strobilurins, are some of the most toxic also known as QoI fungicides, compounds used in agriculture and the triazoles, part of a and for that reason, are not larger fungicide group known as usually recommended. Research demethylation inhibitors (DMI)). has shown that nematicides will All QoI fungicides share a common reduce early season populations biochemical mode of action: they of nematodes to an extent that all interfere with energy production normal yields can be achieved, but in the fungal cell. Triazoles on the nematode populations typically other hand, work by blocking the rebound to preplant levels or even normal development of fungal cell higher by the end of the growing walls. It is generally recommended season. Because of this, annual that products with different modes applications are typically required. of action be rotated and that no Nematode management therefore more than two applications of the is usually best achieved by a same mode of action fungicide be combination of resistant cultivars made in a single year. Combining and extended crop rotations. different modes of action in a single application by tank-mixing Scout to Improve fungicide products also can reduce Disease Management the risk of resistance developing Detecting diseases or disease within a pathogen population. spreading insects in early Pesticide labels often provide developmental stages is critical to specific resistance management an effective disease management strategies for a product. program. Effective scouting For corn, wheat, sunflowers, and requires familiarity with the crop soybeans, examples of commonly and the common diseases and used strobiluron fungicides include insects in a region. A scout should 63 Crop Plant also be familiar with what time of Disease Diagnosis Diseases the growing season the disease is most likely to occur. For instance, With so many factors affecting in Kansas, southern corn rust plant health, it can be difficult usually does not arrive until late to sort out the primary causes of July. Disease prediction models plant damage. Symptoms caused can also help identify weather by pathogens can resemble damage patterns that have been favorable by abiotic factors and vice versa. for disease and direct regional In many cases, multiple factors scouting activities. are interacting and the problem requires a holistic strategy. Where established, scouts should Becoming familiar with reliable also be familiar with the economic sources of information such as damage threshold for a disease. books, university fact sheets, and For example, thresholds for gray credible websites can aid in a leaf spot of corn that would proper diagnosis. Local K-State trigger fungicide applications Research and Extension personnel are a function of the resistance also can assist in assembling these rating of the cultivar, the stage resources. A list of references is of development of the crop, the provided at the end of this section. positioning of lesions within the canopy, the expected yield of the When solving plant health crop, the cost of the fungicide problems, it can be helpful to application and the expected ask questions that may reveal selling price. Tools designed to important clues. Below are some help assess the potential value of questions to keep in mind as you fungicide treatment are available attempt to diagnose a problem. for some crops (See “Economics Which species and cultivars of spraying field crops” at http:// (varieties) are affected? www.agmanager.info/crops/ Pathogens tend to be host specific. prodecon/decision/default.asp). If multiple species or multiple In summary, diligent scouting plant families are affected, this efforts, combined with the use may be a clue that an abiotic factor of host plant resistance, good is involved. cultural practices, and appropriate Which plant parts are affected? fungicide usage will provide Check the leaves, fruit, stem, homeowners, commercial crown, and roots. Comparison horticulture crop producers, with healthy plants may be helpful. and commercial crop producers What is the spatial pattern? with a safe and effective disease Check for patterns. Are all the management program. affected plants clustered together in a patch? Are they all in the same row? Are the diseased plants randomly scattered in a field?

64 Crop Plant How is the problem changing over A good sample with background time? information is the key to the most Diseases If symptoms appeared all at once timely and accurate diagnosis. in a uniform pattern, that can suggest an abiotic stress “event” The Physical Sample such as a sudden exposure to toxic The type of sample needed chemicals, low temperatures, etc. depends on the plant and the If the symptoms spread over time, nature of the problem. In all it is more likely to be a pathogenic cases, try to collect tissue at the problem. transitional area between healthy and damaged areas. That zone, What cultural practices have been the “leading edge,” is where used? pathogens are most active and Consider cropping decisions most readily found. In tissues that such as tillage and crop rotation. are already far in decline or dried Lack of rotation can lead to a out, it is difficult to find the true buildup of pathogens. Is overhead pathogen among all the competing irrigation applied that could lead saprophytic (dead-tissue-eating) to splashing of bacteria or fungi? organisms in the decaying tissue. Are insect vectors present? If possible, send roots. For some Remember that insects can spread tests, the diagnostic lab absolutely certain diseases. needs roots to make an accurate What has the weather been like diagnosis. If the plant is small, dig recently? up the entire plant, tie a plastic Did an unusual weather event bag around the root ball, and place coincide with the onset of another plastic bag around the symptoms? entire sample. For woody plants Are there site problems? send several branches that are at Look for drainage problems, soil least 12 inches long. structure, presence of hardpans, slopes, etc.

Sample Submission A skilled field practitioner should learn about the diseases of crops managed through experience and training. The above guidelines can aid in diagnosis. But many plant health problems require diagnosis by a trained professional using specialized microscopic techniques and laboratory tests. A local extension agent can assist with difficult diagnosis problems and, if required, submit a sample to a laboratory such as the K-State Plant Disease Diagnostic Lab. 65 Crop Plant Packaging and Mailing Photos Diseases Pack the sample in a crush- Digital or print photos often add proof container such as a padded important information about the envelope or a box with packing site and patterns and can greatly material. If possible, send the facilitate the diagnosis. When sample early in the week so that it taking photos, take one or two does not spend a long weekend in of the overall site to show the a hot postal truck. environment. Then, take another few shots at closer range that show Background Information the primary symptoms of concern. Equally important to the physical sample is background information describing the patterns, plants involved, timing — all of the information in the “diagnostic questions” in the previous section.

66 Crop Plant References Vegetables: Midwest Vegetable Production Guide Diseases Each crop can be affected by for Commercial Growers multiple diseases. This study guide provides a framework for Tree Fruit: understanding crop diseases, but Midwest Tree Fruit Spray Guide it will be important to learn more Small Fruit: details about the specific crops Midwest Small Fruit and Grape you manage. Printed materials, Spray Guide websites, pesticide certification renewal classes, and other training Wheat: programs can provide ongoing Wheat variety disease and insect education. ratings (MF-991); Fungicide Efficacy ratings for wheat disease The following three guides are management (EP-130) updated annually by specialists in this region. Contact your local K-State Research and Extension agent or visit the K-State Plant Pathology website for ordering information.

67 Crop Plant Study Questions 5. What are some ways in which Diseases plant-infecting bacteria can These study questions are to help spread? you learn the material on pages 53 through 67. a. seed 1. Discoloration in the vascular tissue b. infected transplants (water conduction tissue) is a c. insects symptom of what kind of disease: d. all of the above a. root rot 6. Which of the following insects is a b. leaf spot common vector of plant viruses: c. wilt a. grubs d. rust b. aphids 2. The four major groups of plant c. moths pathogens include fungi, bacteria, d. flies virus and ______. 7. The three most common groups of a. nematodes pesticides used to manage plant b. aphids diseases are: c. moss a. herbicides, algaecides, d. blights and fungicides 3. Fungi often obtain their food b. herbicides, bactericides, through: and nematicides c. fungicides, bactericides a. photosynthesis and nematicides b. decay of dead plant material d. algaecides, fungicides c. attacking living plants and antibiotics d. both b and c 8. What is one advantage of a 4. What are some ways in which CONTACT fungicide: plant viruses can spread? a. prone to wash-off a. seed b. broad mode of action b. insects c. moves systemically in the c. tools plant d. all of the above d. c an be used with small amounts of water

68 Crop Plant 9. If plants in several different plant 12. In integrated pest management families are affected by symptoms, (IPM) programs, the foundation Diseases the cause is mostly likely to be: of disease control is: a. fungus a. resistant cultivars b. virus b. fungicides c. nematode c. cultural practices d. abiotic factor d. a and c 10. The best type of sample to send to 13. Which factor is not part of the a diagnostic clinic is: “disease triangle?” a. the smallest leaf possible, to a. susceptible host save on shipping costs b. favorable environment b. plant tissue that has been c. the right time dead for a long time d. pathogen presence c. plant tissue from the transitional area between 14. Which of the following is NOT healthy and damaged areas an effective cultural management practice? d. dry plant material a. tillage 11. Cr op rotation can reduce disease pressure only if: b. crop rotation c. insect/vector management a. spor es blow in from distant fields each year d. quarantines b. the pathogen survives locally in soil or crop debris c. the disease is caused by a virus d. the disease has a very wide host range

69 Weed Management Weeds are major pests in coleoptile above ground. Shortly in Field Crops field crops and can reduce the afterward, a cluster of nodes called quantity and quality of the crop. the crown becomes established at Uncontrolled weeds can reduce or just below the soil surface. New crop yields, interfere with harvest, leaves and tillers can develop from and result in contamination of the the nodes in the crown of a grass harvested crop. Weeds reduce crop plant. During early growth stages, yields by competing with the crops all of the growing points are in for water, nutrients, light, and the crown. Eventually, the stem space. Crop production strategies starts to elongate, and the terminal that provide the crop with a growing point moves above ground competitive advantage over weeds and into the seed head. and minimize weed populations Leaf width and length, the and early season competition presence of auricles, ligules, and will help protect crop yields and hairs on the leaf, and stem shape reduce the impact of weeds on the are important features for proper current and future crops. The best identification of grasses. Grasses approach to managing weeds in can have round or flattened stems. cropland is to utilize an integrated Sedges are similar in appearance to weed management approach that grasses, except sedges have three- incorporates cultural, mechanical, sided or triangular-shaped stems. biological, and chemical methods It is important to distinguish of control. Barnyard Grass sedges from grasses because control measures and herbicide Weed Identification choices are different for sedges and Biology than grasses. Weed identification is critical to Dicot plants have two cotyledons an effective weed management in the seed and are commonly program. Weeds can be divided referred to as broadleaves. The into several categories based on cotyledons of most broadleaf their biology and life cycles. The plants are pulled through the soil two primary botanical groups of and unfold above the soil surface plants are monocots and dicots. during emergence. The cotyledons Monocots have one cotyledon in are often called seed leaves and the seed and include grasses and are the lowest growing points on sedges. Grasses and sedges both the shoot following emergence of have long narrow leaves with a young broadleaf seedling. The parallel venation. The seed of true leaves of broadleaf plants grasses remains in the soil when it will develop above the cotyledons Large Crabgrass germinates. The emerging shoot and will have a netlike venation of grasses is enclosed in a structure pattern. The stem will continue called the coleoptile, which helps to elongate on young broadleaf the young shoot push upward plants with nodes spaced along through the soil. When the the stem. New leaves and branches coleoptile emerges through the soil can develop at each of the nodes surface and is exposed to sunlight, along the stem. Eventually, flowers the true leaves emerge through the will develop at the terminal end, 70 Weed Management and/or in the leaf axils along Biennial plants generally germi- the stem of broadleaf plants. nate in the spring or summer in Field Crops Cotyledon shapes, leaf size and and grow vegetatively during the shape, leaf arrangement, and other first year of growth, go dormant leaf and stem characteristics such over winter, reproduce during the as hairs and spines are critical second summer of growth and die to the proper identification of in late summer or fall. Biennial broadleaf plants. weeds are a problem primarily in pasture and noncropland areas, Weed Life Cycles and sometimes in no-till crop production. Examples of biennial Different plant species can weeds are musk thistle, common complete their life cycle in just a mullein, and western salsify. few weeks, or may live for many years. Plants that complete the Perennial plants can grow and life cycle in less than one year are reproduce over multiple years. commonly referred to as annuals; In addition to seed production, Giant Foxtail plants that complete their life cycle perennial plants often can over a period of two years are called reproduce vegetatively by spreading biennials; and plants that can grow root systems, rhizomes, stolons, indefinitely for more than two years tubers, or bulbs. Perennial weeds are called perennials. that do not spread vegetatively are referred to as simple perennials. Annual plants can further be Some examples of simple perennial divided into two groups depending weeds include common dandelion on the time of the year they grow. and curly dock. Perennial weeds Summer annual plants germinate that spread vegetatively are often in the spring or summer, reproduce called creeping perennials and during the summer and die in Green Foxtail frequently occur in dense patches the fall. Large crabgrass, pigweed, arising from the same parent plant. kochia, and devilsclaw are Field bindweed, johnsongrass, examples of summer annual weeds. and Canada thistle are examples Winter annual plants generally of creeping perennial weeds. germinate in the fall, go dormant Once established, perennial over winter, resume growth early weeds generally are very difficult in the spring, and reproduce and to control and can be a serious die by summer. Some examples problem in any crop. of winter annual weeds include Weeds that are similar in biology henbit, tansy mustard, and downy and life cycle to the crop being brome. Summer annual weeds are grown tend to be most common most troublesome in summer crops and troublesome in that crop, such such as corn, sorghum, soybeans, as shattercane in grain sorghum or sunflowers, and cotton, but can cheat in wheat. Table 1, page 75, also be a late season problem in lists some of the common weeds in winter wheat. Winter annual Kansas field crops, their life cycle, weeds are most troublesome in and the crops they commonly winter cereal crops such as winter infest. wheat, but also are a preplant problem in no-till summer crops. 71 Weed Management in Field Crops

Buffalobur Puncturevine

Prairie Cupgrass

Devilsclaw Redroot Pigweed

Witchgrass

Ivyleaf Morningglory Velvetleaf

72 Weed Management in Field Crops

Cheat Common Chickweed

Tansy Mustard

Jointed Goatgrass Henbit

Western Salsify

Italian Ryegrass Horseweed

73 Weed Management in Field Crops

Quackgrass Common Dandelion

Yellow Nutsedge

Windmillgrass Field Bindweed

Johnsongrass

Curly Dock Common Milkweed

74 Weed Management Table 1. Common Weeds in Kansas Field Crops in Field Crops Common Name Scientific Name Crops Summer Annual Grasses Barnyardgrass Echinochloa crus-galli Summer crops, alfalfa Crabgrass, large Digitaria sanguinalis Summer crops, alfalfa Panicum Fall panicum Summer crops, alfalafa dichotomiflorum Foxtail, giant Setaria faberi Summer crops, alfalfa Foxtail, green Setaria viridis Summer crops, alfalfa Foxtail, yellow Setaria glauca Summer crops, alfalfa Longspine sandbur Cenchrus longispinus Summer crops Prairie cupgrass Eriochloa contracta Summer crops, fallow Shattercane Sorghum bicolor Summer crops Stinkgrass Eragrostis cilianensis Fallow Witchgrass Panicaum capillare Summer crops, fallow Summer Annual Broadleaf Weeds Black nightshade, Solanum ptycanthum Summer crops eastern Buffalobur Solanum rostratum Fallow Cocklebur, common Xanthum strumarium Summer crops Devilsclaw Proboscidea lousianica Summer crops Kochia Kochia scoparia All crops, fallow Lambsquarters, Chenopodium album All crops common Morningglory, ivyleaf Ipomoea hederacea Summer crops Morningglory, tall Ipomoea purpurea Summer crops Palmer amaranth Amaranthus palmeri Summer crops, alfalfa Pennsylvania Polygonum Summer crops smartweed pensylvanicum Prickly sida Sida spinosa Summer crops Pigweed, redroot Amaranthus retroflexus Summer crops, alfalfa Puncturevine Tribulus terrestris Summer crops Summer crops, Ragweed, common Ambrosia artimisiifolia burndown Summer crops, Ragweed, giant Ambrosia trifida burndown Russian thistle Salsola iberica All crops, fallow Sunflower, common Helianthus annuus All crops, fallow Velvetleaf Abutilon theophrasti Summer crops Venice mallow Hibiscus trionum Summer crops Waterhemp, common Amaranthus rudis Summer crops Polyngonum Wild buckwheat Wheat, no-till convolvulus

75 Weed Management in Field Crops Common Name Scientific Name Crops Winter Annual Grasses Wheat, alfalfa, Brome, downy Bromus tectorum burndown Brome, Japanese Bromus japanicus Wheat, alfalfa, Cheat Bromus secalinus Wheat, alfalfa Jointed goatgrass Aegilops cylindrica Wheat Ryegrass, Italian Lolium multiflorum Wheat Winter Annual Broadleaf Weeds Wheat, alfalfa, Bushy wallflower Erysimum repandum burndown Chickweed, common Stellaria media Wheat, alfalfa, Flixweed Descurainia sophia burndown Wheat, alfalfa, Henbit Lamium amplexicaule burndown Horseweed Wheat, alfalfa, Conyza canadensis (marestail) burndown Wheat, alfalfa, Mustard, blue Chorispora tenella burndown Wheat, alfalfa, Mustard, tansy Descurainia pinnata burndown Wheat, alfalfa, Pennycress, field Thlaspi arvense burndown Pepperweed, Wheat, alfalfa, Lepidium densiflorum greenflower burndown Wheat, alfalfa, Shepherdspurse Capsella bursa-pastoris burndown Biennial Broadleaf Weeds Mullein, common Verbascum thapsus Pasture, alfalfa Thistle, bull Cirsium vulgare Pasture, alfalfa Thistle, musk Carduus nutans Pasture, alfalfa Salsify, western Tragopogon dubius No-till burndown Perennial Sedges Yellow nutsedge Cyperus esculentus All crops, no-till Perennial Grasses Johnsongrass Sorghum halepense Summer crops, alfalfa Quackgrass Agropyron repens Cool-season grasses Schedonnardus Tumblegrass No-till paniculatus Windmillgrass Chloris verticillata No-till

76 Weed Management Common Name Scientific Name Crops in Field Crops Perennial Broadleaves Burcucumber Sicyos angulatus No-till Canada thistle Cirsium arvensis All crops Sarcostemna Climbing milkweed Summer crops cynanchoides Curly dock Rumex crispus Alfalfa, wet areas Dandelion, common Taraxacum officianale Alfalfa, no-till Field bindweed Convolvulus arvensis All crops Groundcherry, Physalis subglabrata Summer crops smooth Hemp dogbane Apocynum cannabinum Summer crops Horsenettle Solanum carolinense Summer crops Milkweed, common Asclepias syriaca Summer crops Summer crops, wet Swamp smartweed Polygonum coccineum areas Woolyleaf bursage Franseria tomentosa All crops (bur ragweed)

Cultural Weed Control Practices biology, and weed population. Sanitation and good agronomic Tillage continues to be a primary practices that favor quick method of weed control in tillage- establishment and optimal growth based production systems, but of the crop compared to weeds may not be an option in no-till are important cultural practices crop production. Tillage is most to help manage weeds. One of effective for control of seedling the most important cultural weeds and when dry conditions practices for managing weeds over follow the tillage operation. multiple years is crop rotation. A Mowing is most effective to diverse rotation of crops across prevent seed production on annual years can result in a diversity and biennial weeds, but may of herbicide options, weed require multiple operations. Hand control practices, and timings. removal is most practical for small A diverse and integrated weed scale situations, or where low weed management program will help infestations are present. reduce the potential for developing serious weed problems, high Biological Weed Control weed populations, and herbicide Biological weed control involves resistant weeds. the use of other organisms to reduce the populations and impact Mechanical Weed Control of weeds on crops or natural areas. Tillage, mowing, and hand Biological weed control has been removal can be effective weed most successful in noncropland control practices depending on and pasture situations. Examples the crop production system, weed of biological control include 77 Weed Management weed specific insects, diseases, or both broadleaf and grass weeds. in Field Crops herbivores. Herbicide selectivity is relative and depends on several factors, Chemical Weed Control including plant biology, plant Herbicides are chemicals used to genetics, environment, herbicide control weeds. Herbicides may application rate, application be an important component of timing, and application technique. an integrated weed management Even a tolerant plant species program. However, herbicides may be susceptible to a selective must be used in accordance with herbicide if the application rate all label guidelines to achieve good is too high or the herbicide is weed control while not causing missapplied. harm to the crop, environment, wildlife, applicator, worker, or Translocation refers to the consumer. movement of an herbicide inside a plant once it is absorbed through the leaf surface. Systemic Types of Herbicides herbicides are translocated in Herbicides can be grouped into plants, while contact herbicides are categories based on selectivity, not translocated. Translocation of type of application, translocation systemic herbicides to the site of in the plant, and mode of action. action is important to herbicide Herbicide selectivity refers to the performance. differential response of plants to a Contact herbicides are not herbicide. Herbicides that kill or translocated. When applying suppress the growth of most plant foliar-applied contact herbicides, species are considered nonselective. thorough spray coverage is Nonselective herbicide use is essential to kill the entire plant. limited to situations where control Contact herbicides generally are of all plant species is desired, ineffective for long-term perennial or the herbicide is directed on weed control. Contact herbicides the target weed and away from damage top growth that the desirable plants. spray solution reaches, but the Glyphosate and paraquat underground portion of perennial historically have been considered plants remains unaffected and can nonselective herbicides. rapidly initiate new growth. However, glyphosate is a highly Contact herbicides often are more selective herbicide when used in effective on broadleaves than on conjunction with crops that have grasses because the growing points been genetically engineered with of young broadleaf plants are resistance to glyphosate. aboveground and exposed to the Most herbicides used in crop spray treatment. In contrast, the production are selective, which growing point of young grasses is means they kill certain weeds located in the crown region of the but do not injure the crop. Some plant, which is at or below the soil herbicides are primarily for surface, and difficult to reach with control of grasses, while others the spray. Thus, contact herbicides may control just broadleaves, or may not kill all the growing 78 Weed Management points of a tillered grass plant, and Sulfonylaminocarbonyl-triazolinone regrowth can occur. family – Olympus, Olympus in Field Crops Flex, Osprey Herbicide Mode of Action Herbicide mode of action refers to Diterpene Inhibitors how herbicides work. Herbicides Isoxazolidinone family – Command can be classified into “families” based on chemical similarities EPSP Inhibitors and mode of action. The mode of Amino acid derivative family – action is the process by which a Roundup, glyphosate chemical kills or suppresses plant growth. Herbicides of the same HPPD Inhibitors chemical family usually have the Isoxazole family – Balance, Huskie same mode of action. Different Triketone family – Callisto, Impact, chemical families of herbicides also Laudis may have the same mode of action. Repeated use of the same Photosynthetic (PSII) Inhibitors herbicide or herbicides with the Triazine family – atrazine, same mode of action eventually metribuzin, simazine can lead to enhanced degradation, Phenylurea family – Lorox, weed species shifts, herbicide Karmex, Spike resistance, increased carryover, Uracil family – Sinbar, Hyvar and crop injury. Using herbicides with different modes of action in Nitrile family – Buctril, bromoxynil tank mixes and in rotation, along Benzothiadiazole family – Basagran with other cultural weed control practices, will help prevent these Photosystem 1 (PS1) Inhibitors problems from occurring. Bipyridillium family – diquat, Gramoxone, paraquat Herbicide Modes PPO Inhibitors of Action Diphenylether family – Cobra, ET, ALS Inhibitors Flexstar, Phoenix, Reflex, Ultra Imidazolinone family – Arsenal, Blazer, Vida Beyond, Contain, Plateau, N-Phenylphthalimide family – Pursuit, Raptor, Scepter Cadet, Resource Sulfonylurea family – Accent, Aryl-Triazolinone family – Aim, Affinity, Ally, Amber, Basis, Spartan, Valor Beacon, Cimarron, Classic, Escort, Express, Finesse, Glean, Pyrimidinedione family – Sharpen, Harmony, Harmony Extra, Kixor Maverick, Oust, Peak, Permit, Spirit, Steadfast, Synchrony, Telar Sulfonalmide family – Python, FirstRate, PowerFlex

79 Weed Management Synthetic Auxin – Growth before any selection pressure or in Field Crops Regulators genetic manipulation would be Benzoic acid family – Banvel, considered naturally tolerant, but Clarity, dicamba, Distinct, not herbicide resistant. Herbicide Status resistant weed populations are Phenoxy family – 2,4-D, 2,4-DB, generally selected from the native MCPA population in field situations through repeated treatment over Pyridine family – Garlon, time with a given herbicide or Milestone, Remedy, Starane, herbicides having the same mode Stinger, Tordon of action. Herbicide resistance may Semicarbazone family – Distinct, be based on differential absorption, Status translocation, metabolism, or an altered site of action. Lipid synthesis – ACCase Herbicide resistance can result Inhibitors from a single gene mutation or Aryloxyphenoxypropionate family from a combination of multiple – Assure II, Fusilade, Fusion, gene changes. Single gene Targa mutations that alter the site Cyclohexanedione family – Poast, of action generally indicates a Poast Plus, Select, Select Max, relatively high level of resistance Section, Volunteer and population shifts can occur in just a few years. Some examples of Glutamine Synthetase Inhibitors single gene herbicide resistance in Phosphylated amino acid family – Kansas include waterhemp, Palmer Ignite, Liberty amaranth, kochia, sunflower, bushy wallflower, and cheat Mitosis Inhibitors resistance to the ALS-inhibiting Dinitroaniline family – Balan, herbicides, and Palmer amaranth, pendimethalin, Prowl, Treflan, waterhemp, and kochia resistance trifluralin, Sonalan to atrazine. Multi-gene resistance is often a lower level resistance Seedling Root and Shoot that gradually increases over time Inhibitors and is more difficult to confirm. Acetamides – Degree, Dual Waterhemp, marestail, giant Magnum, Harness, Intrro, ragweed, and kochia resistance to metolachlor, Outlook, Surpass glyphosate appears to be a result of multigene herbicide resistance Herbicide Resistance traits. Herbicide resistance is defined Herbicide resistant weed as “the inherited ability of a populations generally result from plant to survive and reproduce heavy reliance on a single herbicide following exposure to a dose or herbicide mode of action for of herbicide normally lethal to weed control over time. Thus, the native population of that an integrated weed management species.” Plant species that are program that incorporates crop not controlled by a herbicide rotation, herbicide rotations, 80 Weed Management mixtures of herbicides with be in soil solution to be absorbed different modes of action, and other by germinating seedlings. Adequate in Field Crops methods of weed control will help precipitation or mechanical minimize the risk of developing incorporation after application is herbicide-resistant weeds. required to get the herbicide into solution or “activate” the herbicide. Herbicide Application The amount of precipitation required to activate the herbicide The optimum timing and method will depend on the individual of herbicide application will depend herbicide and soil properties. on the herbicide, crop, and target weeds. Guidelines and directions Herbicides are generally more for the proper application of active in coarse textured and low each herbicide is provided in the organic matter soils than in finer herbicide label. Failure to follow textured and higher organic matter label directions, warnings, and soils. Consequently, herbicide rates precautions can result in crop may need to be adjusted for soil- injury, poor weed control, off- applied herbicides depending on target plant injury, environmental soil properties. Soil pH also can contamination, human hazards, affect the activity and persistence and/or civil penalties. of certain herbicides. For example, atrazine, and several of the Herbicides can have foliar and/ sulfonylurea herbicides like Finesse or soil activity depending on the and Amber, are more active and chemical. A number of factors can more persistent at high than at low affect the activity or performance soil pH. Consult the herbicide label of soil-applied and foliar-applied for the recommended application herbicides. rates, crop rotation guidelines, and Soil-Applied Herbicides use restrictions as it pertains to soil Soil-applied herbicides persist properties. in the soil for a period of time Foliar-Applied Herbicides and can be absorbed from the Foliar-applied or postemergence soil by plant roots and shoots. herbicides are applied to the Herbicides applied to the soil foliage of emerged plants for and mechanically incorporated control. Some postemergence before planting the crop are herbicides may have both foliar commonly referred to as preplant and soil residual activity.The incorporated treatments. performance of postemergence Herbicides applied to the soil herbicides will depend on surface before the crop and weed species susceptibility, weed emergence are commonly called size, environmental conditions, preemergence applications. spray adjuvants, and application Herbicide properties, soil techniques. Annual weeds properties, environmental and seedling perennial weeds conditions, weed susceptibility, generally are most susceptible to and application rate will affect postemergence herbicides when the performance of soil-applied the weeds are small and actively herbicides. Most herbicides need to growing. The suseptiblity and 81 Weed Management benefits from controlling annual canopy penetration, coverage, and in Field Crops weeds decreases as they mature. herbicide performance. Consult Established perennial weeds each herbicide label for the usually are most susceptible when recommended spray application treated at the early bloom stage guidelines to minimize spray of growth or to active growth in drift and optimize herbicide the fall. Application at these times performance. generally results in the greatest translocation to the roots and the Weed Management Decisions best long-term control. Knowledge of field history and scouting fields to identify Weather conditions can greatly emerging weed problems impact the performance of throughout the growing season postemergence herbicides. are important for making effective Postemergence herbicides are weed control plans and decisions. most effective when applied to Herbicides are just one component actively growing weeds with of an effective weed management favorable growing conditions. program. Consult herbicide Weeds that are under stress labels and other weed control due to extreme temperature or guides, such as the latest edition moisture conditions tend to be less of Chemical Weed Control for Field susceptible to most herbicides. On Crops, Pastures, Rangeland, and the other hand, crops under stress Noncropland (SRP 1045) to assist may actually be more susceptible in making effective herbicide to injury than crops growing choices. The guide is available at with good conditions due to a www.ksre.ksu.edu/library by typing diminished ability to metabolize chemical weed control in the the herbicide. search box. Spray adjuvants are chemicals added to the spray to modify the properties of the spray solution for improved handling or pesticide activity. Adjuvants are often recommended with certain postemergence herbicides to optimize their performance. There are many types of adjuvants that each have a different function. Consult the herbicide label for the recommended type and rate of adjuvant to maximize performance. Inappropriate adjuvant use could result in crop injury, poor weed control, and application problems. Spray volume and droplet size may impact spray deposition,

82 Weed Management Study Questions 6. In cases where available herbicides will not control the weeds, which in Field Crops These study questions are to help of the following management you learn the material on pages 70 practices are helpful? through 82. a. crop rotation 1. Weeds reduce crop yields by competing for: b. tillage c. a and b above a. moisture d. none of the above b. light c. soil nutrients 7. Glyp hosate is an example of a: d. all of the above a. non selective herbicide 2. Important features used to identify b. EPSP inhibitor grassy weeds include: c. selective herbicide when use with Roundup Ready crops a. leaf shape d. all of the above b. auricles and ligules c. leaf arrangement 8. A weed species that has developed resistance to herbicides in Kansas d. all of the above includes: 3. An example of a dicot plant a. kochia includes a: b. cheat a. broadleaf c. palmar amaranth b. sedge d. all of the above c. soybean 9. Summe r crops such as corn, d. both a and c sorghum, and soybeans tend to 4. Field bindweed, dandelion increase: and johnsongrass are: a. summer annual weeds a. summer annuals b. fall annual weeds b. perennials c. winter annual weeds c. winter annuals d. perennials d. biennials 10. The risk of herbicide resistance 5. Winter annual grasses include: can be decreased by using: a. downy brome a. crop rotations b. cheat b. herbicide rotations c. jointed goatgrass c. mixtures of herbicides that d. all of the above have a different mode of action d. all of the above

83 Weed Management 11. Perennial weeds can reproduce 12. Examples of biennial broadleaf in Field Crops from: weeds are: a. stolons a. common mullein b. seed production b. musk thistle c. tubers c. western salsify d. all of the above d. all of the above

84 Pasture and Weeds common in rangeland that incorporate periodic rest, can and pastures in Kansas include help keep a competitive cover. Rangeland Weed annual species such as lanceleaf Improper grazing distribution that ragweed and common broomweed. results in concentrated grazing and Brush Control Biennial plants that take two usually disturbs the soil and years to complete their life cycle, allows unwanted species to invade. include musk thistle and common Unfenced pond dams are a typical mullein. Troublesome perennial disturbed site where noxious weed species include sericea weeds and other unwanted species lespedeza, Baldwin ironweed, occur. Other grazing management woolly verbena, and goldenrods. principles include proper season Grasses such as prairie threeawn, of use and kind of animal. Cattle longspine sandbur, Johnsongrass, are primarily grass eaters, but will Kentucky bluegrass, and old world consume significant amounts of bluestems may also be considered forbs and browse during the year. weeds if they are growing where Sheep prefer palatable forbs, and they are not welcome. Shrubs such goats will eat woody plants if as buckbrush, smooth sumac, and available. roughleaf dogwood, as well as trees Mechanical control includes hand such as common honeylocust, clippers, mowers, tree cutters, and osage orange, and eastern redcedar, bulldozers. Mowing of annual may become problems on range and biennial species before seed and pastureland. production can be an effective There are several options for control method. Non-sprouting control and management of brush species, such as eastern redcedar, and weed species: can be controlled by cutting • management below the lowest green branch. Repeated mowing or top removal • mechanical will be necessary to control most • biological perennial species. Timing for top • prescribed burning removal should correspond with • chemical the low point in the food reserve cycle that generally occurs at floral Proper grazing management can bud initiation. reduce invasion of many problem weed and brush species. Stocking Release of the musk thistle head rate, the number of animals per weevil (Rhinocyllus conicus) and unit area for a given period of rosette weevil (Trichosirocalus time, is the most important factor horridus) has provided reduced influencing livestock and plant seed production and is an example response to grazing. Overstocking of biological control. Attempts can reduce the vigor of the most are being made to introduce a palatable species and allow leaf feeding beetle (Diorhabda invasion of plants that reproduce elongata) for biological control of by seed. Maintaining a competitive saltcedar. Leafy spurge and spotted cover can keep unwanted species knapweed are also targets for at manageable levels. Grazing using biological control. Because systems, such as rotational grazing, of grazing preference, sheep and 85 Pasture and goats can be used to reduce and In many cases an integrated Rangeland Weed manage many broadleaf and approach can be used. For instance, woody plants. grazing management that includes and Brush Control Prescribed burning can be an proper stocking rates combined effective method for brush and with frequent use of prescribed weed control. Late-spring burning burning can prevent most woody when annual grasses, broadleafs, plants from gaining dominance in and woody plants are leafed out is many areas of Kansas. Mechanical the most effective time to burn. A cutting of non-sprouting species single burn can effectively control such as eastern redcedar can be eastern redcedar, but it is necessary very effective. However, cut- to burn two to three consecutive stumps of sprouting species such years to control most woody species. as osage orange will require an herbicide to prevent resprouting. Herbicides can be applied on the soil, as a basal bark or cut-stump Trees or woody vegetation should treatment, or applied to foliage. be cut close to the soil surface Properly applied, herbicides before application. Before spraying, can be an efficient method of brush off any soil or sawdust. controlling unwanted species. Spray the stump immediately after Broadcast application of herbicides cutting. It is especially important on rangeland and pasture should for the herbicide to cover the be done infrequently as many bark, crown buds, and all exposed desirable nontarget species can roots to prevent resprouting. If a be damaged. Care should also be delay occurs in spraying, it may taken when treating poisonous be necessary to use an oil-based plants. Herbicide treatment product or freshen the stump usually increases plant palatability. surface by cutting or chopping to Grazing animals may need to be expose fresh tissue. Do not spray removed from a pasture sprayed when basal stems are wet. for poisonous plants for a period Plant identification is an of time to reduce the chance important aspect of weed and of livestock poisoning. Refer to brush control. The following list the latest edition of the K-State and illustrations categorize and publication, Chemical Weed identify many of the major weed Control for Field Crops, Pastures, and brush species on pasture and Rangeland, and Noncropland rangeland in Kansas. (SRP 1045) for specific herbicide recommendations. Major Weeds in Pasture and Rangeland Common Name Scientific Name Origin Growth Habit Amphiachyris Broomweed Native Annual, summer dracunculoides Xanthium Cocklebur Native Annual, summer strumarium Common Ambrosia Native Annual, summer ragweed artemisiifolia 86 Pasture and Common Name Scientific Name Origin Growth Habit Rangeland Weed Common Helianthus annuus Native Annual, summer sunflower and Brush Control Lanceleaf Ambrosia bidentata Native Annual, summer ragweed Snow-on-the- Eurphorbia Native Annual, summer mountain marginata Texas croton Croton texensis Native Annual, summer Downy brome Bromus tectorum Introduced Annual, winter Japanese brome Bromus japonicus Introduced Annual, winter Little barley Hordeum pusillum Native Annual, winter Bull thistle Cirsium vulgare Introduced Biennial Common mullein Verbascum thaspus Introduced Biennial Musk thistle Carduus nutans Introduced Biennial Tall thistle Cirsium altissimum Native Biennial Baldwin ironweed Vernonia baldwini Native Perennial Broom snakeweed Gutierrezia sarothrae Native Perennial Curlycup Grindelia squarrosa Native Perennial gumweed Sericea lespedeza Lespedeza cuneata Introduced Perennial Tall goldenrod Solidago altissimum Native Perennial Wavyleaf thistle Cirsium undulatum Native Perennial Western ragweed Ambrosia psilostachya Native Perennial Astragalus Woolly loco Native Perennial mollissimus Woolly verbena Verbena stricta Native Perennial Blackberry Rubus spp. Native Perennial Symphoricarpos Buckbrush Native Perennial orbiculatus Common Gleditsia triacanthos Native Perennial honeylocust Common Opuntia humifusa Native Perennial pricklypear Eastern redcedar Juniperus virginiana Native Perennial Mulitflora rose Rosa multiflora Introduced Perennial Osage orange Maclura pomifera Native Perennial Roughleaf Cornus drummondii Native Perennial dogwood Elaeagnus Russian olive Introduced Perennial angustifolia Saltcedar Tamarix ramosissima Introduced Perennial Siberian elm Ulmus pumila Introduced Perennial Smooth sumac Rhus glabra Native Perennial Yucca Yucca glauca Native Perennial

87 Pasture and Rangeland Weed Summer Annual Broadleaf Weeds and Brush Control

Cocklebur Lanceleaf Ragweed

Broomweed

Common Ragweed Snow-on-the-Mountain

Common Sunflower Texas Croton 88 Pasture and Annual or Winter Annual Grasses Rangeland Weed and Brush Control

Downy Brome Little Barley

Japanese Brome

89 Pasture and Rangeland Weed Biennial Broadleaf Weeds and Brush Control

Bull Thistle Musk Thistle

Common Mullein Tall Thistle

90 Pasture and Perennial Broadleaf Weeds Rangeland Weed and Brush Control

Baldwin Ironweed Sericea Lespedeza

Western Ragweed

Brome Snakeweed Tall Goldenrod

Woolly Loco

Curlycup Gumweed Wavyleaf Thistle Woolly Verbena 91 Pasture and Rangeland Weed Woody Plants and Brush Control

Buckbrush Eastern Redcedar

Blackberry

Common Honeylocust Multiflora Rose

Common Pricklypear Osage Orange 92 Pasture and Woody Plants Rangeland Weed and Brush Control

Roughleaf Dogwood Siberian Elm

Russian Olive Smooth Sumac

Saltcedar Yucca 93 Pasture and Study Questions 4. Saltcedar, Russian olive and Rangeland Weed multiflora rose are examples of: These study questions are to help you learn the material on pages 85 a. native perennials and Brush Control through 93. b. introduced perennials 1. Broomweed, ragweed and c. summer annuals sunflower are examples of: d. biennials a. summer annual broadleaf 5. The following are examples of weeds woody plants: b. winter annual and biennial a. sericea lespedeza and weeds ironweed c. perennial broadleaf weeds b. broomweed and sunflower d. woody plants c. sumac and yucca 2. Control options for the d. mullein and thistle management and control of 6. An example of a woody plant that rangeland weed species include: resprouts is: a. chemical control a. elm b. mechanical control b. osage orange c. biological control c. eastern red cedar d. all of above d. both a and b 3. An example of an insect that provides biological control is: a. goats b. the rosette weevil c. sheep d. all of the above

94 Equipment and Commercial applicators are types are extended range flat-fans, applying more and more pesticides turbo or chamber style flat-fans Calibration for in Kansas. Because of high costs and flooding flat-fans, and air- and growing public concern injection/venturi flat-fans of Commercial Field about possible environmental various designs. These nozzle hazards, pesticides must be applied types are described below in Crop Applications accurately and uniformly. This chronological order. chapter discusses the proper selection and use of spray nozzles, Flooding Flat-Fan Nozzles techniques to minimize spray (Old style nozzle. In use before drift, calibration and mixing other nozzles described. Several pesticide formulations, the role of manufacturers have similar designs.) electronics in application, proper Flooding flat-fan nozzles produce maintenance, and record keeping. a wide-angle, flat-fan pattern, and are used for applying herbicides To minimize problems associated and mixtures of herbicides and with pesticide use it has become liquid fertilizers. Nozzle spacing increasingly important to improve should be 40 inches or less. application equipment and develop These nozzles are most effective techniques that facilitate effective in reducing drift when they are use of lower dosages, reduce drift operated within a pressure range of and harmful residues, and protect 8 to 25 psi. Pressure changes affect applicators and the environment. the width of the spray pattern more with the flooding flat-fan Nozzle Selection nozzle than with the extended Select the correct type and size of range flat-fan nozzle. In addition, spray nozzle for each application. the distribution pattern usually The nozzle determines the amount is not as uniform as that of the of spray applied to an area, the extended range flat-fan tip. The uniformity of the application, the best distribution is achieved when coverage of the sprayed surface, the nozzle is mounted at a height and the amount of drift. You and angle to obtain at least double can minimize drift problems coverage or l00 percent overlap. by selecting nozzles that give Uniformity of application depends the largest droplet size while on the pressure, height, spacing, providing adequate coverage and orientation of the nozzles. at the intended application Pressure directly affects droplet rate and pressure. Although size, nozzle flow rate, spray angle, nozzles have been developed for and pattern uniformity. At low practically every kind of spray pressures, flooding nozzles produce application, only a few nozzle large spray drops; at high pressures, types are commonly used to apply these nozzles actually produce crop protection products and smaller drops than flat-fan nozzles fertilizer-pesticide combinations. at an equivalent flow rate. Most crop protection products The spray distribution of flooding are applied with a nozzle type nozzles varies greatly with changes designed to produce a tapered in pressure. At low pressures, flat-spray pattern. These nozzle flooding nozzles produce a fairly 95 Equipment and uniform pattern across the swath, is necessary to overlap adjacent Calibration for but at high pressures the pattern patterns along a boom in order becomes heavier in the center and to obtain uniform coverage. The Commercial Field tapers off toward the edges. The 80-degree fan nozzles are usually width of the spray pattern also mounted on 20-inch centers at a Crop Applications is affected by pressure. To obtain boom height of 17 to 19 inches. an acceptable distribution pattern The 110-degree nozzles could and overlap, you should operate be mounted on 30-inch centers flooding nozzles within a pressure at a boom height of 20 to 22 range of 8 to 25 psi. inches or kept on 20-inch centers Nozzle height is critical in and lowered to 16 to 18 inches. obtaining uniform application Regardless of the spacing and when using flood nozzles. height, for maximum uniformity Flooding nozzles can be mounted in the spray distribution, the spray vertically to spray backwards, patterns should overlap about 50 horizontally to spray downwards, to 60 percent of the nozzle spacing or at any angle between vertical (25 to 30 percent on each edge of and horizontal. When the nozzle the pattern). is mounted horizontally to spray For soil applications, the downwards, heavy concentrations recommended pressure range of spray tend to occur at the edges is from 10 to 30 psi. For foliar of the spray pattern. Rotating the application when smaller drops are nozzles 30 to 45 degrees from the required to increase the coverage, horizontal will usually increase higher pressures from 30 to 60 the pattern uniformity over the psi may be required. However, an recommended pressure range of 8 increase in the likelihood of drift to 25 psi. For uniform distribution may result when pressures above over a range of pressures, mount 25 psi are used. Because of the the nozzles to obtain double potential for increased drift with coverage at the lowest operating this nozzle type and with newer pressure. more drift resistant nozzle designs, this nozzle type is not as highly Extended Range Flat-Fan recommended as it was when first (Replaced regular flat-fan, available introduced. from all nozzle manufacturers.) Extended range flat-fan nozzles are frequently used for soil and foliar applications when better coverage is required than can be obtained from the flooding or turbo flooding flat-fan nozzles. Extended range flat-fan nozzles are available in both 80- and 110-degree fan angles. The pattern from this nozzle type has a tapered edge distribution. Because the outer edges of the spray pattern have reduced volumes, it 96 Equipment and Turbo Flood Nozzles across a wider pressure range Turbo Flood nozzles are nozzles (15 to 90 psi) than comparable Calibration for that combine the precision and low-drift tips, reducing the uniformity of extended range flat amount of driftable particles. The Commercial Field spray tips with the clog resistance wide spray angle will allow for a and wide-angle pattern of flooding 20 or 30-inch nozzle spacing and Crop Applications nozzles. The design of the Turbo requires 50 to 60 percent overlap Flood increases droplet size to achieve uniform application and distribution uniformity by across the boom. Position the tip incorporating a preorifice and so that the preset spray angle is chamber internally and a more directed away from the direction refined exit orifice. The increased of travel. The Turbo flat-fan nozzle turbulence in the spray tip causes is excellent for use with electronic an improvement in pattern spray controllers where speed and uniformity over existing flooding pressure changes occur regularly. nozzles. At operating pressures of 8 to 25 psi, Turbo Flood nozzles Air-Injection/Venturi Nozzles produce larger droplets than Nozzle manufacturers are standard flooding nozzles. Having increasingly focused on designs larger droplets reduces the number for maximum drift reduction. of driftable size droplets in the These designs involve the use of spray pattern, so Turbo Flood air incorporated into the spray nozzles work well in drift-sensitive nozzle to form an air-fluid mix. applications. Turbo Flood nozzles, Several designs are on the market because of their improved pattern and are commonly referred to uniformity, probably need at as air-induction, air-injection or least 50 percent overlap to obtain venturi nozzles. Air is entrapped proper application uniformity. into the spray solution at some Turbo Flood nozzles are highly point (typically a venture section) recommended for soil application within the nozzle. To accomplish of crop protection products. the mixing, some type of inlet port and venturi is typically used to Turbo Flat-Fan draw the air into the tip under a The Turbo Flat-Fan nozzle is reduced pressure. The air-solution designed similar to the Turbo combination forms a larger spray Flood incorporating the preorifice droplet and provides energy to and chamber. It has been adapted help transport the droplets to the to fit in a flat-fan style nozzle body target. By increasing the size of with a greatly improved (uniform) the spray droplets a reduction in wide angle spray pattern when spray drift occurs by minimizing compared to the extended range the smaller driftable fines typically flat-fan and other drift-reduction created in a spray tip. Current flat-fan nozzles. This nozzle was design of these tips calls for a specifically designed for use in higher pressure (70-80 psi) to the application of postemergence perform adequately. Most all products. Turbo flat-fan nozzles venturi nozzles are designed to are wide-angle preorifice nozzles spray a wide-angle flat spray that create larger spray droplets pattern. 97 Equipment and Venturi nozzles, which are more coverage for certain application Calibration for expensive, dramatically reduce scenarios has influenced nozzle drift potential. In addition to manufacturers to redesign these Commercial Field providing good protection against nozzle types so that they can drift, research data on venturi improve coverage while still Crop Applications nozzles indicates that they also maintaining good drift reduction. provide adequate efficacy when The new design reduces the used at the higher pressure. Before droplet spectra when compared to using, understand coverage needs the earlier venturi styles, allowing (systemic vs. contact) for the crop for potential for better coverage protection products being used in while maintaining a reasonable order to ensure adequate droplet amount of drift reduction. The formation. It is also important design also allows for lower to maintain at least 40 psi as an operating pressures (40 psi) when operating pressure to maintain compared to the earlier designs. uniform pattern development while properly atomizing the spray Application Equipment and solution. Adding deposition aids Techniques for Minimizing or drift-reducing products to tank Particle Drift mix solutions sprayed using venturi Minimizing spray drift is and will nozzles also can have a major continue to be a major focus for impact on pattern quality. those involved in the agriculture industry. The most popular and Please note special calibration least costly technology for reducing requirements for the venturi drift has been in the design of nozzles. For example Greenleaf, spray nozzles. Concern has been designer of the TurboDrop venturi expressed that this increased two-piece nozzle, requires the exit emphasis in drift reduction is orifice to be two times the size of compromising crop protection the venturi orifice. Otherwise the product efficacy. A spray droplet exit orifice may create a negative standard (ASABE S-572.1) is in pressure effect in the venturi area place that applicators can use to resulting in failure of the nozzle select the desired droplet spectra. to create the proper spray quality This section will review common (actually reversing flow from the methods for minimizing drift air inlets). Select and calibrate the while providing insight into using TurboDrop nozzle based on the the new standard to properly set venturi orifice, which is color- up spray equipment to increase coded to standard. A chart is efficacy while minimizing drift. available from the manufacturer for this purpose. Other venturi nozzle styles are one piece and do Minimizing Spray Drift not have this precaution. The misapplication of any crop protection product is a Air-Injection/Venturi Nozzles major concern. One form of (New design) misapplication is spray drift. Air-injection/venturi nozzles have Although drift cannot be made a major impact on reducing completely eliminated, the use of drift. So much so that reduced proper equipment and application 98 Equipment and techniques will help maintain drift the off-target movement. The deposits within acceptable limits. ability to reduce drift is no better Calibration for The initial recommendation for than the weakest component drift control is to read the pesticide in the spraying procedure. See Commercial Field label. Instructions are given to the summary of recommended insure the safe and effective use of procedures for reducing particle Crop Applications pesticides with minimal risk to the drift injury in this section. environment. When drift occurs The potential for drift must it is likely that the crop protection be considered when selecting a product you are using is wasted, nozzle type. Of the many nozzle and due to the high potential for types available for applying sensitive areas in crop settings pesticides, a few, especially the (flowers and other aesthetic plants, newer technology nozzles, are water, etc), it is very possible that specifically designed for reducing some damage will occur outside drift by decreasing the amount of the target area. The off-target small driftable spray particles in damage from products like 2,4-D the spray pattern. However, with and glyphosate will be obvious, selecting a nozzle type to deliver while applications of a fungicide larger droplets for maximum drift or insecticide may not be as reduction comes the potential for noticeable. decreased coverage and efficacy. There are two ways chemicals Spray height is also an important move downwind to cause factor in reducing drift losses. damage: particle and vapor drift. Mounting the boom closer to Vapor drift is associated with the ground (without sacrificing the volatilization of pesticide pattern uniformity) can reduce molecules and then movement drift. Nozzle spacing and spray off-target (2,4-D). Particle drift is angle determines correct spray the off-target movement of spray height for each nozzle type. particles formed during or after Wide-angle nozzles can be placed the application. The amount of closer to the ground than nozzles particle drift depends mainly on producing narrow spray angles. the number of small “driftable” On the other hand, older style particles produced by the nozzle. wide-angle nozzles also produce Although excellent coverage can smaller droplets. When this occurs, be achieved with extremely small the advantages of lower boom droplets, decreased deposition and height are negated to some extent. increased drift potential limit the However, the newer technology minimum size that will provide wide-angle drift reduction nozzles effective pest control. (air-induction/venturi) actually Factors Affecting Spray Drift have been designed to reduce the Several equipment and application number of small droplets and will factors greatly determine the assist in drift reduction. amount of spray drift that occurs. Using larger nozzle sizes is The type and size of nozzle another way of minimizing drift. and orientation, pressure, boom Increasing the spray volume by height, and spray volume, all affect using higher capacity spray tips 99 Equipment and (usually at lower pressures to nozzle distribution patterns to Calibration for maintain constant flow rates) be nonuniform. Drift control results in larger droplets that are additives vary in cost depending Commercial Field less likely to move off-target. on rate and formulation, but are Lower pressures also can increase comparatively inexpensive for the Crop Applications droplet size reducing coverage, amount of control provided. It is while higher pressures and lower wise to test these products in your flow rate nozzles will lead to more spray system to ensure they are drift by producing finer spray working properly before adapting droplets. Changing pressure alone this practice. Not all products will also change the flow rate per work equally for all systems. They nozzle and the overall application do not eliminate drift. Common rate. The only effective means of sense must still remain the primary reducing drift by increasing spray factor in reducing drift damage. volume is to increase nozzle size. Focus on Droplet Size Although not directly an equip- Most applicators are familiar with ment factor, one of the better tools how to use flow rate charts from for minimizing drift damage is spray equipment catalogs and the use of drift control additives, websites to determine the nozzle commonly called deposition aids, orifice size needed to deliver a in the spray solution to increase proper application volume (GPA the droplet size. Tests indicate or G/1000 sq. ft.). Applicators are that downwind drift deposits also comfortable in making those can be reduced from 50 to 80 applications with the benefit of percent with the use of drift an automatic rate controller to control additives. In some cases help improve the uniformity of increased drift has occurred when application volume. However, a drift control additives are added properly calibrated sprayer does to the tank mix. Drift control not guarantee the application will additives make up a specific class achieve its highest level of efficacy of chemical adjuvants and should or minimize drift. The next step not be confused with products in calibration is designed to such as surfactants, wetting agents, achieve this, but is one that most spreaders, and stickers. Drift applicators are not familiar with control additives are formulated to yet. This calibration step requires produce a droplet spectrum with applicators to review droplet size fewer small droplets. charts to choose nozzle types and A number of drift control additives pressure levels that will meet a are commercially available, but specified droplet classification they must be mixed and applied listed on the label. The droplet size according to label directions created by a nozzle becomes very in order to be effective. Some important when the efficacy of a products are recommended for particular crop protection product use at a rate of 2 to 8 ounces per is dependent on coverage, or the 100 gallons of spray solution. minimization of material leaving Increased rates may further the target area is a priority. Droplet reduce drift but also may cause specifications or spray quality

100 Equipment and requirements may be printed on Strategies to Reduce Spray Drift the label to guide applicators in This following summary table Calibration for selecting how to best apply that provides several strategies that pesticide. Consulting the nozzle when used in combination, Commercial Field manufacturers’ droplet sizing will result in the best chance to charts is essential. minimize drift. One strategy used Crop Applications To help applicators select nozzles alone will not necessarily prevent according to droplet size, spray drift. A combination of strategies equipment manufacturers are will provide the best insurance including drop size charts with against the off-target movement of their respective catalogs and web the crop protectant product used. sites. These charts classify the droplet size from a given nozzle at Calibration various pressure levels according to Accurate calibration is the a standard set up by the American only way to know how much Society of Agricultural and chemical is applied. Even with Biological Engineers (ASABE). the widespread use of electronics The standard (S-572.1) rates to monitor and control the droplets as extra fine, very fine, application of crop protection fine, medium, coarse, very coarse, products today, a thorough sprayer extra coarse, and ultra coarse (see calibration procedure is essential chart on the next page). Droplet to ensure against misapplication. size categories are color-coded as Failure to calibrate a sprayer can shown in the chart. Remember, injure your crop, cause pollution, if the label specifies a particular and waste money. In addition droplet size category, you are to calibrating the sprayer at the required to set up the sprayer to start of the season, you should meet that particular spray quality. recalibrate regularly. Abrasive The label is the law! pesticide formulations can

Procedures for Reducing Particle Drift Injury Recommended Technique Explanation Select a nozzle to increase Use as large droplets as practical to provide droplet size. necessary coverage. Use lower end of pressure Higher pressures generate many more small range. droplets with greater drift potential. Wind speed increases with height. A few inches lower boom height can reduce off-target drift. Lower boom height. High field travel speeds may result in an unstable boom leading to high boom positions and drift potential. Increase nozzle size, Larger-capacity nozzles can reduce the amount of resulting in higher spray depositing off-target. application volumes.

101 Equipment and Calibration for Recommended Technique Explanation Avoid high application Rate controllers adjusting to speed changes may Commercial Field ground speeds or major result in pressure adjustments causing droplet size speed changes across the variability. Rapid speed increases may create high field. pressure resulting in more drift potential. Crop Applications More of the spray volume will move off-target as Avoid high wind speeds. wind increases. Wind currents can drastically affect spray droplet deposition. Structures drastically affect wind currents, for example, windbreaks, tree lines, buildings, hills and valleys. Avoid light and variable Light winds tend to be variable in direction winds making it hard to identify the sensitive areas. Absolutely calm air generally occurs in early morning or late evening and may indicate the Do not spray when the air is presence of a temperature inversion. Calm air completely calm. reduces air mixing, and leaves a spray cloud that may move slowly downwind at a later time. Consider using buffer Leave a buffer zone/no-spray zone if sensitive zones/no-spray zones. Be areas are downwind. Spray buffer zone when able to identify the sensitive wind changes to a favorable direction. areas. Consider using drift reduction nozzles, i.e., chamber and venturi style nozzles. Also, boom Consider using new shields, hoods, electrostatics, air-assist booms, technologies. pulse width modulation valves are all designed to reduce drift potential. Drift-control additives/deposition aids increase Use an approved drift- the average droplet size produced by the nozzles. control additive/deposition However, these additives should not become aid when needed. your only drift reducing technique. They will not protect against otherwise poor spraying practices.

ASABE Standard S-572.1 Spray Quality Categories Category Color Extra Fine (XF) purple Very Fine (VF) red Fine (F) orange Medium (M) yellow Coarse (C) blue Very Coarse (VC) green Extra Coarse white Ultra Coarse black 102 Equipment and wear nozzle tips resulting in application is acceptable. No single increased nozzle flow rate and method is best for everyone. Calibration for the development of poor spray The calibration method described patterns. below has four advantages. First, Commercial Field To obtain uniform coverage, you it allows you to select the number must consider the spray angle, of gallons to apply per acre and to Crop Applications spacing, and height of the nozzle. complete most of the calibration The height must be readjusted before going to the field. Second, for uniform coverage with various it provides a simple means for spray angles and nozzle spacings. frequently adjusting the calibration Do not use nozzles with different to compensate for changes due spray angles on the same boom for to nozzle wear. Third, it can be broadcast spraying. Be sure nozzle used for broadcast, band, directed, tips are clean. If necessary, clean and row-crop spraying. This with a soft bristle brush. A nail, method requires a knowledge of wire, or pocket knife can damage nozzle types and sizes and the the tip and ruin spray pattern recommended operating pressure uniformity. While the sprayer is ranges for each type of nozzle running, observe each spray tip for used. Finally, when using the distortions in the patterns. method below, the applicator will Worn or partially plugged nozzles have a better understanding of produce nonuniform patterns. how each variable will affect the Misalignment of nozzle tips application rate. As each of the is a common cause of uneven variables change, the influence coverage. The boom must be level on the rate (gallons per acre) is at all times to maintain uniform apparent. coverage. Skips and uneven The gallons of spray applied per coverage will result if one end of acre can be determined by using the boom is allowed to droop. the following equation: A good method for determining the exact nozzle height that Equation 1 will produce the most uniform GPA = GPM ×5,940 coverage is to spray on a warm MPH×W surface, such as a road, and observe the drying rate. Streaks in the GPM = out put per nozzle in spray pattern should be obvious. gallons per minute Replace nozzles that are not MPH = gr ound speed in miles performing correctly. per hour When you are convinced the W = effective width sprayed per sprayer is operating properly, you nozzle in inches are ready to calibrate. There are many methods for calibrating 5,940 = a constant to convert low‑pressure sprayers, but they all gallons per minute, involve the use of the variables in miles per hour, and the equation on page 104. Any inches to gallons per technique for calibration that acre provides accurate and uniform 103 Equipment and The size of the nozzle tip will Step 1 – Select the spray Calibration for depend on the application rate application rate in gallons per (GPA), ground speed (MPH), acre (GPA). Pesticide labels Commercial Field and effective width sprayed recommend ranges for various (W) that you plan to use. types of equipment. The spray Crop Applications Some manufacturers advertise application rate is the gallons of “gallon‑per‑acre” nozzles, but carrier (water, fertilizer, etc.) and this rating is useful only for pesticide applied per treated acre. standard conditions (usually 30 psi, Step 2 – Select or measure an 4 MPH, and 20‑inch spacing). The appropriate ground speed in gallons‑per‑acre rating is useless if miles per hour (MPH) according any one of your conditions varies to existing field conditions. Do from the standard. not rely on speedometers as A more exact method for an accurate measure of speed. choosing the correct nozzle tip Slippage and variation in tire sizes is to determine the gallons per can result in speedometer errors of minute (GPM) required for 20 percent or more. If you do not your conditions. Then select know the actual ground speed, you nozzles that provide this flow can easily measure it. Instructions rate when operating within the for measuring ground speed are recommended pressure range. By given below. following the five steps described Step 3 – Determine the effective below, you can select the nozzles width sprayed per nozzle (W) in required for each application well inches. ahead of the spraying season. For broadcasting spraying, W = the nozzle spacing For band spraying, W = the band width For row‑crop applications, such as spraying from drop pipes or directed spraying, W = row spacing (or band width) number of nozzles per row (or band)

Step 4 – Determine the flow rate required from each nozzle in gallons per minute (GPM) by using a nozzle catalog, tables, or the following equation. Using Equation 2 allows the applicator to determine flow rates for each application scenario needed for the application season. This can be done before the application season

104 Equipment and begins, thus not interfering with Broadcast application: critical time available during the Calibration for application time. Example 1: You want to broadcast a preplant Commercial Field Equation 2 incorporated herbicide at 15 GPA (Step 1) at a speed GPA× MPH×W GPM = of 7 MPH (Step 2), using Crop Applications 5,940 TurboFlood nozzles spaced GPM = gallons per minute of 40 inches apart on the boom output required from (Step 3). What TurboFlood each nozzle nozzle tip should you select? GPA = gallons per acre from The required flow rate for each Step 1 nozzle (Step 4) is as follows: MPH = miles per hour from GPM = GPA×MPH×W Step 2 5,940 W = inc hes sprayed per nozzle GPM = 15×7×40 = 4,200 = 0.71 from Step 3 5,940 5,940 5,940 = a constant to convert gallons per minute, The nozzle that you select must miles per hour, and have a flow rate of 0.71 GPM when inches to gallons per operated within the recommended acre pressure range of 10 to 40 psi. Table 2 shows the GPM at various Step 5 – Select a nozzle that will pressures for several Spraying give the flow rate determined in Systems TF nozzles. For example, Step 4 when the nozzle is operated the Spraying Systems TF‑5 nozzle within the recommended pressure has a rated output of 0.71 GPM at range. You should obtain a catalog 20 psi (Step 5). This nozzle could of available nozzle tips. These be installed for this application. catalogs can be obtained free of charge from equipment dealers Herbicide Band Applications or nozzle manufacturers. If you for Cost-Effective Weed Control decide to use nozzles that you Band applications of herbicides already have, return to Step 2 and can reduce costs for postemergence select a speed that allows you to and preemergent weed control operate within the recommended treatments. In band applications, pressure range. the treated acre is the acres actually sprayed and, depending on the row spacing and the band width, is some fraction of the total field acres. Remember, herbicides are applied in bands at the same rate of active ingredients per treated acre as in broadcast applications. Treating a field with 30-inch rows in 15-inch bands has the effect of reducing the herbicide cost by one-half.

105 Equipment and When banding soil-applied over the top of the plant. Special Calibration for herbicides to control weeds in band-application row kits or drops row crops, use spray tips designed are available for this purpose. Commercial Field for band application. They are Special attention should be given commonly referred to as even flat when using a multiple nozzle kit Crop Applications spray tips and are designated in to properly calibrate for the correct the nozzle nomenclature with the nozzle orifice size. letter ‘E’ . (See Table 1.) Even flat spray tips are designed to apply Over-the-Row Band Application a uniform pattern on the target across the width of the angle. Example 2: You want to apply Extended range flat spray tips, a preemergence herbicide on the other hand, are designed in a 15‑inch band over each to apply a tapered edge pattern 30‑inch corn row. The desired and would not uniformly cover application rate is 15 GPA at the targeted band width. For even 7.5 MPH. Which even flat‑fan spray tips, the nozzle spray angle nozzle should you select? and height above the target will The required flow rate is as determine the spray width. follows: Band applications also can be used GPM = GPA×MPH×W to apply postemergence materials. 5,940 To obtain thorough coverage to all plant material it may be necessary GPM = 15×7.5×15 = 1,687.5 = 0.28 to direct the spray in a multi- 5,940 5,940 nozzle arrangement around and Table 1. Explanation of Typical Nozzle Numbering Systems XR – Extended Range Flat-Fan Extended Range Flat-Fan XR 11004 TT – Turbo Flat-Fan Turbo Flat-Fan TT 11004 AI – Air-Induction/Venturi Flat-Fan Venturi Flat-Fan AI 11004 110 – 110 degree fan angle 04 – 0.4 gallon per minute flow rate @ 40 psi E – Even spray pattern TP8002E Even-Fan 80 – 80 degree fan angle, 95 degree fan angle AI 9502E 02 – 0.2 gallon per minute flow rate @ 40 psi TF – Turbo Flood Turbo Flooding TF-4 4 – 0.4 gallon per minute flow rate @ 10 psi TTJ – Turbo Turf Flood Turf Flood TTJ04 4 – 0.4 gallon per minute flow rate @ 40 psi QCTF – Quick attach Turbo Flood Turbo Flooding QCTF 40 40 – 4.0 gallons per minute @ 10 psi

106 Equipment and Table 2. Turbo Flooding Flat-Fan Nozzle Chart Calibration for Capacity Spraying Systems Liquid Pressure Orifice Designation (PSI) Gal/min Oz/min Commercial Field (GPM) (OPM) 10 .20 26 Crop Applications 20 .28 36 TF-2 30 .35 45 40 .40 51 10 .25 32 20 .35 45 TF-2.5 30 .43 55 40 .50 64 10 .30 38 20 .42 54 TF-3 30 .52 67 40 .60 77 10 .40 51 20 .57 73 TF-4 30 .69 88 40 .80 102 10 .50 64 20 .71 91 TF-5 30 .87 111 40 1.00 128 10 .75 96 20 1.1 136 TF-7.5 30 1.3 166 40 1.5 192 10 1.0 128 20 1.4 180 TF-10 30 1.7 221 40 2.0 256

107 Equipment and Calibration for Table 3. Banding and Directed Application Nozzle Chart Liquid Capacity Commercial Field Spraying Systems Pressure Gal/Min Oz/Min Orifice Designation Crop Applications (PSI) (GPM) (OPM) 30 0.087 11 40 0.10 13 TP8001E 50 0.11 15 60 0.12 15 30 0.13 17 40 0.15 19 TP80015E, 50 0.17 22 AI95015E 60 0.18 23 70 0.20 26 80 0.21 27 30 0.17 22 40 0.20 26 50 0.22 28 TP8002E, AI9502E 60 0.24 31 70 0.26 33 80 0.28 36 30 0.22 28 40 0.25 42 50 0.28 36 AI9525E 60 0.32 41 70 0.33 42 80 0.35 45 30 0.26 33 40 0.30 38 50 0.34 44 TP8003E, AI9503E 60 0.37 47 70 0.40 51 80 0.42 54 30 0.35 45 40 0.40 51 50 0.45 58 TP8004E, AI9504E 60 0.49 63 70 0.53 68 80 0.57 73 30 0.43 55 40 0.50 64 50 0.56 72 TP8005E, AI9505E 60 0.61 78 70 0.66 84 80 0.71 91 108 Equipment and Liquid Capacity Spraying Systems Pressure Gal/Min Oz/Min Calibration for Orifice Designation (PSI) (GPM) (OPM) 30 0.52 67 Commercial Field 40 0.60 77 TP8006E, AI9506E 50 0.67 86 Crop Applications 60 0.73 93 30 0.69 88 40 0.80 102 TP8008E, AI9508E 50 0.89 114 60 0.98 125 30 0.87 111 40 1.00 128 TP8010E 50 1.12 143 60 1.22 156

The nozzle you select must have Step 6. Determine the required a flow rate of 0.28 GPM when flow rate for each nozzle in ounces operated within the recommended per minute (OPM).To convert pressure range. The Spraying GPM (Step 4) to OPM, use the Systems TP8003E or AI9503E following equation: nozzles shown in Table 3 have a rated output of 0.28 GPM at Equation 3 approximately 35 psi. Either of OPM = GPM×128 these nozzles could be used for this (1 gallon = 128 ounces) application. From Example 1, the required Now that you have selected flow rate = 0.71 GPM and installed the proper nozzle tips (Steps 1–5) you are ready OPM = 0.71×128 = 91 to complete the calibration of From Example 2, the required your sprayer (Steps 6–10 below). flow rate = 0.28 GPM Check the calibration every few days during the season or when OPM = 0.28×128 = 36 changing the crop protection Step 7. Collect the output from products being applied. New one of the nozzles in a container nozzles do not lessen the need to marked in ounces. Adjust the calibrate because some nozzles pressure until the ounces per “wear in,” increasing their flow minute (OPM) collected is rate more rapidly during the first the same as the amount you few hours of use. Once you have determined in Step 6. Check learned the following method, you several other or all of the nozzles can check application rates quickly to determine if their outputs fall and easily. within 5 percent of the desired OPM.

109 Equipment and If it becomes impossible to obtain Remember, to apply crop Calibration for the desired output within the protection products accurately, you recommended range of operating must maintain the proper ground Commercial Field pressures, select larger or smaller speed. Because speedometers do nozzle tips or a new ground speed, not always provide an accurate Crop Applications then recalibrate. It is important measure of speed, you may want for spray nozzles to be operated to check the accuracy of the within the recommended pressure speedometer with an electronic range. The range of operating kit or radar gun. If your sprayer pressures is indicated at the nozzle does not have a speedometer or if tip. Line losses, nozzle check your speedometer is not accurate, valves, etc., may require the main you must measure the speed at pressure gauge at the boom or at all of the settings that you plan the controls to read much higher. to use in the field. By measuring Step 8. Determine the amount and recording the ground speed at of pesticide needed for each several gear and throttle settings, tankful or for the acreage to be you will not have to remeasure sprayed. Add the pesticide to speed each time you change a partially filled tank of carrier settings. (water, fertilizer, etc.). Then add To measure ground speed, lay out the carrier to the desired level with a known distance in the field you continuous agitation. Examples intend to spray or in another field for determining the amount of with similar surface conditions. pesticide to add to the tank are Suggested distances are 100 feet illustrated later. for speeds up to 5 MPH, 200 feet Step 9. Operate the sprayer in for speeds from 5 to 10 MPH, and the field at the ground speed you at least 300 feet for speeds above measured in Step 2 and at the 10 MPH. At the engine throttle pressure you determined in setting and in the gear you plan Step 7. You will be spraying at the to use during spraying with a application rate you selected in half-loaded sprayer, determine the Step 1. After spraying a known travel time between the measured number of acres, check the liquid stakes in each direction. Average level in the tank to verify that the these speeds and use the following application rate is correct. equation to determine ground speed. Step 10. Check the nozzle flow rate frequently Adjust the pressure to compensate for small changes in nozzle output due to nozzle wear or variations in other spraying components. Replace the nozzle tips and recalibrate when the output has changed 5 percent or more from that of a new nozzle, or when the pattern has become uneven.

110 Equipment and occurs because tank capacities are distance(feet)×60 Speed (MPH) = measured inaccurately. To determine time (seconds)×88 Calibration for tank capacity, add measured volumes 1 MPH = 88 feet per 60 seconds of water (5 to 50 gallons) and mark Commercial Field Example: After measuring a the level on the gauge as you fill the 200‑foot course, you discover tank. You can use flow meters to Crop Applications that 22 seconds are required for measure the quantity of water as it the first pass and 24 seconds for flows into the tank. Flow meters are the return pass. much easier to use than containers when calibrating sight gauge marks Average time = 22+24 = 23 seconds on large tanks. 2 The calibrated output of your MPH = 200×60 = 12,000 = 5.9 sprayer determines the number 23×88 2,024 of gallons that will be applied per Once you have decided on a acre. Pesticide labels recommend particular speed, record the ranges of application rates for throttle setting and drive gear various types of equipment. used. Sometimes crop protection products are applied in fertilizer solutions. In these cases, the Mixing Formulations desired fertilizer application rate To determine how much pesticide determines the number of gallons to add to your spray tank, you per acre that must be applied. Also, must know (1) the recommended most fertilizers are more dense pesticide application rate, (2) the than water and will have different capacity of the spray tank, and flow characteristics. Adjustments (3) the calibrated output of the for differences in flow rate are sprayer. required to achieve the calibrated application rate. Follow the label instructions or university recommendations to Once you have figured out the determine the rate at which to apply exact capacity of your tank and the pesticide. The rate is usually have calibrated your sprayer indicated in pounds per acre for accurately, you can determine how wettable powders, and in pints, many acres you can spray with quarts, or gallons per acre for liquids. every tankful of spray solution. Sometimes the recommended rate is Divide the number of gallons given in pounds of active ingredient the tank holds by the number of per acre (lb a.i./A) rather than the gallons you intend to apply to amount of product per acre. In each acre. The amount of pesticide these cases, you must convert the to add to the tank is determined quantity of active ingredient to the by multiplying the number of corresponding quantity of the actual acres sprayed per tankful by product. the recommended pesticide application rate. The following You should verify that the sight examples illustrate this procedure. gauge marks are accurate for your spray tank. Misapplication often

111 Equipment and Maintenance and Cleaning components. Thoroughly clean Calibration for spray equipment to prevent injury Proper maintenance and cleaning to crops susceptible to a previously Commercial Field are important to keep foreign applied pesticide. Some pesticides materials out of the sprayer. These will cause equipment to deteriorate Crop Applications materials can clog nozzles and if they remain in the sprayer for damage the pump and other sprayer an extended period of time. The

Example (Dry Formulation): An atrazine Example (Liquid Formulation): A trifluralin recommendation calls for 11 pounds of active recommendation calls for 1 pound of active ingredient per acre (lb a.i./A). You have purchased ingredient per acre. You have purchased Treflan 4E AAtrex 90DF (90 percent dry flowable). Your (4 pounds per gallon formulation). Your sprayer has a sprayer has a 400‑gallon tank and is calibrated to 500‑gallon tank and is calibrated to deliver 20 GPA. apply 20 gallons per acre. How much AAtrex should How much Treflan should you add to the spray tank? you add to the spray tank? Step 1. Determine the number of acres that you can Step 1. Determine the number of acres you can spray with each tankful. spray with each tankful. tank capacity (gallons per tank) = 500 tank capacity (gallons per tank) = 400 spray rate (gallons per acre) = 20 spray rate (gallons per acre) = 20 = 25 acres per tankful = 20 acres per tankful Step 2. To determine the amount of product needed per Step 2. Determine the number of pounds of acre, divide the recommended amount of active ingredient pesticide product needed per acre. Since not all of per acre by the concentration of the formulation. the atrazine in the bag is an active ingredient, you 1 lb a.i./A = 1 gallon per acre will obviously have to add more than 11 pounds of 4 lb a.i./gal. the product to each “acre’s worth” of water in your Step 3. Determine the amount of pesticide to tank. To determine how much more, divide the add to each tankful. You will cover 25 acres with percentage of active ingredient (in this case, 90) into each tankful (Step 1), and want to apply 1 gallon the total (100). (1 quart) of product per acre (Step 2). 11 lb a.i./A×100% = 11×1.11 = 1.66 pounds of 25 A×1 qt/A = 25 quarts (6.25 gallons)of Treflan per tankful 90% product per acre Example (Adjuvant): It is often recommended that a small amount of an adjuvant, such as a For each “acre’s worth” of water in the tank, you will spreader‑sticker or a surfactant, be added to the need 1.66 pounds of product to apply 11 pounds of chemical you plan to spray. The amount to be added active ingredient per acre. is frequently given as percent concentration. Step 3. Determine the amount of pesticide to add If you use an adjuvant at 1/percent concentration by to each tankful. With each tankful you will cover 20 volume, how much should you add to a 500‑gallon tank? acres (Step 1), and you want to apply 1.66 pounds of Solution 1: product per acre (Step 2). 1 percent of 100 gallons = 1 gallon (100×0.01 = 1) 20 A×1.66 lb/A = 33.3 pounds of product per tankful 1 percent of 100 gallons = 1 gallon You will need 1 gallon for 100 gallons, or 21 gallons for 500 gallons (1×5 = 21). Solution 2: 1 percent = 0.5 percent = 0.5 = 0.005 100 0.005×500 gallons = 2.5 gallons of adjuvant per 500‑gallon tank

112 Equipment and following practices will help you After rinsing the equipment maintain and clean your spray with oil or a water detergent Calibration for equipment properly. solution, fill the tank 1. U se only water that appears one‑quarter to one‑half full Commercial Field clean enough to drink. Small with a water‑ammonia solution particles often found in water (1 quart of household ammonia Crop Applications from ditches, ponds, or lakes can to 25 gallons of water) or a clog nozzles and strainers. If you water‑trisodium phosphate are in doubt, filter the water as (TSP) solution (1 cup TSP to you fill the tank. 25 gallons of water). Circulate the solution through the system 2. Check and clean strainers daily. for a few minutes, allowing a Partially plugged strainers will small amount to pass through create a pressure drop and reduce the nozzles. Let the remainder the nozzle flow rate. Most of the solution stand at least six sprayers have three different hours; then pump it through strainers: one on the suction hose the nozzles. Remove the nozzles to protect the pump, another in and strainers and flush the the line between the pump and system twice with clean water. the boom, and a third, which has the smallest openings, in the Equipment in which wettable nozzle body. powders, amine forms, or water‑soluble liquids have been 3. Do not use a metal object for used should be thoroughly rinsed cleaning nozzles. Metal objects with a water‑detergent solution will destroy the orifice. When a (2 pounds of detergent to 30 nozzle becomes clogged, always to 40 gallons of water). Water- remove it for cleaning. soluble materials should be 4. F lush a new sprayer before treated as water‑soluble liquids. using. A new sprayer invariably Allow the water‑detergent contains metal chips and solution to circulate through dirt from the manufacturing the system for several minutes. process. Remove the nozzles and Remove the nozzles and strainers. Then flush the sprayer strainers, and flush the system and boom with clean water. twice with clean water. Thoroughly clean each nozzle 6. When it is time to store your before reinstalling. sprayer, add 1 to 5 gallons of 5. Clean your sprayer according to lightweight oil, depending on the type of pesticide formulation the size of your tank, before used. Residues from some the final flushing. As water is formulations are more difficult pumped from the sprayer, the to remove from the tank. To oil will leave a protective coating remove residues of oil‑based inside the tank, pump, and herbicides, such as esters of plumbing. To prevent corrosion, 2,4‑D and similar materials, remove the nozzle tips and rinse the sprayer with kerosene, strainers, dry them, and store in diesel fuel, or a comparable light a can of light oil, such as diesel oil. Do not use gasoline. fuel or kerosene. 113 Equipment and 7. Corrosive fertilizer solutions how many acres does it contain? Calibration for should not be used in certain What nozzle type, boom pressure, sprayers. Liquid fertilizers are and travel speed are required? corrosive to copper, galvanized Commercial Field Record keeping is the key in surfaces, brass, bronze, and steel. providing the proper information You can irreparably damage Crop Applications to the operator so that application an ordinary sprayer after one errors can be avoided. You should use with a liquid fertilizer. Use begin keeping records of the sprayers made completely of pesticides and rates used during stainless steel or aluminum your first consultation. A detailed for applying liquid fertilizers. map of each field, including notes Aluminum is satisfactory for about what products are to be some nitrogen fertilizers, but applied, will allow the operator to not for mixed fertilizers. compare the load he or she receives with what the map shows. Record Keeping Written records prepared at the The number of days available time of application are required for applying pesticides to field for every field treated. Numerous crops is limited, and applicators record forms are available that are work under considerable pressure easy to complete. Each commercial to treat as many acres per day operation is unique and will need as possible. It is tempting to cut to adapt the forms to suit their corners to increase output, but needs. The form should indicate decreased profits often result where the application started, because more mistakes are made where it ended, where pesticide in application. In planning your transfer (nursing) took place, spraying schedule, you must allow whether the application quantity sufficient time for calibration, was long or short, what the equipment maintenance, and weather conditions were, including record keeping. wind velocity and direction, The competence of the operator and the extent of calibration is the essential element in or mechanical problems. All achieving accurate and uniform operators make occasional errors, application. The operator must and these errors should be a part of know how, when, and where to the record. use each pesticide, and under what Many misapplications are the conditions not to use a particular result of operator fatigue. Provide pesticide. He or she must as much support as possible to understand calibration procedures, assist with refueling, washing, and be aware of the importance of general equipment maintenance uniform application, and know and allow a minimum amount how to communicate with the of rest each day. Remember it farmer. The operator needs as is easier and less expensive to much information as possible apply pesticides properly than about every application site. What to handle complaints because of pesticide rate should be used? misapplication. Where is the field located, and 114 Equipment and Study Questions 3. D rift can be minimized by ______. Calibration for These study questions are to help you learn the material on pages 95 a. decreasing nozzle size. to 114. b. spraying when the air is Commercial Field completely calm. 1. Calibration is the process of: Crop Applications c. increasing nozzle size. a. measuring the horsepower of d. no ne of the above. your sprayer. b. measuring and adjusting the 4. In order to determine how much amount of pesticide applied pesticide to add to the tank, you by the equipment. need to know ______. c. measuring the size of the field. a. the pesticide application rate. d. measur ing the boom length. b. the capacity of the tank. 2. The correct type and size of c. calibrated output. spray nozzle is essential for d. al l of the above. ______. 5. Vapor drift is the result of: a. drift reduction. a. using the wrong pesticide. b. uniform coverage. b. the volatilization of an active c. the correct application rate. ingredient. d. al l of the above. c. spraying with too high a pressure. d. spr aying too fast.

115 Aerial Application Requirements for Effective Liquid Systems Aerial Application Liquid dispersal systems may • good cooperation between be wind-driven, hydraulic or pilot and grower when electric motor powered, or directly developing an aerial powered by the aircraft engine. A application program liquid dispersal system includes • consideration of the these components: environmental effects • tank/hopper • recognition of potential • agitation system dangers to people, animals, • pump and other crops • hoses, metal piping and fittings • correct and well-maintained equipment • control valves with suck-back features • accurate and uniform application • filters (screens) • a competent pilot • pressure gauge • adherence to the planned aerial • o ne or more booms application program • nozzles Limitations of Aerial Application Tank – The tank should be • w eather hazards leakproof and resistant to corrosion. Materials used for tanks • diff iculty in treating areas with and hoppers include fiberglass, fixed obstacles stainless steel, high-density • diff iculty in treating irregular polypropylene, or polyethylene. field size and shape The tank also should have a • the distance from the mechanism, such as a large valve application to the landing area or port (door, gate) through which the load can be dumped in case of • the danger of contamination emergency. The aircraft must have of nearby areas due to a gauge or visual level viewable misapplication or drift from the cockpit to measure tank contents. Tanks should be fitted Dispersal Equipment with an air vent to prevent a Fixed and rotary wing aircraft vacuum from developing. Baffles are used for aerial application. It limit the amount of sloshing of is important that metering and liquid in the tank. dispersal equipment meter correct Agitation System – Agitation is quantities of pesticide formulations required by many of the pesticide and deliver them uniformly. In formulations such as emulsifiable order to correctly calibrate, the concentrates, wettable powders, equipment must be accurate. and flowables, during application in order to maintain the spray mixture. Hydraulic agitation or recirculation of all or part of the

116 Aerial Application pump output into the tank is a when the boom is located near common form of agitation. the trailing edge of the wing. On Pump – The pump system must fixed wing aircraft, drop booms or be able to deliver large quantities drop pipes are commonly used to of liquid pesticides per unit of place the nozzles in clean air flow. time. This ensures uniform and End caps on the boom may be proper flow volume, produces the removable for cleaning and make desired atomization from nozzles, it easier to flush the boom and and maintains suspensions. Pumps nozzles. However, end caps will must be able to meet the system’s prevent positioning of nozzles at nozzle output, flow volume, and or near the boom ends. agitation requirements. Extra Nozzles – Aircraft systems capacity for line friction loss and use special nozzles which are to operate nozzle anti-drip check equipped with antisiphon or valves are also important. The nondrip check valves. Select the most common centrifugal pumps appropriate nozzle based on the are made from aluminum with manufacturers’ recommendations. bronze or steel internal parts. Nozzle selection, location, Piping and Fittings – Main piping calibration and testing are critical and fittings should have a large to the effectiveness of the aircraft diameter of up to 3 inches in order spray system. A uniform spray to apply high volumes of liquids, pattern depends on correct nozzle and a smaller diameter of 1 inch placement on the boom. for low-volume applications. Hoses Propeller rotation shifts the spray should be large enough to carry pattern from right to left as the the flow and corrosion resistant. pilot sees it. Adjustments to the Helicopters slower application number of nozzles, lowering the speed makes smaller piping nozzles, and possible shifting adequate. under the fuselage may be required Filters – Nozzle clogging and to compensate for this. Placing wear may be prevented by using end nozzles inboard will prevent correctly sized filter screens and the wingtip vortex from trapping line filters. Screens range in size fine droplets, causing uneven from 10 to 200 mesh. They should distribution and drift. be located between the tank Common nozzle types available and the pump, or when using a for aerial application are straight centrifugal pump, they should be stream, flat-fan, variable orifice located between the pump and flood, hollow-cone, and rotary the boom. Line filters should atomizers. Nozzle orientation on be cleaned daily during spray the boom greatly affects droplet operations. size. Orienting nozzles with Boom – The boom provides the direction of flight obtains support to the nozzles along the more shear and liquid break-up. wingspan of the aircraft. Clearance In higher speed applications, between control surfaces of the orienting nozzles parallel to the wing and the boom is essential direction of travel will reduce the secondary atomization 117 Aerial Application effects dramatically. Research Calibration also documents that at higher application speeds, higher Calibration is important for aerial application pressure (40+ psi) will applications because large areas are reduce the number of driftable covered in a short time. Calibrate fines on nondeflector nozzle often to ensure that equipment is types. Research also indicates calibrated correctly and does not that using nozzles that produce exhibit wear. larger droplets can result in more The application rate (gallons secondary air shear. The density, per acre) is determined by the viscosity, and surface tension of chemical being applied and the the pesticide and the evaporation crop being treated as listed on the conditions in the air can affect the label. An applicator can calculate droplet size. acres per minute by converting the Nozzle placement on a helicopter airspeed from miles per hour to boom may be uniform except feet per minute using the formula where the spray may hit parts of below: the aircraft such as the skids. A MPH×5,280 feet/mile rear section boom is sometimes 60 minutes/hour used to help keep spray off the = feet/minute helicopter. The angle of the nozzle in relation to the direction of travel Then, multiply the effective spray affects droplet size. Flight speed width by the feet per minute also may affect droplet size. airspeed to determine the area, in square feet, covered in one minute. Dry Systems Divide by 43,560 square feet/acre Granular dispersal systems may be to convert the area into acres as used for applying dry formulations illustrated in the equation below: such as pellets, impregnated granules, fertilizers, and seeds. Feet/minute×swath width The application equipment and 43,560 square feet/acre size, shape, density, and flowability = acres per minute of the material affect the swath width, application rate, and Using acres per minute being pattern. A hopper with agitation treated and spray mix requirements must be provided to prevent from the label, select nozzles from bridging of fine material that the manufacturers’ data. Give are less than 60 mesh. Frequent careful attention to the nozzle inspection of metering gates is type and the pressure at which required to ensure against leakage they must operate to deliver the and to make sure it is set correctly. correct volume and droplet size. The use of granular systems is on This pressure must be used in the decline for agricultural work. all calibrations and the airspeed should be exactly the same as will be used in the field.

118 Aerial Application Liquid Systems Step 2. Determine gallons per Follow these basic steps in sprayer minute (GPM) required. In this calibration. example. 3×18.4 = 55.2 gallons • Figure the acres your aircraft's per minute. Be sure the pump can system treats per minute at the deliver this volume. speed and height you plan to fly. Step 3. Select the nozzles. First • Determine the gallons you determine the GPM per nozzle must spray per minute to apply that would deliver the required the recommended rate. 55.2 gpm flow. Most agricultural aircraft can accommodate about • Select the nozzle size and of 50 nozzles. The GPM per nozzle number of nozzles needed to is determined this way: deliver the correct number of gallons per minute at your total flow system's operating pressure. Number of nozzles Use the nozzle manufacturers’ = GPM per nozzle guidelines. Our example: 55.2 • Make a trial run. 50 • Deter mine the amount of = 1.1 GPM per nozzle chemical to add to the tank. Example: Your aircraft has a 400 Based on this calculation and the gallon tank. The effective swath manufacturer’s charts, select a width is 65 feet. You plan to spray nozzle delivering 1.1 gpm in the at 140 mph at the height of 8 desired pressure of 30 psi. You to 10 feet. The chemical is to be may find that the nozzle closest applied at the rate of 1 pint per to your needs delivers at only 0.95 3 gallons of spray per acre. The GPM. This small difference can be operation pressure will be 30 psi. adjusted by increasing the pressure. Step 1. Determine acres per Step 4. Make a trial run to test minute using the formulas the system. After installing 50 of presented above. the selected nozzles, make a trial calibration test flight to be sure you 140 mph×5,280 feet/mile are spraying at the correct rate. Fill 60 minutes/hour the tanks with water to a known = 12,320 feet/minute level on a level apron or strip. Fly the aircraft at the selected 140 mph 12,320 feet/minute×65 feet airspeed and at the selected pressure 43,560 square feet/acre for a timed period (60 seconds in this example). Bring the aircraft = 18. 4 acres/minute back to the same point and measure the amount of water needed to refill the tank to the original mark. Divide the number of gallons used by the number of acres (18.4 in this example) treated to determine the gallons you are spraying per acre. 119 Aerial Application Step 5. Determine the amount of Drift Reduction chemical to add to the tank. • Make applications when Chemical per tank = acres per tank air movement is away from × chemical sensitive areas. Selecting recommended proper wind direction can be per acre used as an aid to avoid drift. Acres per tank = gallons per tank • Use the largest droplet size gallons per acre compatible with proper In the example above: coverage required from the mode-of-action of the 400 gallons per tank pesticide being used. 3 gallons per acre • Orient nozzles so their = 133.3 acres per tank discharge is parallel to the direction of the air flow around them. 133.3 acres per tank 133.3 pints × 1 pint per acre = (16.7 gallons) • Select a nozzle that will expose per tank a minimum amount of the spray to the air stream to limit Granular Systems shear formation of smaller Make several test flights with the droplets. These nozzles include spreader installed to determine straight stream nozzles and the quantity of material metered narrow angle fan nozzles. out for a given gate setting. If the dispensing equipment can • Position outboard nozzles at be run with the aircraft on the no more than 75 percent of ground, the material can be caught the wingspan for both fixed in large linen or paper bags and wing and rotary wing aircraft weighed. Blank granulars should span. Nozzles placed beyond be used when flight is needed to this boom position contribute calibrate the system. Operate the to vortex-influenced drift and spreader for a measured period of non-uniform deposition, and time (at least 30 seconds). Weigh do not increase the effective the quantity needed to refill the swath width of the aircraft. hopper. It may take three or more • Make applications at a height trial gate settings to determine of 8 to 10 feet from boom to the one that will give the required target canopy. Flying too low amount in pounds per acre being can lead to narrow swaths, applied. To find the pounds per non-uniform distribution, acre being applied, divide the and streaking. It may also lead pounds per minute by the acres to increased drift potential per minute. due to the excessive control surface movements generally associated with “wheels in the crop” flying. • Do not use excessive aircraft speeds. As air speed increases, 120 Aerial Application the amount of particle breakup should be the same as for the and “rooster tailing” potential actual application. The best time increases. Higher airspeeds for testing is early morning before also increase the hazards of the sun heats the ground and low-altitude flying due to causes thermal turbulence. It is reduced pilot reaction time. desirable to choose a time when • Equip the spray boom for the wind is blowing steadily and immediate/positive shut-off from one direction at less than through properly installed 10 miles per hour so that pattern bleed lines and well- nonuniformities can be identified maintained equipment. and corrected. For best results, fly into the wind during the test. • U se an appropriately sized The best way to test a liquid buffer zone away from pattern is to add tracer (dye or sensitive areas. florescent material) to the water • U se a viscosity-modifying in the tank(s) of the aircraft. For adjuvant to help control dry pattern testing, use a blank particle size, suppress the (nontoxic) material with properties formation of driftable fines, similar to the formulation to be and reduce evaporation applied. Collect the test material during critical humidity on paper (for liquids) or in buckets and temperature conditions. (for dry materials) placed across Test these products in your the flight path on the ground. spray system to determine Observation of the collected effectiveness. materials will show the actual swath pattern. • De velop a good customer follow-up policy and use it. A rectangular pattern gives perfect distribution if flight swaths are • Keep accurate and detailed spaced perfectly. The trapezoidal records. and triangular patterns are better • A ttend educational meetings because they allow for some error frequently and read available in spacing swaths. They give information to increase your uniform distribution across the knowledge about factors that field except for the first and last contribute to drift. swaths. Pattern Testing Operations Check the swath pattern to make When an aircraft has been sure the distribution across the calibrated, the airspeed, spraying swath is as uniform as possible. pressure (or gate setting for dry Both helicopters and fixed-wing materials), height of flight and aircraft create wind currents effective swath width are fixed. (vortices) that affect the swath Applications must be made at the pattern. The pattern tests must same settings. duplicate field situations; therefore the airspeed, height of flight, spray pressure, and nozzle arrangement

121 Aerial Application Pressure Turnaround Pressure should be around 30 At the end of each swath, the psi (pound per square inch) or pilot should shut off the dispersal higher. Choose the pressure that equipment and pull out of the will combine with selected swath field before beginning his turn. width, airspeed, and nozzle type to The turn should be completed give the correct rate of application soon enough to permit slight and desired droplet size. Use course corrections before dropping pressure gauges to indicate boom into the field again for the next pressure. swath. Be careful when executing a turnaround because a considerable Field Flight Patterns number of aerial applications occur For rectangular fields, fly back and due to stalls. forth across the field in parallel lines. Flying parallel to the long Obstructions axis of the field reduces the If obstructions such as trees, number of turns. Treatment should power or telephone lines or start on the downwind side of the buildings occur outside the field field where low-speed crosswinds at the beginning or end of the occur. This prevents the pilot swath, turn the equipment on from flying through the previous late or shut it off early. When the swath. To prevent skips and drift, field is completed, fly one or two stop flying if wind speed increases swaths crosswise (parallel to the excessively. obstructions) to complete the job. If the area is too rugged or steep Obstructions inside the field for this pattern, flight lines should be treated in the same should follow the contours of the way. Skip the area around the slopes. When the area is too steep obstruction and spot treat it later. for the contour work, make all Areas next to buildings, residences, applications downslope. livestock, nontarget crops or Swath Marking waterways should be treated with Straight, parallel passes produce extreme caution: the most uniform spray pattern. • Fly parallel to the sensitive Use a reliable method, such as area. differential global positioning • Leave a border of untreated systems (DGPS), to mark each crop to avoid possible drift swath to ensure uniform coverage onto the area. and avoid excessive overlap or gaps. • Avoid making turns over dwellings.

122 Aerial Application Study Questions 4. A ll pattern tests should be run ______to the wind These study questions are to help direction. you learn the material on pages 116 to 122. a. opposite 1. Aerial dispersal systems may be b. at right angles wind driven or _____ powered by c. parallel the aircraft engine. d. at 45 degree angles a. hydraulic 5. A minimum spraying pressure b. mechanical for aerial application should be c. chemical around: d. a and b a. 10 psi 2. Aircraft nozzles must be equipped b. 30 psi with a(n) ______. c. 70 psi a. spring-loaded flapper valve d. 110 psi b. tube-type valve 6. A t the end of each swath, complete c. antisiphon or nondrip check the turn soon enough to allow valve ______before let-down for the next swath. d. positiv e shut-off valve a. pesticide drift to settle out 3. Calibration is very important in aerial application because: b. for missing obstructions c. flagmen to get in position a. chemicals used for aerial application are much more d. slight course corrections toxic b. vortices can change application rates c. large areas are covered in a short time d. m uch higher pressures are used during aerial application

123 Answers to Answers to Page 29 (Wheat) Study Questions 1. d 2. b 3. d 4. c Study Questions Page 31 (Beneficials) Pages 6 – 9 (IPM) 1. a 2. b 1. d 2. b 3. d 4. a 5. b 6. d Pages 33 – 37 (Fruit) Pages 11 – 15 (Insect Pests) 1. a, 2. b 3. c 4. b 5. a 6. a 7. c 8. a 1. b 2. d 3. a 4. b 5. b 6. c 7. d 8. b 9. a 10. a Pages 39 – 50 (Vegetable) 1. d 2. b 3. c 4. a 5. b 6. b 7. b 8. b Page 17 (Alfalfa) 9. c 10. a 11. a 12. d 1. d 2. c 3. b 4. b Pages 53 – 67 (Diseases) Page 19 (Corn) 1. c 2. a 3. d 4. d 5. c 6. b 7. c 8. b 1. a 2. c 3. b 4. d 5. a 9. d 10. c 11. b 12. d 13. c 14. d Page 21 (Cotton) Pages 70 – 82 (Weeds) 1. d 2. b 1. d 2. b 3. d 4. b 5. d 6. c 7. d 8. d Page 23 (Sorghum) 9. a 10. d 11. d 12. d 1. a 2. b 3. c 4. a Pages 85 – 93 (Rangeland) Page 25 (Soybeans) 1. a 2. d 3. b 4. b 5. c 6. d 1. b 2. b 3. c 4. d Pages 95 – 114 (Equipment) Page 27 (Sunflowers) 1. b 2. d 3. c 4. d 5. b 1. c 2. b 3. d Pages 116 – 122 (Aerial) 1. d 2. c 3. c 4. c 5. b 6. d

124 References References and Credits Bauer, Erin, Agricultural Pest Control for the Commercial/Noncommercial Pesticide Applicator. University of Nebraska. November 2005. O’Connor Marer, Pat. 2010. Aerial Applicator’s Manual: A National Pesticide Certification Study Guide. National Association of State Departments of Agriculture Research Foundation. Ogg, Clyde, Aerial Pest Control for the Commercial/Noncommercial Pesticide Applicator. University of Nebraska. November 2006.

Credits for Photographs and Illustrations Photographs and illustrations were obtained from the following sources: USDA, NRCS. 2010. The PLANTS Database (http://plants.usda.gov, 19 July 2010). National Plant Data Center, Baton Rouge, LA 70874– 4490 USA. Patrick J. Alexander @ USDA–NRCS PLANTS Database Buffalobur, Common Ragweed, Common Sunflower, Devilsclaw, Green Foxtail, Puncturevine, Tansy Mustard, Texas Croton, Wavyleaf Thistle Larry Allain @ USDA–NRCS PLANTS Database Barnyardgrass, Broomweed, Cocklebur, Common Chickweed, Western Ragweed Wynn Anderson @ USDA–NRCS PLANTS Database Wooly Loco Thomas G. Barnes @ USDA–NRCS PLANTS Database / Barnes, T.G., and S.W. Francis. 2004. Wildflowers and ferns of Kentucky. University Press of Kentucky. Curlycup Gumweed , Tall Goldenrod Ted Bodner @ USDA–NRCS PLANTS Database / James H. Miller and Karl V. Miller. 2005. Forest plants of the southeast and their wildlife uses. University of Georgia Press., Athens. Horseweed, Johnsongrass Elaine Haug @ USDA–NRCS PLANTS Database Curly Dock, Henbit D.E. Herman et al. @ USDA–NRCS PLANTS Database / USDA NRCS, 1996. North Dakota tree handbook. USDA NRCS ND State Soil Conservation Committee; NDSU Extension and Western Area Power Administration, Bismarck. Common Honeylocust, Eastern Redcedar, Russian olive, Siberian Elm

125 References R.A. Howard @ USDA–NRCS PLANTS Database and Credits Field Bindweed Jeff McMillian @ USDA–NRCS PLANTS Database Common Dandelion, Osage Orange James H. Miller @ USDA–NRCS PLANTS Database / Miller, J.H. and K.V. Miller. 2005. Forest plants of the southeast and their wildlife uses. University of Georgia Press, Athens. Sericea Lespedeza Robert H. Mohlenbrock @ USDA–NRCS PLANTS Database / USDA SCS. 1991. Southern wetland flora: Field office guide to plant species. South National Technical Center, Fort Worth. Blackberry, Buckbrush, Giant Foxtail, Large Crabgrass, Little Barley, Redroot Pigweed, Roughleafed Dogwood Gary A. Monroe @ USDA–NRCS PLANTS Database Downy Brome Steven Perkins @ USDA–NRCS PLANTS Database Saltcedar Clarence A. Rechenthin @ USDA–NRCS PLANTS Database Baldwin Ironweed, Smooth Sumac Rusty Russell @ USDA–NRCS PLANTS Database Common Milkweed Al Schneider @ USDA–NRCS PLANTS Database Brome Snakeweed, Bull Thistle, Common Mullein, Musk Thistle Robert Soreng @ USDA–NRCS PLANTS Database Windmillgrass W.L. Wagner @ USDA–NRCS PLANTS Database Japanese Brome Mike Haddock, Kansas Wildflowers and Grasses. Retrieved April 4, 2011, from http://www.kswildflower.org,. Jointed Goatgrass

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Frannie L. Miller Pesticide Coordinator

Authors Appreciation is expressed to the following for the preparation of the material in this manual: Bob Bauernfeind, Entomologist, Horticulture Raymond Cloyd, Entomologist, Ornamentals Erick DeWolf, Plant Pathologist, Small Grains and Forages Walt Fick, Agronomist, Range Management Doug Jardine, Plant Pathologist, Row Crops Megan Kennelly, Plant Pathologist, Horticulture and Turf Dallas Peterson, Agronomist, Weed Science Jeff Whitworth, Entomologist, Row Crops Robert E. Wolf, Professor (Retired), Biological and Agricultural Engineering

Acknowledgments Appreciation is expressed to the following for cooperation in the Commercial Applicator Training Program: Jeanne Fox, Certification and Training Section Chief, Pesticide and Fertilizer Program, Kansas Department of Agriculture

Brand names appearing in this publication are for product identification purposes only. No endorsement is intended, nor is criticism implied of similar products not mentioned. Publications from Kansas State University are available at:www.bookstore.ksre.ksu.edu Contents of this publication may be freely reproduced for educational purposes. All other rights reserved. In each case, credit Frannie L. Miller, et al., Agricultural Plant Pest Control, Kansas State University, July 2011. Kansas State University Agricultural Experiment Station and Cooperative Extension Service S-19 July 2011 K-State Research and Extension is an equal opportunity provider and employer. Issued in furtherance of Cooperative Extension Work, Acts of May 8 and June 30, 1914, as amended. Kansas State University, County Extension Councils, Extension Districts, and United States Department of Agriculture Cooperating, Gary Pierzynski, Interim Director.