TERRY COUNTY AG NEWS

June 25, 2013 — Cotton

th 209 South 5 Street Brownfield, TX 79316 Chris Bishop, Terry Co. CEA-AG Phone: 806-637-4060 Fax: 806-637-2588 http://terry-tx.tamu.edu/

Cotton Agronomy

Crop Update received some moisture following dry planting Recent storms have provided much needed and were beginning to emerge. With high tem- moisture across much of the High Plains peratures forecast in the 90s for the next ten and parts of the Panhandle. Unfortunately, days and only slight chances for additional these storms also brought hail and high rainfall, cotton crops that have begun squar- winds that have caused varying levels of ing should be watched closely for moisture damage to already delayed cotton crops. stress, especially in areas where little rainfall Some fields were completely destroyed in was experienced during the recent storm the areas where large amounts of hail events. and/or high winds were observed. Cur- rently, there is no hard number to report in Plant Growth Regulators terms of lost cotton crops. Reports from Questions concerning mepiquat-based (Pix, Texas A&M AgriLife County Extension Ag Pix Plus, Mepex, Mepichlor, Mepiquat Chlo- Agents and IPM Agents indicate that some ride, Mepex GinOut, Stance, and others) plant fields have already been replanted to cotton growth regulators (PGRs) are being asked. or sorghum. Rainfall amounts reported by Mepiquat chloride (MC) reduces production of the Texas Tech University West Texas gibberellic acid in plant cells that in turn re- Mesonet System vary greatly thus far for duces cell expansion, ultimately resulting in the month of June and range from a high of shorter internode length. MC will not help the 5.13” to a low of 0.93” for Anton and Friona, plants compensate for earlier weather or dis- respectively. These amounts have provided ease damage by increasing growth rate. It enough moisture to germinate cotton may, under good growing conditions, increase planted to dryland production fields in some fruit retention, control growth and promote areas but more is needed at timely intervals earliness. MC should not be applied if crop is to maintain established stands. Based on under any stresses including moisture; heat; data from the CottonHeatUnits.com web- severe spider mite, insect, or nematode dam- site, heat unit accumulations at Lubbock age; disease stress; herbicide injury; or fertil- total 699 DD60s, which is 95 above our long ity stress. Results from our replicated testing term average of 604. In general, the cotton indicates that we observed from 5 to 20% re- stands that have been established and man- duction in plant height (compared to the con- aged to dodge the weather bullet appear to trol) from 16 oz of 4.2% a.i. MC material ap- be in fair to good condition. Growth stages plied in up to 4 sequential 4-oz/acre applica- of these crops range from just emerged or tions starting at match head square (MHS) emerging to very early squaring. During my and ending at early bloom. We have been able travels to the eastern part of the region ear- to "shave" about 1 node from the growth of the lier last week I determined that two dry- main stem at some locations, which can result land variety trial locations we planted had Continued on page 2

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Continued from page 1 Pentia Consistent yield increases Mepiquat pentaborate mole- have not been observed from Plant Growth Regulators cule (different from MC) any of the MC materials we 9.6% a.i./gallon or 0.82 have investigated. A good in about 3-5 days earlier cut- lb/gallon a.i. fruit load will normally help out. Low rate multiple ap- control plant growth. Fields plications beginning at Mepex Gin Out with poor early-season fruit MHS have generally pro- 4.2% a.i./gallon or 0.35 retention, excellent soil mois- vided more growth control lb/gallon a.i. with 0.0025% Ki- ture, and high nitrogen fertil- than higher rate applica- netin (a cytokinin). ity status may be candidates tions made at first bloom Cytokinins are plant hor- for poor vegetative/fruiting or later. mones that promote cell divi- balance and should be sion and growth and delay the watched carefully. Our results have shown that senescence of leaves. This we usually do not get statisti- product has use guidelines Growers who have planted cally significant increases in similar to other MC materials. varieties with vigorous yields, but do get excellent growth potential and have growth control. Many times Stance fields with excellent growing we don't see a lot of differ- Bayer CropScience's Stance conditions need to be con- ences in performance of these product is a mepiquat chloride cerned. For brush roll header products when comes to based PGR. It is a 4 to 1 ratio stripper harvest, 28-32 inch growth control. of mepiquat chloride and cy- tall plants optimize stripper- clanilide (0.736 lbs/gallon me- harvesting efficiency. If possi- Mepiquat chloride (MC) piquat chloride plus 0.184 ble, target a maximum plant based products have been lbs/gallon cyclanilide). Cy- size of about 32 inches for cot- around for many years. Sev- clanilide is an auxin synthesis ton plants under high input eral plant growth regulators and transport inhibitor. Aux- irrigation (drip or high capac- (PGRs) based on the same ac- ins are generally referred to as ity pivots). If plants get larger tive ingredient are now avail- compounds which have the ca- than 36 inches, harvest effi- able. Pentia is a formulation pacity to induce cell elonga- ciency and productivity drop of mepiquat pentaborate - a tion. The inhibition of auxins significantly. With some spin- different molecular structure could reduce cell elongation dle picker harvesters working than MC. Mepex Gin Out and inhibit growth. Produc- in the region, plant size for contains the same amount of ers should be aware that high yielding cotton is not as MC active ingredient as oth- the mepiquat chloride con- much of a harvesting consid- ers, but contains an addi- centration in Stance is eration. Pickers can handle tional PGR. Refer to the prod- about twice as high as most higher yielding, taller uct labels or contact local rep- of the other materials we plants with much greater resentatives to ensure you have become accustomed ease than stripper har- understand the correct use of to applying. THEREFORE vesters, especially when these products. THERE IS A CORRE- the stalks are still alive (or SPONDING REDUCED “green”). However, if Mepex, Mepichlor, Mepiquat RATE. If you have specific weather constraints at Chloride and other generics questions concerning this harvest time delay har- 4.2% active ingredient (a.i.)/ product, visit with your local vesting after freezing gallon or 0.35 lb/gallon a.i. Bayer CropScience rep. weather, the large brittle

The articles in this newsletter were published in a recent issue of FOCUS on South Plains Agriculture, a newsletter from the Lubbock Research and Extension Center. http://lubbock.tamu.edu/focus. FOCUS Editor—Patrick Porter

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plants can still result in temperatures, southwest fall conditions are encoun- picker harvesting difficul- winds at 30 mph at 10% rela- tered. The situation that has ties. tive humidity? If so, those arisen due to the release and conditions will limit plant availability of new genetics is Determination of application growth in many fields with challenging. Visit with your rates is generally more "art" low irrigation capacity. seed company representative than "science" for these prod- to determine which new va- ucts. Applications should be- Watch high growth potential rieties should be watched gin when 50% of the plants varieties and fruit retention. closely for MC needs under have one or more matchhead If a high growth potential va- field-specific conditions. Se- squares (see specific product riety has been planted and quential applications can be label for more information). It has encountered low fruit re- adjusted to meet subsequent is best to get a handle on ex- tention, then MC rate should crop conditions and growth cessive growth potential early be increased, especially under potential. For any questions if conditions favor excessive high water, fertility, and good concerning this information, growth for an extended period growth conditions. One producers are welcome to con- of time. Herein lies the High should target applications to tact Mark Kelley at 806-781- Plains dilemma: It is un- fields with high growth po- 6572 (mob), or 806-746-6101. known at that time as to how tential. Some newer varieties weather will affect the crop in may need aggressive manage- Mark Kelly July and on into early Au- ment under high irrigation Extension Agronomist gust. Will we get 100+ degree capacity and/or if heavy rain-

Cotton Disease Update

Root-knot Nematode roots. These symptoms often reproduction of the nematode Despite the rainfall that has resemble nutrient deficien- and adversely affecting plant been received the past few cies, which arise from dam- growth. Such feeding activity weeks, dry conditions con- age that occurs to plant roots in conjunction with reproduc- tinue to be experienced and rendering them unfit for ac- tion of the nematode is re- the crop is off to a relatively quiring water and/or nutri- sponsible for the develop- slow start to this growing ents. The feeding conducted ment of the galls mentioned season. Recent travels and damage caused by root- previously. Nematode popu- throughout the High Plains knot nematodes, results in lations within the soil deter- revealed symptoms of nema- the appearance of galls which mine potential management tode damage being observed are key in diagnosing the options, as well as determine in fields infested with the problem. Nematodes hatch the severity of symptoms Southern root-knot nematode from eggs and locate a host that may be observed. Nema- ( Meloidogyne incognita ). during a juvenile stage via todes are considered stress Symptoms consist of a gen- compounds that are produced multipliers and damage is eral decline in plant vigor, by developing root systems often more severe when stunting and ultimately a re- and diffuse in the soil. Con- plants are experiencing other duced boll load. Under ex- tinued feeding results in the adverse factors such as harsh treme conditions, plants may production of specialized environmental conditions, completely die. Nematodes feeding sites (giant cells), water stress, etc. Promoting typically attack developing which serve as a metabolic vigorous growth is effective tap roots and secondary sink capable of supporting Continued on page 4

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Continued from page 3 4288B2F have demonstrated (requiring adequate moisture Cotton Disease Update consistent performance in re- to “activate” them). Benefits search trials focusing on in fields with low to moderate at minimizing damage. With nematodes. Preliminary re- nematode pressure have been the loss of Temik 15G, chemi- sults from studies in 2012 in- observed, as well as when cal management options are dicate that some newer varie- these nematicides are used in limited. Partially resistant or ties, such as Fibermax conjunction with partially re- tolerant varieties including 2011GT and Stoneville sistant varieties. Further- Deltapine 174RF, Phytogen 4946B2F contain genes that more, there has been in- 367WRF, Stoneville confer nematode resistance. creased interest in foliar ap- 5458B2F, and Stoneville These varieties along with plications of Vydate, as it is others and several breeding the only in-season product lines are being evaluated in labeled for use in cotton. In multiple locations on the the past, Vydate was used as High Plains. These materials a supplement to early season were derived from breeding nematode control programs programs emphasizing nema- comprised of Temik; however, tode resistance or have been the use pattern of Vydate has identified as possessing resis- changed in the absence of tance genes using Marker As- Temik. Vydate is taken up sisted Selection. We will be through the foliage and reporting results from those transported to the roots, thus trials as they become avail- deposition is critical in maxi- able. mizing efficacy when applied to young cotton. Hail damage In addition to varieties the received during recent thun- seed applied nematicides, derstorms affected cotton such as Acceleron-N, Aeris growth and may compromise and Avicta can be applied to uptake of Vydate. When seed to help combat nema- making applications, a mini- ABOVE: Characteristic galling caused tode problems. Performance mum of two healthy, actively by root-knot nematode. of these products is depend- growing leaves are needed to ant on soil conditions ensure that enough product BELOW: Uneven growth resulting from root-knot nematode damage is taken up by the plant. Ini- tial application made to young cotton can be followed by a sequential application approximately 14 days later. Kerry Siders, Extension Agent-IPM in Hockley and Cochran Counties, has work extensively with Vydate and encourages producers to be mindful of applications made during the later squaring pe- riod, as this may negatively affect beneficials, thus in- creasing the risk of flaring aphids. It is the applicators

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Continued from page 4 Cotton Disease Update Cotton Insects Early season cotton insect pest: Cotton fleahopper responsibility to read, under- stand and adhere to all label Cotton which is at the 5 to 7 High Plains producers is that recommendations. Refer to true leaf stage has passed the cotton fleahopper pressure in the following link for the window of economic loss due this area is typically very low complete Vydate label to thrips injury and plants and not consistent, but insect (http://www.cdms.net/LDat/ld are now entering into the populations are unpredict- 264021.pdf). While there has squaring stage. After the re- able like our weather and been much research con- gion finally started receiving therefore we must keep an ducted to address rot-knot desperately needed precipita- eye on this insect by scouting nematodes in High Plains tion in recent days, cotton our crop for this and other cotton, there are several ar- plants across most of the threatening pests. eas that are being and can be area are starting to grow well further be explored to limit and should compensate for Biology: Cotton fleahoppers damage and maximize profit- some of the earlier thrips in- belong to the so called “plant ability in areas where the jury. During this early squar- bug” family, which includes pest is present. If you have ing stage of cotton, we must other cotton insect pests such any questions regarding root- protect small squares as Lygus, verde plant bug knot nematodes or any other (pinhead to match-head sized and clouded plant bug. How- cotton diseases please contact fruiting buds) from any in- ever, the cotton fleahopper is Jason Woodward @ 806-632- sect injury, as these first- much smaller than the other 0762, or via e-mail jewood- position squares will eventu- plant bugs mentioned here. [email protected] . ally contribute to a majority Upon close inspection, sev- of the lint produced by a cot- eral black dots can be seen on Article and photographs by ton plant. Considering our the antenna and legs of an Jason Woodward relatively short growing sea- adult cotton fleahopper. Im- Extension Plant Pathologist son, protection of these early matures are also pale green season squares and small in color and feed on small Cotton fleahopper is a small, pale, dusty, bolls is particularly true squares and tender parts of a green colored insect. Adults are about 1/8 of an inch in length. Both imma- when a cotton crop gets a late cotton plant by sucking plant tures and adults are capable of causing start or grows slowly in the juice (phloem sap). Cotton injury to the plant. seedling stage. Therefore the fleahoppers overwinter as

Adult cotton fleahopper main objective at this point of eggs laid into the tissues of a (placed near a dime for comparison) time (during early season) limited number of host plant should be to protect the crop species. Eggs hatch during and have maximum square early spring, after receiving retention. One of the major some rain showers and warm pests during this early weather. Later the insect growth stage of cotton is a goes through five different small but destructive insect, immature stages, called in- the cotton fleahopper. Texas stars. Immatures do not have in general and specifically wings and grow bigger in south-Texas experience the each successive developmen- highest pressure and associ- tal stage. It takes cotton flea- ated damage from this insect hoppers about 25 days from compared to other cotton belt the egg to adult stage. Adults states. The good news for our Continued on page 6

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Continued from page 5 to some extent. If a cotton 2nd and 75% during the 3rd Cotton Insects field is surrounded by lots of week of squaring to the time silverleaf nightshade and/or of 1st bloom. If percent square live approximately 2-3 weeks evening primrose, they may set drops below the specified and reproduction occurs dur- act as a source of cotton flea- number corresponding to the ing this adult period. hoppers. In that situation, if week of squaring, insecticide it is feasible, I suggest not to intervention is justified. I Damage symptoms: Upon disturb the patches of those suggest not to solely relying feeding by cotton fleahopper weeds present near the cot- on the square set percentage on pinhead size squares, the ton field when your crop is in for threshold, but also finding small fruit (square) turn pale the early squaring stage. By cotton fleahoppers on the yellow and eventually dry doing so, you may be able to plants. Because there are out. Later, the dried out restrict some movement of other environmental factors squares fall off the plant cotton fleahoppers to cotton which can result loss of (referred to as a “blasted” from these weed host plants. squares in cotton plants. square) and a scar forms at the point of square attach- Scouting and thresholds: Management: For our re- ment to the plant. Following Depending on the crop gion, it is rare for cotton flea- severe cotton fleahopper in- growth stage and plant vigor, hopper populations to reach jury to the terminals of scouting methods for cotton and go beyond the economic young cotton plants, plants fleahopper could be different. threshold level, at which do not grow normally and ir- When plants are in the early level chemical intervention is regular branching patterns squaring stage, non- warranted. There are several can be seen, which is often destructive, whole plant vis- natural enemies (beneficials) referred to as “crazy cotton”. ual sampling is recom- which have the potential to mended. Whole plant visual suppress the cotton fleahop- Habitat: Cotton is not the inspections will not only help per populations to some ex- primary host of cotton flea- in finding cotton fleahoppers, tent. Among those, spiders, hopper. Rather, this insect but also will help you calcu- big-eyed bug, assassin bug, prefers other host plants late an estimate of square and damsel bugs are the such as horsemint, woolly retention. However, once the most common predators of croton, silverleaf nightshade, crop attains the flowering fleahoppers in cotton. Re- and evening primrose. While stage and beyond, the use of moval of weeds such as horsemint and woolly croton beat- bucket or drop-cloth silverleaf nightshade should are the two most preferred methods of sampling will be significantly lower potential and abundant host plant spe- more efficient for detecting fleahopper population in cot- cies for cotton fleahoppers in presence of cotton fleahopper. ton. For chemical control op- south and south-east Texas, The current economic thresh- tions, there are several effec- these plants are rare in the old for cotton fleahoppers in tive insecticides available for High Plains area. That may our High Plains region is 25- cotton fleahoppers such as well explain why we see 30 insects per 100 plants in- Centric ® 40WG @1.25 fewer cotton fleahoppers in spected. Another method of oz/acre, Intruder ® WSP @ High Plains compared to determining the threshold for 0.6 oz/acre, Belay ® @ 4 south Texas. However, silver- cotton fleahoppers is through oz/acre, Orthene ® 97 @ 8 leaf nightshade and evening an estimation of square re- oz/acre, Carbine TM 50WG @ primrose are two prevalent tention on the plants. The 1.7 oz/acre, Bidrin ® 1.6-3.2 weeds or volunteered plants recommended threshold for oz/acre and Transform ® WG seen across the High Plains percent square set in cotton 0.75 oz/acre. and these two plants support is 90% during 1st, 85% during Apurba Barman cotton fleahopper populations Extension Entomologist 6