Volume 7, Number1, Page 1 Winter 2003 Department of Environmental Horticulture • University of California, Davis GROWING Points UC Davis Environmental Horticulture Department Establishes IR-4 Center by Heiner Lieth, Ron Lane and Linda Dodge http://envhort.ucdavis.edu The Department of Environmental Hor- regional Research Project #4 in 1963 to Registering a material to provide a dif- ticulture at UC Davis has taken on the task address the shortage of pest control options ferent class of chemical to use in a spray of working with growers and the USDA for minor crops. A separate Ornamentals rotation. Interregional Research Project #4 (IR-4) to Program was created in 1977 and, since Registering a material that provides a develop data needed for registration of crop then, over 9000 registrations have been shorter reentry interval. protection materials that are of interest to processed for ornamentals. The Registering a material that is currently growers of specialty crops in the Western Biopesticide Program to support research registered, but does not contain provisions United States. and registration activities on biological pest for commonly used application equipment IR-4 is the only publicly funded pro- control agents began in 1982, and 1998 saw such as ultra-low volume or electrostatic gram in the U.S. that conducts research and the establishment of a Methyl Bromide Al- sprayers. submits petitions to the Environmental Pro- ternatives Program. (Note that “material” refers to insecti- tection Agency (EPA) for registration of The IR-4 Program has evolved as a cides, miticides, fungicides, plant growth pest control agents on specialty crops. Spe- bridge to registration by generating and regulators, insect growth regulators, as well cialty crops include nursery and landscape supplying independent, high-quality re- as various biological pest control agents.) plants as well as cut flowers and potted search data needed by EPA in order to In addition to industry input, we also plants (in addition to most vegetable, fruit, register compounds for use on specialty seek assistance to help us obtain plants and nut, herb, and spice crops). crops. Collaborations are the strength of related resources for the experiments. The The crop protection industry lacks in- the IR-4 program. Input is sought continu- expectation of the IR-4 program is that the centive to pursue registrations on specialty ally from the commodity production side of manufacturers supply the materials and that crops for many materials because the low agriculture as well as from the crop protec- growers supply plants. The funding pro- acreage involved means low return on in- tion industry, USDA and federal and state vided to us by the IR-4 program is fairly vestment. Recognizing this, the state land regulators. minimal and earmarked entirely for sala- grant universities and the U.S. Department The Environmental Horticulture Depart- ries. It is also of obvious interest to the of Agriculture (USDA) organized the Inter- ment at UC Davis has made a commitment industry to have us work with new plants to develop an IR-4 Center at the Depart- and fresh materials for each experiment. The IR-4 ment and we have begun to set up research- Both growers and manufacturers benefit Program able projects. We have established a website from this process in having their products facilitates at http://envhort.ucdavis.edu/ir4. In order included in the trials. the to make the program most effective, we Our highest priority is to respond to the registration need industry input to identify labeling is- needs of the California ornamentals indus- of pest sues that will provide the greatest benefit to try. We have identified a set of experiments control growers. Some examples of projects that that we will work on for the next few months. agents for would be considered for funding include: In addition, we are seeking industry input to specialty Registering a material for a particular identify experiments that we could begin crops. application where there is currently no ef- this summer and fall, or at some time in the fective, registered product. future. GP In This Issue... Brass Buttons on Golf Courses- page 2, EH Hosts Ag. Science Field Day for FFA Students-page 3, Kat Anderson Co-Edits Book on Habitat Burning- page 3, Popular New Garden Plants- page 4, New Diagnostic Guide for Abiotic Disorders- page 5, Chair Notes- page 6, Urban Foresty News- page 7 The University of California prohibits discrimination against or harassment of any person on the basis of race, color, national origin, religion, sex, physical or mental disability, medical condition (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizenship, or status as a covered veteran (special disabled veteran, Vietnam-era veteran or any other veteran who served on active duty during a war or in a campaign or expedition for which a campaign badge has been authorized). University Policy is intended to be consistent with the provisions of applicable State and Federal laws. Inquiries regarding the University’s nondiscrimination policies may be directed to the Affirmative Action/Staff Personnel Services Director, University of California, Agriculture and Natural Resources, 1111 Franklin, 6th Floor, Oakland, CA 94607-5200 (510) 987-0096. Volume 7, Number1, Page 2 Winter 2003 Cotula sp. (Brass Buttons) and Its Control on Golf Courses in the Sacramento Valley by Dr. Lin Wu, Dept. of Environmental Horticulture A small, dicotyledonous plant known as (Asteraceae), Solvia sessilis. Cotula and both erect and prostrate phenotypes Brass Buttons (Cotula sp.) has become a mexicana was found on golf greens as well have been found adaptive to different field noxious weed on some golf greens in as on fairways and rough areas. Cotula habitats (Lloyd, 1981). Cotula dioica and California’s Sacramento Valley. This low australis and Solvia sessilis were growing weed forms large, rough patches only found on fairways and rough on golf greens (Fig. 1). Broadleaf herbicide areas. Twenty samples collected control has not been successful because of from the golf greens all were C. reoccurrence of the weed after eradication mexicana. Cotula mexicana is a of the existing vegetation. The current perennial herb, rhizomatous and method to deal with this problem is to stoloniferous, with prostrate remove it with a cup cutter and replant with branches and glabrous leaves bentgrass plugs. This management strategy aggregated at branch tips. It can 4mm is laborious but not successful because of reproduce both by seeds and veg- the constant invasion of this weed on put- etatively by short rhizomes and ting greens. One-third of golf greens on stolons (Fig. 2). Figure 2. Individual tillers of Cotula mexicana from some of the golf courses in the Sacramento Plant samples of C. mexicana sod samples collected on a Sacramento Valley Valley are infested. In the summer of 2000, were grown in the greenhouse putting green. At left, a tiller with attached rhizome the Department of Environmental Horticul- (Fig. 3) and plugs collected from and roots; center, a single tiller; and right, a ture at UC Davis collected plant samples the golf course were transplanted vegetatively reproduced secondary tiller. from the Haggin Oaks Golf Course, which onto the experimental green in had suffered a large infestation. Samples the Department of Environmen- were collected in May 2000 from golf tal Horticulture at UC Davis. Both the C. maniototo have been used for bowling greens, fairways and roughs and were grown greenhouse-grown and transplanted plants greens in New Zealand, but weed control is were treated with the difficult compared with grass (Evans, 1984). herbicide Weed-B- Infestations of C. mexicana on golf greens Gon, which contains in California seem to be increasing. This 10.60% mecoprop, plant is capable of out competing a low-cut 3.05% 2,4-D and bentgrass sod. Without appropriate man- 1.30% dicamba. The agement, Brass Buttons can become a seri- rate of application was ous pest on putting greens in the Sacra- diluted 25 times with mento Valley. deionized water. Both greenhouse-grown and Management recommendations transplanted plants 1. Remove existing large weed were killed after two patches on the golf green using a cup cutter weeks of herbicide ap- and replace them with bentgrass plugs. plication. However, Apply broadleaf herbicide over the golf seedlings emerged green to control small weed spots and seed- from the killed spots lings. after four weeks of her- 2. To prevent introduction of weeds bicide application (Fig. by foot and equipment from fairway and Figure 1. Dense, low growing patches of Cotula mexicana 4). The emergence of rough onto the golf greens use broadleaf adapted to close mowing found on putting greens in the weed seedlings after herbicides to control the weed sources on Sacramento Valley. the eradication of the the fairway and rough areas. existing weeds sug- 3. Brass Buttons seed begin germi- in the greenhouse. When the plants reached gests that seeds produced by the weeds nating in late March. Apply broadleaf her- flowering stage, they were checked for tax- under low mowing conditions were able to bicides on golf greens in April to kill the onomy, flower morphology and vegetative reestablish themselves after killing of the infesting seedlings. Monitor golf greens growth habits. Three species having simi- existing plants. through the year and apply herbicide if lar growth patterns were identified. They Plant species in the family Asteraceae, weed seedlings appear. were Cotula australis, Cotula mexicana, such as C. mexicana, C. australis, and and a species in the same family Leptinella filicula, are genetically variable Continued on page 8 Volume 7, Number1, Page 3 Winter 2003 EH Hosts Ag. Science Field Day for Local FFA Students Early on Saturday morning, March 1st, vines and groundcovers (see photo).