Pyrithiobac sodium controls nightshade without long-term effect on cotton
Tomé M. Martin-Duvall
Authors AffiliationsR. Vargas is Farm Advisor; T.M. Martin-Duvall is Staff Research Associate, UC Cooperative Extension, Madera County; S. Wright is Farm Advisor; M. Jimenez Jr. is Staff Research Associate, UCCE, Tulare County.
Hilgardia 52(5):34-38. DOI:10.3733/ca.v052n05p34. September 1998.
Nightshades are some of the most difficult weeds to control in Upland Acala varieties of cotton. A herbicide in the newest class of acetolactase synthase inhibitors has been developed for use as a selective over-the-top broadleaf herbicide in cotton. Studies were conducted in Upland Acala cotton varieties in 1991, 1992 and 1993 to evaluate the efficacy of Staple (pyrithiobac sodium) in controlling nightshade. The herbicide was applied as early postemergence, mid-postemergence and sequential applications at rates of 0.25, 0.50, 0.75, 1.0, 2.0 and 3.0 oz of active ingredient per acre (ai/acre). Acceptable nightshade control was achieved at all rates, when applied as a single application or as sequential applications, except for the 0.25 and 0.50 oz ai/acre applications. The best control was achieved when the herbicide was applied at rates of 1.0 to 3.0 oz ai/acre over the top of cotton in the cotyledon to eight true-leaf stage, with nightshade in the cotyledon to six-leaf stage. Cotton injury symptoms were evident with all treatments at 7 days after application but were nonexistent by 90 days after application. There was no evidence to indicate that pyrithiobac sodium has any long-term effect on cotton growth and development or on cotton lint yield.
Jachetta J. Amino acid inhibition herbicides. California Weed Science Society Proc 1996. 48: Sacramento, CA: pp.135-41. Jan 21-23, 1996
Keeley PE, Thullen RJ. Growth and early production of black nightshade in cotton. California Weed Science Society Proc 1988. 40: Sacramento, CA: pp.220-1. Jan 18-21, 1988
Keeley PE, Thullen RJ. Biology and control of black nightshade (Solanum nigrum) in cotton (Gossypium hirsutum). Weed Technology. 1991. 5:713-22.
Kempen HM. Nightshade, cotton's no 1 enemy. California Weed Science Society Proc 1986. 38: Fresno, CA: pp.136-44. Jan 27-30, 1986
Martin-Duvall TM. Effects of adjuvants and Fusilade on the efficacy of Staple on nightshade in cotton. 1996. Fresno, CA: California State University Fresno.
Vargas RN, Fischer WB, Kempen HM, Wright SD. Cotton weed management. Cotton Production Manual 1996. University of California, DANR, Publication #3352. p.187.
Vargas RN, Wright SD. Nightshade control with pyrithiobac sodium (Staple) in California cotton. Challenging the Future. World Cotton Conference Proc 1994. 1: Brisbane, Australia.: pp.191-3. Feb. 14-17, 1994.
Vargas RN, Wright SD, Martin-Duvall TM, Jimenez Jr. M. Control of nightshade in cotton with Staple (pyrithiobac sodium) and its effect on rotational crops in California. 1996e. 49:Western Society of Weed Science Proc. p.90. Mar 11-14,1996 Albuquerque, NM.
Vargas RN, Martin-Duvall TM, Wright SD, Jimenez Jr. M. Staple: Is it the silver bullet for cotton. 1996b. 48: Sacramento. CA: California Weed Science Society Proc. pp.100-6. Jan 22-24,1996.
Also in this issue:Effect of malathion-bait sprays on biological control of insect pests of olive, citrus, and walnut
Veterinary medicine: Mandates and missions for the 21st century
Readers respond to “Farming at the edge”
Growth reflects society's changing views of animals
Growers strive to reduce selenium discharges
Innovative strategies reduce selenium in Grasslands drainage
Subsurface drainage systems have little impact on water tables, salinity of clay soils
Beneficial insects move from flowering plants to nearby crops
Can cover crops reduce leafhopper abundance in vineyards?
Curly top virus found in perennial shrubs in foothills