Dr. Larry Godfrey
Statement of Problem: Cotton is an important crop in CA, although acreage has declined in recent years. In addition, the species of cotton grown has shifted over the last 10 years from exclusively Acala to now ~45% Pima cotton. These changes have largely been because of economics and in particular pest control costs. Yield losses from insects and mites were estimated at 0.4% in 1991 and peaked at 11.3% in mid-late 1990’s. Concomitant with this, costs for pest control were $10/A in 1991 and peaked at $100-125/A. The primary culprit was the cotton aphid (Aphis gossypii), but spider mites, lygus bugs, silverleaf whitefly, and beet armyworm were also problematic. At my laboratory at the UC Cotton Research and Extension Center, I have a fulltime Staff Research Associate, and several graduate students have done their research there over the last several years. Several undergraduate assistants work during the summer. We work closely with the other Univ. of California personnel, including the Cotton Agronomist, Cotton Farm Advisors, and UC-IPM Advisor, as well as with USDA-ARS personnel located on-site.
Examples of Work during Recent Years
- The role of insecticides, particularly reduced-risk materials, in the management of key arthropod pests such as spider mites, cotton aphids, lygus bugs, and beet armyworms is being investigated.
- The role of nitrogen and pyrethroid insecticides in the increase in cotton aphid pest status has been studied.
- Damage potential of silverleaf whitefly in the SJV was studied.
- Studies on the seasonal life history of Cotton Aphid were done.
- Treatment thresholds, plant biomass and physiological responses to mid-season cotton aphid infestations in SJV cotton have been evaluated.
- The utility of releases of predatory mites for the management of spider mites in cotton.
- Applicability of remote sensing for detecting developing spider mite, lygus bug, and cotton aphid infestations.
- Factors influencing sticky cotton occurrence and severity.