ABSTRACT

The high cost of production inputs and narrow profit margins of the cotton industry constantly forces producers to rapidly adopt the newest and most advanced technologies. Many precision agricultural technologies are now available to cotton producers. Field management decisions have been historically based on the average data representing a whole field. Global positioning systems/geographical information systems (GIS) technologies allow producers to identify and reference intra-field variability, divide the field into management zones, and selectively apply inputs. This experiment compared the efficacy and value of spatially variable insecticide (SVI) applications to that of whole-field broadcast treatments. Yield and profit maps were created from previous (2001) cotton yield/production data and were used to develop SVI prescriptions. Treatments included whole-field broadcast sprays, yield-based SVI sprays, and profit-based SVI sprays. Five successful aerial applications were made to the test field during the 2003 growing season. There were no significant differences in yields among treatments. The whole-field, SVI-yield, and SVI-profit treatments produced lint yields of 880 lb/acre, 839 lb/acre, and 828 lb/acre, respectively. Seasonal insecticide costs per acre (based on the entire area) were $42, $28, and $31 for the whole-field, SVI-yield, and SVI-profit treatments. There was a 32% and 25% reduction in area sprayed using the SVI-yield and SVI-profit treatments compared to the whole-field sprays. The SVI treatments showed promise in this test and warrant further evaluation.