Browsing Vegetable Report 1999 by Authors
Application and Timing of Insecticides for Aphid Management in Head LettucePalumbo, John; Mullis, Clayton Jr.; Reyez, Francisco; Amaya, Andreas; Ledesma, Luis; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)The timing and application methods of new insecticide chemistries for aphid control were compared to imidacloprid in several studies in 1998 and 1999. Foliar applications of Fulllfill, Aphistar, Actara and Acetamiprid appear to provide an alternative method of controlling aphids on lettuce comparable to prophylactic applications of Admire. Timing applications as aphids began to colonize was critical for preventing head contamination at harvest. In addition, at planting and side dress soil applications of Platinum provided aphid control comparable to Admire. Residual activity of the new foliar alternatives appeared to differ depending on spray timing relative to aphid density and plant stage. These studies suggest that more than one application of the foliar products will be necessary to adequately suppress aphid contamination in heads. Evaluations of thiamethoxam suggest that it is more mobile in the soil than Admire and may be a candidate for side dress applications for aphid management.
Cross Commodity Management of Whiteflies and Chemical Efficacy in ArizonaPalumbo, John; Ellsworth, Peter; Umeda, Kai; Dennehy, Tim; Arbogast, Mike; Evans, Lin; Hannan, Todd; Minch, Ed; Nichols, Bob; Byrne, David N.; et al. (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)The Western Growers Association and Arizona Cotton Growers Association worked cooperatively with a group of University of Arizona scientists, Arizona Department of Agriculture officials and regional pest control advisors to develop general guidelines for managing whiteflies and specific recommendations for Applaud and Admire use. This was achieved by identifying differences in crop production, insecticide use, and whitefly population dynamics on key host crops within three distinct growing regions in Arizona. Data was compiled that when graphically illustrated identified important, multidimensional interactions within cropping systems. Based on the patterns resulting from our analysis, initial recommendations have been formulated to harmonize chemical use across commodities by restricting Applaud use to only once per crop season in use windows, with additional guidelines for reducing the possibility of exposing successive whitefly generations to the same mode of action. The diversification and limitation of Admire and other active ingredients, and the employment of cultural practices are also be considered. Should this model of cooperation be successful, valuable and scarce modes of action may also be shared in the future within diverse, integrated use systems.
Implementation of a Pest Monitoring Network for Vegetable Growers in Yuma CountyPalumbo, John; Kerns, David; Mullis, Clay; Reyes, Francisco; Byrne, David N.; Baciewicz, Patti (College of Agriculture, University of Arizona (Tucson, AZ), 1999-10)An insect pest monitoring network spanning the major growing areas in Yuma was implemented in 1998-1999. This project was designed to measure the relative activity and movement of adult populations during the growing season and provide important information to growers and PCA’s. A series of pheromonebaited and yellow sticky traps were placed in 11 locations among the growing areas in the Yuma, Gila and Dome Valleys in Yuma county. Numbers of adults / trap /night were recorded weekly from September-April. Seasonal differences in insect species activity and abundance among locations were observed, but difficult to precisely explain because of the lack of historical trap data. Information gathered from the trapping network will provide historical baseline data for pest activity on an area wide basis from which relationships between insect trap captures and seasonal factors that influence their activity and abundance may be explained. The results of the monitoring network during the 1998-1999 growing season for is provided in this report.