Foliar Sprays to Control Aphids on Fall Spinach, 1995

Spinach was planted on 5 Sep in a commercial field owned by VanKesteren Farms in Tasley, VA. The crop was planted across the field in beds 5 ft wide with 2 ft of bare ground between beds. Each bed contained 6 rows of spinach. For the experiment, an area of the field with high numbers of GPA was selected and divided into 20 ft X 5 ft plots. Each treatment was replicated 3 times in a RCB. A single application of each treatment was made with a backpack sprayer using 3 hollow cone nozzles/row. Evaluation criteria consisted of counts of the number of GPA on 10 randomly picked leaves/plot on the dates indicated in the table. On the last date, the number of mummies/10 leaves was also counted. The mummies were aphids killed by entomopathic fungi and, in much lower numbers, by parasitic wasps. Mummies attached to the leaves, as well as live aphids, render the produce unmarketable.