Chemical Control/New Products Chemical Control of Navel Orangeworm in Pistachios

This trial was conducted in the lower San Joaquin Valley, near Bakersfield, CA, to compare the efficacy of a conventional treatment (Imidan/permethrin) and an IGR (Intrepid) in single and multiple spray approaches to control plots receiving no treatment. Twenty-acre treatment plots were replicated four times in a completely randomized design. Applications were made on May 11 (395 dd), August 28 (2854 dd), and/or Sept 9 (3103 dd). All single application treatments (Imidan or Intrepid on Aug 28, Intrepid on Sept 9) reduced damage from 40 to 55% whereas the multiple spray programs (2 or 3 applications at timings noted above) reduced damage 42 to 73% compared to controls. Greatest damage reductions were observed in treatments that included an application directed at the first generation.