Effect of Insecticides on Pepper Insects, 2014 *

To determine the effect of insecticides on pepper insect control, seedlings were transplanted in a sandy loam type soil on 10 June at the University of California’s South Coast Research and Extension Center. Experimental plots were three rows in width (5-ft centers) by 40 ft in length and separated by a 3-ft buffer. The pepper transplants were drip irrigated (water pH 7.2–7.5). Treatments were replicated four times in an RCB block design. A treatment list is shown in Table 1 . Treatments of Radiant, and Intrepid plus Warrior, were applied on a weekly basis at first flowering (17, 24, and 31 July and 7, 14, 21, and 28 August). Verimark was applied once as a soil drench on 26 June. Actara plus BeetleGone! was applied on 17 and 24 July. Closer plus BeetleGone! was applied on 31 July and 7, 14, and 21 August. Lannate plus Pounce was applied on 17, 24, and 31 July and 7, 14, and 21 August. All applications were made at twilight. A tractor-mounted boom sprayer with 6 nozzles per row incorporated D-3 orifice disks, no. 25 cores, and 50 mesh screens. Operating pressure was 125 psi delivering 100 gpa. All treatments included Dyne-amic as an adjuvant at 0.25% vol/vol. On 11 September, 100 mature-green to ripe fruit were harvested from the center row of each replicate (400 per treatment) and examined for Lepidopterous internal damage TFW, external damage BAW, hemipterous pests (lygus and SB), and PW. Data were analyzed with analysis of variance and Fisher’s protected LSD analysis to detect differences among treatment means ( P  < 0.05 level, Fisher’s protected LSD test).

Lepidopteran pressure was estimated to be moderate to high in the categories of External damage by BAW, and there were no significant differences between any treatments for Lepidopterous insect damage. Internal damage by PW was moderate this year with the untreated control sustaining 15% damage. We did see some differences between treatments for TP numbers. Intrepid 2F plus Warrior CS and Lannate 2.4LV plus Pounce 3.2 EC treatments had higher psyllid numbers. Damage to the calyx showed statistical differences between treatments and can be attributed to TFW, BAW, and PW feeding. No phytotoxicity was observed in any of the treatments.

Author notes