(E70) PUMPKIN: Cucurbita maxima L., ‘Magic Lantern’ EVALUATION OF INSECTICIDES IN PUMPKINS, 2004 Thomas P. Kuhar Virginia Tech Eastern Shore AREC 33446 Research Drive Painter, VA 23420 Phone: (757) 414-0724 ext 14 E-mail:
[email protected] John Speese III E-mail:
[email protected] Roberto J. Cordero Vonny M. Barlow Squash bug: Anasa tristis (DeGeer) Melon aphid: Aphis gossipyii Glover Pumpkins were seeded in the greenhouse in mid-May and then transplanted in the field on 9 Jun no-till in wheat stubble at the Eastern Shore Agricultural Research and Extension Center near Painter, VA. Each plot consisted of a single 30-ft row with 6 ft spacing between rows. Ten transplants were set in each plot. The experiment had eight treatments plus an untreated check arranged in a RCB design with four replications. The Platinum 2SC and Admire 2F treatments were applied as a soil drench in 4-gal water/treatment on 9 Jun after transplants were set in the ground. After squash bug adults were observed ovipositing on the plants, foliar spray treatments were applied on 8, 19, and 26 Jul using a propanepressurized sprayer that delivered 30 gpa at 40 psi through a boom using three hollow-cone nozzles/row. Numbers of melon aphid were counted on two random leaves per plot on 12 Jul. Numbers of squash bug nymphs were counted on 20 random leaves per plot on 26 and 29 Jul. The marketable pumpkins in each plot were counted on 20 Aug. Data were analyzed using ANOVA and treatment means were compared using Tukey’s HSD (P ≤ 0.05). On 12 Jul, the Platinum, Admire, and Assail plots had the fewest melon aphids. The pyrethroid treatments (Asana and Danitol) flared melon aphid densities and these treatments, in particular the high rate of Danitol (0.3 lb (AI)/acre), had significantly more melon aphids than any other treatment including the check. The Platinum and Assail 30DG treatments had significantly fewer aphids than the check. Squash bug pressure was moderate in this test. The check had the most squash bug egg masses and nymphs on both dates. On 26 Jul, there was no statistically significant treatment effect on egg masses or nymphs. On 29 Jul, all treatments except Platinum, Admire and Asana had significantly fewer squash bug egg masses than the check, and all treatments except Platinum, Admire, and the 0.2 lb (AI)/acre rate of Danitol had significantly fewer squash bug nymphs than the check. No significant differences were obtained in yields of marketable fruit/acre. No visible sign of phytotoxicity was observed from any treatment.
Mean no. squash bugs/20 leaves Treatment/ formulation
26 Jul 29 Jul 12 Jul Rate Yield marketable lb (AI)/acre Egg masses Nymphs Egg masses Nymphs Aphids/2 leaves fruit/acre
Platinum 2SC 0.125 Admire 2F 0.38 Assail 70WP 0.097 Assail 30DG 0.097 Asana XL 0.66EC 0.05 Danitol 2.4EC 0.20 Danitol 2.4EC 0.30 Venom 20SG 14.3 oz Untreated check --
3.25a 3.00a 3.00a 1.75a 4.00a 4.50a 3.50a 1.00a 9.25a
0.75a 5.25a 0.00a 2.75a 0.25a 3.25a 7.25a 1.25a 11.75a
4.00ab 2.25b 1.00b 1.25b 3.75ab 2.25b 0.50b 1.25b 14.25a
6.25ab 2.00ab 0.00b 1.25b 0.00b 4.25ab 0.00b 0.00b 18.50a
1.00b 9.50b 4.50b 0.00b 200.00ab 223.00ab 500.75a 182.00ab 146.00b
Means in a column with a letter in common are not significantly different (P > 0.05, Tukey’s HSD).
3934.6a 3389.8a 3874.1a 3692.5a 3571.4a 3389.8a 3571.4a 3389.8a 3692.5a
