(E28) BELL PEPPER: Capsicum annuum L., ‘Paladin’ EVALUATION OF FOLIAR INSECTICIDES ON BELL PEPPERS, 2006 Thomas P. Kuhar Department of Entomology Virginia Tech Eastern Shore Agricultural Research & Extension Center 33446 Research Drive Painter, VA 23420 Phone: (757) 414-0724 ext. 14 e-mail:
[email protected] Helene Doughty Anna Chapman Vonny Barlow European corn borer (ECB): Ostrinia nubilalis (Hübner) Corn earworm (CEW): Helicoverpa Zea (Boddie) Beet armyworm (BAW): Spodoptera exigua (Hübner) Fall armyworm (FAW): Spodoptera frugiperda (J.E. Smith) ‘Paladin’ Bell peppers were transplanted on 20 Jun at the Virginia Tech ESAREC near Painter, VA using a commercial transplanter. Plants were spaced 12 inches (30.5 cm) apart. Plots consisted of one row 20 ft (6.1 m) long with unplanted guard rows on each side. Rows were planted on a 6 ft row center (0.9 m) in a 6 tier field design with 8 ft (2.4 m) alleys between tiers and a 16 ft (4.9 m) center alley. Treatments were arranged in a RCB design with four replicates. All plots were maintained according to local standard practices. Foliar treatments were applied with 26 gpa of spray using a 3-nozzle boom (one hollow cone nozzle over the top of the row and two hollow cone drop nozzles directed at each side of the row) and a CO2 backpack sprayer at 40 psi. Foliar treatments were applied approximately weekly 6 times on the following dates: 9, 15, 22, 28 Aug and 5 and 13 Sep. The first application was made when fruit were present. On three dates (21 Aug, 5 and 19 Sep), all market-sized fruit were harvested from each plot and examined for lepideptoran larval feeding damage. Numbers of damaged and marketable fruit were recorded for each plot. Results were analyzed as proportion damaged fruit on each harvest date, and cumulative marketable yield for the three harvests (no. fruit / plot). All data were analyzed using ANOVA procedures. Means were separated using Fisher’s LSD at the 0.05 level of significance. Lepidopteran pest pressure was fairly heavy with damaged fruit in the untreated controls (UTC) on the first two harvest dates (21 Aug and 5 Sep) reaching 51.4% and 40.4%, respectively. European corn borer (ECB) was the predominant insect pest infecting fruit with several signs of damage typical of beet armyworms. Fall armyworms and corn earworms were also found attacking fruit. We probably commenced spraying 1 week too late, as we suffered a little damage in the insecticide plots on the first harvest only. There was a significant treatment effect on fruit damage on all three harvest dates. All insecticide treatments had significantly less fruit damage than the UTC. There were no statistically significant differences among the insecticide treatments in efficacy. As many of the insect-infested pepper fruit rot before they can be picked, another indicator of insect damage is the number of marketable fruit harvested out of plot. There was a significant treatment effect on the number of cumulative marketable fruit per plot. Results showed the same trend displayed with fruit damage with the UTC having significantly less fruit than the insecticide treatments. The 3 oz rate of Synapse 24WG had the highest marketable yield (almost 3 times that of the UTC). No visible sign of phytotoxicity was observed from any treatment. Treatment/ formulation
Rate/acre
1. Synapse 24WG 2. Synapse 24WG 3. Synapse 24WG 4. Spintor 2SC 5. Warrior ZT 6. Mustang Max 7. Mustang Max 8. Orthene 97 9. UTC P-Value from ANOVA
1 oz 2 oz 3 oz 6 fl oz 3.84 fl oz 2.25 fl oz 3.13 fl oz 16 oz
% damaged fruit 21 Aug (6 DAT) 19.6bc 24.9bc 13bc 31.9ab 14.2c 29.2abc 18.2bc 19.4bc 51.4a 0.049
% damaged fruit 5 Sep (8 DAT) 5.4b 3.9b 1.5b 2.4b 10.2b 3.6b 4.5b 5.8b 40.4a 0
% damaged fruit 19 Sep (6 DAT)
Cumulative marketable yield
3.8b 7.0ab 6.0b 6.0b 8.3ab 14.8ab 6.1ab 11.4ab 18.8a
68.8abc 88.3ab 100.8a 72.5ab 65.3abc 73.0ab 73.0ab 63.5bc 35.0c
0.13
0.08
All data were analyzed using ANOVA procedures. Means were separated using Fisher’s LSD at the 0.05 level of significance. Means followed by the same letter within a column are not significantly different (P > 0.05).
