The objective of this experiment was to assess the efficacy ofseveral biological insecticide products for control of corn earworm(CEW) on grain hemp in Virginia. A field experiment wasconducted on planting of ‘Felina 32’ hemp direct seeded with agrain drill at 30 lb. seed per acre on 24 Jun 2019 at the VirginiaTech Eastern Shore Agricultural Research and Extension Centerin Painter, VA. The experiment had six treatments: Gemstar(Helicoverpa zea nuclear polyhedrosis virus [HzNPV]), Javelin(Bacillus thuringiensis var. kurstaki), BoteGHA (Beauveriabassiana strain GHA), Entrust (Spinosad), DiPel (Bacillusthuringiensis var. kurstaki), and an untreated check arranged inan RCBD with four replicates. Individual plots were 3 × 10 ft(0.91 × 3.05 m). Hemp plants were sprayed with insecticides inthe field using a single-nozzle boom equipped with D3 spray tipspowered by a CO2 backpack sprayer at 40 psi. For each treatment,40.6 fl. oz (1200 ml) was applied to all four replicates, whichequates to 58 gallons per acre. All treatments were applied twicewith a 7-d interval, except for Gemstar, which was applied threetimes at 3-d intervals. Treatments were applied on 13 Aug (alltreatments), 16 Aug (Gemstar only), 19 Aug (Gemstar only), and20 Aug (all treatments except Gemstar). On 12 (pre-count), 20, 27Aug, and 3 Sep, the number of lepidopteran larvae were recordedper inspection of 10 randomly selected plants per plot. On 3 Sep,10 plants were examined for feeding damage by CEW accordingto the following rating scale: 0 = no feeding, 1 = some browning/damage, 2 = advanced browning and feeding damage/holes inseeds, 3 = advanced feeding damage/clipped bud (Table 1). Alldata were analyzed using ANOVA procedures. Means wereseparated using Fisher’s LSD at the 0.05 level of significance.
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