Chemigation-Applied Neonicotinoids for Stink Bug Control on Tomato, 2014 *

This study was conducted at the Mountain Horticultural Crops Research and Extension Center in Mills River, NC. Six-week-old ‘Amelia’ tomato transplants were set on 14 May on black plastic mulch with drip irrigation. Plots consisted of two 25-ft-long rows on 5-ft centers, and plants were spaced 1.5 ft within rows. Each treatment was replicated four times and arranged in an RCB design. Tomatoes were staked and strung as needed and sprayed with a standard fungicide program. Insecticide treatments consisted of Admire Pro 4.6SC (10.5 fl oz/acre), Platinum 75SG (3.67 oz/acre), Belay 2.13SC (12 fl oz/acre), and Venom 70SG (6 oz/acre), all of which were applied into drip irrigation lines via a CO ₂ injector on 8 Jul. In addition, all plots including the check were treated with Coragen (4 fl oz/acre) through the drip system at 2 and 8 wks after planting. FT populations were monitored by collecting 10 flowers per plot, placing them in a vial of 50% ETOH, and counting dislodged thrips under a stereomicroscope. PA were sampled by observing 10 recent, fully expanded leaves per plot and recording the total number of leaves infested with apterous aphids. TSSM were counted on 10 terminal leaflets per plot. Season total insect-days were calculated by multiplying the average count between sample dates by the time between samples (days) and summing values from all sample dates. On 31 Jul and 14, 21, and 28 Aug, mature fruit were harvested from the eight middle plants of one of the plot rows and graded for damage by stink bugs. All data were subjected to two-way ANOVA, and means were separated by LSD ( P  = 0.05). Prior to ANOVA, cumulative PA-days were transformed by log(x+ 1) and SB damage data were transformed by square root.

FT populations were relatively low in this trial, with less than three thrips per flower recorded during the peak on 9 Jul and an average of 55.9 cumulative thrips-days per treatment at the end of the season ( Table 1 ). There were no differences among treatments. PA populations began building in the check and Venom treatments in mid Jul, peaking in the check on 25 Aug with 17.4 aphids per leaflet. All treatments except Venom significantly reduced PA populations below the check when cumulative aphid-days were calculated. TSSM populations were relatively low when counts were ended in early Aug, with an average of 393.1 cumulative mite-days across treatments and no significant differences among treatments.

There was an average of 153.6 season-total fruit harvested per plot. Stink bug damage was relatively high, peaking on 21 Aug with a range of 21.6% (Venom) to 38.8% (Platinum) damage. The majority of damage was caused by H. halys . There were no significant differences on that date, but on 14 Aug, and when season-total stink bug damage was calculated, the Venom treatment had significantly lower damage than all other treatments, none of which differed from the check. These results suggest that Venom provided 4–5 wks control of stink bugs when applied through the drip irrigation line.

Author notes