The objective of this study was to compare the efficacy of variousfoliar insecticides against aphids on tomatoes. The trial wasconducted from 2 Oct to 24 Oct 2019 at the North Carolina StateUniversity Mountain Horticultural Crops Research Station locatedin Mills River, NC. Tomato ‘Plum Regal’ transplants were set intoblack plastic mulched beds on 11 Jun, staked and strung as needed,and sprayed with a standard fungicide program. The entire trial plotconsisted of 8 rows, 100 ft long, with 10 ft between rows. Eachtreatment consisted of a 20-ft-long section of tomato plants, spaced1.5 ft apart, replicated four times, and arranged in an RCB design.Treatments on the same row were separated by 2–3 untreated tomatoplants. Prior to the start of the trial, all plots were sprayedwith the miticides Acramite on 13 Sep and Agri-Mek on 27 Sep tosuppress populations of the twospotted spider mite, Tetranychusurticae (Koch). Insecticide treatments were applied on 2 Oct whenpotato aphids infested 56% of leaves (~15 aphids per leaf). Potatoaphids were the only aphid species detected on tomatoes throughoutthe trial. Treatments were applied with a CO2 backpack sprayerdelivering 62 GPA through four hollow cone nozzles (D4/25) at 40psi. Each side of the row was sprayed with a two-nozzle wand. Plotswere evaluated 2, 7, 9, 14, and 22 DAT by recording the number ofliving, apterous aphids on each of 10 leaves from the upper portionof the plant per plot. Season cumulative aphid days were calculatedby multiplying the average mite density on successive sample datesby the sample interval (days) and summing values over all dates. Ifnecessary, data on aphids per 10 leaves were log10(x+1)-transformedprior to statistical analysis using a two-way ANOVA. Means fromsignificant ANOVA tests were separated by LSD (P = 0.5).
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