Assessment and evaluation of different treatment schedules against plant and tuber damage caused by soil pests on potato

Abstract

Bio-efficacy of various treatment schedules, viz T 1 (phorate + chlorpyriphos + imidacloprid + cartap hydrochloride), T 2 (imidacloprid + acephate + chlorpyriphos + cypermethrin), T 3 (phorate + chlorpyriphos + azadirachtin + Bacillus thuringiensis var. Kurstaki), T 4 (Bacillus thuringiensis var. Kurstaki + azadirachtin ), T 5 (phorate + imidacloprid + chlorpyriphos + cypermethrin), T 6 (phorate + azadirachtin + Bacillus thuringiensis var. Kurstaki) and T 7 (control) were evaluated against Agrotis ipsilon (Hufner) and mole cricket, Gryllotalpa africana, P.de. Beau. in single potato variety, Kufi Chandramukhi during rabi season of two potato-growing years in 2013-2014 and 2014-2015 from November to February. The percentage of plant (shoot) damage was found low in T 1 (5.82 -5.87%), than by T 3 (6.12 -6.49%), T 2 (6.86 -6.92%), T 5 (7.31 -7.62%), T 6 (8.21 -8.81%), T 4 (8.61 -9.32%) and T 7 (10.70 -11.13%) respectively. Similarly percentage of tuber damage of potato was noted highest in T 7 (34.29 -43.90 %) and it was lowest in T 2 (13.15-15.66 %). Maximum marketable yield (t/ha) of potato tubers was obtained in T 2 (26.28-26.80 t/ha), which was succeeded by T 1 (26.19 -26.92 t/ha) than other treatments and it was recorded minimum in control T 7 (11.17-12.69 t/ha). Maximum cost-benefit ratio (CBR) was recorded in T 5 (1:2.03 -1:2.04) while it was found minimum in T 6 (1:1.11 -1:1.17). Among the different treatment schedules T 5 and T 2 were most effective in increasing marketable yield of potato tubers and reduction of soil pest incidence over control T 7 and also over other treatments.