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 T1 (phorate + chlorpyriphos + imidacloprid + cartap hydrochloride), T2 (imidacloprid + acephate + chlorpyriphos + cypermethrin), T3 (phorate + chlorpyriphos + azadirachtin + Bacillus thuringiensis var. Kurstaki), T4 (Bacillus thuringiensis var. Kurstaki + azadirachtin ), T5 (phorate + imidacloprid + chlorpyriphos + cypermethrin), T6 (phorate + azadirachtin + Bacillus thuringiensis var. Kurstaki) and T7 (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 T1 (5.82 - 5.87%), than by T3 (6.12 - 6.49%), T2 (6.86 - 6.92%), T5 (7.31 - 7.62%), T6 (8.21 - 8.81%), T4 (8.61 - 9.32%) and T7 (10.70 - 11.13%) respectively. Similarly percentage of tuber damage of potato was noted highest in T7 (34.29 - 43.90 %) and it was lowest in T2 (13.15-15.66 %). Maximum marketable yield (t/ha) of potato tubers was obtained in T2 (26.28-26.80 t/ha), which was succeeded by T1 (26.19 - 26.92 t/ha) than other treatments and it was recorded minimum in control T7 (11.17-12.69 t/ha). Maximum cost-benefit ratio (CBR) was recorded in T5 (1:2.03 - 1:2.04) while it was found minimum in T6 (1:1.11 - 1:1.17). Among the different treatment schedules T5 and T2 were most effective in increasing marketable yield of potato tubers and reduction of soil pest incidence over control T7 and also over other treatments.