Development of a management tactics against thrips (Thrips tabaci) in onion

抄録

A field study was conducted during the Rabi season of 2022-2023 at the Spices Research Centre, BARI, Shibganj, Bogura, Bangladesh (geographic coordinates 25.0167° N, 89.3167° E) to evaluate the efficacy of various management strategies against thrips in onion. BARI Piaz-4 was the test crop. Treatments included: T₁= White sticky trap at 40 trap/ha; T₂= White sticky trap at 40 trap/ha + spraying of Spirotetramet (Movento 150OD) at 1ml/L of water; T₃= Alternate spraying of Azadirachtin (Bioneem plus 1EC) at 1ml/l of water and Spirotetramet (Movento 150OD) at 1ml/L of water; T₄= Alternate spraying of Spinosad (Success 2.5SC) at 1.2ml/L of water and Spirotetramet (Movento 150OD) at 1ml/L of water and T₅= Untreated control. The greatest reduction in thrips population (90.33%, 91.6%, 89.09% and 77.8%) was observed in T₃ (Alternate spraying of Azadirachtin and Spirotetramet) followed by T₄ (Alternate spraying of Spinosad and Spirotetramet) after 42, 52, 62, and 72 days after treatment (DAT), respectively. These two treatments were statistically similar after all sprays. The highest bulb yield (18.74t/ha) and the highest marginal benefit-cost ratio (MBCR) (11.26) was also obtained from T₄ followed by T₃ with a yield of 16.56 t/ha and MBCR of 10.07.