Thrips (Thrips tabaci) is most injurious insect pests of onion. These are common all over the country where onion crop is grown. Onions infected with thrips develop spotted appearance on leaves which turn pale-white blotches due to drainage of sap. Sometimes 50-60% losses in bulb crop are observed due to thrips attack. Seed production including viability of seeds are hampered due to attack of thrips. The insect is very minute and yellow to dark brown in colour. The life-cycle of insect is 8-10 days. It is found in the axil of green leaves where it sucks juice of early-emerging leaves. The adults hibernate in soil, on grass and other plants in onion fields. The thrips also over-winter in bulbs and act as source of infestation in the following year. They multiply in a large number during March-April on seed and bulb onions in Northern parts of India. The infested plants show stunted growth with twisted leaves. If the infestation comes in early stage of growth, bulb formation stops completely and plants die slowly. Bulbs in store are also attacked by thrips. Profenofos 50%EC @ 45 Ml/pump or Emamectin Benzoate @ 15 Gm/pump or Spinosad @ 10 Ml/Pump should be sprayed along with silicon base solvent to control the insect. Soil application of Fipronil 0.03% GR @ 5 Kg /Acre or Phorate or Carbofuran granules @ 4 kg /Acre is also recommended.
Like and share with other farmers by clicking on button below.
Share
