As the wheat crop is at earhead stage, the aphids may cause damage to the crop, cautioned the experts of the Punjab Agricultural University (PAU) here today. The Head, Department of Entomology, Dr Balwinder Singh explained that aphids are soft bodied, green to blackish green louse like insects. These are found in small colonies on leaves and earheads, said he, adding that aphid develops colonies on leaves, leaf sheath, flag leaf and in the spikelets of the earheads. Both nymphs and adults suck the sap from the leaves and maturing grains. Dr Singh elaborated that due to heavy feeding by aphids, the grains cannot develop and remain shriveled. The aphids also excrete honeydew on which black sooty mould develops that hinders photosynthetic activity of the leaves. He added that the high population of aphids at the earhead stage can cause substantial losses in yield.
Dr Singh has advised the farmers to inspect their fields twice a week and record aphid population from 10 randomly selected earheads in each of the four quarters of one acre. If the aphid population reaches five aphids per earhead (ETL), spray the wheat crop with 40 ml imdacloprid 17.8 SL or 20 g thiamethoxam 25 WG or 12 g Dantop 50 WDG (clothianidin) or 150 ml Rogor 30 EC (dimethoate) by dissolving in 80-100 litres of water per acre with knap-sack sprayer, he told. Since the aphid attack starts from the periphery of the field, spray only infected strip to check their further spread, advised Dr Singh.
