Grain storage systems and insect management in Punjab (north India)

Abstract

A food bowl of India, Punjab contributes 17% to wheat and 12% to rice production per year from the country’s 3% of the net sown area. The grains thus produced are either moved along the supply chain to meet the market demands or are held under storage for future use. The types and conditions of storage structures are the most important factors in handling and storage of food grains. In Punjab, a part of the produced grains is generally stored at farm level, in structures like Bukhari (3.5 to 18 tonnes) made of mud and bricks, earthen egg shaped Bharola (40-80 kg) and galvanized metal bins (PAU model - 0.15 to 1.5 tonne). The large amount is stored commercially by government agencies or hired storage structures that accounts for 14.6 million tonnes (Mt) in warehouses, uncovered Cover and Plinth (CAP) structures and silos. Major storage is done by agencies such as: Punjab State Warehousing Corporation (covered: 5.22 Mt and uncovered: 1.03 Mt), Food Corporation of India (covered: 4.43 Mt and uncovered: 2.41 Mt), Central Warehousing Corporation (1.26 Mt) and silos (FCI and private sector 0.25 Mt). About 97% of the commercial storage is done in bags (made of jute or polypropylene woven) under covered or uncovered conditions either inside warehouse or CAP storage as compared to 3% in bulk modernized silos. The biotic agents like beetles (Coleoptera) and moths (Lepidoptera) are the common insects attacking grains under storage deteriorating the quality and affecting the quantity of stored grains. The effective management of these insects found under the prevailing storage conditions is a major challenge in Punjab, presently relying on earlier developed storage protocols for fumigation (Aluminium phosphide at 3 tablets of 3 g each/tonne with polythene cover on grain stack, for shed fumigation at 21 tablets of 3 g each/28 m3); along with prophylactic sprays, i.e., every 15 d with Malathion 50 EC (Emulsifiable Concentrate), and every three months with Deltamethrin 2.5 WP (Wettable Powder). The structures are built in such a way that aeration is carried out by opening opposite doors of the warehouse, side wall vents, and roof turbo vents. In farm level small scale storages, plant extracts such as from neem, black pepper, turmeric, and sweet flag are being used (dosage at 10 g extract/kg of grains). Research on the effect of abiotic, biotic factors, physical methods, and stored product entomology in specific grain storage of Punjab is meagre, which limits insect management and results in significant use of chemical fumigants and insecticides