Bio-fumigants as grain protectants in storage-A review

Agriculture is a global lifeline, especially in developing nations like India, where over 70% of the population relies on it. Protecting food grains from insect pests during post-harvest storage is crucial, particularly in regions lacking advanced storage technologies, leading to significant losses. Fumigation is still a key strategy for safeguarding stored grains. Methyl bromide (MBr) and aluminium phosphide (AlP) are the widely used chemical fumigants. Phosphine is used to a greater extent today, but there are frequent reports that several storage pests have developed resistance to this fumigant. The United Nations World Meteorological Organization declared methyl bromide as an ozone-depleting chemical in 1995, and hence, most of the developed countries have phased out its use. Therefore, there is an urgent requirement to develop alternatives having a possible replacement for these fumigants. Biofumigants are organic compounds derived from various plant sources, including essential oils, botanical powders, and plant residues or from microbial volatiles. They release volatile compounds toxic to pests but safe for humans and the environment, offering a sustainable pest management approach. Plants such as mustard and radish produce glucosinolates that release isothiocyanates, known for their pesticidal properties. Essential oils from eucalyptus, clove, and mint and volatiles from certain fungi and bacteria also exhibit fumigant properties. Biofumigants disrupt insect physiological and biochemical processes, leading to mortality or reduced reproduction. Studies showed their efficacy against pests like red flour beetle, lesser grain borer, and rice weevil. Unlike chemical fumigants, biofumigants do not leave harmful residues, preserving grain quality and aligning with organic farming practices. Shifting to biofumigants offers a promising, eco-friendly, and effective alternative for post-harvest pest management, ensuring food safety and sustainability