Vol. 12, Issue 5 (2023)

Author(s):
Ranjitha MR and Ram Singh Umrao

Abstract:
Chickpea is the leading pulse crop in terms of area and production in the Indian subcontinent. Bruchids (Callosobruchus chinensis L.) are the major biotic factor causing severe economic losses in stored chickpeas. They enter storage via several routes and hence, the proper disinfestation of bruchid infested grains is highly necessary before storage. The current study compared the efficacy of four Gamma irradiation doses (0.1, 0.2, 0.3, and 0.5 kGy based on Cobalt⁶⁰ source) with the previously recommended phosphine fumigation dose and an untreated control. Among the irradiation doses, 0.2, 0.3, and 0.5 kGy completely eliminated all the infestation parameters; however, these doses proved lethal for seed germination. However, a dose of 0.1 kGy was found to be equally effective in reducing infestation parameters without having a lethal effect on seed germination. Apart from this, the percent reduction was better over grains exposed to recommended dosage of phosphine and untreated control. Hence, irradiation with 0.1 kGy would be the most effective, efficient, and cost-effective method of disinfesting bruchid-infested chickpea grains. This method would be a better combination before storing grains in modern packaging materials such as LDPE, HDPE, PPW, and PICS bags, as the initial elimination of infestation would prevent further perpetuation inside bags, as bruchid does not actively enter the bags by puncturing but rather passively enters through natural openings (gunny bags). The current findings would also provide an opportunity to identify the effective irradiation doses for the other major bruchid species that infest chickpea and other pulse crops.