Effects of low-dose gamma radiation on quality and storability of groundnut (Arachis hypogaea L.)

Groundnut seed losses viability easily compared with other legumes. Knowledge of storage potential of these seeds is highly important in preventing quality reduction during storage. The study assessed radiation dose that provide optimum protection while maintaining seed viability to acceptable standards. Shelled and unshelled groundnut seeds ( cv. Chinese ), subjected to low doses of gamma irradiation (0,1,2,3,4 and 5 Gy) and stored under ambient conditions, were evaluated using eight tri-weekly intervals over a five-month storage period for seed quality and storability. The experimental design adopted was a Completely Randomized Design (CRD) with each of the twelve treatments replicated three times. For the field study on evaluating vigour, a Randomized Complete Block Design (RCDB) was employed. Data comprising physiological, sanitary and genetic seed qualities were taken. Statistically significant differences between irradiated shelled and unshelled seeds and their controls were observed for root and shoot lengths as well as speed of germination. Unshelled seeds showed significantly lower seed moisture content with higher values for percentage germination, speed and peak of germination. Pathogen infectivity, however, rose significantly from 22 to 79.9% over the storage period. Days to seedling emergence, was not significantly affected by irradiation as both shelled and unshelled seed forms showed similar seed emergence rates. A dose range of 2–4 Gy showed slight stimulatory effect on seed emergence and seedling vigour of both seed forms. Petiole and leaf colours of both seed forms were not affected by irradiation. The use of low doses of gamma radiation (2–4 Gy) has the potential to enhance the quality of groundnut seeds, thereby helping to maintain and prolong groundnut seeds in storage.