Effect of Specific gravity separation and storage environment on the seed quality of onion (Allium cepa L.)

A study was carried out for evaluating the effectiveness of the specific gravity separation in improving the seed quality of onion. The seeds of onion cultivar Agrifound Dark Red were used as the experimental material and the seeds were obtained from three locations viz. Indore, Rajkot and Lasargaon. The statistical analysis revealed that there were significant differences between the seed lots procured from Rajkot and Indore with respect to moisture content, germination percentage and vigour attributes. Depending upon the germination percentage and incidence of mycoflora, the seed lot from Rajkot was selected for further studies. The seeds were subjected to specific gravity separation and divided into five different grades and investigated for different seed quality attributes. Subsequently, the seeds of different grades were packed in cloth bags and stored under two storage conditions viz., Low Temperature (15 ± 1°C)-Low Humidity (30 ± 5%) condition (LTLH) as well as under ambient conditions for a period of one year. The results revealed that specific gravity separation improved the seed quality parameters significantly over the original seed lot. Hence, specific gravity separation can be useful for seed quality enhancement in high value vegetable crops, like onion. The storage environment also exerted a marked influence on the seeds and those kept under LTLH storage conditions maintained better seed quality as compared to ambient storage.