Productivity, water use and quality of onion (Allium cepa) seed production under different irrigation scheduling through drip

A field experiment was conducted for three consecutive years from 2008 to 2010 to study the different irriga- tion scheduling through drip irrigation for onion ( Allium cepa L.) seed production. The experiment comprised of twelve treatments under drip method of irrigation with combination of three irrigation regimes viz. 75 %, 100 % and 125 % of cumulative pan evaporation (CPE) and four irrigation intervals viz. 1, 3, 7, and 10 days and con- ventional irrigation at 50 mm CPE as an control treatment. The study showed that drip resulted into 41 to 62 % water saving with 4 to 26 % increase in yield of onion seed as compared to surface irrigation. The growth and yield attributes in drip irrigated treatments showed decreasing trend with increase in irrigation interval and CPE. When drip irrigation applied daily at 100 % of CPE, the yield increased upto 26 % as compared to control. These results were on par with drip irrigation applied daily and at every 3 days with 75 % of cumulative pan evapora- tion (CPE) with 20-24 % increase in yield as compared to seed yield obtained from surface irrigation at 50 mm CPE. The application of drip at 7 days interval did not increase the seed yield whereas, drip at 10 days interval resulted into 14 % reduction in yield as compared to surface irrigation yield. The water use efficiency was found maximum (16.9 kg/ha/cm) in drip irrigation with 75 per cent of cumulative pan evaporation (CPE) at 3 days inter- val. The economics revealed that higher benefit: cost ratio was obtained under drip irrigation at daily and 3 days application. The drip application at every 3 days interval with 75 % CPE was found to be optimum and effective for growth, yield, and quality as well as economically viable for onion seed production.