Seed invigoration studies in ash guard (Benincasa hispida Thunb.)

Abstract

"Seed invigoration studies in ash gourd (Benincasa hispida Thunb.)"was carried out at Department of Olericulture, College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur during 2002-2004. The study was conducted to find out the effect of invigoration to break seed dormancy in ash gourd, to find out the storage potential of invigorated seeds and to compare the field performance of invigorated seeds with certain traditional farmers' practices. Among the different invigoration treatments tried, growth regulators were found to be effective in breaking dormancy of fresh ash gourd seed and to improve vigour GA3 was effective at 25, 50 and 100 ppm and NAA at 25 and 50 ppm. Acid treatment or water soaking did not have any effect in breaking dormancy, thus indicating the inefficiency of scarification. Seed dormancy in ash gourd is found to be endogenous in nature which is due to certain chemical blocks, caused either by the presence of growth inhibiting factors or due to deficiency of some essential compounds. Seed invigoration was not effective in breaking dormancy of fresh seeds. But fresh seeds can be given an after ripening for a period of two months and invigorated with growth regulators for increased vigour. Though there was a gradual reduction in quality parameters like germination percentage, speed of germination and vigour index. Invigorated seeds can be safely stored for a period upto five months indicating that invigorated seeds can be directly supplied to farmers for immediate use. The practice of using seeds from previous rainy season crop was found to give superior field performance during next summer. Storing the harvested fruits as such and extracting seeds at the time of sowing gives better vegetable yield, where as storing the extracted seeds till next summer gave better fruit yield for seed purpose and seed yield. Among the growth regulators seeds invigorated with NAA 50 ppm gave increased vegetable yield and GA3 50 ppm gave increased seed yield. KN03 was not effective in breaking dormancy, improving vigour or giving improved field performance in ash gourd. Using seeds of previous summer crop for next summer is found to give inferior field performance and seed quality.