Efficacy of dormancy breaking methods in paddy genotypes

Abstract

Paddy plays a pivotal role in Indian agriculture. It also possesses dormancy which needs to be studied thoroughly. Duration of dormancy usually ranges from 7 to 35 days. Environmental conditions that facilitate after-ripening in paddy is generally cool, moist substrate conditions referred to as stratification, chilling, or moist chilling, oxygen and other gases. 12 paddy genotypes were selected for the present investigation with various physical and chemical dormancy, breaking methods for freshly harvested seeds and the standard germination test was conducted thereafter. At 1% level of significance, heat treatment at 45°C for 72 h showed significantly highest mean germination (82.86%), seedling vigour index (2753), dehydrogenase activity (0.0449) and alpha amylase activity (12.14 mm) compared to other treatments and control.. The vigour index increased to 2753 (GA3 @ 50 ppm) from 985 in control. Significantly higher EC leachates was recorded in control (0.602) and lowest in heat treatment at 45°C for 72 hr (0.182) followed by HNO3 @ 1.5% (0.202) and GA3 @ 50 ppm (0.250) irrespective of the genotypes at 1% level of significance. Pre-heat treatment was followed by, HNO3 @ 1.5% and GA3 @ 50 ppm for germination (80.75%, 77.72%), dehydrogenase activity (0.0446,0.0443) and alpha amylase activity (12.10 cm,11.60 cm) respectively. The study is an exploration of cost effective treatment to alleviate seed dormancy in paddy with the background of biochemical observations for scientific explanation.