Ponnaiya, B W XGopinathan Nair, VKAU2020-07-152020-07-151961http://krishikosh.egranth.ac.in/handle/1/5810149133PGWork done in cereals and other crop plants on the factors related to seed dormancy (causes, tissues involved, stage of maturity at harvest, variation in period and genetics), which are important from a practical breeding point of view, has been critically reviewed with special reference to rice. Studies were undertaken on six short duration varieties of rice and their hybrids to estimate the period of dormancy, to understand the relative roles of the hull and the embryo and also to understand the mode of inheritance of the character. A new method was adopted in the estimation of dormancy. The period required for germination from flowering, determined by germination tests at periodic intervals, rendered a reliable estimate of inter and intravarietal variability for germination and formed the criterion for comparison of varieties and hybrids.ennullThesis