Y.L . Hor and Khuzaimah Bte Hj. Mohamed Noor
Pertanika Journal of Tropical Agricultural Science, Volume 9, Issue 1, April 1986
Keywords: Dormancy breaking; Oryza sativa
Published on:
Four local cultivars of padi, namely MR 71, MR 73, MR 77 and IR 42, have more than 80%0 dormant seeds when freshly harvested. After-ripening, especially in the air-conditioned room was effective in overcoming their dormancy and increasing germination to more than 80%o and 90%> after eight and sixteen weeks respectively. Heat and nitric acid treatments were less effective than after ripening. Except for MR 71 where dormancy was less severe, germination of only 78%0, 72%) and 69%) was obtained for MR 77, MR 73 and IR 42 respectively with the best heat or nitric acid treatments. Exposure to 45°C for four days was best. The effect of nitric acid varies between varieties. For MR 71 and MR 73, soaking for 6-12 hours in 0.3 M nitric acid was optimal. For MR 77 and IR 42, soaking in 0.5 M nitric acid for 3-6 hours and 12 hours respectively was best. The practical implications of the study are discussed.
ISSN 1511-3701
e-ISSN 2231-8542