A critical period of lowland rice to weed competition

Abstract

There was no significant difference between duration of weeds-free 12, 4, 6 and 8 weeks after-planting, and the whole-life) period of lowland rice on its vegetative growth, but there was a significant difference on the number of productive tillers and grains per panicle. The critical period of a lowland rice var. I R 28 to the weed competition was found at the first 8 weeks after planting.