Weed control in rice seedling nurseries

Experiments were conducted in farmers' fields at Guimba, Nueva Ecija and at the International Rice Research Institute (IRRI), Los Baños, Laguna to test the efficacy of different methods of controlling weeds in rice (Oryza sativa L.) seedling nurseries. Hand weeding was laborious and ineffective due to the morphological similarities between rice and the Echinochloa species and the regeneration of perennial weeds. It was also injurious to rice seedlings. Manual separation of weed seedlings from rice seedlings before transplanting was ineffective, laborious, time consuming and expensive. Thiobencarb, butachlor, pretilachlor+fenclorim, propanil and quinclorac+bensulfuron were inexpensive and effective in controlling weeds in seedling nurseries without any deleterious effect on rice.