Weed-suppression ability of Oryza longistaminata and Oryza sativa
Abstract
The effects of 5 accessions of Oryza Longistaminata and Oryza sativa [PI 312777, RD 23, O. longistaminata, O. rufipogon and F1 (O. longistaminata×RD23)] at different leaf stages was investigated on the growth of barnyardgrass [Echinochloa crus-galli (L) Beauv.]. The rice accessions suppressed the weed growth by allelopathic activity more than competition for growth resources. The PI312777, O. longistaminata and F1 (O. longistaminata ×RD23) at 2-leaf stage suppressed 63.6, 62.3 and 61.5% of banyardgrass growth, while their competitive effects were only 5.8, 9.3 and 7.2%, respectively. The competitive ability of rice to weeds increased with age of rice plant. Nevertheless, allelopathy of rice changed with the seedling growth stages. The allelopathic activity of wild rice (O. longistaminata) and its F1 was stronger at 2 leafstages and 6-leaf-stages than other growth phases, but the strongest allelopathic activity of PI312777 was at 2~4 leaf-stage.
Keywords
Allelopathy, competition, Oryza Longistaminata, weed management