Evaluation of allelopathic potential of rice landraces (Oryza sativa L.) on the growth of barnyardgrass (Echinochloa crus-galli P. Beauv) in different screening conditions

摘要

The objectives of this study were to evaluate allelopathic potential of the total 51 Vietnamese rice landraces ( Oryza sativa L.) collected from different ecosystems on the growth of barnyardgrass ( Echinochloa crus-galli ) in the different screening conditions. In laboratory screening, Nanh chon, Lua Tho, Nang Quat Bien, Ble Blau and Vang Thom landraces exhibited the greatest weed suppressing against the shoot length (SL) and root length (RL) of barnyardgrass by over 60%. In greenhouse, 5 landraces, Vang Quat Bien, Nanh Chon, Lua Tho, Bulu Pan dark, Huong Chiem and Nang Quat Vang revealed significant inhibition from 60.0% - 70.0% on SL of barnyardgrass. In field trial, 8 landraces demonstrated SL inhibition over 70.0%. The highest average inhibition (AI) was found in 3 rice landraces including Ble Blau do, Huong Chiem and Vang Quat Bien by over 50.0%. Rice allelopathic activity is landraces ─ dependent and varietal groups ─ dependent, of which the traditional none sticky group landraces (TNS) were the highest, followed by the improved varieties (IV), while the least was the traditional sticky landraces (TS). The correlation coefficient showed strikingly different allelopathic potential values in laboratory – greenhouse and laboratory ─ field and field ─ greenhouse screenings. The results have provided useful information to further develop allelopathic rice lines via breeding program for sustainable weed management in this country.