Recent reports indicate that vegetative growth and yield of C 3 crops are enhanced by foliar methanol application and that overall crop water use is reduced by methanol sprays. In order to evaluate the effects of methanol and barnyard grass density on rice (Oryza sativa cv. Shiroudi) yield and its components, a field experiment was conducted at the Rice Research Station of Tonekabon, Iran in 2012. The experiment was carried out as a randomized complete block design with a factorial arrangement in three replicates. Studied factors were aqueous methanol solutions (0, 6, 12, 18 and 24% (v/v)) and barnyard grass (Echinochloa crus-galli) densities (0, 16, 24 and 32 plants m -2 ). Methanol was sprayed on the foliage of rice three times during its growth period with two-week intervals. Results indicated that effect of methanol was significant for tiller number and grain yield (P < 0.05), while the effect of barnyard grass density was significant for grain and biological yields (P < 0.01). Moreover, the interaction between methanol and barnyard grass density was significant for grain yield (P < 0.05) and 1000-grain weight (P < 0.01). The greatest mean values for grain yield and 1000-grain weights obtained at 18% (v/v) with weed-free condition, with 7440.8 kg ha -1 and 28.07 g, respectively. Under weed-free conditions grain yield increased as methanol dose increased from 0 to 18% (v/v) and then reduced significantly. At the highest weed density, grain yield decreased significantly as the methanol dose increased. It appears that foliar sprays of aqueous methanol may be recommended for rice under weed-free conditions.Key words: rice, barnyard grass, grain yield, methanol, weed density. de 0, 6, 12, 18 y 24% (v/v)
RESUMEN
El crecimiento vegetativo y la producción de cultivos C3 se estimulan por la aplicación foliar de metanol y mejoran la eficiencia del uso total de agua. El objetivo de este trabajo fue evaluar el efecto de la aplicación foliar con metanol y la densidad de las pasto dentado en el rendimiento de arroz (Oryza sativa cv. Shiroudi). El experimento se realizó en la Estación Experimental del Arroz de Tonekabon, Irán en 2012. El diseño experimental fue de bloques completos al azar con un arreglo factorial 5X4, con tres repeticiones. Los factores estudiados fueron soluciones acuosas de metanol en concentraciones