Effect of Different Irrigation Levels on the Population of Barnyard grass (Echinocloa crus-galli L.) and Agronomical Traits Related to Paddy Yield of Two Rice Cultivars

An experiment was conducted at research farms of the Rice Research Institute of Iran (at Amol, Mazandaran province) to study the effect of different irrigation levels on the population of barnyardgrass (Echinocloa crus-galli (L.) Beauv.) and agronomical traits related to paddy yield of two rice cultivars (Tarom-Mahali and Shafagh). Treatments were arranged in split plot experiment based on randomized complete block design with three replications. Main-plots were two rice cultivars (Tarom-Mahali and Shafagh) and sub-plots were five levels, four levels of irrigation (0, 5, 8, 12 cm of water depth) and a weed control treatment. Results showed that cultivars and irrigation levels had significant effects on density and biomass of barnyard grass and also paddy and biological yield of rice. Generally, this highest seed yield was obtained in weed control using Shafagh cultivar (6344 kg.ha-1) and water level of 12 cm Shafagh cultivar (6074 kg.ha-1) while, the lowest seed yield was in the 5cm level of water Tarrom cultivar (3693 kg.ha-1). As a whote it could be concluded, water depth treatment of 12 cm Shafagh cultivar, were identified as the most appropriate treatment.