Evaluation growth indices of two cultivars of Native and Corrected rice (Oryza sativa L.) in different irrigation Management

In order to determine the effect of different irrigation managements on rice growth indices, an experiment was done in factorial based on randomized complete block design in Rice Research Institute of Iran, Deputy of Mazandaran, Amol during 2011. Treatments were different irrigation managements including Alternate Wet and Drying (AWD), Semi-Dry Cultivation (SDC), combining Shallow water depth with Wetting and Drying (SWD) and Traditional Irrigation (TI) and two contrast cultivars of Tarom and Fajr as native and improved cultivars, respectively. Growth indices were fitted using measuring the dry weight and leaf area over seven sampling times during rice growing stages. The results showed that IT (with an average of 7694 kg) had the highest paddy yield followed by AWD (with an average of 7056 kg), SDC (with an average of 6856/8 kg) and SWD (with an average of 6358/7 kg). Leaf area index in Tarom cultivar varied from 2.99 in the combining Shallow water depth with wetting and drying to 4.6 in alternate wet and drying regimes. By contrast, LAI in Fajr cultivar ranged from 4.1 in the alternate wet and drying to 5.6 in traditional irrigation regimes. In conclusion, the maximum leaf area index, net assimilation rate in Tarom and Fajr cultivars to AWD and SDC irrigation managements could be introduced.