Evaluation of rice cultivars in weeds control different periods under non-stress and stress conditions

Abstract

In order to evolution the effect of different periods of weed control on yield and agronomic characteristics and determine the drought tolerant variety under two separate conditions, flooding and drought, two experiment were conducted as a spilt-plot based on Randomized Completed Blocked Design with three replications at the Research Farm of Gonbad Kavus University, during spring 2010. The different levels of weed control were as the main plot treatment and the rice cultivars Shiroudi, Domsiah (native cultivar), IR70358-84-1-1, IR70358-84-1-2, WAB56-125, IR83752-B-B-12-3 and KORAL were as the sub plots. Results showed that differences among flooding and drought conditions, different levels of weed control and cultivars both flooding and drought conditions had significant effect. Grain yield in drought condition rate to flooding condition decreased 49.42%. Both flooding and drought conditions with weed control to tillering maximum stage compared to other control conditions, for all of traits the most profitable. Shiroudi cultivar perspective grain yield, harvest index, filled grain number and the number of fertile tillers was highest rate. At both flooding and drought conditions, Shiroudi (weed control to tillering maximum stage, weed control of tillering maximum to maturity and un-weeded) was the most profitable. Shiroudi cultivar can as the tolerant variety recommended and with weed control to maximum tillering stage. In this cultivar, the maximum amount of characters can be achieved.