Determination the most important yield related traits and competition with weeds in rice cultivars by path analysis

ABSTRACT: With respect to the soil pollution and current surface water contamination, human life being in serious danger, change of flora and increase on resistance of weeds, because of using herbicides, that makes us to study about to control of the weed without using chemical products. Using of rice cultivars is one of the low cost, and healthy factors for integrated weed management programming. In orther to recognize the relative characteristics with growth of weeds in four different rice cultivars, and two treatments of competition (weed exist or not) , an experiment was conducted in 2009 at research farm in College of Agriculture , Azad University of Qaemshahr.Analysis of variance was shown which there is a significant difference among cultivars about their properties. Besides the Fajr cultivar, had the largest yield and also had the highest competition index, correlation analysis showed seed number in panicle had the most relationship with yield. Path analysis proved numbers of seed per panicle and relative growth rate have the most direct effects on seed yield. The most indirect effect on yield were , rice biomass during the early tillering stage .Therefore in order to choose the best cultivar , selection the larger amount biomass, during the tillering phase, is suggested.