Abstract

To evaluate the competitive ability of two rice cultivars with rice barnyardgrass (ECPH), a pot experiment was carried out in a replacement series study. Treatments were arranged as a factorial with two cultivars (Hashemi, and Deylamani) and five rice: rice barnyardgrass mixture proportions (8:0, 6:2, 4:4, 2:6 and 0:8). The experiment was conducted as a randomized complete block design with three replications. Relative yield total of above ground dry weight, root dry weight and leaf area showed that rice cultivars and rice barnyardgrass were competing for the same resources. In general, replacement series curves and RCC values demonstrated that Deylamani was more competitive than rice barnyardgrass and rice barnyardgrass was more competitive than Hahsemi. This experiment confirmed that there are differences in weed competitiveness among rice cultivars.

Key words: Competitiveness, rice, rice barnyardgrass, relative yield total.

Abbreviation

ECPH, Rice barnyardgrass; RCC, relative crowding coefficient;RY, relative yield; RYT, relative yield total; CEC, cation exchange capacity; df, degree of freedom; LAI, leaf area index.