در شرايط گلخانه : اثرات تراكم گياهي TRITICUM AESTIVUM L. با سه رقم گندم AVENA FATUA L. رقابت يولاف وحشي

Competition of wild oat (Avena fatua L.) with three wheat (Triticum aestivum L.)cultivars in greenhouse: Plant Density Effect

A greenhouse experiment was conducted to examine wild oat competiton with three winter wheat cultivars. The experiment was performed as factorical in randomized complete block design using replacement series with 3 replications. Results showed that in all cultivars and in all mixture ratios, relative yield total (RYT) was 1, or approximately less than 1. This showed that wild oat and wheat compete for the same resources. Relative crowding coefficient (RCC) of Cross Azadi and Nik Nejad cultivars to wild oat and wild oat RCC to these cultivars were equal. This indicated that competitive ability of the two plants was similar. Wild oat was 0.7 times more aggressive than Darab 2, the most sensitive cultivar to wild oat density. Height and final leaf area of all wheat cultivars decreased as the number of wild oat plants per pot increased. The differences between final height of all cultivars in 1:3 (one wheat plant and 3 wild oat plants) and 2:2 ratios with 4:0 ratio (4 wheat plants) were statistically significant. Leaf area reduction in Cross Azadi, Nik Nejad and Darab2 was 5, 10.4 and 12 percent, respectively. There seemed to be a negative correlation between the number of plants for one species and dry weight of other species. In Darab 2 cultivar, the sum of the two speciesʹ dry weight showed more reduction as compared with other two cultivars. With an increase in density of one species, the number of wheat head and wild oat panicle decreased significantly. In addition, an increase in density of one species in mixture significantly reduced weight of 1000 kernels in other specie. There was a negative relationship between plant density of one species with grain yield of the other specie, and the sum of Darab 2 and wild at grain yield reduction was more than the other two cultivars. In density ratios of 1:3 and 2:2, there was no competition between wild oat and wheat for grain yield.