بررسي تداخل گندم، گاودانه و يولاف وحشي در اجتماع دو گونه اي و سه گونه اي با استفاده از شاخص هاي رقابتي

Assessment of Interference of Wheat, Bitter vetch and Wild-Oat in Two and Three Combinations by Using Competition Indices

In order to assess interference of wheat, bitter vetch and wild oat intercroppings, a green house experiment was conducted at the Faculty of Agriculture of Islamic Azad University of Tabriz in 2006. Experimental design was a randomized complete block, with 3 replications. Treatments were: 1) monoculture of each one of these three species , 2) intercropping of one species without weed control, 3) intercropping of one species with a weed species, and 4) intercropping of all three species (wheat, bitter vetch and wild oat) as particle additive series with different densities. Results showed that RYT for wheat-wild oat was less than unity (1), showing that the two species competed with each other intercropping, having 8-10 wheat plant per pot, for the same environmental resources. Relative crowding coefficient of wheat in wheat-wild oat was greater than unity (1). Bitter vetch had lowest competitive ability in comparison with wheat and wild oat. Results also showed that aggressively index of wheat against bitter vetch-wild oat intercropping and wheat with different densities was positive, while in the case of two and three intercropping treatment combinations was negative. This indicates that aggressivety of wheat in higher plant densities was more than wild oat and bitter vetch. It can be concluded that all combinations of species in intercroppings, as compared with monocroppings, exhibited competition among each other.