با استفاده از مدل عكس عملكرد )ECHINCHOLA CRUSS GALI )L.BEAUV.( و سوروف )LYCOPERISCUM ESCULEMEN TUML( بررسي رقابت بين گوجه فرنگي نشايي

Assessment of competition between Tomato(Lycopersicum esculentum) and Barnyard grass (Echinochloa cruss gall) by using reciprocal yield model

Barnyard grass is one of the most important noxious weeds in tomato fields, which makes a huge damage on tomato fruit yield. In order to study the competition effects by using reciprocal yield model between tomato and barnyard grass, an experiment was conducted at the research center of Varamin in the year of 2000. The experimental design was randomized complete block with 15 treatments and 3 replications. The competition design was bivariate factorial. The treatments included the pure stands of tomato at three-plant densities 2, 4 and 6 plant/m^2 and barnyard grass at 10, 60 and 110 plant/m^2 and mixed stands of two crops at complete factorial densities. Results showed that the tomato plant was a stronger competitor compared to barnyard grass. The biologic and economic yields of tomato were mainly affected by intraspecific competition, while the interspecific competition was mostly responsible for the variation of these characteristics in the barnyard grass. Evaluation of competitive ability by using regression coefficient showed that the effect of each tomato plant on its economic and biologic yields was equivalent to 29 and 31 plant of barnyard grass, respectively. In other words, each 0.034 and 0.032 plants of tomato had an equivalent effect of one barnyard grass on reciprocal biologic and economic yields of the tomato crop.