) AVENA FATUAL( در مقابل علف هرز يولاف وحشي )BRASSICA NAPUSL( بررسي قدرت رقابت شش رقم كلزا

Determination of competitive ability of six canola cultivars (Brassica napes) with wild oat (Avena fatua)

In order to study the competitiveness of six canola cultivars (three resistant and three susceptible canola cultivars to herbicide) against two wild oat populations (UM5 and Organic), an experiment was conducted under controlled environment conditions at Saskatoon Research Center during 2000. The competition pattern was replacement series at five canola: wild oat ratios (100:0, 75:25, 50:50, 25:75, 0:100) and two total high densities (20 p m-2) and low densities (12 p m-2). Results through analysis of replacement series and derivation of relative crowding coefficient, based on shoot dry weight and leaf area, indicated that both resistant and susceptible canola cultivars to herbicides were stronger competitors compared to wild oat. Results showed that resistant canola cultivars to herbicides at low density in both of wild oat populations had higher competitive ability compared to susceptible canola cultivars. Susceptible canola cultivars showed higher competitive ability compared to resistant canola cultivars at high density in both of wild oat populations. Comparison of resistant and susceptible canola cultivars indicated that the wild oat population of UM5 is strong competitor compared to wild oat population of Organic.