نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
To evaluate the competitive effects of lambsquarters (Chenopodium album L.) on phenology and grain yield of maize ( Zea mays ), cv. hybrid 604, an experiment was carried out at Kakaj, Tabriz, Iran in 2008 growing season. Factorial experiment was established in randomized complete block design with three replications. Treatments included combination of five lambsquarters densities (1, 4, 8, 12 and 16 plants m-1 of row) and four relative times of weed emergence (emerged with maize 10, 20 and 30 days after maize emergence) and a weed free control plot. Results revealed that 30 days delay in weed emergence, phyllochron in maize decreased by 1.5 days. Days to tassel emergence increased from 61 days in weed free plot to 66 and 67 days in 12 and 16 weeds per meter of row, respectively. Weed competition caused a significant loss in maize yield. Time of weed emergence was more effective on grain yield loss than weed density. Grain yield loss in maize at different weed emergence times were 64%, 38%, 15%, 8% and at different weed densities were zero, 23%, 35%, 46%, 53%, respectively. Two parameters model of Cousens et al., (1987) was of higher precision and efficiency in estimating of grain yield of maize.
کلیدواژهها [English]
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