sediqe latifi; alireza yousefi; khalil jamshidi
Abstract
In order to evaluate the effects of crop cultivars and living mulchon sunflower yield and weed control, a field experiment was carried out as factorial arrangement based on a randomized complete block design with three replications in 2013. Treatements were sunflower cultivars (‘Azargol’, ...
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In order to evaluate the effects of crop cultivars and living mulchon sunflower yield and weed control, a field experiment was carried out as factorial arrangement based on a randomized complete block design with three replications in 2013. Treatements were sunflower cultivars (‘Azargol’, ‘Allstar’, ‘Farokh’) and weed control treatments (weed-free, weed-infestation and intercropping of Fagopyrum esculentum, Medicago scutellata, Vicia villosa as living mulch alone and in combination with one hand-weeding).In comparison to weedy treatement, F. esculentum, M. scutellataand V.villosa cover crops were reduced total weed biomass 43.7, 33.8 and 25 percent, and weed density 57.1, 38.1 and 29, respectively. Weed control was improved significantly when cover crops used in combination with one hand-weeding. The lowest weed biomass and density were recorded in the ‘Azargol’ cultivar. The highest Sunflower leaf area index (LAI) was obtained in ‘Azargol’ cultivar under weed-free condition. Weed interference decreased grain yield of ‘Azargol’, ‘Allstar’ and ‘Farokh’ by 18.6, 22.1 and 33.4 percent, respectively compared to weed-free plots. The highest grain yield was obtained in ‘Azargol’ cultivar. Medicago scutellataas cover crop in combination with one hand weeding resulted in yields similar to the weed-free treatment. Overall, the results of this study revealed that the use of M. scutellataas living mulch and ‘Azargol’ as competitor cultivar can be used as part of an integrated weed management for sustainable sunflower production.
mojtaba khazaie; mohammad hassan hadizadeh; ehsan zaidali
Abstract
In order to determine the critical period of weed control (CPWC) in Corn (Zea mays L.), an experiment was carried out in a randomized complete blocks design with 14 treatments and three replications during 2013 growing season in the Nahavand climatic conditions. Two series of the treatments including ...
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In order to determine the critical period of weed control (CPWC) in Corn (Zea mays L.), an experiment was carried out in a randomized complete blocks design with 14 treatments and three replications during 2013 growing season in the Nahavand climatic conditions. Two series of the treatments including weed-free and weed-infested were applied in the regular time distances of 10, 20, 30, 40, 50 and 60 days after Corn emergence. Two check treatments including full and no control of weed during the whole season were also included. The nonlinear models kind of Logistic and Gompertz were applied to determine the start and end of critical period of weed control respectively. Major weed species were field bindweed (Convolvulus arvensis L.), red root pigweed(Amaranthus retroflexus L.), pigweed(Amaranthus blitoides L.) and lambsquarters(Chenopodium album L.) with greater biomass and size. The results showed that periods of weed- free and weed- infested differently affected the dry weight and number of weeds in all treatments. The critical periods of weed control in Corn by accepting a 5% acceptable yield loss, it is necessary to control weeds in a period between 14-47 days after planting or 117- 566 growth degree day(4-12 leaf stage) and by accepting a 10% acceptable yield loss it is necessary to control weeds in a period between 23-36 days after planting or 220- 419 growth degree day(6-10 leaf stage).