بررسي اثر گاوپنبه (Abutilon theophrasti) بر عملكرد و اجزاي عملكرد سويا (Glycine max) در تراكم هاي مختلف گياهي و تاريخ هاي مختلف كاشت

The competitive aspect of soybean ( Glysine max) and velvetleaf ( Abutilon theophrasti) in response to population density and planning date

In order to study different of velvetleaf ( Abutilon theophrasti Medicus) and simultaneous planting date of ( Glisine max (L.) Merril) and velvetleaf on yield and yield components of soybean, an experiment was conducted in 2004, at Ferdowsi University of Mashhad, College of Agriculture Experimental Station. The type of experiment was Completely Randomized Design in factorial arrangement with 3 replication in witch velvetleaf density ( 0, 2, 4, 8, plan/m2) and planting date of soybean and velvetleaf at 3 levels( April 23, May 13 and June 3) were used. Study of grain yield and yield components indicated that increase in velvetleaf density due to significant decrease in pod and grain number of soybean plant caused significant reduction of grain yield. Different planting dates had significant effect on yield and all yield components and delaying planting date, resulted in a significant reduction of yield components and yield. The interaction between density and planting date, was based on number of pod in plant and number of grain in soybean pod but it had no significant effects on grain number per plant, 1000 grain weight and grain yield of soybean.