of Planting Date and Bentazon Application Effect on Control of Weeds and Soybean (Glycine max L.) Yield

In this research the effect of planting date and Bentazon application on control of weeds, and soybean yield was investigated.

Methods and Materials:

 Experiment conducted as split plot in a randomized complete block design with 4 replicates. Mainfactor included five planting dates (20 April, 4 May, 18 May, 2 June and 16 June) and subfactor was herbicide application including without and with bentazone application.

Delay in planting date and herbicide application, wild melon, and black nightshade control increased both at 10 and 30 days after spraying. The late planting date reduced soybean economic (29.2%) and biological yield (41.1%). Delay in planting date reduced the biomass of wild melon (99%) and black nightshade (61%) and other weeds (82%). Herbicide application decreased the biomass of wild melon (51%) and black nightshade (92%) and other weeds (71%). Soybean yield in early planting date was higher (71%) than late planting date. In the late planting date, density of wild melon and black nightshade was lower than early planting date. Delay in planting date accelerated flowering, and reduced ripening period, seed production, and yield.

The early planting date of soybean along with the application of bentazone reduces weed growth, crop damage and increases soybean yield that can be recommended to farmers.