The critical period of weed control in double-cropped soybean

ARSLAN M. , Üremiş İ., Uludağ A.

PHYTOPARASITICA, vol.34, no.2, pp.159-166, 2006 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 34 Issue: 2
  • Publication Date: 2006
  • Doi Number: 10.1007/bf02981316
  • Title of Journal : PHYTOPARASITICA
  • Page Numbers: pp.159-166


Double-cropped soybean after winter cereals is the most common soybean production system in the eastern Mediterranean region of Turkey. Weeds are among the main obstacles to double-cropped soybean. A study was conducted in 2002 and 2003 to determine the critical period of weed control (CPWC) for double-cropped soybean. The treatments consisted of either allowing weeds to infest the crop for increasing durations after sowing, or maintaining plots weed-free for increasing durations after sowing. The Gompertz and logistic equations were fitted to relative yields representing the critical weed-free period and the critical time of weed removal, respectively. Johnsongrass (Sorghum halepense), common cocklebur (Xanthium strumarium) and field bindweed (Convolvulus arvensis) were the dominant weeds. For 5% crop loss level, the CPWC was almost all season long, whereas it was from VI to R6-R7 growth stages for 10% yield loss level. These findings indicate that pre-sowing or pre-emergence control methods should be applied in the region to avoid greater crop losses.