Mohamad Jahanbakhshi, Saeed Saeedipour
Identification and Weeds Control Department of Agronomy, Shoushtar Branch, Islamic Azad University, Shoushtar, Iran
Key words: French bean, Critical period, Control, Interference, Weeds.
An experiment was conducted in 2009-2010 to determine the critical period of weeds control in snap bean in climate conditions of Iran. The experimental design was a completely randomized block with 16 treatments and 3 replications. Treatments were divided into two groups based on 12 days periods. First group consisted of treatments of weeds competition with interested plant from the emergence of snap bean to 12, 24, 36, 48, 60, 72 and 84 days after emergence along with control treatment. Second group consisted of weeds free treatments in above stages. The results showed that with the increase of the length of weeds competition periods the performance of green pod decreased significantly so that the highest performance was seen in throughout season control treatment by 1990.38 gm-2.The lowest performance was seen in throughout season interference control treatment by 334.27 gm-2. On the other hand, wide leaf weeds had more effects on snap bean than narrow leaf weeds. Finally, with acceptance of 5 and 10 percent yield reduction, a period of 61 days from 10 to 71 days after emergence (2-6 leaf stage up to 50% pod production) and a period of 51 days from 13 to 63 days after emergence (6-10 leaf stage up to 50% flowering) of French bean were determined as critical periods of weeds control.