Evaluating some Herbicides and Mechanical Control for Swallow-wort Management (Cynanchum acutum) in Yazd

Swallow-wort (Cynanchum acutum) is a problematic weed which has recently infested many agricultural fields in Iran especially orchards. Therefore، a three-year experiment was conducted in a randomized complete blocks design with 3 replications in a pistachio orchard in Yazd. Treatments included post-emergence herbicides glyphosate (Roundup 41% SL) at 2، 4، and 6 L/ha+ammonium sulphate (8 kg/ha)، paraquqt (Gramaxon 20% SL) at 3 L/ha، garlon (Triclopyr 62% EC) at 2 L/ha، cutting of swallowort، and weed infested control. Results of the first year showed that the best treatment for the control of swallowort was 3 times spraying with glyphosate 6 L/ha. In the second year، the best treatment for the control of swallowort was 3 times spraying with glyphosate 6 L/ha or 3 times spraying with Triclopyr 2 L/ha. Based on the results of the third year، the best treatments for the control of swallowort were 3 times spraying with glyphosate 6 L/ha، 2 and 3 times spraying with triclopyr 2 L/ha or 2 times cutting + triclopyr 2 L/ha. Therefore، it seemed that the systemic herbicides glyphosate and triclopyr had more efficiency in the control of swallow wort، compared to the contact herbicide paraquat.