Control methods of alfalfa witches’ broom phytoplasma disease

Alfalfa witches’ broom (AWB) is the most important alfalfa disease in Iran. The infected plants appear severely stunted, erect and excessively branched and yellowish. Different methods of AWB disease control were studied in a randomized complete blocks design at three replications in Ardakan (Yazd province, Iran). The methods were dense planting of alfalfa, use of sorghum as windbreak and spraying with metasystox-R. The results indicated that sorghum and metasystox-R had no significant effect on disease control. Only dense planting of alfalfa in the field using twice the usual seed quantity significantly reduced the disease incidence by 16% compared the control that resulted at the 5% probability level. According to this findings, dense planting of alfalfa stands is recommended for the prevention of AWB disease in alfalfa farms.