Response of Common Cocklebur (Xanthium strumarium) toAlternaria helianthi

Abstract

A common sunflower isolate ofAlternaria helianthicollected near Stoneville, MS, was pathogenic to cultivated sunflower and common cocklebur. Soybean, cotton, rice, grain sorghum, corn, wheat, and 22 other weed and crop species/varieties in nine botanical families showed no response or only minor symptoms. Therefore, further research is warranted to determine the potential ofA. helianthias a biocontrol agent against common cocklebur in geographic areas where sunflower is not a crop.