Evaluation ofFusarium lateritiumas a Biological Herbicide for Controlling Velvetleaf (Abutilon theophrasti) and Prickly Sida (Sida spinosa)

In greenhouse studies, Fusarium lateritium Nees ex Fr. was effective in suppressing the growth of velvetleaf ( Abutilon theophrasti Medic. # ABUTH) and prickly sida ( Sida spinosa L. # SIDSP). Sprays containing conidia of the fungus and fungus-infested sodium alginate-kaolin clay granules controlled both weeds in corn ( Zea mays L.), cotton ( Gossypium hirsutum L.), and soybeans [ Glycine max (L.) Merr.] without causing a reduction in dry weight of the crops. In field tests, postemergence foliar applications of the fungus controlled velvetleaf and prickly sida 40 and 80%, respectively, in 1982, but controlled only 27 and 34% of velvetleaf and prickly sida, respectively, in 1983. Preemergence applications of the fungus in the granule formulation controlled velvetleaf and prickly sida 46 and 59%, respectively, in 1982. In 1983, this treatment controlled the weeds 35 and 38%, respectively.