Fallow management input strategies for weed management in Florida cabbage production

Fallow period weed management is an important Florida production consideration due to its duration and impact on the cash crop. Cover cropping is a valuable summer fallow period option for weed suppression. Sorghum-sudangrass is a commonly used, competitive, and allelopathic Florida summer cover crop. The effect of increased seeding rate, a herbicide application, and added fertilizer inputs during the fallow period on the cover crop, weed populations, and cabbage yield was explored and compared to nontreated and chemical fallow controls.

Increased sorghum-sudangrass seeding rates had no effect on the resultant stand density or biomass compared to the standard seeding rate. Cover cropping did not consistently suppress purple nutsedge, Florida pusley, or wild radish and added fertilizer inputs produced variable results. S-metolachlor enhanced purple nutsedge suppression at low densities but did not improve grass, wild radish, and Florida pusley suppression.

Increased fallow management inputs did not consistently enhance weed suppression or provide benefit to the cash crop. Sorghum-sudangrass suppressed Poaceae densities during the fallow period but did not adequately suppress nutsedge, wild radish, or Florida pusley densities over time. We conclude that weed management inputs should be focused on the cash crop and that enhanced management during the fallow period has limited benefit. © 2021 Society of Chemical Industry.