Strawberry crop termination, weed control and Macrophomina phaseolina inoculum control with metam potassium at season end

Abstract

Metam potassium (metam-K) is one of the commonly used soil fumigants in Florida strawberry production. It is typically injected into the drip irrigation system at the end of the season for control of weeds, nematodes, soil-borne pathogens and to terminate the crops. Field trials were conducted to determine the optimal application rate of metam-K for adequate strawberry crop termination, weed control and control of Macrophomina phaseolina inoculum. Our results indicate that 65 kg active ingredient per treated hectare killed strawberry plants, actively growing purple nutsedge and Carolina geranium, tubers (yellow nutsedge) and seeds of Carolina geranium, black medic, goosegrass, and Florida pusley, as well as controlled M. phaseolina inoculum at bed center. Control of pests located at the bed edge is better at maximum registered label rate (~400 kg ha ha−1) which indicates improved lateral movement of metam-K at higher application rates. Seeds of goosegrass and Florida pusley were more susceptible to metam-K than black medic and Carolina geranium. This may be attributed to the difference in their seed coat thickness. This research confirms that metam-K can be used at season end for crop termination and the optimal application rate varies with pests and their location within the raised bed. Crop termination with metam-K could be an integral part of an integrated pest management.