ABSTRACT
Strawberry is a high value crop with a robust weed management system consisting of multiple tools that growers use to protect the crop from weeds. Preplant fumigants such as chloropicrin plus 1, 3-dichloropropene control part of the soil seedbank and reduce weed emergence during the cropping season. Herbicides like flumioxazin, napropamide and oxyfluorfen provide residual weed control during the production season. These herbicides are frequently co-applied with contact herbicides such as paraquat for row middle weed control in Florida where mechanical cultivation is not utilized. The role of physical weed control in strawberry is considerable including use of plastic mulches to block weed growth, mechanical cultivation in the furrows as practiced in California, and hand weeding. Organic producers do not utilize fumigants and rarely use organic compliant herbicides, but are dependent on crop rotations, dark colored plastic mulches to block weeds, mechanical cultivation in row middles and hand weeding. The majority of growers also utilize cover crops, tillage or herbicides during fallow periods which help reduce weed pressure during the cropping period.
There are several threats to the sustainability of the weed management system in strawberry including increasing resistance of the public to the use of soil fumigants, dependency of the cropping system on plastic mulches most of which is discarded in landfills, and dependency on labor for hand weeding as well as fruit harvest. Perennial weeds such as yellow and purple nutsedge are difficult to control with current available weed control tools following the loss of methyl bromide. Considerable research is in progress to reduce dependency on soil fumigants by breeding for increased levels of disease resistance and management of soil microbial communities to suppress soilborne pests. Evaluation of biodegradable mulches that protect strawberry from contact with the soil and from weeds is in progress. Labor shortages will continue to impact strawberry weed control programs by increasing dependence on crop rotations, herbicides and mulches to suppress weeds. Weed management in strawberry is in the midst of a significant transition. The loss of methyl bromide combined with increasingly stringent regulations on fumigant use has had a long-lasting impact on growers who continue to modify their production systems and look for economically viable weed management approaches.
