The life cycles of weeds, diseases, and insects are studied to determine when they are most susceptible to control. Models of pest development in relation to temperature have been developed to assist growers in predicting pest outbreaks. Using these principles, pesticide applications have been significantly reduced in the past few years. Computer software has been developed to assist growers to apply these models and interpret the results. Because cranberries are low growing, weeds are a major pest problem.
Weeds compete with cranberries for water, nutrients and most importantly light.
Weedy beds are also difficult to harvest because weeds become tangled in harvesting equipment. Weeds can be controlled mechanically and chemically. Mechanical means of managing weeds include pulling weeds by hand or mowing off the tops of weeds to allow light to the cranberry vines. Once the vines completely cover the soil surface the vines will shade out many germinating weeds seeds, reducing the need for other weed management measures. Chemical weed management has become more widespread as herbicides have been labeled for cranberries.