Managing the weed seedbank

Weed control is essential in field vegetables but there has been a continual decline in the range of herbicides available. Growers aim to keep crops weed‐free throughout to maintain yield, but a short weed‐free period or even a single weeding can achieve the same result. In order to predict the optimum weeding period in advance, a realistic estimate is needed of the size, timing and duration of a flush of weed emergence in the crop. The weed seeds in the soil are the primary source of future weed populations, and this seedbank provides a unique resource for predictive management purposes. A preliminary model has been developed that combines information on the effect of burial depth of weed seeds on seedling emergence with a simulation of the incorporation and movement of seeds in soil following the use of different cultivation implements. The objective is to develop a suite of models which will provide a decision support system for weed control in field vegetables.