It took disking every two weeks for two years to eliminate nutsedges in a scientific study. It is recommended that this process be repeated at least one more time for adequate control and more times for fields with high weed populations. Cultivation and hoeing are acceptable methods of weed control and in several vegetable crops, the only in-season method of weed control. A study with watermelon has shown that hoeing twice at the proper timing is as effective as using PRE and POST herbicides. Care must be taken not to cultivate too deeply in many crops where the roots are shallow.
Deep cultivation can prune the crops roots and reduce yield.
In most cases, early season weed control is most important. In studies with watermelon and tomatoes, pigweeds must be controlled during the first four weeks of the crops growth. Sedges and grasses should be controlled from 3-6 weeks during the crops growth to eliminate yield loss. When done properly, it does not matter whether the control method is chemical or mechanical. Cultural control methods include mulching, crop rotation, cover cropping, flooding and other.