Generally, this is at cultivation time. Avoid planting time applications before mid-May. Do not reduce the rate and don't split it, i.e. half at planting and half at cultivation. The application should be according to label instructions, either directed at the base of the plants or over the row. Incorporate with I to 2 inches of soil in either case.
Some moisture is needed for chemical activation.
If excessive moisture conditions persist, aerial application is an alternative. However, when incorporation is not possible, control effectiveness may be decreased. Applications after mid-June become progressively less effective because damage by the growing larvae increases. If insecticide is applied at planting time, apply the granules as a band about 7 inches wide directly over the row or in the seed furrow, depending upon grower preference and insecticide label restrictions. Some chemicals may cause reduced stands if they come in direct contact with the seed.