Safe periods for copper applications

With the ongoing wet weather, often humid conditions and with fast growing fruit to consider, growers are reminded to take care with the timing of copper applications for Psa control after the fruit set period.

Research has shown that due to the differences in “skin types” between varieties (i.e., morphology/skin structure) different varieties have different periods deemed “skin sensitive periods”. Previous work has identified the skin sensitive periods for Hayward and Gold3 outlined below. Application of copper products through these sensitive periods increases the chance of skin damage on fruit.

For Red19, research to date shows that Red19 is not highly susceptible to copper-induced skin damage in the 14 days immediately after fruit set or from 70 to 95 days, but there is a risk of skin marking from copper sprays applied between 21 and 46 days after fruit set. Research on the risk timings for Red19 continues.

Aureo Gold is available to growers through this higher risk period.

See year-round spray information on the KVH website here.