We were fortunate to dodge a bullet in the form of Hurricane Ian. Before the storm track began to take a more definite shape, growers turned off irrigation in their orchards, whcih was the right thing to do. But, it has been and continues to be extremely dry. The forecast looks pretty much the same for at least the next week. Even though the kernels have filled and the crop is about made, it is vitally important with the crop load on most trees out there to continue running irrigation until you are 5-7 days away from shaking the tree in order to ensure normal shuck split and avoid problems.
I have seen some shuck decline already in a few orchards. Though our temperatures are expected to be no higher than the mid-high 80’s over the next week, conditions are dry enough to lead to delays in shuck split and shuck decline with no irrigation. Shuck decline results from tree stress primarily related to overloaded trees and dry soil conditions after kernel filling is complete. Fungal organisms that cause anthracnose jump onto these nuts after the damage is done.
If soils remain dry and we get some humidity, with temperatures warming up into the 90’s we could also begin to see some sprouting and embryo rot. By continuing to irrigate you promote shuck split and minimize this problem if conditions do arrive. Adequate water is required for the shuck dehiscence process to take place properly. Continue irrigating at 50-60% of full capacity until you are a week or so away form shaking trees for harvest.