The pecan harvest season is underway and so far, the Pawnee harvest has been light . Even where trees appeared to have a good crop load, the wagons are weighing light with a fair amount of stick-tights and pops blowing out at the cleaning plants. This has been a common occurrence throughout much of Georgia. The most likely culprit for this is the extended cloudy, rainy conditions we had throughout much of the growing season, followed by severe drought. While size has been off or variable in some orchards, quality of the Pawnee nuts in terms of color and percent kernel have largely been excellent for those nuts that have made it through the cleaning process.
As some growers have moved into the next varieties ready for harvest—Creek, Caddo, Oconee—there have been reports of lighter than expected loads in terms of volume based on the number of dumps and wagons coming out of the orchard.
The greatest concern at this point is the ongoing hot, dry conditions throughout much of the state. Once kernel filling is completed the water use of the tree declines but the trees still need water to complete the nut maturity and shuck split process. Since mid-August, the rains have been few and far between. We had a lot of rainfall all summer to that point so the trees have grown accustomed to plenty of soil moisture–even outside the irrigated zone. When the rain turned off in August and stayed off, it was a shock to the trees’ system because now only a portion of that root zone is getting water. This has led to some premature leaf drop and even some shuck decline in a number of orchards. This type of stress has also triggered the expression of secondary foliar diseases like anthracnose and Neofusicoccum, which led to further leaf drop. Temperatures are also still warm. These are the conditions in which we can see stick tights, sprouting, and embryo rot develop. Therefore, growers should be sure to continue irrigation in their orchards until they are 5-7 days away from shaking. 7-8 hours every other day should be enough to stimulate shuck split and minimize these problems but do not turn the water off too early. It is critically important under these conditions.
Hot, dry conditions this time of year can cause under-irrigated trees, or those that have fallen too far behind, to stress, especially under a heavy crop load, until the shuck split process has been completed. Such stress causes the nuts to be stimulated by conditions that mimic those needed for germination as moisture is conserved inside the shuck. This combined with the high temperatures can lead to premature germination. So, again–keep the water going until you are a week or so away from shaking.
