Just a few months ago, the United States Department of Agriculture predicted Oklahoma pecan production would be around 20 million pounds, and Texas production would be around 36 million pounds. This prediction indicated an above average crop for Oklahoma and a below-average crop for Texas. Prices were forecast to be high, which was very good news for pecan producers. However, by the time the final counts are in, it appears we may fall below these predictions.
Early crop set in Oklahoma looked good, while crop set in Texas started on a bad note. First-generation pecan casebearer was later than computer models predicted. Therefore, scouting for this pest was critical in controlling it. Producers who actively scouted and sprayed at the appropriate time easily controlled not only first generation pests, but also the second generation when they used chemicals with a long-acting residual. With the lack of rain, scab was not a problem this year, even on varieties that are very susceptible to the disease. At the same time, the lack of rain caused severe physiological problems with the pecan crop. Water is required for pecan sizing, which occurs during the early summer. Without water, this year's pecans did not size normally. In most areas without irrigation, pecans were one-third to one-half normal size. Even with irrigation, this was a problem in some locations because producers could not make up the water deficit. However, this was not all bad news. With the lack of water during pecan fill in late summer (August), the smaller-sized pecans were able to fill, resulting in higher-quality pecans.
In some locations, the lack of rain affected crop retention, as well as leaf retention on the tree. It is extremely important for the trees to retain leaves as long as possible. As the soil moisture decreased, the trees started to struggle to find enough water to fulfill their daily requirements. Most other plants start to wilt when they are stressed, however, pecans do not. Therefore, when we finally notice the signs of the tree stressing, it may be too late. Some trees aborted their crops some lightly, while others lost the entire crop. Some trees even dropped their leaves, their last effort in an attempt to survive the drought.
The final straw was the damage caused by pecan weevil. Weevils usually emerge after a good rainfall. After the few rains came, it was time for the weevil explosion. Producers who trapped and scouted were able to make spray applications when weevils were out and not just after the rains, resulting in optimal control. Producers who did not trap and scout may have missed the late emergence. This late emergence is the one that most likely caused the most damage to the 2006 crop.
Many lessons can be learned from 2006. The first is the importance of water. The second is the importance of trapping and scouting for pests in the orchards. If producers used only computer models or the calendar to determine when to spray for pecan casebearer, then they sprayed too early. If producers sprayed for weevil only after rainfalls, they may have missed the explosion of mid and late emergence that has caused the most damage this year.
Contact The Noble Research Institute at (580) 224-6500 for more information about trapping and scouting for pests in pecan orchards.
