We are seeing nut drop right now from various things. The Pawnee drop was much heavier than normal ranging from about 30%-70% as you move southward in the state. This correlates well with chill hours (Byron, GA —574 chill hrs; Valdosta, GA—264 chill hours), which is strong evidence for this being the result of self-pollination brought about by the warm winter and sporadic budbreak we saw this year as I discussed in the last post. This brings concern that we will see more pollination -related problems on Pawnee and potentially other varieties as the season progresses. Research from the late 1980’s showed conclusively that in addition to nut drop, self pollination results in 17% less nut wt and 11% smaller volume.
Shuckworm and curculio drop are also taking place right now. See previous posts on identification of these pests. Use a targeted material like Intrepid or Dimilin for shuckworm. Chlorpyrifos applications right now will flare aphids and mites and lead to further sprays for these pests as well. If you have curculio I would look very closely at the crop size and the amount of drop before pulling the trigger on these. If you have a good crop, you can take a little drop from curculio and allow them to thin it for you. The lighter crop you have the more you must consider spraying. The issue is that you will have to spray a pyrethroid to get curculio and this will cause you problems with aphids and mites the rest of the season, which will get expensive , so be sure you have a serious enough problem with curculio before pulling the trigger on them.
Symptoms of nut damage by hickory shuckworm (top 2 nuts) and nut curculio (bottom nut)
Its also time (July 7-Aug 7) to collect leaf samples. See previous post here on this process.
The frequent rains are driving scab pressure right now. We still look pretty good in the state at this point but don’t let up on scab sprays. We are at the peak of susceptibility so Elast needs to be one of the main components in your program right now. Use with tin at 1/2 rate of each. If you are concerned about resistance issues with Tin in your orchard, use the full rate (50 oz) of Elast alone. Do not apply surfactant with Elast. Rotate in one of the dmi/strobi materials like Absolute with a surfactant or use Quadris Top alone occasionally and then go back to Elast or Elast/Tin.