Walnut Orchard Management Considerations for September

  • Keep an eye on your irrigation! Cutting it short on water during hull split can lead to hull tights and darkened kernels. Profit margins are likely to be tight this year, so don’t sacrifice nut quality and value.
  • You should be finished applying nitrogen by about now; walnuts don’t uptake much N during the fall. Adding N late in the season is like dumping your money into the groundwater supply.
  • Using ethephon can advance harvest. Earlier harvest helps maintain kernel color, and reduce navel orangeworm or mold damage. Sample frequently for 100% packing tissue brown (PTB) to time the ethephon application properly.
  • Collect harvest samples so that navel orangeworm or codling moth damage can be distinguished. Use a similar sampling protocol as described here for almonds to collect walnut harvest samples.
  • Prune blighted branches and deadwood immediately after harvest (or earlier) to remove possible Botryosphaeria (Bot)/Phomopsis or branch wilt infected wood. It is easiest to tell dead, diseased from healthy wood when there are still leaves on the tree, rather than during dormant season. Additionally, pruning while the forecast is dry will help avoid infection of fresh pruning wounds.


Leave a Reply

Your email address will not be published. Required fields are marked *