AVG could be a valuable new tool, along with NAA, for preventing premature fruit drop in pears. Some questions for future research are:

  • Can the initiation of internal ethylene development in pear be predicted to better time applications? Ethylene curves have been developed for pear once harvested, but not for fruit on the tree.
  • What active ingredient concentration is needed for different cultivars, tree size, and crop loads? Large trees may require more material per tree to achieve desired results.
  • How do growing season and weather affect maturity and enhance or impede results?  Drop control in apples is better during cool versus warm years. Results in pear may differ in cool (premature ripening) versus warm years.
  • NAA costs about $45 versus about $265 per acre for AVG. One potential cost-saving strategy is to utilize lower rates of both NAA and AVG to control drop while allowing extended harvest. Data thus far in pears in California suggest that NAA alone generally controls drop better than AVG alone, and NAA plus AVG controls drop better than either alone. Can these materials be used synergistically to allow for a more orderly harvest of larger fruit using less labor, while improving fruit quality as well? More research is needed under varying conditions.
  • Could preharvest applications of Harvista (sprayable 1-methylcyclopropene) be used as a potential stop-drop?