Tools to help manage apple harvest

Recommendations to assist spreading the harvest window in 2013.

This year, 2013, it may become difficult to harvest all varieties on time due to many reasons. Shortages of labor or condensed ripening of multiple varieties and strains, and variations in blocks and farms may delay timely harvest for some blocks. This is a list compiled by Michigan State University Extension of a few treatments that can help harvest management and the successful maximum capture of prime maturity fruit.

Three harvest management material choices

ReTain, NAA and Harvista are excellent maturity delay and stop drop materials. If the blocks are already treated with any of these materials, rest assured they will keep the fruit in prime condition and on the trees until harvest can be performed. The exception is if NAA is the only pre-harvest material you have on the fruit.

If the block is ripening and it appears harvest will be too late and no harvest materials have been applied, consider the following choices:

  1. NAA at 10 ppm will provide stop drop for up to 10 days. If harvest is delayed longer than 10 days, apply a second NAA treatment on day seven after the initial application. NAA will hasten ripening and drop after 10 days if no second spray is applied. NAA is good for a short window of stop drop control.
  2. ReTain at one-quarter rate plus NAA at 10 ppm is a better choice if harvest needs to be delayed more than 10 days. The ReTain will control the ethylene that the NAA promotes and a second treatment will not be necessary. ReTain has a seven-day pre-harvest interval (PHI). Gala, Jonagold and Honeycrisp only should get a one-quarter rate of ReTain. Other varieties could be treated with higher rates such as one-third to one-half rate ReTain which is the best for short to medium stop drop control and maturity delay.
  3. Harvista would also provide the same stop drop and maturity delay as ReTain plus NAA and is excellent for stop drop and maturity delay.

These late pre-harvest treatments will provide a reprieve from excessive loss of fruit due to the inability to harvest fruit on time. Use NAA for short-term fruit control and ReTain plus NAA, or Harvista for longer control.

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