Champlain Valley Harvest Maturity Program Report: Week 4
Mike Basedow and Jenn Stanton, CCE-ENYCHP, Northern NY
This week we are reporting on Gala, McIntosh, and Honeycrisp. The Retain treated Gala block still has at least another week to go. Some early maturing McIntosh and Honeycrisp blocks are likely going to be ready for spot picking this week for long term storage.
This week’s samples were collected Tuesday September 3rd and processed the same day. Fruit were picked from orchards in Peru.
Sample size is 10 fruit picked for average maturity, from multiple trees, on both sides of the row for the McIntosh. Honeycrisp and Gala were “spot-picked” for the most red fruit.
As blocks receive harvest management PGR’s we will update their treatment in the final data column so you can better compare against your blocks.
Due to the large amount of variability associated with strains, rootstock selections, planting systems, the widespread use of ReTain, Harvista, ethephon, and local orchard microclimates, it is impossible to sample and process enough locations to make specific harvest recommendations. ENYCHP HMP data is meant to be used as a general indicator of apple harvest maturity, and nothing more.
When I have them, I’ll also include data from previous years to serve as a comparison.
Weekly Summary of Fruit Maturity Progress
Gala for 9/3/2024
Comments: Color is fairly good this week in the fruit sampled. Fruit are still on the small side. Background color is starting to change from more green to a cream. DA is still well above 0.4. Flavor is still minimal, SPI and brix are low, and fruit are still very firm. I think we’ve still got time in this block.
For Gala, firmness is not a major issue, and the starch pattern is an unreliable indicator of maturity. It is not uncommon to have a range of 1-7 or 2-8 in SPI’s from one 10 apple sample from a block, in which all the fruit (externally) look to be of nearly the same maturity. However, you want to target an average SPI of 3-4 for longer-term CA fruit and 5-6 for short-term RA fruit. Target a brix above 12%, and varietal flavor development. For long term CA stored fruit, you do not need to wait for background color change from light green to cream. Fruit with a bright yellow background are over-mature and should not be stored long-term, instead market these fruit immediately. DA for long term storage is generally above 0.4. We will continue testing this block again next week.
McIntosh for 9/3/2024
Comments: Starch in both of these blocks is still below the recommended 5-6 for CA storage. However, color is looking good, and firmness is now below 16 pounds in the Ruby Macs. Fruit still tasted somewhat starchy when sampled today. I think the Ruby Macs might be ready for a pick near the end of the week, and the Roger Macs probably starting next week.
For long-term storage with Macs, you are targeting a firmness of >15 lbs, and an SPI of 5-6. Note that starch conversion can be variable. We will continue testing these blocks next week.
Honeycrisp for 9/3/2024
Comments: I looked at two Honeycrisp blocks this week. Block 1 fruit are starting to pick up creaminess to the background color, and SPI is now in the 5-6 range in the fruit that we spot picked this week. Brix is still low, but I think we may have somewhat lower values this season with all the moisture we had this season. Fruit still have very good firmness, but dropped quite a bit from fruit sampled last week. I believe this block is ready for spot picking, and it has in fact had a light spot picking earlier in the week already. This helps to explain the drop in color in our sample this week.
Block 2 is generally later to mature, and this continues to be the case this season. Fruit are a little bit firmer, and the starch pattern and DA meter readings suggest fruit are less advanced. Fruit in this block did not yet have much flavor development compared to block 1. I think this block will likely be ready for a spot pick sometime next week for fruit heading to CA storage.
Block 1 fruit (top) are further along in SPI than Block 2 (bottom).
To determine harvest readiness for spot picking, look for color that “jumps out” when the yellow background color makes the red almost florescent or iridescent. Ideal is the ground color turning to cream with 80% bright red cheek. SPI is not relevant, but generally they’re over 7 in most fruit that are ready to pick. Target 5-6 for fruit destined for CA. A firmness greater than 14 pounds and a brix above 13% are desirable. Stem clipping is tedious, but will reduce the incidence of stem punctures in this high-value apple. Once color change has happened, then an every other day walk-through is warranted to determine readiness. We will continue testing these blocks next week.
We will continue testing the Gala, Mac, and Honeycrisp blocks next week.