This is the third maturity update for Honeycrisp using the example regions. Starch conversion to sugars is underway at several regions and just beginning at others. There are comparisons with last week and historical comparisons for this same time over the past three years.
Important Note - The following information is for general industry purposes only. Growers are encouraged to use their own discretion to harvest trees that are exhibiting delayed colour development or exhibiting maturity indices that disagree with what is being reported here. Values were measured on an average of fruit that were representative of the block's crop load and tree vigour. Fruit representative of size and colour were taken from all sides but not from the interior of the canopy where maturity is expected to be delayed and is most likely targeted for a second pick timing.
Table 2: Maturity indices for regular Honeycrisp fruit sampled in the current year on Sept 8, 2025 in Rockland and Lakeville, and Sept 9, 2025 in North Medford. Values are compared with the samples taken one week ago on Sept 2 & 3, 2025.
Table 2 Discussion:
- Starch conversion to sugars is progressing in Rockland and Lakeville.
- Starch index values are currently below 5.0 so they are not yet within the range for harvest. The starch flavour is still present.
- My harvest maturity estimate for Lakeville is in 2 weeks' time around Sept 22 unless ReTain is indeed effective at slowing the rate of maturity. Stay tuned.
- A new site is being monitored in Rockland so my estimate is less certain but the current rate of change would suggest harvest maturity in 1.5 weeks' time around Sept 19.
- In North Medford, it is too early to give a harvest estimate because starch has only recently started to convert. The starch flavour is still very pronounced.
- The average DA value currently ranges from 0.83 to 1.21 depending on the site.
- The DA values are higher than what was recorded at this same time last year, suggesting fruit are less mature. Last year was a very early year. Unfamiliar weather conditions like the drought may affect the reliability of the DA value so rely on multiple maturity indicators.
- Even if DA values do not make sense for comparing years, the values should still be useful for comparing blocks to decide which to harvest first. The two North Medford samples suggest the usefulness of DA values for comparing blocks. The DA meter value is lower in the mature trees on CG30 where starch conversion has begun versus the 7 yr trees on M106 with no starch conversion and a higher DA value.
More observations (data not shown):
- There is less red colour development at this time than there was at this same time last year. However, colour is progressing in these cool temperatures and the change has been notable over the last week. Also, in Rockland and Lakeville the background green colour is changing from a less intense green to yellowish tones.
- Honeycrisp fruit on trees with deep root systems and limited drought stress weighed 209 g and measured 78 mm (3.07") in diameter. Fruit on young trees with drought stress weighed 145 g and measured 71 mm (2.8") in diameter. Fruit size will vary by crop load and soil moisture, but this information is shared for your general knowledge.
- Old trees or varieties grafted onto rootstocks with deep roots are producing the largest fruit sizes.
- Preharvest fruit drop has not been observed at the monitoring sites but it is recommended that the industry be on high alert and consider the use of ReTain or Harvista if there are early signs of drop.
- Some fruit are growing without seeds meaning they are parthenocarpic, and in those cases pollination was poor this past spring.
Table 3: Maturity indices for regular Honeycrisp fruit relative to the past 3-yr average (combined years 2022, 2023, and 2024) sampled on a similar calendar date. Rockland is not included because a new site is being monitored and there is no data for comparison.
Table 3 Discussion:
- Depending on the site, starch index is either slightly advanced or delayed compared to the 3-year average. Compared to last year, the starch index is relatively similar.
- Soluble solids values in our region for Honeycrisp tend to be 11% brix at harvest maturity but it depends on many factors including crop load. This year, without the diluting effect of water the soluble solids continue to be much higher than usual.
- The DA values are higher than average in North Medford, suggesting fruit are less mature than average.
About each maturity measurement:
Starch Index - Starch is converted to sugars as ripening progresses. The starch-iodine test is used because iodine binds to starch molecules turning them blue/black, whereas sugars are not stained and remain clear. The Cornell chart on a scale of 1 to 8 was used above and values are an average of ten representative samples from each block.
Soluble Solids - Approximates the percentage of sugar content of the fruit. Measured using a digital refractometer. Values are an average of ten representative samples from each block taken on the blush side of each fruit.
DA Meter - The delta absorbance (DA) value is related to the chlorophyll content of the peel. AAFC researchers in Kentville developed a protocol for Honeycrisp. Values above 0.60 are immature, values 0.6 to 0.36 are ideal for long term storage, and values below 0.35 are best for short term storage because they are more prone to storage disorders. Values shown above are the average of twenty fruit taken throughout a block, with readings taken on the transition area between the sun and shade exposed sides. DA values will be noticeably different between the most mature and least mature fruit on a tree.
Perennia Food and Agriculture Corp.
Edited by Michelle Cortens, Tree Fruit Specialist
Edited by Michelle Cortens, Tree Fruit Specialist
