This is the fourth maturity update for Honeycrisp using the example regions. Early blocks are becoming ready for a light first pick this week according to monitoring and industry discussion. Colour has progressed notably well over the past week. Please note that the DA meter is misaligned with maturity indices this year and is giving variable results, therefore our preference is for relying on starch and flavour as maturity indicators. The orchard outlook committee met this morning for discussion.
Weather
Degree Day Accumulations
Total degree day accumulations are similar to the 5-year average and slightly warmer than the 10-year average (Figure 1). Harvest dates are difficult to predict based on degree day accumulations alone. However, it's likely that harvest will be on the early side and should be monitored closely.
Figure 1: Heating degree day accumulations for plant (above 5°C) and insect (above 10°C) development from March 1 to September 15 for the past 17 seasons. Provided by Jeff Franklin (AAFC).
- Approximately the same plant development heat units compared to the 5-year average, and 4% more compared to the 10-year average.
- Approximately 1% less plant development heat units compared to 2024, and 2% more compared with 2023.
- Approximately 2% less insect development heat units compared to the 5-year average, and 2% more compared to the 10-year average.
Honeycrisp Fruit Maturity Report
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 1: Maturity indices for regular Honeycrisp fruit sampled in the current year on Sept 15, 2025. Values are compared with the samples taken one week ago on Sept 8 & 9, 2025.
Table 1 Discussion:
- Please note that the DA meter is misaligned with maturity indices this year and is giving variable results, therefore our preference is for relying on starch and flavour as maturity indicators. The DA meter was developed as a tool based on the relationship between chlorophyll degradation and the rate of change of maturity indices and in some years the relationship may not align.
- 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.
- Starch conversion to sugars is underway in all regions being monitored. Over the past week, the rate of change stayed constant in Rockland where maturity was ahead, and sped up in Lakeville and North Medford.
- The Rockland site has entered the harvest window with a starch index value greater than 5.0 and the fruit taste ready. Do not be misled by the DA value.
- Early blocks are becoming ready for a light first pick this week according to monitoring and industry discussion.
- First pick Honeycrisp beginning this week is considered on the early side compared to even last year. But if it's ready, start getting it off in case maturity speeds up due to tree stress.
- Samples in Lakeville and North Medford indicate starch values currently below 5.0 so they are not yet within the range for harvest. However, maturity should be monitored closely.
- My harvest maturity estimate for the Lakeville site remains around Sept 22. Starch flavour is noticeably less than last week.
- My harvest maturity estimate for the North Medford blocks is Sept 26 to 29. Starch flavour is present.
- Local research by John Delong et al. 2013 showed that optimal values of the starch index for long-term storage for Honeycrisp are between 5.0 and 7.5. When harvested earlier than this, the fruit are at greater risk of developing bitter pit in storage.
More observations (data not shown):
- Dr. Harrison Wright confirms that production of the ethylene ripening hormone is well underway, driving forward starch conversion, loss of acidity, and red colour development.
- Honeycrisp fruit on trees with deep root systems and limited drought stress weighed 202 g and measured 78 mm (3.07") in diameter. Fruit on young trees with drought stress weighed 167 g and measured 73 mm (2.87") in diameter. Severely drought affected trees have non-marketable fruit weighing 84-95 g and measuring 55-62 mm (2.2"-2.4") in diameter. Fruit size will vary by crop load and soil moisture, but this information is shared for your general knowledge.
- 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.
Table 2: Maturity indices for regular Honeycrisp fruit sampled on Sept 15 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 2 Discussion:
- Depending on the site, starch index is either slightly advanced or delayed compared to the 3-year average. However, last year's harvest dates should give some guidance.
- 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 quite variable but may hint at maturity differences between blocks.
- The mass and diameter data show a significant impact of the drought on fruit from young trees and less so on mature trees.
Comments on colour progression:
- Red blush colour progressed well over the past week with more colour coverage and deeper red intensity (Figure 2). In the examples, red colour is averaging around 40-60% in the outer canopy that would be targeted for a first pick, which is a 20-30% increase from last week.
- The change corresponds with more frequent cool (<10°C) nighttime temperatures.
- The forecast for later this week looks conducive to good colour development.
- There is about 10-20% less red colour development at this time than there was at this same time last year.
- At all sites, the background colour has changed to a less intense green (Figure 3). Cream coloured background colour is becoming visible and signals approaching harvest maturity.
Figure 2: Progression of red blush colour change over time in 2025. Samples from each region are included from top to bottom over four sample dates. The last week has contributed a notable amount of red blush.
Figure 3: Progression of ground colour change over time in 2025. Samples from each region are included from top to bottom over four sample dates. The last week has revealed less intense green and more fruit with a creamy tone indicative of maturity.
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
