Revised 6:25 PM Sept 22: In Figure 1 the photo on the left is in fact Rockland fruit, not Lakeville fruit.
Hello folks, I hope harvest is off to a good start! At the last minute this year I've decided to provide you with a weekly update on Honeycrisp fruit maturity at four different regions throughout the Valley. It will be a test run to see if the information is worthwhile. Enjoy!
Honeycrisp Maturity Report - September 22
Important Note - This 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 (ie. not representative of a first pick prioritizing the most mature fruit).
About each 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 five 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 five representative samples from each block.
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 both the red and green sides.
Update on 2021 Degree Day Accumulations
Figure 2: Heating degree day accumulations for plant (above 5°C) and insect (above 10°C) development from March 1st to Sept 19th for the past 17 seasons. Provided by Jeff Franklin (AAFC).
- Approximately 5% more plant development heat units compared to the 5-year average, and 5% more compared to the 10-year average.
- Approximately 4% more plant development heat units compared to 2020, and 14% more compared with 2019.
- Approximately 5% more insect development heat units compared to the 5-year average, and 5% more compared to the 10-year average.
