MSU Extension

General apple harvest comments

Apple harvest is about three-quarters complete for most growers. Several apple varieties are ready for harvest this week; the following list may surprise some growers as the order of harvest continues to be much different this season. Varieties ready for harvest this week fall into three groups: those that are a bit over mature for long-term storage, those that are ready to harvest now and those that are quickly approaching maturity. Law Rome falls into this first group as being a bit over mature. For the second group, at their prime this week are Fuji, Northern Spy and Crispen. For the last group, Red Delicious is quickly approaching maturity. Varieties needing more time to mature include Ida Red, Cameo, Winesap and Braeburn.

The apple crop continues to pick out short for most growers in east Michigan. Overall, fruit quality is excellent for most varieties with the exception for some bitter pit in a few varieties, like Ida Red and Northern Spy, and blister spot in Crispen. Most apple varieties continue to pick hard this season with the exception of Red Delicious. There has been little to no pre-harvest drop or picking loss. Internal ethylene levels are finally coming up to their normal levels in the past two weeks. Fruit color has improved in the past week and fruit firmness or pressure has remained firm. The brix or sugar levels have risen in the last week, especially for Red Delicious, Northern Spy, Fuji and Cameo. Lastly, many varieties are finally starting to eat well.

This week I repeated apple maturity testing on seven varieties tested last week and added two new varieties, Law Rome and Braeburn. I will have one more apple harvest report next week.

Apple maturity in southeast Michigan for apples harvested Oct. 13, 2014

Individual variety results

Red Delicious (Redchief strain) was sampled for the fourth week of the season and continues to be very slow to mature. Early maturing strains were harvested last week and most other strains are at the cusp of being ready. There was quite a gap in maturity between Golden Delicious and Red Delicious this season. This week, 95 percent of fruit tested produced internal ethylene levels greater than 0.2 parts per million (ppm), with 65 percent at this level last week. Fruit color is good at 90 percent and pressure averaged the same as last week at15.8 pounds. The background color has changed in the last week to mostly yellow. The starch removal averaged 3.4, up from 2.8 last week. The brix has jumped to 12.5 percent this week, up from 11.1 percent last week. Water core and moldy core are being found in 10 to 30 percent of the fruit. Lastly, Red Delicious is the only variety to pick easy this week.

Ida Red was sampled for the fourth week of the season and, like Red Delicious, appears to be slow to mature this season. This week, 90 percent of fruit tested produced internal ethylene levels greater than 0.2 ppm. Fruit color is unchanged at 62 percent this week and pressure averaged 15.9 pounds. The starch removal averaged 2.6 this week, up from 2.1 last week. The brix is at 12.4 percent. Like I said in last week’s report, while Ida Red are maturing, they are not ready for harvest at this time.

Northern Spy was sampled for the fifth week of the season and ready for harvest. Internal ethylene levels in fruit greater than 0.2 ppm is at 100 percent this week. Fruit color is much improved over last week at 64 percent, pressure averaged 18.8 pounds, and starch removal averaged 4.4. The brix has climbed from 12.3 percent last week to 13.2 percent this week.

Fuji was sampled for the third week of the season and maturity has moved along quickly in the past week. Some were harvested last week. Most strains are at their peak of perfection right now, and a few are past their prime for longer term and controlled atmosphere (CA) storage. Fuiji are more mature than Red Delicious, Ida Red and Northern Spy. This week, 100 percent of fruit tested produced internal ethylene levels greater than 0.2 ppm. Fruit color has improved from 56 percent last week to 67 percent this week. Fruit firmness or pressure averaged 17.9 pounds. The starch removal averaged 4.8 this week, with the brix very high at 14.6 percent.

Cameo was sampled for the third week of the season and is at least a week away from being ready to harvest. This week, 90 percent of fruit sampled produced internal ethylene levels greater than 0.2 ppm. Fruit color is average at 51 percent and pressure averaged 21.5 pounds. The starch removal averaged 2.4 this week, up from 1.7 last week. Brix was the best of any variety tested again this week, up a hooping 1.5 percent to 15.7 percent.

Crispen or Mutsu was sampled for the third week of the season and is now ready for harvest. This week, 73 percent of fruit sampled produced internal ethylene levels greater than 0.2 ppm. Fruit color or blush is average at 13 percent and pressure averaged 17.8 pounds. The starch removal averaged 4.2 this week, up from 2.9 last week, and a brix of 13.4 percent. Most blocks have a good amount of blister spot.

Winesap was sampled for the second week of the season and still appears to be a long way off. This week, 100 percent of fruit sampled produced internal ethylene levels greater than 0.2 ppm. Fruit color has improved to 72 percent this week, up from 56 percent last week. The pressure averaged 17.9 pounds and starch removal averaged 1.9. Brix is 11.8 percent.

Law Rome was sampled for the first week of the season and appears to be over mature for long-term and CA storage and ready to harvest for sales this fall. I should have sampled this variety last week to check maturity. This week, 60 percent of fruit sampled produced internal ethylene levels greater than 0.2 ppm. Fruit color is good at 85 percent and pressure averaged 19.3 pounds. The starch removal averaged 5.3 with a brix of 11.8 percent.

Braeburn was sampled for the first week of the season and appears to be a very long way off. This week, 60 percent of fruit sampled produced internal ethylene levels greater than 0.2 ppm. Fruit color is good at 69 percent and pressure averaged 22.7 pounds. The starch removal averaged 1.3 with a brix of 12.4 percent.

Predicted apple harvest dates

Each year we publish a predicted harvest date for three varieties for many locations across the state. This year’s dates can be seen at “Predicted 2014 apple harvest dates,” published July 17. The table below lists the bloom and harvest dates for the Michigan cities Deerfield and Romeo. You can adjust your predicted harvest dates based on your bloom dates. The harvest dates are based on a long established formula using the bloom date and temperatures for 30 days post-bloom. These dates are an estimate, and from the data I generated from this week’s samples, I believe that these harvest days are going to be fairly close to the actual dates for a variety nearing maturity.

Predicted harvest dates for southeast Michigan

Looking for more? View Michigan State University Extension’s Apple Maturity Program and Reports resource page for regional reports throughout the state and additional resources.