MSU Extension

General apple harvest comments

Apple harvest continues to move forward at a rapid pace. In the past week, most growers report they are back up to full speed after a week of slow picking where varieties were not ripening at their normal rate. Growers are harvesting Empire, Jonathan and Jonagold, and in the southern parts of our region Golden Delicious. There are wide swings in maturity from farm to farm in many varieties this week, including Empire, Cortland, Jonathan, Jonagold, Golden Delicious and Red Delicious. This week, I repeated apple maturity testing on the seven varieties tested last week, and added three new varieties – Fuji, Cameo and Crispen – that are approaching maturity. Some Fuji blocks are much more mature than I expected.

With abundant soil moisture supplies this season at most fruit farms, fruit size is generally good to excellent. Fruit color has continued to improve again this past week. Internal ethylene levels are finally coming up to their normal levels as are brix or sugar levels, up an average of 1.5 percent over last week. Most apple varieties are picking hard this season with little to no pre-harvest drop or picking loss. Bitter pit is being seen in some Jonagold, Ida Red and Northern Spy blocks this past week.   

Apple maturity in southeast Michigan for apples harvested Sept. 30, 2014

Individual variety results

Empire was sampled for the fourth week of the season and is being harvested at most farms. Approximately 40 percent of fruit tested are producing internal ethylene levels greater than 0.2 parts per million (ppm). Fruit color has improved greatly to 84 percent, up from 71 percent last week. Pressure is averaging 14.6 pounds, dropping from 16.3 pounds last week. The starch removal averaged 2.7, but several blocks tested at 6 and above, being over mature. The brix is up from 11.2 percent last week to 12.9 percent this week. In a few words, Empire is ready to harvest at most farms.

Cortland was sampled for the fourth week of the season and is finally moving toward maturity and is now ready for harvest. Approximately 40 percent of fruit tested are producing internal ethylene levels greater than 0.2 ppm. Fruit color is good and averaging 85 percent, up from 74 percent last week. Pressure is averaging 14.5 pounds. The starch removal averaged 4.2 this week, jumping up from 1.6 last week. The brix is 11.4 percent this week. This variety is ready for harvest.

Jonathan was sampled for the third week of the season and is ready for harvest at many farms. This week, 80 percent of fruit tested are producing internal ethylene levels greater than 0.2 ppm. Fruit color is excellent averaging 93 percent and pressure is excellent averaging 15.9 pounds. The starch removal averaged 4.2 this week, up from 2.7 last week. The brix levels have increased from 12.8 percent last week to 14.2 percent this week.

Jonagold was sampled for the third week of the season and many blocks and strains are ready for harvest. This week, 73 percent of fruit tested are producing internal ethylene levels greater than 0.2 ppm. Fruit color is good, for Jonagold, averaging 64 percent and pressure is averaging 15.2 pounds. The starch removal averaged 3.7 with a brix rising over 2 percent in the last week to 14.5 percent.

Golden Delicious (Smoothee strain) was sampled for the third week of the season. Early maturing strains and early sites are ready for harvest in the southern parts of our region. This week, 60 percent of fruit tested are producing internal ethylene levels greater than 0.2 ppm. Fruit color or blush is poor to fair, averaging 16 percent and pressure is averaging 16.7 pounds. The starch removal averaged 3.1, up sharply from 1.8 last week, with a brix at 14.4 percent. Many Golden Delicious blocks are eating well at this time.

Red Delicious (Redchief strain) was sampled for the second week of the season and is still a long way from being mature. There is quite a gap in maturity between Golden Delicious and Red Delicious this season. A third of the fruit sampled are producing internal ethylene levels greater than 0.2 ppm. Fruit color is average at 85 percent and pressure is averaging 16.1 pounds. The starch removal averaged 1.3, the same as last week, and the brix is moving from 9.5 percent last week to 11.0 percent this week.

Ida Red was sampled for the second week of the season and like Red Delicious appears to be a long way off at this time. This week, 40 percent of fruit tested are producing internal ethylene levels greater than 0.2 ppm. Fruit color has improved to 76 percent this week and pressure is averaging 16.1 pounds. The starch removal averaged 1.1, with a brix low at 11.7 percent.

Northern Spy was sampled for the third week of the season and while its maturity is progressing nicely, it is not ready for harvest. Internal ethylene levels in fruit greater than 0.2 ppm rose to 100 percent this week. Fruit color has improved from 34 percent last week to 53 percent this week. Pressure is averaging 18.4 pounds. The starch removal averaged 2.0 with a brix at 11 percent.

Fuji was sampled for the first week of the season and appears to be a very long way off. This week, 80 percent of fruit tested are producing internal ethylene levels greater than 0.2 ppm. Fruit color is average at 50 percent and pressure is averaging 17.4 pounds. The starch removal averaged a surprising 3.3 with a brix good at 13.8 percent. Some blocks are ready for harvest now, but most appear to be a week away from being ready. Growers need to keep an eye on Fuji maturity this season.

Cameo was sampled for the first week of the season and appears to be a very long way off. None of the fruit sampled are producing internal ethylene levels greater than 0.2 ppm. Fruit color is average at 55 percent and pressure is averaging 20.9 pounds. The starch removal averaged 1.0 with a brix at 13.8 percent.

Crispen or Mutsu was sampled for the first week of the season and also appears to be a very long way off. None of the fruit sampled are producing internal ethylene levels greater than 0.2 ppm. Fruit color or blush is average at 15 percent and pressure is averaging 17.7 pounds. The starch removal averaged 1.5 with a brix at 12.4 percent. Most blocks have a good amount of blister spot, developing in the last week or so.

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.