Michigan apple maturity reports – October 12, 2011

Each week, MSU Extension educators test apples for maturity in their region and report the status.

This week’s regional reports:

Southwest Michigan – Bill Shane, Mark Longstroth and Diane Brown, Michigan State University Extension

Southwest Michigan
Southwest Michigan

This is the sixth and final weekly apple maturity report for southwest Michigan for the 2011 season. We wish to thank you for your support of this program.

The samples for these reports are collected primarily in Berrien and Van Buren counties. The maturity is only a broad indication of trends for this area. Samples represent the more mature fruit in the blocks. Individual orchards may differ from these results.

Summary of Berrien County area apple maturity samples collected October 10, 2011

Variety Firmness lbs. pressure (range) Starch (range) Brix degrees (range)
Fuji 18.5 (17.2 – 20.5) 6.4 (5.2 – 7.0) 15.4 (12.7 – 17.9)
Idared 16.0 (15.4 – 16.9) 3.8 (2.6 – 4.6) 12.3 (10.7 – 13.4)
Rome 20.8 (18.2 – 20.8) 5.3 (2.6 – 7.0) 12.8 (11.8 – 13.9)
Braeburn 22.4 (20.7 – 24.2) 3.9 (3.0 – 4.4) 13.4 (11.0 – 15.9)

Fuji (seven sample sites). Firmness averaged 18.5 compared to 19.3 lbs. for last week. Starch removal for this week averaged 6.4 compared to 4.6 for last week, with a brix average of 15.4 compared to 14.1 for last week. Firmness is testing in the excellent to long-term controlled atmosphere (CA) range with starch removal for all sites in the mature zone. These sites could all be harvested now for long-term CA storage according to these tests, providing skin color is sufficient.

Idared (four sites). Flesh firmness averages 16.0, 1 pound less than last week. Starch removal is now averaging 3.8, quite a jump from last week’s 2.7, with an average brix of 12.3, slightly higher than last week. Firmness is excellent to long-term CA storage. This combined with starch tests generally in the mature range for CA storage signals that these are ready for harvesting for long-term storage. Harvest of Idared for processing is complete in most area orchards.

Rome (five sites). Flesh firmness this week averaged 20.8 lbs. compared to last week’s 22.3 lbs. Starch removal averaged 5.3 (range 2.6 to 7.0), a huge jump from last week’s 2.8, and current brix average is 12.8 compared to last week’s 12.2. Similar to last year at this time, starch conversion has proceeded rapidly, although flesh firmness is still excellent. Firmness allows harvest to be delayed if desired, but quality in long-term storage is apt to be better if the fruit are harvested now rather than later because starch conversion is in the over-mature range for some sites.

Braeburn (five sites). Flesh firmness is still excellent at 22.4 lbs., about the same as last week. Starch conversion is averaging 3.9 compared to an average of 2.4 for last week. Brix is averaging 13.4, about 1.0 more than last week. Firmness will allow harvest to be delayed to wait for better skin color, size and brix. All sites are testing mature according to the starch conversion test, indicating that this variety is in good condition for long-term CA storage.

Contact MSU fruit educator Bill Shane at the Southwest Michigan Research and Extension Center at 269-944-1477 ext. 205 if you would like to have samples from your farm tested for maturity. See the MSU Extension News for Agriculture website for more information, including reports from other regions, and the MSU apple website for information about apple maturity and apples in general.

This report and project is made possible by the support of our sponsors, which include Valent Biosciences, Michigan Apple Committee, Michigan State Horticultural Society,MSU’s AgBioResearch and Michigan State University Extension. Southwest Michigan growers providing apples include Grandview Orchards, Mammoth Farms, Oak Hill, Bixby Orchards, Weber Farms, Meachum Farms, Kevin Winkel Farms, Weckwerth Farms, Willmeng Farms, and Czuba Farms.

Apple maturity trends for southwest Michigan. Each dot is the average for an orchard based on a 10 apple sample.
Samples were taken in Berrien and Van Buren counties.
Click here to view larger image.

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Southeast Michigan – Bob Tritten and Debbie Clark, Michigan State University Extension

Southeast Michigan
Southeast Michigan

General harvest comments

Apple harvest is rolling along very quickly this year. With our streak of nine days of warm weather, apple harvest has been unimpeded by any weather delays. Most apple growers have finished up harvesting Empire, Cortland and Golden Delicious, and are currently working away at harvesting Red Delicious, Northern Spy and Fuji. Growers are also going back to finish harvesting ReTain-treated Jonagold and Gala blocks.

The order of maturity of apple varieties continues to unfold differently this year than most years. The example for this week is with Fuji, Idared and Northern Spy; all are maturing before many strains of Red Delicious this year.

This week I sampled a total of nine varieties and included two new varieties in this list, Granny Smith and Enterprise.

Apple maturity in southeast Michigan for apples harvested on October 10

Variety % fruits with Ethylene over 0.2 ppm (Range) Color (Range) Firmness lbs. (Range) Starch (Range) Brix %
Red Delicious 93% (80-100%) 96% (95-100%) 16.8 lbs (16.0-17.8) 4.2 (2.8-5.5) 12.1%
Northern Spy 85% (70-100%) 59% (34-83%) 19.7 lbs (18.5-20.9) 4.3 (3.4-5.2) 12.1%
Idared 95% (90-100%) 79% (75-83%) 16.3 lbs (14.9-18.5) 3.8 (3.4-4.3) 12.2%
Fuji 73% (60-80%) 73% (61-87%) 18.6 lbs (18.0-19.6) 5.2 (2.9-5.0) 13.7%
Law Rome 50% (0-100%) 92% (90-94%) 19.6 lbs (19.5-19.6) 5.1 (3.7-6.5) 12.4%
Winesap 85% (70-100%) 73% (57-89%) 19.2 lbs (18.9-19.4) 2.3 (2.1-2.4) 12.1%
Braeburn 65% (60-70%) 61% (54-67%) 19.7 lbs (19.5-19.9) 2.8 (2.6-3.0) 11.8%
Granny Smith 10% (10-10%) 0% (0-0%) 19.5 lbs (18.5-20.0) 2.6 (2.0-3.0) 11.7%
Enterprise 20% (20-20%) 83% (55-90%) 19.2 lbs (16.8-19.8) 2.3 (1.0-4.0) 12.8%

Individual variety results

Red Delicious were sampled for the fourth week of the season with Red Chief being the most common strain tested. Red Delicious was picking very easy when I collected my samples on Monday of this week (October 10), and some fruit drop is being seen. I also spotted some light amounts of water core. The color on Red Delicious has improved and while fruit remain firm, the starch index is slowly moving on an upward pace, now averaging 4.2.

There are several blocks of Red Delicious that have been harvested and others that are currently ready for long-term and controlled atmosphere storage as well as immediate sales. Please note that at several farms, there are other strains that are well-ahead of Red Chief this year. One thing that is curious this week on Red Delicious is that I am seeing a great amount of yellowed foliage and leaves that are beginning to drop to the orchard floor.

Northern Spy were sampled for the third week of the season with fewer samples being taken due to many blocks of Spys already being harvested. The color of Northern Spy is starting to improve a bit, with fruit remaining very firm and the starch has moving from 3.6 last week to 4.3 this week. With the exception of one farm, all other farms that I sampled have Northern Spys that are ready for long-term storage and fresh or immediate sales.

Idared were sampled for the third week of the harvest season with a good number of samples being taken this week. Idared is producing a great deal of ethylene over the last week and color has remained about the same at 79 percent. The fruit remain firm at 16.3 lbs. and the starch index has progressed nicely to 3.8 this week. There are a few blocks of Idas that are now ready for long-term and controlled atmosphere storage harvest, others that are for fresh sales need a few more days to mature. I expect many growers to be harvesting Idareds on a regular basis by the weekend.

Fuji were sampled for the fourth week of the season. Remember that there are many strains of Fuji that mature over a long period of time. Fuji have developed a bit more internal ethylene over the last week, now at 73 percent with levels greater than 0.2 parts per million (ppm). The color has improved a bit on Fuji to 73 percent and fruit remain firm at 18.6 lbs. The starch index has jumped one point over the last week, now averaging 5.2. The brix on Fuji have also improved nicely to 13.7 percent. Most strains of Fuji are ready for intermediate and short-term storage, as well as fresh sales. Some blocks of Fuji are over-mature for long-term and controlled atmosphere storage harvest. Because the brix is so high in Fuji, I am encouraging several growers to delay harvest in Red Delicious blocks and move on to Fuji.

Law Rome were sampled for the second week of the season with a few more samples being taken this week. Again, there is a fair amount of variability in maturity of the Law Rome samples taken this week. Over the week I am seeing that internal ethylene levels have jumped to 50 percent, fruit color is very good at 92 percent and fruit is still very firm at 19.6 lbs. The average starch is 5.1, however there is quite a spread of maturity between farms with a few having fruit that are over-mature for long-term and controlled atmosphere storage while others are still on the green side. I would encourage growers to check Law Rome blocks fairly quickly for maturity.

Winesap were sampled for the second week of the season with a few more blocks added this week. The internal ethylene levels greater than 0.2 ppm has jumped dramatically to 85 percent this week. Color has improved to 73 percent, the fruit remain very firm at 19.2 lbs. and the starch has moved to 2.3. I have not seen any blocks of Winesaps that are ready for harvest; I expect that they are about 7 to 10 days away from being mature.

Braeburn were sampled for the second week of the season, with a few more blocks added to the collection process. Braeburn have not colored very well over the last week, with fruit color now at 61 percent. Fruit remain very firm at 19.7 lbs. and the starch is about the same at 2.8. Brix has improved to 11.8 percent and they are beginning to eat a little bit better. There are no blocks that are ready for harvest; most are requiring 7 to 10 days before they will begin to creep into the controlled atmosphere and long-term storage window.

Granny Smith were sampled for the first time of the season. With the long growing season that we have had this year, this may be the year that we actually mature Granny Smith. There is only 10 percent of fruit with internal ethylene levels greater than 0.2 ppm. The fruit color is still very green and the background color is also green. The fruit are very firm at 19.5 lbs. and the starch is averaging 2.6. I would estimate that we are still close to three weeks away from harvest of Granny Smith.

Enterprise were sampled for the first week of the season with only one block being tested. Enterprise are not widely planted across the region. Twenty percent of the fruit are showing internal ethylene levels greater than 0.2 ppm. Fruit is well colored at 83 percent and still very firm at 19.2 lbs. The starch index is averaging 2.3 and brix is a surprising 12.8 percent. While Enterprise are not close to being ready to harvest, I estimate that they will most likely be maturing a few days ahead of Granny Smith this year, or in other words, toward the end of the month.

Predicted harvest dates

Full bloom date Original Predicted Harvest Dates Revised Predicted Harvest Dates
Station McIntosh Jons Reds McIntosh Jons Reds McIntosh Jons Reds
Deerfield 5/13 5/15 5/17 9/15 9/29 10/5 9/20 10/4 10/10
Romeo 5/19 5/21 5/21 9/17 10/2 10/8 9/22 10/7 10/13

If you have any questions regarding this apple maturity report or apple harvest in southeast Michigan, don’t hesitate to email me, call my office (810-244-8555) or cell (810-516-3800).

This report and project is made possible by the support of our sponsors, which include Valent Biosciences,Michigan Apple Committee, Michigan State Horticultural Society,MSU’s AgBioResearch and Michigan State University Extension. Southeast Michigan apple growers that are providing apples on a weekly basis include Spicer Orchards in Hartland, Erwin Orchards in South Lyon, Westview Orchards in Romeo and Hy’s Cider Mill in Romeo. Many thanks to the support of these growers.

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