MSU Extension Apples

General harvest comments

The long wait for Gala is finally over. Growers started getting into this variety late last week and will continue to pick in earnest for several days. The variety is moving quickly, so many orchards will be picked clean by this time next week. Honeycrisp is also mature throughout the region and appears to be moving very quickly this year. Some sites are much further along than they appear, as background color on mature Honeycrisp seems to be trending towards the greener side this year at many locations. Growers will need to prioritize both varieties to get through before fruits move towards over maturity.

Processing apple harvest kicked off in earnest with McIntosh last week, and most Macs are already gone. Jonathan harvest is underway or complete. Empires are still about a week or more out, as are Golden Delicious. The maturity window of several prominent varieties has been compressed this season due to the long wait for varieties we are used to picking in the first half of September. This will be a big week for local operations to stay on schedule and avoid over-maturity in coming weeks.

Fruit quality continues to be excellent; color, firmness and brix have been ideal so far this season. Ample soil moisture all season means that fruit size is generally excellent. Varieties like Empire that tend to have small fruit size are an obvious exception to this, but generally growers are pleased with size on the crop this year. Another common observation among growers right now is that there are a lot more apples out there than many folks had realized. This is a pretty heavy crop for many varieties, and it is already binning out higher than farmers were anticipating. This has been particularly true for the picks on Gala that have been conducted thus far.

Growers who are feeling stressed about getting through prominent varieties before things move into over-maturity are reminded that ReTain at reduced rates combined with NAA can delay harvest by several days and reduce fruit drop. One-quarter pouch of ReTain plus 10 parts per million (ppm) NAA is a common rate to see used for this purpose on Honeycrisp and Gala at this time of year. Since the effect of ReTain is rate dependent, variable rates can be used within a single block to stagger the harvest of a variety, allowing you to prolong the acceptable range while your pickers move through. It can also be used after a first pick for color to stick the second pick on the tree for a few days. This practice is becoming particularly popular with Honeycrisp, as a low rate can be used immediately after a first color pick to stick the remainder of the fruit on the tree a few more days to wait for better color.

Brown marmorated stink bug pressure continues to be low so far this season in west central, but a significant uptick has been reported in other areas of the state. Only one adult brown marmorated stink bug was captured in the trap line this week. Our orchards are already boxed and no insecticides will be applied at this point in most cases, but we will continue to monitor the brown marmorated stink bug situation until harvest has concluded.

San Jose Scale can be seen on the calyx ends of fruits at this time in affected orchards. Generally, there seems to be less this year than last year, thanks in part to many operations targeting this pest early this year with oil plus Lorsban. No management for this pest is conducted at this time of year, but harvest time is a valuable opportunity to take note of areas on your farm that pressure seems to be building. This pest tends to begin in several localized hot spots within a field and radiate outwards over several years. Flagging affected trees or regions of an orchard can allow for targeted pruning and oil plus Lorsban applications next spring to combat spread.

Individual variety maturity results

The scales used to rate these different metrics on these charts are as follows:

• Background color: scale 1-4, 1 is fully yellow and 4 is fully green.
• Russet: 1-4, 1 is no russet and 4 is severe russet.
• Pressure: always listed in pounds, and two pressure scores are recorded for each apple tested.
• Watercore: 0-4, 1 is no watercore and 4 is severe watercore.
• Bleeding: 0-4, 0 is no bleeding of red color into flesh and 4 is severe bleeding of red color into flesh.
• Red: listed as a percentage of the whole fruit with red color.

Gala

It’s go-time for this variety at all but the very latest sites in the region. It is in the prime window for controlled atmosphere (CA) storage harvest now, so don’t delay sending pickers after it. Keep in mind that data collected this week listed below includes some second pick as well as a couple of sites that were treated with ReTain, thus some of the variability we see here. Harvest of this variety started late last week throughout the region and will continue in earnest all week long. Gala took a huge jump forward in maturity in the past week and will be moving towards over-maturity in a week’s time at many locations in the area.

This is one of the best years for Gala in recent memory. Size is outstanding, color is excellent and orchards are carrying a heavier crop than many growers had expected earlier this year. Gala are considered mature for CA storage at a starch index of 3 with suggested firmness between 16 and 18 pounds. They are considered over-mature for CA at a starch index of 6 or higher.

Jonathan

This variety was sampled for the third and final time this week and is ready to be picked if it hasn’t been harvested already. It was harvested for CA storage in the second half of last week and early this week in many earlier locations in Oceana County, and the rest of it will probably be gone within the week at later sites in Oceana and Mason counties. This variety is mature for CA harvest at a starch index of 3 with suggested firmness between 14 and 16 pounds. Fruits tested this week were in the early maturity range based on starch index, and were still very firm. Jonathan are quite small this year, and quite a bit of russet was recorded as well. Color is good, and no bleeding of color into flesh has been observed.

Honeycrisp

This variety throws curve balls at all times of year in every season, and this year is no exception. This variety needs to be a top priority for all fresh market growers throughout the region—if you think you aren’t on the list because you tend to be later, think again. This variety was actually extremely consistent this week throughout the region, regardless of appearance it’s ripe and will already be speeding towards over maturity by this time next week based on how quickly it moved in a week’s time.

The tricky thing with Honeycrisp this season that is causing many growers to wait to send pickers in is that background color seems to be trending towards the green side on even very ripe fruit, particularly on larger trees. This makes fruits in some locations look less mature than they actually are, but don’t be fooled. We tested fruits from a wide range of colors and tree ages, and they were all ready for harvest this week. Get after at least a first pick on them to avoid soft, overly sugary fruits a week from now.

Also, consider using low rates of ReTain to slow down fruits that you plan on leaving after first pick. I talked with several growers who farm later sites on Monday who were thinking they might get into Honeycrisp next week for the first time, but based on what we saw in the lab this week, that’s definitely going to be too late.

We have seen very little bitter pit this season in spite of a lighter crop at many farms, which is something of a surprise. We have also noted very little watercore.

Empire

This variety needs at least another week, probably more. Most Empire in the area are treated with ReTain due to processor requirements, so they continue to advance slowly. This is a good thing given the glut of other varieties that need to be picked this week. Size on Empire can always be a bit of an issue, and this year is no exception. It has been small this year at all of our test sites, so growers will continue to hope that the variety picks up some size in the next week.

Empire is considered mature for CA storage at a starch index of 3.5 and suggested firmness of 14-16 pounds. It may start to test in the low end of that range by this time next week, but it’s likely to be closer to 10-14 days before we get into the optimal harvest window.

Jonagold

We are less than a week away from Jonagold testing in the mature range for CA at many farms, and they are eating really well already at earlier sites in our area. A few have already been picked for fresh market deals, but peak harvest of this variety should be planned for next week at most sites in Oceana County, probably three to five days later in much of Mason County. Jonagold is considered mature for CA storage at a starch index of 3.5 with suggested firmness of 15-17 pounds, and were very close to that starch index mark this week with firmness dropping into the 14-17 pound range already. Color and size are both excellent on Jonagold this season.

Golden Delicious

This variety tested very consistently throughout west central this week. It’s likely about a week or less away from the early end of maturity for CA storage harvest. It is considered mature for CA at a starch index of 3 with suggested firmness between 15 and 17 pounds. Growers who are picking for the fresh market are probably looking at closer to two weeks on harvest, but anybody selling for processing is looking at more like a week before they get rolling. Golden Delicious has a noticeable side blush this year due to the quality of coloring weather that we have had. Size and brix also look very good this year.

Mutsu/Crispin

We tested this variety for the first time this season and it still needs at least a week before it is harvested for CA storage, probably closer to two weeks at many locations. Mutsu/Crispin is considered mature for CA storage harvest at a starch index of 3 with suggested firmness between 16 and 18 pounds, and fruits are well shy of that mark.

This variety has had a tendency to be harvested prematurely in the area in recent years, but growers seem to be holding fire this year. That’s great news for everyone involved, as premature harvest results in increased post-harvest issues, including bitterpit. That hurts everyone, farmer and processor alike. No blister spot was observed on Mutsu/Crispin at either site we tested this week. As per usual, size is excellent on the variety.

Rome

This variety was tested for the first time this week and is likely at least a week away from maturity for CA storage at even the earliest locations. Rome is considered mature for CA storage harvest at a starch index of 3 with suggested firmness between 15 and 18 pounds. Fruits this week are still well shy of this mark, and need some time. Color is always good in Rome, and this year is no exception. In spite of very strong color development, no bleeding of the red color into flesh was observed this week in any of our samples.

*Firmness is measured with a mechanical 11-mm wide probe inserted into the pared flesh of a fruit to a distance of 8 mm. Starch index is measured on equatorial cross section of an apple stained with iodine solution and rated using the Cornell University starch-iodine index chart for apples on a 1-8 scale (Predicting Harvest Date Window for Apples by Blanpied and Silsbey, Cornell Extension Bulletin 221.)