MSU Extension Apples

General harvest comments

Fresh market growers have moved through Gala and completely stripped most blocks in the past week. Color and size were excellent, and growers generally felt that size of the crop was normal to slightly higher than they had anticipated. Honeycrisp orchards need to be a top priority for all growers in the region in the second half of this week; the fruits left on trees after the first pick are moving rapidly towards over-maturity, even in blocks that were treated with ReTain a few days ago.

Processing apple harvest is in its peak weeks at this time. Empire and Jonagold are ready to go and have both been cleared by local processors for harvest this week; they are being boxed up as fast as growers can get to them. Quality of both varieties is excellent, most Empire and Jonagold are used for sliced apple product and should perform well for growers at the plant this year based on size, color and firmness that we have seen. Golden Delicious is just entering maturity for controlled atmosphere (CA) storage harvest at most locations, and Rome will likely be cleared for harvest by the end of the week if it has not been already. Red Delicious maturity for CA storage looks to be about a week out at this time. Ida Reds will be tested for the first time next week, but harvest of that variety is likely still at least two weeks out.

Fruit quality continues to be excellent; color, firmness and brix have been ideal so far this season. The high amount of precipitation does not appear to be causing soft fruit. The constant rain is presenting inconvenience to crews as they move through orchards, but growers are doing a great job of staying on top of harvest this year. Bitter pit is also relatively low this year, which comes as a surprise to many growers given a light Honeycrisp crop in many locations. Improvements in calcium application strategies throughout the season and management of potassium in soils has helped growers out.

Brown marmorated stink bug pressure continues to be very low so far this season in west central, and activity in hot spots in the southern part of the state was slightly down this week as well. Another single adult brown marmorated stink bug was captured in the trap line this week, so although we can find them every once in a while, we are confident the pest does not pose an economic risk to our crop this season. There is no reason to be using an insecticide to manage it this year.

San Jose scale can be seen on the calyx ends of fruits in affected orchards. Generally, there seems to be less this year than last year, thanks in part to many operations targeting the pest early this spring 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

Growers have completely stripped most Gala blocks in the past 10 days. This was the right call, the variety ripened up very quickly in that span after a long delay through the first three weeks of September. Although growers often attribute differences in ripening between sites to strain, it’s important to remember there are really only two Gala strains that ripen at significantly different times for us, those being ‘Wildfire’ and ‘Autumn.’ The rest of them ripen up at roughly the same time with maybe a day or two of difference when grown on the same site. Differences we see that are attributed to different strains of Gala in this area have more to do with differences between site and the usage of ReTain. There are a few ReTain-treated Gala and a couple of our latest sites that will be picked through the weekend, but this week is going to be it for Gala in our area.

This is the last report on the variety for the season, we were already down to just one site in Benona, Michigan, this week. This particular location is always one of the latest sites in the area and it will be picked this weekend.

Honeycrisp

This variety should be completely out of orchards by this time next week if possible, even second picks. Fruits are trending towards the over-mature range very quickly, even those treated with ReTain. Remember, treating Honeycrisp near harvest with one-quarter pouch rate of ReTain plus 10 parts per million (ppm) of NAA will only delay ripening by about a week. That delay is even less when used at the same rate after first pick, closer to a three- to four-day delay in ripening. The NAA at 10 ppm will keep fruits stuck to the tree for 10 or more days, but it will not stop those fruits from becoming over-mature while they hang there.

Even green looking fruit on canopy interiors that is left on larger trees after a first pick is moving fast, regardless of what it looks like. Background color on Honeycrisp is trending on the green side this year, which can lead to some confusion about how ripe it is. Don’t be deceived, it is ready to go and will be over the hill at nearly all sites in our region by this time next week. Honeycrisp is considered over-mature for CA storage once it hits a starch index of 7, and we are already seeing firmness that falls below recommended ranges at some sites.

Empire

Last week’s data indicated this would be Empire week for the area, and that ended up being the case. This variety is being harvested as you read this report across the region, and much of it is already in bins. It is ready to go, and now that it has been cleared for harvest by local processors it will be gone within the next few days. Size is on the small side on Empire this year, but other parameters are excellent. This will be the last report on this variety for the season.

Jonagold

As we suspected after last week’s testing, Jonagold is ready for harvest at most locations in the region this week. The Elbridge, Michigan, location we have used over the past couple of weeks had already started harvest on Monday, Sept. 30, and others are following suit as the week goes on. Processor requirements can sometimes differ from CA parameters, but those picking Jonagold for CA storage are reminded that it is considered mature at a starch index of 3.5 with suggested firmness between 15 and 17 pounds. This variety is moving fast this season, so growers will need to get after it as soon as they are able. Color is generally excellent this season, and size is good as well.

Since most of our Jonagold are used for sliced apple product, growers typically shoot for a medium-sized apple, and they were generally successful with that this year. It is certainly unusual to see Jonagold harvest be so close to Gala harvest, but this is a somewhat unusual harvest season. We are seeing a compression of all our September and early October varieties.

Golden Delicious

This variety is ready for harvest at most Oceana County locations where ReTain was not used. ReTain-treated Goldens and some late sites in Oceana and Mason counties are about a week off from maturity. There is a lot of russet on the variety this year. This shouldn’t be an issue for processing growers, but growers trying to sell Goldens on the fresh market may want to weigh their options carefully before sending them for this purpose. Many orchards are looking at russet levels that would make a significant portion of the crop unsuitable for fresh market sales. The variety will likely be cleared by processing buyers for harvest in the second half of this week if it hasn’t been already at many sites across the region.

Mutsu/Crispin

This variety is about a week to 10 days off from maturity at most orchards in our area. Growers in all but the latest areas of the region can likely anticipate getting started in the second half of next week based on this week’s results. Mutsu/Crispin is considered mature for CA storage at a starch index of 3 with suggested firmness between 16 and 18 pounds and if current pace of maturation continues, it should be right in this window about a week from now. As per usual, size is excellent on the variety. No blister spot has been observed this season, and they have a nice side of blush thanks to some excellent weather for color development.

Rome

The samples picked up on Monday were testing just under suggested starch index values for CA storage with good firmness and acceptable sugar content, so they will likely be cleared for harvest in the second half of this week or early next week by processors. Despite excellent red color development on the variety, the bleeding we tend to see with the ‘Law’ strain appears to be minimal so far, although it can be found. This can change quickly, so growers may end up picking it in the earliest possible maturity stage to avoid this issue at the plant.

Red Delicious

This variety is about a week away from the low range of CA storage maturity. Red Delicious is considered mature for CA storage at a starch index of 2.5 with suggested firmness between 16 and 18 pounds. Growers can likely expect to get started with this variety when they find the time in the second half of next week

EverCrisp

This variety was sampled for the first time this week and still needs a couple more weeks to ripen up. Unlike some of our more established varieties, we do not have specifications defining storage maturity for the variety. It has Fuji parentage and its harvest season and appearance can be somewhat reminiscent of that variety, so we have used Fuji maturity specs as estimates for EverCrisp in the first couple of years fruits have come on to the market. Further study in future years will hone this approach, but at this time we feel EverCrisp ripens three to five days before Fuji in west central Michigan.

Fuji is considered mature for CA storage at a starch index of 3 with suggested firmness of 16-18 pounds. EverCrisp always takes top prize on fruit firmness during testing season, and data collected this week demonstrate this. It also tends to be a very sweet apple, with brix readings in past years as high as 18 by harvest time. Color is much improved on the EverCrisp that we are starting to run through the lab as trees we have been sampling from over the past couple of years reach maturity and full bearing potential. Based on our findings from these same orchards going back three years, early crops on EverCrisp tend to exhibit the less desirable “Fuji red” that standard strain Fuji was known for, but fruits coming into the lab from these now-mature orchards over the past couple of years are much improved from that color.

We will add additional EverCrisp sites from the Ludington, Michigan, area and the Hart, Michigan, area next week and track them through harvest.

Fuji

This variety is two or more weeks away from maturity in the region. Fuji is considered mature at a starch index of 3 with suggested firmness between 16 and 18 pounds. Fruits sampled this week had poor color and size, but this should improve in the next couple of weeks as we get closer to harvest time.

*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.)