May 15, 2007Honeycrisp a Beauty To Buyers, a Pain for producers
At $60 to $70 a box wholesale, Honeycrisp apples are well worth talking about – and that’s what the Fruit Ridge Pomesters did during their annual meeting this spring. Growers, processors and researchers all had their say about how they think this touchy variety should be grown and handled. It takes an effort all along the path.
Don Armock, of Riverridge Produce Marketing near Kent City, Mich., summed it up when he said:
“Honeycrisp has captured the consumer imagination. We need to turn it into a significant part of our variety mix. But in the long term, we need a plan. We need to take the shrink out of this variety.
“If retailers spend $66 to $68 a box, they can’t throw away 20 to 30 apples,” Armock said.
In percentages, Riverridge’s growth in Honeycrisp sales has been explosive – 900 percent over three years. In actual numbers, the growth has been from 0.3 percent to 2.7 percent of sales – but the potential is there for a much larger share for Honeycrisp, Armock said.
He predicted demand would exceed supply for several years, but Michigan growers need to position themselves to be preferred suppliers.
Dennis Courtier, owner of Pepin Heights orchard in Lake City, Minn., also explored some numbers. He estimated that, nationally, there are 4 million Honeycrisp trees in the ground and another half-million being planted this spring. About 800,000 boxes of the apple were sold in the 2006 crop year, and by 2010, that will grow to 4 million to 5 million.
“Consumers have shown they will pay twice as much for an apple they like, but there are a lot of bad Honeycrisp coming. It will take a lot of collective self-discipline to keep quality up.”
Both upper Midwest apple marketers are eager to exploit a variety they believe grows better in – and tastes better grown in -– their production area. They don’t think the far West or South will produce good Honeycrisp. That doesn’t mean they won’t grow them. Washington has 750,000 bearing trees, 1.75 million non-bearing and another 750,000 going into the ground, Courtier said.
As a packer, Armock has to cope with Honeycrisp’s problems with rot forming at stem punctures, bitter pit, bruising, soft scald, uneven coloring and ripening and short storage period.
But the problems with Honeycrisp start long before harvest.
Pepin Heights Orchard has been growing the native Minnesota variety since 1990, when the University of Minnesota formally released it.
If growers choose the right site, “80 percent of the problems with Honeycrisp go away,” Courtier said. The variety must be “starved to perfection,” grown on low organic matter soils.
“Grow it on the best McIntosh sites,” he said. “It’s not a Gala. It’s not going to produce 1,500 boxes per acre.”
It takes real effort to fight its over-vigorous, alternate-bearing tendencies. It needs chemical thinning followed by hand thinning.
“You have to spread the fruit out.”
Courtier thinks a tree-by-tree fertility program may be needed since trees seem variable in vigor, some growing large while others stunt and fail to fill their space.
To avoid damage from stems, where punctures rapidly turn black and rot, Pepin pickers clip the stems at picking time. That reduces the amount of apples a picker can pick, so pickers are paid hourly, not by piece rate. They pick apples into foam-lined picking baskets to reduce bruising. The variety ripens over about a month, but individual apples ripen to perfection in about a week, he said. That means picking three or four times.
“The higher pack-out will pay the higher cost of picking,” he said.
Run them slowly in the packing plant and pay attention to detail.
“Don’t screw it up for the rest of us,” he said. “We can either take this variety to its potential or turn it into junk. This is pickier than any other apple we’ve ever dealt with.”
Courtier thinks the variety should store – if the secrets can be found. The apple is firm and juicy and does not release much ethylene, so it doesn’t soften and should be easy to store. He thinks it may be too juicy – and growers report better success with storing the apples if they are left at ambient temperature to “dry out” for a few days before moving them to cold storage.
Wally Heuser from Summit Tree Sales agreed that thinning is critical – no more than one apple on a spur, achieved by both chemical and hand thinning.
“Crop load is the key to quality with this variety,” he said.
On really sandy soils, he thinks M 106 might be a “little stronger” rootstock, but agreed with Courtier that M 9 and Bud 9 are probably good rootstock choices, except on the poorest soils.
Mike Wittenbach, a grower from Belding and past president of the Michigan State Horticultural Society, said Japanese beetles are a huge problem on the foliage.
“If you over-thin, you’re done. A light crop will lead to bitter pit, no matter how much calcium you spray.”
Large fruit is prone to bitter pit, Wittenbach said.
Grower Tom Moelker said, “It’s a nice apple, but it takes as much attention as peaches.”
Moelker finds that when crop load is heavy, the fruit doesn’t color well and there will be large color differences tree to tree. He also found that letting harvested apples sit four to seven days to “dry out” before moving them to cold storage helps.
Growers report that pests like Honeycrisp as much as consumers do. Moelker finds that yellow jackets are drawn to Honeycrisp at harvest time, and so are squirrels and birds, including wild turkeys. Japanese beetles love the foliage.
Peter McGhee, Michigan State University tree fruit entomologist, said codling moths “like Honeycrisp as well as they do Idareds and Paulareds. It’s like they have a GPS for it.”
Leafrollers are a problem because Honeycrisp sets fruit in clusters, and leafrollers “go crazy in fruit clusters,” where females lay groups of eggs and larvae can damage all the apples in the cluster.
Since Honeycrisp is a high-value apple, he advises monitoring for leafrollers late in the season, and “spray like you mean it.” Use the right product at the right rate and, if you’re using newer reduced-risk insecticides, know their mode of action and try to attack pests with the proper material at the proper time – and attack all the life stages.
While older chemicals like Guthion kill insects at all life stages, the new ones have narrow modes of action and narrow windows of application. Some, like Rimon, kill eggs but few larvae and no adults. Materials like Calypso and Assail, and virus materials, attack larvae but not other stages.
McGhee said the strategy growers have to learn is how to take two or three shots at a pest, targeting critical stages with specialized materials.
Another strategy is to plant the trees in small blocks or with trees of other varieties to reduce the attractive power of Honeycrisp.
Randy Beaudry, MSU’s specialist in post-harvest handling of apples, characterized Honeycrisp as “the poster child for bad fruit,” the worst of all to store.
It’s not a year-round apple, he said, but can be stored for about three months at 38? F or higher and not in controlled atmosphere (CA) storage. It is susceptible to cold injury when stored at less than 38? F.
The fruit, while firm, has a thin skin that bruises easily and is susceptible to stem punctures. Storage disorders include bitter pit, soft scald, soggy breakdown, internal browning, CA injury, carbon dioxide injury and soft rots. It is the most susceptible variety to penicillium decay organisms, he said.
If picked too green, it doesn’t ripen or build up the flavor or color. If picked too ripe, it develops fermentation odors and flavors. He thinks the development of fermentation products – alcohol and acetaldehyde -– may be toxic to the fruit and cause some of the other storage breakdown disorders.
Delaying storage appears to help. Keeping apples at 50? F for a week or so before moving them to cold storage appears to reduce soft scald, but can increase bitter pit and storage rot.
The variety is susceptible to ReTain, which delays ripening and helps avoid fruit drop, another of Honeycrisp’s problems. A half dose of ReTain before harvest may help, he said.
Harvesting at optimum maturity is important, but telling when that is isn’t easy. The fruit appears to have multiple strains and colors.
The fungicide Penbotec reduces storage rots. Use of SmartFresh (1-MCP) will reduce fruit greasiness and keep the young fruit flavor, he said, but it worsens carbon dioxide injury. Using DPA with 1-MCP controls carbon dioxide injury. The fruit is considered generally unresponsive to 1-MCP.
Bitter pit problems can be severe, affecting half or more of the fruit. These darkened, depressed spots on the skin may appear before harvest and widen and deepen after harvest.
The cause of bitter pit is a mineral imbalance associated with low levels of calcium, he said, and calcium sprays and avoiding excessive nitrogen help reduce the problem.
Soft scald can be a severe problem, affecting entire lots of fruit. It is associated with over-mature fruit: dull, cool, wet summers; light crops; large fruit and low temperatures in storage.
Phil Schwallier, Extension horticulture agent and coordinator of the Horticultural Experiment Station at Clarksville, has worked to find orchard protocols to correct Honeycrisp’s problems.
One of those problems is crop load.
“Honeycrisp is frost tolerant, late blooming, and this promotes the tendency to overset,” he said. “Heavy fruit set will lead to no return bloom and quite variable late-apple maturity with many fruits not maturing at all. Honeycrisp tends to set clusters of twos and threes easily, and even some fours. Fruits need to be thinned to single fruits, with adequate spacing between fruits. Honeycrisp needs to have resting spurs to have a chance for return bloom.”
Younger trees thin more easily than older ones, and early thinning when fruits are about 8 millimeters in diameter seems to increase chances for good return bloom.
“Perhaps Honeycrisp requires early resting spurs to achieve return flower initiation,” he said.
Early chemical thinning should be followed by hand thinning to space single fruits. He recommends young trees be thinned with NAA at 10 ppm when fruits are 8 to 10 millimeters. For maturing trees, use Sevin plus NAA or Sevin plus 6-BA. Rates are one pint of Sevin with either 8 ppm of NAA or 75 ppm of 6-BA when fruits are 8 to 15 millimeters in diameter.
Summer Ethrel applications and/or NAA increase return bloom significantly, he said. Thinning with BA increases return bloom significantly better than thinning with NAA.
The maximum crop load, he has found, should be five fruits per square centimeter of trunk cross-sectional area. A tree with a 3-inch trunk could support 250 fruits, given that rule of thumb.
To combat bitter pit, internal browning and other post-harvest disorders, Schwallier recommends starting calcium sprays in early June after petal fall and continuing every two weeks up to two weeks before harvest. The recommended rate is 6 pounds of calcium chloride per 100 gallons of spray.
Sprays with Apogee reduced post-harvest bitter pit similar to summer calcium sprays, he said. Neither summer calcium nor Apogee reduced fruit rot in storage.
For the future
MSU horticulturist Jim Flore is leading a large project with the goal of providing growers with simple tools to evaluate what they need to do to produce superior Honeycrisp.
One simple tool is the notion of using trunk cross-sectional area to determine how many fruit a tree should have. That applies to all varieties, not just Honeycrisp. That way a grower could simply measure the diameter of a tree trunk and read off a chart how many apples the tree should have.
Right now, that appears to be four to six, but it has not been the same for younger trees as for older ones. It’s being worked on.
Flore has been using a digital camera to take photos of hundreds of trees, trying to correlate the degree of yellowing (zonal chlorosis) in one year with return bloom the next year. He is doing the same with bloom – comparing the “whiteness” of a tree in bloom this year with degree of return bloom the next year.
In Flore’s studies, yield and fruit quality were related to crop load. As crop load increased, yield per tree and percent drops increased, while color, fruit weight, fruit diameter and bitter pit decreased. Yield was affected by tree age.
Zonal chlorosis decreased as crop load increased. The effect of rootstock, tree vigor, tree age and location have not been fully analyzed.
“We are investigating the effect of this disorder on current crop load and size and on return bloom,” he said.
Other correlations may be possible, as researchers try to figure out how conditions of bloom, crop load, zonal chlorosis, tree age, tree vigor, location, rootstock and thinning regimen in one year work in the crop year and the years following. The Michigan Apple Committee is funding a lot of the research work.
Everybody seems to agree: Honeycrisp is a great apple, but there’s a lot to be learned about how to grow it well.