WSU Tree Fruit Research & Extension Center

Postharvest Information Network

Sunday, February 17, 2019

WSU-TFREC/Postharvest Information Network/Harvesting Jonagolds

Harvesting Jonagolds


I am a grower/shipper whose orchards and packing facility are located west of Yakima in the Naches Valley. I first got interested in Jonagolds after a Gene Kupferman postharvest tour to Europe in February of 1984. At that time, Jonagolds were the "apple of the future" in Europe, and they were being very heavily planted. The biggest complaint, other than a known bitterpit problem, was that Jonagolds grew too big for most Europeans. Now in Europe, a size 72 or a size 64 is a big apple.

Here in America, though, what do most Americans seem to like? They like things that are big-- big buildings, big cars, big stereos, big speakers. Why not big produce? Furthermore, the Jonagold at that time was the number one leader in apple taste tests throughout the world and still is to this day in many places. Having seen the success of growers with early plantings of Granny Smith and Gala, I elected to stake my company's future in the new variety arena on the Jonagold. I also believed my available sites in the upper Yakima Valley would be more favorable to producing Jonagolds than Gala or Fuji.

In 1985, I planted my first 15 acres of Nicobel Jonagolds. Since then I have planted an additional 5 blocks of Jonagolds totaling a little over 40 acres. Each of those blocks has been a learning experience and I am here today to share some of that experience with you.


The topic of my presentation is "Harvesting Jonagolds." I will confine my remarks to why and when to harvest Jonagolds, and I will leave it to you to figure out what works best for your particular operation. Those of you involved with Jonagolds for more than two or three harvests will probably relate very readily to the progression of ideas my company has used to determine when to harvest Jonagolds.

Hopefully, for the rest of you, my presentation will save you some of the frustrations the rest of us have had to go through. Let me say right now, the techniques I will later describe are the techniques I use in my operation and encourage my 22 growers to use. They are definitely the result of trial and error and may or may not work with your particular strain or location. Hopefully, though, it will give you a foundation on which to develop a harvest program which works for you and your warehouse.

Our first attempt at determining harvest maturity was to use tools we were already familiar with, that being starch/iodine testing. We squirted lots of Jonagolds and discovered that by the time we were just about ready to make our first pick, most of the apples we tested were almost totally white inside, meaning the starch had already converted to sugar. There were no consistent black patterns with which to base any kind of logical comparison or evaluation. We have found this to be fairly consistent over the years and my advice to you is don't waste your iodine testing Jonagolds. For us, starch/iodine testing has not proved to be a useful tool for determining when we need to make our Jonagolds picks.

The next thing we tried was "background color." The Europeans talked about background color, the Galas were being picked by background color, why not Jonagolds? Well it seems that Jonagolds usually color on the outside sun exposed part of the fruit first. As soon as you turn that nice big 64 size apple around to see the background color on the backside, you just picked it! Commercially this was not acceptable as too many apples were getting picked that we didn't want to be picked. So for us, this method was abandoned even quicker than the starch/iodine testing.


Now to 1996-97. The realities of commercial Jonagold growing are that we, as Jonagold growers, get paid for red color, no blemishes, and firmness, which in reality is no different than any other variety of red apple. A problem unique to the Jonagold, though, is that it is a less firm apple than a Fuji or a Braeburn right from the start. As a result, Jonagolds need a lot more attention to detail during harvest to avoid losing their firmness.

Most warehouses require a Jonagold to have at least 50% to 60% good red color before it will be put in that company's top grade. Notice this criteria doesn't mention anything about yellow or green background color. The primary thing your fruit is going to be graded on is the percentage and intensity of red color. Red, therefore, is obviously one of the primary factors we need to focus on in determining when to harvest.

The other factor we need to focus on is firmness. As a rule of thumb, I try to use 15 lb as the cutoff point for harvesting CA fruit. Fruit that is between 15 and 14 lb will normally be designated for regular storage. When the fruit in a block gets to 14 lb, we consider color picking to no longer be a harvest option, and we urge our growers to finish picking everything left in that block as expeditiously as possible. Unfortunately, mother nature has a way of interjecting her own variables into our nice little plan, so adjustments will always have to be made in the field and at the warehouse level. We have found it very difficult to add firmness back to fruit which has been left on the tree too long.

At this time, I am going to mention a phenomenon which we and several other warehouses have noticed in relation to the rate of decline of Jonagold firmness. We have observed that Jonagolds harvested prior to a certain point, and right now we don't know exactly were that point is, will decline in firmness very little throughout their CA or regular storage life. Fruit that is harvested after this "point" will lose its firmness at a much higher rate. Next year we will be watching our harvest pressures much more closely and doing some ethylene testing to see if we determine at what point our Jonagolds will become susceptible to what I call: "the Jonagold plunge". Perhaps, this is an area our WSU scientists can do some investigative research which would be extremely valuable to the Jonagold grower/shipper community.

“Bite Checking”

I want to introduce the concept of "bite checking" apples. Many of my growers have very small plantings and initially did not own pressure testers. As a result we developed the Phill Fossum "bite check" method of pressure testing Jonagolds. By walking through our orchards and taking bites out of selected apples, firmness changes became very noticeable. All of my growers can easily tell a 16 lb Jonagold from a 15 lb Jonagold from a 14 lb Jonagold, and most are able to correlate their bite checks to within half a pound of what my pressure tester would be telling them. We have found this method to be very useful in giving us quick indices of how fast the firmness is declining in a block and how soon we need to start thinking about making that next pick. For a fieldman or a grower, this is a much faster and less sticky method of testing while covering a lot of orchard in a short time and it gives us a good general picture of the condition of the fruit.

Harvest Scenarios

I am now going to describe two harvest scenarios: the first will be for a Nicobel or standard type Jonagold block, and the second will be for a Decoster block. I do not have any hands-on experience with other strains of Jonagold such as King or Jonagored, so you will have to take my remarks and extrapolate them to your particular situation.

The first scenario will be for a Nicobel or standard type Jonagold block. There are four areas which intertwine and determine when each grower is going to harvest his Jonagolds. They are weather, management considerations, red color on the apple and firmness. Initially, all pressures in our block should be above 15 lb, which, as I indicated earlier, is our CA or first pressure cutoff point. As long as our pressures remain above 15 lb, pressure will not be one of our considerations as to when to pick.

Our initial picking will be based primarily on red color, crew availability, weather, and how the fruit is going to be handled by the warehouse. That is, is it going to be immediately packed and shipped for an early market, or will it be going directly into CA storage? As we approach our first pick, I have my growers walk through the blocks and observe how the red color is developing. As they do this I have them bite check some of their larger red apples. When they feel they have a high enough quantity of acceptably colored apples to justify sending a crew through, it is time to make that 1st pick. If, as the grower does his bite checks, he starts detecting a slight drop in firmness in his larger red apples, that indicates it is also time to start thinking about getting a crew in for that first pick. Crews should be instructed to pick only apples with a certain percentage of good red color. What that percentage is will have to be defined by the owner, his supervisors, and his warehouse fieldman.

Historically, second picks are anywhere from 5 to 10 days after the first. The grower now needs to start watching both pressure and color in his block. As pressures start to drop to the 15-lb level, a management decision needs to be made as to whether the grower will make another pick for CA and perhaps include some lesser colored fruit, or wait for more color and put the next pick into regular storage. Experience over the past several years indicates that growers who put more Jonagolds into CA, even though they might have had a higher percentage of lighter colored fruit, did much better on their returns than growers who waited for color and sent less firm fruit into the regular storage marketplace. This season (1996 crop), we had 2/3 of our state's Jonagolds in regular storage and the marketing of these was a major challenge and headache for most of our sales organizations. If we, as an industry, can get 2/3's of our Jonagolds into CA rather than regular storage, we will all make a lot more money.

When the pressure on medium to large size fruit approaches 14 lb our bite checks will show a noticeable loss in firmness. At this point, color should cease to be a factor in determining when to make that next pick.... It's now! A majority of those greener Jonagolds still on the tree will never get to a commercial color level at an acceptable level of firmness. You and your warehouse will have to make a serious evaluation at this point as to the disposition of the remaining crop. Does it have enough color and pressure to warrant going into regular storage, or should some or all of the last pick be sent to the processor for field run peelers? This is a very tough decision and one that has to be decided on an individual block-by-block basis.

I know that the high quantities of light colored, and/or soft Jonagolds available for sale during this year's regular storage destroyed our price structure for top grade Jonagolds and cost us all a great deal of money. Again, and I'm preaching, we need to get more Jonagolds into CA and refrain from packing too many Jonagolds, especially those of lower color and pressure quality, through our regular storage Jonagold pools. The warehouse needs to get a little tougher by not always accepting and packing everything our growers give us.

Decoster Jonagolds

Now for Decoster Jonagolds. Decoster blocks tend to have a much higher percentage of commercially red apples per tree than do the Nicobel or standard strains of Jonagold. I must say, though, that a second or third leaf Decoster Jonagold is probably the ugliest and worst-tasting apple I run through my warehouse. By the fourth and fifth leaf, though, it is probably the best. In either case, the Decosters, in general, return more money than any other Jonagold strain I run through my warehouse.

As you walk through your Decoster block you will have a tree here or a tree there which will have a limb, or the whole tree, with fully red fruit on it a week or more before the rest of the orchard. I've observed this in every Decoster block I have ever been in. Unfortunately, most of this fruit is also usually very large, which means it will have a natural tendency to lose firmness quite quickly. The red color also means it is already much more mature than the rest of the fruit in the orchard. I have my growers bite check these early "pumpkins" frequently. As soon as they start detecting a drop in firmness, I recommend they send a small crew through and pick anything that's red enough to get marketed. They need to get this fruit into storage as soon as possible. There may be only 10% of the crop picked at this time, but if the grower waits and picks this fruit with his normal "first pick", these huge red ones will usually be over-ripe and below commercial quality for firmness. If I have a Decoster grower who has not done this initial skimming pick, we will probably program all his 56's and larger to go directly into the cull bin because a majority of this large fruit will be too soft to market without adjustments. Unfortunately, he will probably lose quite a bit of good fruit in the process. Once science develops an on-line nondestructive pressure sorter for our industry, we won't have this problem.

Once past this "skim pick" the decisions for picking Decoster will be identical to the Nicobels or standard types, with the exception that there will be a lot more "red" apples available to pick on each pass through the orchard.

In summary, above 15 lb, you are pretty much free to pick whenever you can market. At 15 lb you need to make a last pick for CA, or let the fruit hang a little longer for color, but plan to put that pick into regular storage. At 14 lb, color is no longer a factor of determining when to make that next pick and you need to make your final commercial pick soon. Lighter colored regular storage fruit, especially if it is low in pressure, should be diverted to the processor because it will not have the legs to sit in a box waiting to be sold.

I would like to mention that the western Washington Jonagold growers are putting together a two-day Jonagold conference to be held July 31st and August 1st in Mount Vernon, Washington. I've seen the proposed program and it looks great! Besides local speakers and tours, it will feature a couple of speakers from the east coast who are Jonagold nutritional experts. I am helping them by putting together an address data base of northwest Jonagold growers. If you would like to be on that list feel free to contact me.

Phill Fossum

Fossum Orchards

13th Annual Postharvest Conference
March 1997

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