Re- evaluating bagging fruit

General Fruit Growing
#342

I am getting coddling moth damage on bagged apples.

The site is a local elementary school having a fairly substantial number of dwarf apple trees planted in two rows with guide wires in “tall spindle” practice. They are “modern”, disease resistant, late-season varieties of Liberty, Crimson Crisp and Enterprise, which are good choices for the school setting.

The idea behind bagging is the available pool of multiple volunteers contributing their time doing this, it is educational to the students to compare the bagged against the not-bagged apples for insect damage, it is motivational for the students that they get to eat apples that aren’t completely wrecked, it is a school yard and we are constrained to a non-chemical practice.

It is disappointing to me to see so much codling moth damage because it may discourage the parent-volunteers from continuing this next year.

We are using plastic Ziplock-type bags with knife cuts for the stem and for water drain slits. Not all the bags were put on tightly – some of them were bags that I put on where the zipper opened up on account of wind from thunderstorms tugging on them, others were bags prepped and applied by other volunteers who made too-large knife cuts. Maybe, diplomatically, additional training is required, but perhaps the other volunteers will observe how things work out and make changes – you have to give people some credit to build on experience.

Some of the losses are in my bags that were still holding their zipper seal. What I am observing is a lot of frass, wet frass that appears to be coming out of the calyx and getting all over the inside of the bags that I don’t want to reuse them on un-bagged, un-stung apples. I guess I should cut these apples open to confirm the presence of a coddling moth larva, but the amount of “stuff” in the bag looks a lot more than just the wet “flower petals.”

Petal fall was the end of May, and I, along with other volunteers working independently on account of virus distancing, put them on “progressively” over the month of June. There is heavy curculio presence in that orchard and we got warm, humid weather early in June here in Wisconsin, so I wanted to balance fending off the curculio against putting bags on and having the fruit drop from natural “June drop” thinning. Spreading this out also makes prepping and applying the bags more of a fun hobby activity than to have to place, I estimate between me and other volunteers, about 600 bags.

I am hand-thinning as a put bags on what looks to be the king blossom, but pollination is hit-and-miss in our climate and there were a goodly number of bags that I picked up to not litter the school yard. But lately I am getting drops (along with bags still on the tree) of golf-ball sized apples with frass coming out the calyx.

Do you think me and the other volunteers need better quality control on our bagging? Or were we getting coddling moth strikes in mid June?

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#343

@mamuang Does Blakes Pride have inferior taste? If so, I’ll graft over more of it to Warren, Magness, Harrow Sweet.

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#344

Hambone,
The two years that I had it, it was subpar and had some grit to it (I like smooth-textured pears. But do not remove your BP until you try it yourself. In your location, it may be very good. Our climate and soil is quite different. The result may be, too.

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#345

Paul,
It is a nice project you and other volunteers have done for the school.

I’d loke to offer my opinion as I’ve bagged apples for several years now. I also want to use chemical spray minimally.

As you know, there are several apple pests. Big ones are coddling moths, plum curculio and apple maggot flies.

Bagging is effective against all these but timing is not on our side.
CM and PC emerge right sround the time apples flowers and/or petal fall. You need to spray right at petal fall. If you wait until apples size up for bagging, many of them may be already damaged/infected. CM’s entry may not hard to notice. PC’s bites are easier to spot.

The only spray that could be possible in your situation is kaoliin clay, brand name Surround. It is a crop protectant and is non toxic. You may need to spray Surround 2-3 times 7-10 days apart, (sooner or later depending on how much rain you get) before apples size up big enough to bag.

If you don’t want to spray at all, there are lures to trap them but those are expensive. If you don’t spray, you will run a risk of apples are damaged even before bags are put on like you have experienced.

Also, these bugs work fast, they can do a lot of damage in a couple of nights. Spending weeks bagging apples is not recommended. It should be done as soon and as fast as possible.

Cutting a slit in the middle of a bag makes it much easier to ziplock a bag. Cutting two lower corners of a bag for ventilation is important but the size of those cuts can vary. It is more important that a bag gets ziplocked properly.

In short, I think your problem is timing. The pests did damage before you had opportunities to bag. Your bagging needs to start earlier and finsh much soinet, IMHO.

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#346

I use a paper punch on the zipper, which works quite well. I try to bag early, but whenever I have bagged, early or late, I get a huge number, hundreds, of bags on the ground, even with diligent spraying with Surround and Spinosad before bagging. In the end I manage to eke out enough apples for the two of us, but it is frustrating.

#347

The bags on the ground are more likely the regular June fruit drop - they’d drop regardless, bags or no

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#348

A retired teacher who is in charge of the orchard volunteers told me that they had sprayers to apply Surround, and I might recommend that as a pre-bagging plan.

You have to let the apples get to a certain size or putting bags on them may pull them off as soon as the wind blows. The usual recommendation on bagging is that you are going to get some insect strikes, put you pick and choose which apples to bag as part of the thinning that goes with bagging. Certainly, if one is going to the trouble to apply bags, there is really no reason not to thin as you apply bags.

Your explanation that the CM can get to the apple quite early explains what I am experiencing, and if it comes in through the calyx, it might be nigh impossible to tell that an apple got “stung.” It might take sharper eyes than mine with astigmatism adding to my aging loss of near vision (yes, I have a prescription, but peering through glasses is not the same as my youthful eyesight) to discern a CM strike, which wrecks the apple from a PC strike, which is merely cosmetic, provided there are so many that the apple puckers and shrivels.

I guess I will accept these losses rather than being anxious about them, perhaps asking the other volunteers if they would consider a plan to use Surround prior to bagging next season.

#349

It is harder to tell a moth strike of a bagged apple, especially with the large amount of rain we have had and how the frass gets smeared over the inside of the bag. But some bags have a much higher foreign-matter load and other bags look pretty clean, suggesting that the moth got to some of these apples.

#350

Yes, probably.

http://datcpservices.wisconsin.gov/pb/pests.jsp?categoryid=37&issueid=348

… but seerwiously, codling moths are not as put off by bags as apple maggots are. They may be just crawling in.

I figured my biofix was 19 Jun, here on the shores of Lake Michigan, but that was really late. As the article states, most everyone should have been at biofix by 1 Jun.

Larvicides are applied at biofix + 250 GDDF. This corresponds to the 50th percentile of first flight and the start of egg hatching. I figure I’d reached this point by 1 Jul and did my second cover spray on that date. I did my third cover spray yesterday.

#351

Paul,
“You have to let apples get to a certain size…”. That my point exactly.

To get from tiny apples to a size when bags can be applied is a few weeks. Coddling moths and plum curculios are not waiting. I’ve seen PC scars on tiny apples before.

If you use a search function here and search for Surround, there are threads talking about how to mix and spray it.

June drops of apples are apple’s way to get rid of fruit they can’t carry. I mininmize June drop by thinning off baby appples in hundreds. Most of the time I leave two apples per cluster. By the time I bag, I thin them more. Some clusters were taken out completely. With such aggressive thinning, I don’t suffer many June drop. I can do this because I only have 5 apple trees.

Even my aggressive thinning, today I surveyed my Gold Rush, I think I have left too many so I thinned some more out. I looked for bug-damaged ones first but did not have many.

Here the discarded apples.

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You can see that most were clean apples. A few had bug damage, mostly from plum curculio from the crescent moon shape characteristic. The middle one in the front row had damage from coddling moth. It is very difficult to see that tiny entry hole at the bottom of the fruit.

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image3264×2448 2.67 MB

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#352

Some of those damages were only skin deep.

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#353

I agree with mamuang, timing is everything. I bag mine at pea size and even smaller before pc are even here on the early blooming varieties and do no thinning at this time. When the bags start to drop and they will i find apples with no hits and reapply the bags until i can find no clean apples. All this usually takes aweek to 10 days for me and that is on about 60 producing trees this season. Things will change when all of my trees start producing I’m sure.

Bag prep is the key, if your bags are dropping and there is no apple inside the slit you are putting in the bags needs to be addressed.

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#354

Isn’t necessarily moths making that frass. Earwigs can make a mess in a bag

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#355

Yup. I am seeing earwigs in the bags, especially the bags that pulled loose in a thunderstorm.

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#356

Korean Giant has handled being ziploc bagged better than my other pear varieties but they have had some that went bad. On a positive note this is the time of the year that the bags start to fill out.

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#357

Each year a have few bags of apples with a mess inside and I’m guessing earwigs is the cause. Normally there are only a few and I pick them and discard.

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#358

@Auburn,
Bill,
How many Asian pears did you bags. I have a full size KG and 20th Century. There are too many pears so I don’t bag them.

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#359

I don’t have many KG. Estimating about 30. Although they are smaller I have more Harrow Sweet. Last year my KG had a lot of stink bug damage so I bagged earlier this time and they seem to be okay. Everyone loves the KG so I tried to bag all of the ones that looked like they would survive. I’ve grafted in more KG scions so eventually I should have plenty. Glad yours are doing well.

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#360

Mine are still small. I just trimmed off more this evening. I bagged most of my Euro pears as I don’t have many.

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#361

I’ve bagged my Seckels - all five of them, this year.

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