Here in Idaho we do have problems with codling moth, and a few fungal problems too!
I have tried for seven years to get more non-wormy fruit. I have failed all but 2 years. Often having 90+% wormy apples!
Last year I sprayed every 2 weeks with various chemicals; Diazinon, Malathion, Combination fruit tree spray, Neem, Copper Soap Spray. For some of the trees I had 90+% good fruit.
This year I began the spray thing, then reading here I thought I would try the apple bagging. I did spray 2-3 times with Diazinon, timing this at the peak for codling moth egg hatch. then following with more at 7-14 day intervals.
I bagged 1000 apples with my 2 children helping in about 3-4 hours total. We used fold top baggies, and zip lock bags that both types needed a staple or 2 to keep them on the 3/4″ – 1″ fruit. I used plastic, as not yet hearing about paper.
I have 5 apple varieties that I bagged and tried to get good coverage on most trees.
The Gravenstein I probably bagged 60% of the 1000 apples. Of the bagged apples they were 99-100% clean with out worms or other damage. Compared to the un-bagged; 50% clean: no bugs or damage, 30-40% had worms, 20% had bird damage eating the best fruit. So I consider this a success! It kept the birds away and the second generation of codling moth was kept off most of the fruit.
On the other trees I did have some success, but it varied depending on the tree.
The Gold Blush, the tree had 90% of the apples bagged. I did not notice much difference in the unbagged for wormy apples. But I did notice there was a new problem with the bagged fruit; the blossom end of the apple having a fungal black spot, even going slightly into the core. This happened on about 30% of the bagged fruit. I did have the corners trimmed on most of the bags, as a drain hole. I did not notice water in those particular apples. Other trees and apples had a few tablespoons of water in the bag, with out the black spot.
The Jonathan Sport, had 80-90 % bagged fruit. I did have some wormy fruit on this tree this year. I may have not sprayed it as many times. I did have several apples even in the bags with wormy apples. So they may have gotten in there early than I bagged them. These colored up just as well with or without the bags. Beautiful fruit and yes probably a reduction in the percentage of wormy fruit. But not as good as the others. This is the tree that I have problems with powdery mildew. This was never a problem with the fruit once it is set, but more a problem with the leaves and buds for next year. No noticible difference in Powdery Mildew.
The Golden Delicious, we bagged a few hundred apples trying to save a heavy and nice crop. We thinned heavily before bagging and noticed a few spots on some of the apples, maybe hail. We bagged 90% of the apples and had 99% clean non-wormy fruit. As these were ripening the birds were busy and got several unbagged and even a few of the bagged apples were eaten by birds and squirrls. We did have some sun burn on a few apples, bagged and unbagged. Then I probably picked these a bit too late and we did have lots of the apples in storage now wrinkling up and getting soft. I do not have refrigeration or even a very cool shed, in September it was still very warm, and now we have just had our first frost 10/26/04. So I am just wondering if the bags added to the wrinkling of the skin of the stored fruit? I did not keep them separate after bringing them in and puting them away. So I am not sure if the wrinkling was related to bags or just ripeness.
The Fuji, was the last one that we just picked. I did a much better job of the #’s on this one. It had only about 30-40# of apples on the whole tree. After several samples and some going to the fair and such. We picked 30 apples that were bagged. of these there were 21 clear no worms or damage. 3 bagged apples had worms, and 6 bagged apples showed some damage: bird, splits (3 apples in bags had water in the bag and had splits in the skin some damaged badly) or spots bigger than 1/4″. Of the 37 unbagged apples; 20 were clean with out damage or worms. 10 unbagged apples had worms. and 7 unbagged apples had damage.
Note: these are observations from the surface on most of these apples. I have not cut into these to find worms, in most cases. We did not have problems with bagged apples falling early, and we did loose a few bags to wind.