At what age/size are the trees too old to retrain their growth? Some are much taller than I'd like, is it too late to prune for height?
R. Steele wrote:Hi Bonnie,
Despite what many people say, the standard in Arboriculture is never prune more then 25%. Many orchardists were taught different, but as imperical testing proves otherwise, many orchardists are slowly adapting. Those experienced Arborist quickly learn less is better in prunings, as it doesn't shock the trees chemistry. Shocking the trees chemistry can increase water sprouts, and the need for corrective maintenance in structure many years down the road. If you can get by with 10% prunnings, until you restore your trees, maybe over a 3 year period. I would recomend that, to decrease the need for maintenance after restoration. The less you need to prune after restoration in maintenence, the healthier and more productive the tree will be in bearing fruit. Every family and species of tree is different, and can respond very different to prunings: some better then others.
It looks like you have sun scald on some of your truncks or scaffolding branches, though its hard to see in the pictures the extent of this, or see if its related to what may be a bacterial infection causing the ooze. You will need to properly edge those open wounds on the trunks and scaffolding, if they are not actively showing any growth to compartmentalize. The ooze may be a bacterial canker that's common in many stone fruits. Boosting the health of the tree, and it's immunity will help drastically. Get your soil healthy, proper water, and the trees will suprise you. I would recomend a well balenced properly made, multi imput aerated compost tea, foiler feed and root drenched, to give immediate help, while you establish that BTE mulching system. If you want I'll share my compost tea recipe, which in unhealthy plants can do amazing things to help restore health.
For the coddling moth, the larve I suspect is whats leaving its frass on your apples, or those orangish blobs. I'm not sure if BT has an effect on coddling moth larve, but if it does, treating now will be fine to break the reproduction cycle, which those larve from now, will likely be attacking your trees next year. The BT bacteria will persist like a contaminated bio hazard zone for a given length of time, to those pest which are susceptible to it. There are other strains of paracitizing bacteria used in agriculture that may work, if BT doesn't host on coddling moth larve. The treatments won't save this years fruit, but will infect the larve from this year while they try to reach pupation. Eliminating them will drastically help reduce next years moth population, as sometimes many reproductive cycles of pests happen in a given season. If bacteria doesn't work on them, there are things that will. Though the coddling moth most likely pupates like other moths, maybe rolled up in a leaf, in dense foliage. When you get your soil and irrigation fugured out, it will be worth the effort to introduce a variety of paracitizing nematodes to your soil. They will stop the pupation of larve, that after exiting the fruit, pupate in the ground, like the apple magot, which in most areas is a problem too. The paracitizing nematodes are specifically selected, and harmless to anything but their spacific host range. So they only host most ground pests, including destructive root nematodes. You may also look into hormone traps for the mature coddling moths, and a bug zapper on at night, during the beginning of the adult coddling moth season, where the first moths of the season are flying about. If it gets to the worst case scenario, you can see if suround clay is an option you want to consider, especially if you run into other problems, like with cuculio weaves on your stone fruits; however, that weavel is a whole other subject....lol.
I hope that helps!
F Agricola wrote:Those sappy holes are likely to be borers. These can be killed by various means – remove the sap by hand and poke a piece of wire in the hole to kill the grub (organic), and/or, using a systemic spray to kill them (not organic).
The split bark could be caused by two main things – heat and irregular watering. The bark could be painted with a lime solution similar to Europeans painting fig and citrus trunks. The irregular watering issue is pretty straightforward – compost, mulch, keep them consistently moist.
(Organic lime paint mix: 500ml water in a bucket, add 1 cup of hydrated (builders) lime, add 5ml of linseed oil. Mix and add more lime or water to make a slurry like house paint, use a sturdy paintbrush to apply. It will wear-off, but also feed the plant and keep many bugs away – when all the trees are painted that way, it looks rather neat and tidy too.)
In regards to pruning, there are two basic shapes for pruned fruit trees (notwithstanding espalier):
1. Stone fruits, or drupes, should be made into a vase shape – an inverted pyramid.
2. Pome fruits, like apples and pears, should be trained into a pyramid shape.
Best to trim AFTER the last fruit are picked, when the leaves are still there – that way the trees will put on more buds and flowers next year. If you trim in winter, when they’re dormant, the trees will put on more new growth and less fruit.
Codling Moth isn’t an easy bugger to control – it’ll take several seasons. The following link is very helpful:
CODLING MOTH TREATMENT