Apple Tree Blight / Fungus

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outdoorsnz

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#295761 21-Apr-2022 13:55

I have a couple of apple trees that have a white fungus or mold looking substance growing on the stems / main branches. See photo below.

Prefer organic solution, but not apposed to using a spray if I have to.

Feels oily when rubbed between fingers. Concerned could easily spread with wind onto other trees.

MikeAqua

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#2904858 21-Apr-2022 14:26

Hose of as much as you can. Any minor branches that are very badly affected I would prune off.

Go to the hardware store and get some copper fungicide. A couple of hits of that about 5 days apart.

Over winter apply some winter oil, and a week later fungus treat again.

Repeat in late winter before bud burst.

Mike

outdoorsnz

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#2904863 21-Apr-2022 14:44

MikeAqua:

Hose of as much as you can. Any minor branches that are very badly affected I would prune off.

Go to the hardware store and get some copper fungicide. A couple of hits of that about 5 days apart.

Over winter apply some winter oil, and a week later fungus treat again.

Repeat in late winter before bud burst.

Thanks for that good advice. Do you know what that fungus is called?

Will hose now before the rain.

Yetti92

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#2904888 21-Apr-2022 15:56

Have a close look at the damage just to rule out Woolly Aphids. If it is woolly aphids them you could try a neem oil spray and apply it every few days as it will smother them and slow down their reproduction or try the Bioforce website they sell Aphidius parasitic wasps to the public and will post them out for a reasonable price. I have used these in a commercial setting before against green peach aphids with excellent effect but they do have some effect against woolly aphids. You release them and let them do their thing parasitizing the aphids by laying eggs in them.

If it's not aphids, then its probably fungal and then copper could work but it's more a protective product which will stop the fungus moving and starting rather than killing it (curative) so removing as much as you can first will help. If you buy copper try and get copper oxychloride (usually this is in a powdered form from Yates I think) rather than the liquid copper ammonium acetate. I have always had better results on crops I've managed after using copper oxychloride. Its a small difference but it matters.

The other pipfruit alternative for a low toxicity fungicide that's available to the public is Lime Sulfur, it can be very effective against fungus too probably better than copper.

Both Lime sulfur and Copper are broadspectrum, low toxicity fungicides.

MikeAqua

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#2905211 22-Apr-2022 10:09

outdoorsnz:

Thanks for that good advice. Do you know what that fungus is called?

Will hose now before the rain.

No idea, sorry. I've not seen downy fungus like that on a fruit tree before.

If it does turn out to be woolly aphids as another member suggested then winter oil (e.g. yates conqueror) with a few drops of sunlight liquid will sort them out. it works by asphyxiation and isn't inherently toxic. Neem oil as suggested will also work.

If you are spraying oil onto a plant with non-waxy foliage (most non-citrus fruit trees), do it late afternoon, when the temperature has cooled. Otherwise the oil can 'burn' the leaves. I accidentally did that to my Jalapeno's this year.

I know you are trying to stay organic-ish so I have steered away from advising you to use a chemical insecticide. But I would personally hit the fruit trees in the dead of winter and again just before bud burst. Many problems come from bugs and winter is good time to clean them out, while removing any diseased wood and any old fruit on or under the trees. Lime Sulphur is an insecticide that a lot of organic orchardists use.

Mike