Dead trees

We have a small cider apple orchard - 500 trees on B118. 8 + varieties. Orchard 5 years old.

This spring (the coldest and wettest in 20 years) we have lost 50+ trees - over 3 or 4 varieties. Some were definitely in standing water for weeks.. Up until now they seemed to be thriving.

They all leafed out and then just died. No evidence of powdery mildew or the like.

How do we ascertain the cause of their demise?


Thanks
Joanne

G2V Farm
Zone 5B/6
Gaspereau Valley, Nova Scotia
Canada



Edited 1 time(s). Last edit at 06/12/2019 06:22AM by Michael Phillips.

Look below, Joanne. I suspect that Phytophthora is the issue. Root rot fungi claimed the niche at the buried base of the tree and destroyed the cambium. You will find extant bark down to the soil line and then things turn soft and mushy. The demarcation will be a sharp line between the reddish-brown (diseased) and white (healthy) portion of the crown or major roots. This reddish discoloration between diseased and healthy tissue distinguishes root and crown rot from other causes of tree decline and collapse such as “wet feet” (drowning) or winter injury. Asphyxiation is the other possibility . . . wet ground for an extended period is hard on trees.

Lost Nation Orchard
Zone 4b in New Hampshire

Thanks Michael

I have cut into a few of the trees and there is no demarcation - just brown tissue. The roots are not mushy or smelly - but they are dark. The smaller roots are paler.

They were in wet, wet soil last fall (and high winds which almost toppled many of them) and this spring were certainly soaked. They mostly started to leaf out and then just shriveled and died.

I am attaching a couple of photos of a tree we dug up an rinsed the roots.

The majority of dead trees were 3 years old. Someone else has suggested apple replant disease? Last summer all these trees were spectacular....very healthy looking and vigorous.

Our local agriculture person will come next week and make a diagnosis and suggestions .




Hope the images work


Joanne

Bingo Michael!

Phytophthora it is (

We continue to have wet weather and so I anticipate losing even more trees.

We installed some tile drainage 7 years ago but obviously not enough. Will see if we can introduce some more to alleviate our issues and commence to digging up dead trees.


Joanne