I seem to have a problem that is progressing. I have some trees on B9 in a trellis row. Various ages from 1st leaf to 3rd leaf. Have never had this problem in the past. Problem started with the youngest trees and is now progressing into the older trees. New growth is yellow, lacks vigor, eventually dies back. On the shortest tree, which is Linda Sweet, it was grafted this year. It pushed 12-14" of healthy looking growth and now is showing the yellowing on the newest growth. Trees in the same row showed excellent vigor last year. Now some of the older trees are showing some yellowing on the growing tips.
First picture is a 3rd leaf Liberty, 2nd picture is a 2nd leaf Williams pride (tip eventually died back and broke off) 3rd picture is the Linda Sweet that was grafted onto a 2 year old B9 root stock that showed excellent growth until recently. The B9 grew vigorously last year.
The 1st pic looks a little like iron deficiency but could be herbicide damage. The 2nd could just be a mechanical injury. Last looks like herbicide or possibly a nutrient issue.
What is pH of your soil? Any iron deficiency in the past? Any herbicides used this yr?
These trees border my nursery. I have 100s of young trees within a few steps of these permanent trees that are healthy. The older trees in this permanent row didnt show these symptoms last year, or even earlier in this growing season. The one with the broken off terminal growth started out yellow and then appeared to be die back and was then broken off by something. Soil pH is around 6.0. Which I know is a tad low but havent had issues in the past relating to pH. Herbicide use is very limited and I am quite vigilant about how I spray. The start of the yellowing has not been same for all trees.
What Levers suggests beat me to the punch. If its leaf hoppers you can see them leap off when you disturb the tips. The problem with the theory is you mention it is only affecting a few trees when here they are usually equal opportunity pests with all apple varieties. It is essential for me to control them on grafts or they can suck the life out of one after it seems to be successful.
Define heat wave! Our weather is any thing but predictable here. It has been unseasonably hot for most of June. 90s or above most days, where we would normally be low 80s. We do have strong winds most days. May was cool, overcast and damp but not overly wet for the most part. Trees are on drip. I dug down this morning and the soil was what I felt was adequately moist.
I will pay closer attention to possible insects. It doesnt seem like insect pressure has been very high this year. The small bench grafts just a few feet over dont show the same symptoms.
From the pictures you posted, I would have to say the tress didn’t get enough water especially when the hot winds kick in. As your trees become older, it shouldn’t be an issue as the roots will be larger and supply enough water to the leaves. Often when the plant is stressed, the bugs since this and will attack the plant. To me, it looks to be spider mites but it’s hard to tell from the pics.
If it were leaf hoppers, glassy winged sharp shooters, it would be a lot more than leaf damage.
I’ve had plenty of experience with drought and that’s not lack of water. Also not spider mites. I fight them all summer every yr. It could be another insect but doesn’t have that look to me.
You are a highly respected member here with a lot more experience than I and probably most members. I have a few apple trees that looked very similar and was only stating IMO, what the cause may be.
That is not true of leaf hoppers here, they only damage the young leaves as they form. That is where the protein is most concentrated- the damage they create looks just like I’m seeing in the photographs, with older leaves absolutely healthy I don’t get the sharp shooters so maybe you are speaking primarily of them. .
You are confident that sudden high heat with wind couldn’t cause the new leaves to singe? I live in a humid climate so I really don’t know. Desiccation tends to be a bit gradual here, as it is doing right now.
Yes, glassy winged sharpshooters are the only leaf hoppers that bother my trees here in Tustin CA. If a certain type of leaf hopper causes those problems, I’m sure glad I don’t have to deal them.
Its not the typical heat and wind stress I see here. But who knows maybe the heat stress just manifested itself in other ways this year. Typically the heat and wind stress manifests itself on healthy looking leaves that end up with just brown scorched looking leaf margins.
We dont typically have this high of temps in early summer so that maybe the factor that is causing these symptoms I havent seen before. Seems like the trees with the yellow leaves have hit a wall early this year and just arent pushing growth like normal. Most years my trees show continuous growth through the summer.
I think after spending some time reading today and your guys thoughts I am going to lean towards not enough irrigation for the time being and see how things progress. Thanks for the inputs.
I had something look like that on my apples and these trees are down by the creek - not dry at all. I thought it might be a nute deficiency, but new growth was right behind it. This happened elsewhere with other kinds of trees. I thought it was too much water.
