I have two issues.
The first is large shoots of pale crinkled up unhealthy looking leaves. I have a hunch this is a fertilizer issue, but I’m not sure what to do about it. I really tried to find citrus specific fertilizer, but they sell no such thing or anything close in my area. So at the start of the season I put a lot of age chicken manure down which helped, and to boost growth I’ve been giving it ammonia sulfate crystals and a bit of 7-7-10-1.5(magnesium) time release fertilizer. Here’s a mikan and eureka lemon for example:
Second issue only happens to my Kabosu tree, and it happened last year exactly the same. No matter what I do, about half the leaves get pale and then fall off starting midsummer.
x2 on what @Richard said, that’s definitely leaf miner…don’t know about the other issue, I was going to guess a nutrient deficiency. just noticed you’re in Japan…guess you can’t run out to the local walmart and grab a bag of sunniland 6-4-6…fish emulsion might also help.
The coloration is a symptom of stagnant processing in the roots. Notice that the veins and edges are green but the interior of panels is yellowing. Adding more fertilizer is unlikely to help. Check the roots and soil down at least 18" about 1 foot away from the central trunk.
That’s very interesting about the leaf miner. They must be very active, as almost all my new citrus growth is affected. I don’t suppose Fenitrothion or Permethrin would work on them? I have got more on hand then I’ll probably ever be able to use.
Regarding the Kabosu, it can’t be waterlogged roots, as the area it’s planted in is likely to have the opposite problem, not enough water. I do have mole trouble, which is damaging a lot of roots on all my plants.
Leaf miners only go after new growth. The general advice over here has been, as long as you have a healthy tree is to ignore them, as it’s more of an eye sore than anything.
Ok, i’m just trying to boost new growth as much as I can this year. Every year I lose a bunch of leaves and a few branches to the winter cold. I’m going to try and protect them better this winter and hopefully get a decent harvest next year.
The adults insert their eggs into new leaf growth when the leaves are very tiny … 1/8 to 3/16 inch. At that time if you spray with Spinosad it will soak into the leaves and kill the eggs. Otherwise, over the following months you’ll notice a slight distortion as the leaves grow and then total distortion when the eggs hatch and the larvae “mine” (chew) patterns through the leaves and finally emerge.
Went to two stores today, and the staff had no idea what citrus leaf miner was, even when I showed them the pictures, no idea what to do.
There is a larger store some distance away I may be able to schedule some time to get there. No guarantees about a suitable pesticide there.
I’ll spray a little bit of fenitrothion on the new leaves tonight, as it’s all I have on hand.
I was reading on the Internet someone used ivermectin. I actually have some extra liquid ivermectin used for worms in birds and dogs.
Well, I may have found a source of Spenosad based pesticide, I should have some time tomorrow to go check it out and see how much it costs.
Acetamiprid is widely available, and was also recommended for CLM.
