You bet, you can remove them.
Not a problem at all.

Josh

In short: Can you? Yes. Should you? Probably not. But if it's just a few, go ahead.

A CLM damaged leaf will still function normally in the parts that weren't damaged and if the damage wasn't severe near the base of the middle vein (almost never is). There are stomata on both the underside and top of each leaf.

But IMHO, assuming the tree is otherwise healthy and *is in a current flush*, if an individual leaf has more than 50% damage on the top or is severely crinkled/warped/curled, I remove it. It just ends up shading below it to limit light to good leaves or limiting the spots for new growth flushes. However, I would be reasonable and never remove more than 1/5 of the leaves! That's asking for trouble.

Several websites claim CLM damage isn't detrimental to the tree and is cosmetic only. That is not entirely true or is missing the fine print *for mature trees*. For young trees even a moderate case can weaken it and the next stress that comes will take it out.

I am in the same boat with several of mine.

So just curious, what tools are you using for this year?

I agree with cebury. Better not to trim away the damaged leaves. They will provide shade for fruit and the trunk, as well as provide photosythesis. And for treating CLM, most citrus nurseries in my area are using a combination of Volk Oil and Spinosad during your infestation time. For me, it is when it starts to warm up in the spring, and then again, in the fall. I am spraying every 3 weeks in the evening, for 3 to 4 applications. Then repeating that in the fall. So far, knock on wood, this has worked for me.

Patty S.

Patty, that's not quite was Cebury said ;-)

He said the unhealthy leaf will end up limiting light available to healthy leaves below it.

Josh

Didn't mean to misquote, but those lower affected leaves are probably not going to be shading new flush, as new flush is usually above older growth, or out at the tips of branches beyond last year's leaves. And the leaves really aren't "unhealthy", just "unsightly" :-) They DO provide shade for the fruit, so if you're in an area of the country that might have strong enough sunshine to sunburn young fruit, better to leave the affected leaves. I am in an area that is heavily affected by CLM, and every one of my trees suffered damage to the existing citrus trees before we purchased the place in the fall of '09. Last season, with phermone traps and spraying, I was able to significantly reduce the attacks, but still had some damage. Here's the advice I have been following, and there is no "fine print", but in bold print about managing young trees and mature trees. It is important NOT to overprune young trees, "...Avoid pruning live branches more than once a year, so that the cycles of flushing are uniform and short. " These instructions are very thorough, and take into account several different scenarios and growing practices. I prefer not to use Imidacloprid, as it is very toxic to honey bees, and have been using a combination Volk + Spinosad, as well as phermone traps instead, and apply the spray in the evening, and just to new flush. I also try to avoid spraying during bloom times if at all possible (obviously for my area, not possible with my lemons, and they bloom all year round.) I am going to be trialing SPLAT in the home orchard setting for ISCA Technologies. I have had their regular CLM phermone traps up, which has helped, but not entirely eliminated my CLM, so I'm hoping their newer product will alliviate my issue, so I can stop the spraying. I'd really rather not spray at all, to protect my bee population. Here's info on ISCA Technologies: http://www.lbamspray.com/00_Documents/2008/ISCA%20Technologies%20SPLAT%20Page.htm

Their SPLAT product has been approved for both commercial and residential use in Florida, commercial use in California (and residential application recommendaitons are being finalized right now), and they are also working on several other FDA approvals in other citrus states as well. Great company, lots of brainpower there being applied to non-insecticidal management options from CLM, as well as other pests.

Patty S.

Here is a link that might be useful: UC IPM: CLM Management

Jaybird,
how big is your tree? How many leaves affected?
If your tree is small, keep the leaves for the time being.
If the tree is large, pluck those leaves as you please.

Josh

Thanks to everyone for your responses. I have a very large HB pummelo and large marsh grapefruit that were not significatly affected, but I have a medium sized meyer lemon, 2 satsumas medium sized and a small Ambersweet orange that were hit hard in spots. I would say the damage is over 50% on some leaves. I figured it might make them susceptible to disease, etc. In addition to just being unsightly.

I would say a big mistake I made last year was trying to fiddle with the little suckers by crushing/pinching etc. to get rid of them. Seems like i just damaged the leaves more when I tried to do that. Plus it was just an exercise in futility.

As far as my "tools" go, nothing special. Just spinosad and neem oil. I haven't sprayed yet. I have been vigelently looking for any sign. Last year I was totally taken off guard by the quantity and veracity. Hadn't been a big issue before.

Jay, depends on whether or not your state has a problem with citrus canker. Here in California, we really don't, so we don't worry so much about the CLM damage and removing it (except that it looks terrible). But, if you're in a state that has to deal with citrus canker, damage from CLM can make a tree more suseceptible to canker. I shared California's UC IPM's recommendations for CLM management, but you might want to check your state extension service's recommendations for CLM, and see if citrus canker is an issue for you.

Patty S.

Thanks Patty S.

I will probably remove them just because they are unsightly and see how that works out this year.