Problem with Black Locust

[pkalisz]

Most of the Black Locust in the central Kentucky area where I live look unusually thin and poor this Spring. Although there was a good locust bloom, now that the flowers are gone you can clearly see that the foliage is sparse with some yellowing and wilting of leaves and die-back of branches that were alive last year. I would appreciate any ideas concerning what could be causing this condition. Thanks

[Ron Scott]

Have you had abnormally cool weather with  any "killing Frosts" lately?

[Jasperfield]

The problem is an infestation of a type of leaf minor. They attack the tree beneath the bark. During the Winter the minors return to the ground; in Spring they emerge and resume attacking the tree.

Here, in the high Southern Appalachians, the Locusts have been (dead and) dying for about 10-12 years. An infected tree will leaf out normally, albeit not vigorously, and green-up until about the middle of June. By July the Locusts have all turned brown.

The leaf minors progressively weaken the tree year by year. At the end of the growing season, chlorophyl will be down by about 70%. During Winters the tree struggles because it hasn't been able to store enough food during the growing season.

In my part of the mountains, I doubt that a live Locust will exist within three to four years. They are now almost all dead or dying.

No cure is available. The Locusts are passing into history.

[John Mc]

Another one bites the dust?!

This is getting scary. EAB wiping out Ash, HWA wiping out Hemlock, ALB going for the Maples, Beech bark disease... what are we going to have left?

[Tom]

Don't forget the new Laurel wilt that is wiping out the Red Bays and the all-time crisis of modern time, the American Chestnut, lethal Yellowing of coconut palm and the Dutch Elm disease.

Oh!  crisis!  crisis! 
Danger Master Robinson!

It's not very funny, is it. 

[SwampDonkey]

And ash yellows or some kind of microbe causing sudden dead. I had an ash that was growing vigourous and no sign of anything and was dead in a week. From green to wilted dried up leaves. I see a few line trees that seem to go quick to. We have a lot of ash in these parts, so I think we are heading down hill with that species once EAB gets here, and it will.

[woodtroll]

Another reason to keep diversity in your forest, if you can. When one species is to dominate a pathogen can easily cause disastrous affect.
Black locust and sassafras grow in stands from sucker sprouts, may be a patch of a few acres in size.  Ash and elm both planted heavy in towns, ash planted heavy in crp plantings. They are both light seeded and are early succession look at old fields they are some of the first to come in and dominate.
Pine beetle out west, stands of 1 species for thousands of acres. It is part of nature, get a dense, stressed stand and the pathogens do not have far to go to find the next host. Next thing you know it is an epidemic. 

[pkalisz]

I have concluded that the problem here was Black Locust Anthracnose (caused by the fungus Colletotrichum gloeosporioides). From what I have found anthracnose in Black Locust has only been recognized for 10-15 years. Symptoms in Black Locust looked similar to those I see in Sycamore - the first flush of leaves were small in size, turned brown and dropped from the trees; a second flush of leaves has occurred and many trees look fine now although there is more branch die-back than normal and some trees still look thin and healthy.

[chain]

I live in an intensively managed row-crop area, rice, cotton, corn, soybeans, watermelons, etc. There are many ,many, herbicides used and several of those can and will kill or damage trees, gardens, shrubs. One such herbicide will turn tomatoe, roses, and other sensitve plant leaves white. If your locusts were near crop lands then, could well be herbicide injury.

[Phorester]

Lots of variables to consider when trying to figure out what's killing particular trees. Hard to tell sometimes without looking at the trees, and more particular at the surrounding landscape to see what's going on with other trees and plants, what's been done (herbicide spraying as chain mentioned, etc.)

Black locust are indeed sensitive to herbicides. One of my old supervisors used to say that to kill a black locust all you had to do was show it a herbicide label and it'd croak.

[ncsuclell]

Will fire not help control some of these infestations?  From some studies I've read, fire has been a natural part of the landscape for most of the continent.  Some forest types need frequent, low intensity fires and some need more intense, less frequent fires.  In the SE most pests can be controlled with fire.  Laurel wilt is not one of those examples.  Just curious as to if fire could control some of these issues.

[Phorester]

I agree with using prescribed fire. I've said it before in this forum that I feel that fire is the most underutliized tool in a forest landowner's tool box. We do about 8 - 12 burns in my 2 counties each year.  About 1/2 are for site prep before replanting a clearcut with trees, about 1/4 wildlife field burns, about 1/4 understory burns.  Should be doing more of the last 2.  

Specific to black locust, in my area it's not unusual to have hundreds of black locust seedlings sprout on a site prep burn 2 - 3 days later if there is a nearby locust tree for a seed source.  It's a pioneer plant species and seeds in readily on bare ground.  But young black locust saplings can't survive an understory burn due to their thin bark.  Then of course they resprout since fire only kills the above ground portion.  But the new sprouts are shorter which makes them more likely to be eventually shaded out than the original parent tree.  Older locust with its thicker bark can survive fire. But not herbicides.....  

[SwampDonkey]

Up here hardwood forest very rarely burns and it would have to have a lot of softwood mixed in it. Most fires here are in pine and other softwoods. We will sometimes have cedar forest fires, but our ceder is in small pockets and usually wet. I've found old charcoal in white cedar from a fire about 100 years ago on the woodlot. The aspen that came back were 25-30" and almost 80 feet. It's been harvested and those that were not, fell down from old age.

We seem to have what they have termed aspen decline. I don't know if we will have large aspen. Across the country it (aspen) looks sick some summers and other years not so bad.

[Phorester]

Swamp, here in the mid-Atlantic and farther south fire was a common occurence in forests for 10's of 1000's of years and the forests evolved from its influence.  That's the reason for oak forests which could withstand fires that other species can't.  In the last few hundred years with the influence of Europeans who thought all fires were bad and didn't use it as a land managment tool like the Indians did, the fire sensitive species like maple, ash, etc., now proliferate. The decline of oak in southern hardwood forests forests are a result of highgrading that took out the seed source, but mostly a lack of fire which allowed shade loving species to shade out the oak seedlings did sprout.  And of course deer damage.......

I wouldn't think that fire was as common in your area.  Is this true or historically was there a lot fire there too?