VARDAMAN VIRTUAL FORESTRY COMPANY

The Most Direct Link to Knowledge Workers in the Southeast Forest Economy

CRP SYNDROME: A NEW DANGER FROM FAMILIAR PESTS

In February 1990 JMV&CO arranged for and supervised tree planting on a tract that was entered in the Conservation Reserve Program (CRP). Survival was adequate when the area was inspected in May, but mortality that may eventually exceed 75% began during the summer and is continuing. Surprised and mystified at such unusual results, we searched for the cause by discussing them with the many scientists who regularly help us, and we finally learned about CRP Syndrome.

CRP Syndrome is JMV&CO's handy term for referring to the depredations caused by the white-fringed beetle and the charcoal root rot fungus acting singly or together with their allies. Although these pests have been known to scientists for years, their disastrous impacts on new pine plantations took on new importance recently when large areas formerly used for row crops began to be planted under CRP. Losses have been large, often large enough to stop the annual cash payments, so anyone considering such plantations should understand what dangers CRP Syndrome represents.

Terry S. Price, Georgia Forestry Commission's entomologist, examined our dead and dying trees on the ground and in his lab in November 1990, and we interviewed him on the spot. Here's what we learned:

JMV:	Let's take these pests one at a time. Tell us about the white-fringed beetles.
TSP:	They are South American species that were first collected in North America in 1936 and have since spread to all southern states. They have long been recognized as serious pests of cotton, peanuts, soybeans, and other crops. Adults feed on the leaves, and larvae develop in the ground where they feed on the roots. Populations build up under the row crops, where they can be controlled with insecticides. When the crops are discontinued, however, larvae go after whatever is available and feed on roots of pine seedlings.
JMV:	How can we tell that death was caused by the beetles?
TSP:	Don't pull up the seedling; this might strip off the bark. Take a spade with a long blade, and break loose a ball of soil containing the seedling. With your fingers, carefully remove the dirt from around the roots. Start at the root collar and work down to the tip. Look for areas where the bark has been nibbled off by the larvae. The bare spots are easy to see.
JMV:	Should you expect to find larvae in the soil?
TSP:	Sometimes you will find them, especially from September through May, but they move up and down in the soil. Look for yellowish-white grubs about one-quarter inch long.
JMV:	How can you tell in advance whether the beetles are there? Will they stay there forever?
TSP:	You dig up soil samples and sift them, which is probably a job for a trained entomologist. If your land is in Florida, Georgia, or the Carolinas, you probably have beetles. They will be there as long as they can find enough food, perhaps as long as three or four years after cropping ends, but the seedling roots soon grow larger, so that they are better able to withstand a little gnawing.
JMV:	Now tell us about charcoal root rot fungus.
TSP:	This fungus has been with us long as the pines have. Charcoal root rot has been predominantly recognized as a disease of pines in tree nurseries, where it is adequately controlled by soil fumigation. But the fungus also occurs in agricultural cropland soils and is known to build up under crops such as soybeans and peanuts. It is particularly active as a disease-causing agent on pines under stress (all planted pines are initially under stress) on hot, dry, sandy soils.
JMV:	How do you detect its presence?
TSP:	Under the bark at the root collar of dead seedlings, use a hand lens, and look for little black specks smaller than pepper. But the surest way is to take the seedlings in the lab and culture them. This again is a job for a trained scientist.
JMV:	Landowners cannot afford losses of this magnitude, yet they hate to let the land lie fallow for years until Nature cures the problem. How can they avoid CRP Syndrome?
TSP:	The only reasonably sure way is to scalp the planting area with a tractor-drawn plow blade, creating a bare furrow about 30 inches wide and three to four inches deep. Doing this several months ahead of planting will affect enough of both pests to reduce the hazard. Harrowing the area may be better than nothing, but as we have seen on your site, it was not good enough to save the seedlings.
JMV:	This is obviously a complicated matter. Where can landowners get more detailed information?
TSP:	If their lands are in Georgia, they can call me at our headquarters in Macon. Most of the scientific work on this problem has been done by Drs. E.L. Barnard and W.N. Dixon of the Florida Division of Forestry, PO Box 1269, Gainesville, Florida 32602, with grant support from the University of Florida's Integrated Forest Pest ManagementCo-op. The telephone there is (904) 372-3505.