Pecan weevils are beginning to emerge in eastern North Carolina. Pecan weevil is the most serious late season pest of pecan. It attacks the nut of both pecan and hickory. The adult weevils can be recognized as reddish brown to gray beetles with long snouts. Like other members of the beetle order, these weevils go through four distinct stages of development: egg, larval, pupal and adult. The eggs are white and are laid inside the pecan nuts. These eggs then hatch out into a creamy white grub that feeds and develops inside the nut. The larva then exits the nut and goes into the ground where it goes through the pupal stage. Finally the pupal stage develops into the adult that is emerging now and will continue to do so for the next 30 days or so.

Pecan weevils cause damage first by puncturing the nuts during the initial feeding. This puncturing causes the nuts to drop from the tree. Eggs are also laid in the nuts and the larvae that hatch from these eggs feed on the nut. Then, when the larvae mature, they chew an exit hole in the nut when they descend into the soil.

Pecan weevil adults usually begin emerging in August, after a heavy rain of 1 inch or more, and continue emerging through September. Pecan weevils are difficult to control but this time of the year is the best time to use control measures against the pecan weevil while the adults are emerging from the soil. Foliar sprays are the most effective control measure but they are not practical for most pecan growers, especially homeowners. For foliar sprays to be effective, the spray needs to be directed into the canopy that requires the use of commercial spray equipment. For those who do not have access to such equipment, I suggest you use the following program:

Wrap a sheet of burlap around the trunk of one or more of your pecan trees. This burlap wrap should be a few feet from the base of the tree. You will be using this burlap as a monitoring trap for the weevil. Check the trap weekly and when you find adult pecan weevils in the trap, then you need to start a spray program. A weekly spray of carbaryl has been shown to help reduce weevil populations. Soak the ground underneath the trees with the spray and soak the trunk for as high as you can reach. Spray as far into the canopy as you can but follow all safety precautions to prevent the spray from getting on you! You should count on following this program for at least four weeks or through September.

Be on the lookout for southern green stink bugs and leaf-footed bugs that cause similar damage. For more information about pecan insects and their control, see the insect note Pecan Insects and Their Management or Insects and Related Pests of Pecan.

Stem and root rot, caused by Rhizoctonia solani, can be a devastating disease of begonia. The fungus that causes this disease, is the same species that can causedamping off in seedling beds of many crops. It is also the same species that causes brown patch in turf.

Symptoms of Rhizoctonia stem and root rot include wilting, stunting and leaf yellowing. Upon careful observation, you may find at the base of the stem a soft rot. Sometimes the rotten area may dry up and form a sunken lesion. During wet weather, you may see some cream-colored or brown fungal growth. With severe cases, the plant will eventually die.

Rhizoctonia solani is a soil inhabitant and will overwinter in the soil, seeds and plant debris. The fungus attacks plant parts that contact infested soil. The fungus is spread by splashing rain or irrigation water. It is also spread by tools or anything that allows contaminated soil to contact the plant. It can be spread by propagative materials such as seed and cuttings.

There are several races of the species Rhizoctonia solani. Some of these species are host specific and some of them infect during specific weather conditions. Because of these different races, having stem rot on begonia doesn't necessarily mean that you are going to have brown patch on your lawn. Also, some races infect plants during cool and wet conditions, while other races may only infect at higher temperatures.

Once an area becomes infested with Rhizoctonia, it is very difficult to control. If possible, try to avoid planting in the contaminated area. Rotate the species of plant that you use with other species. Remove the plant debris at the end of the growing season that can harbor the fungus during the winter and can be a source of infection during the next season. If you grow your own transplants, make sure that you are using disease free seed. If you buy transplants, avoid unhealthy plants. Avoid poorly drained areas and plant in raised beds if possible.

A couple of fungicides will give some control of this disease. They include thiophanate methyl and iprodione. If you must plant in an area that has a history of stem rot, then you should make fungicide applications every 7-14 days. Otherwise, begin applications at the first sign of disease.

Powdery mildew is a common fungal disease that attacks numerous species of ornamental plants. Some plants that commonly contract powdery mildew include: Euonymus, Hydrangea, red-tips, roses, Viburnum and oaks. The disease usually occurs during cool weather with high relative humidity and is usually worse in shady areas.

The symptoms of powdery mildew can be recognized as a fluffy, powdery, light grey growth on young leaves, stems and buds. The disease can cause leaf stunting, curling and deformation. In some plants, such as crape myrtle, it may cause the flower buds to drop.

On many trees, powdery mildew causes little or no damage, therefore control measures may not be necessary. It may be wise, if possible, to avoid planting highly susceptible plants. If you do have plants known to be susceptible, then you should follow a regular spray program with one or more of the following fungicides: benomyl, sulfur, triforine, tridimefon or fenarimol. Be sure and check the label to make sure that the product is labeled for the species of plant that you will be spraying.

SEPTEMBER

09/09/96-09/10/96 - Raleigh, NC - 8 hours in A N D (for entire 2-day shortcourse) INTEGRATED AQUATIC WEED MANAGEMENT SHORTCOURSE, registration required; fee; contact Joni Tanner, 919-515-8171

09/12/96-09/13/96 - Griffin, GA - 4 hours in N T D PLANT OPERATOR'S WORKSHOP, contact Kathy D. Stubbs, 404-228-8484

09/12/96-09/13/96 - Sunset Beach, NC - credits in categories as follows: Concurrent workshops, Sept. 12, 8:00 a.m. to 12 noon, 3 hours, L N D

Session I, Sept. 12, 1:00 p.m. to 5:30 p.m., 3 hours in L N D

Seminars, Sept. 13, 8:00 a.m. to 12:30. p.m., 3 hours in A L N D; all at the 1996 SE NORTH CAROLINA TURFGRASS CONFERENCE, contact Dr. Bruce Williams, 910-452-6393

For a complete listing of pesticide credit opportunities, call me at (910) 484-7156 or E-Mail me at:

To read previous issues of the Cumberland County Nurseryman and Landscaper, click on Nursery News Archives.

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