Tomato Spotted Wilt Virus Alert UNIVERSITY PARK (Centre Co.) Tomato spotted wilt virus (TSWV) has a wide host range and is a serious threat to many greenhouse crops. The chances of having TSWV infection in your greenhouse may be greater in the spring than at any other time simp ly because you are growing more susceptible plants coming from a number of different places. More than 175 plant species can be infected with TSWV. The chart below lists a number of these. There is no cure for infected plants. Infected plants should be destroyed. The western flower thrips is the chief TSWV vector in green houses, although nine thrips spe cies have been identified as vec tors, according to John Sanderson, Dept, of Entomology, Cornell University. Prevention of TSWV depends on control of western flower thrips. Only a larval stage of thrips can become infected with the disease, and transmission is almost always by adult thrips. Adults do not transmit TSWV to their offspring. Overlapping generations account for the continuous spread of the disease. Plants may develop the disease within 5 days of infection. There is no cure for the disease which spreads rapidly in the greenhouse and has been a parti cularly serious problem with glox inias and tomatoes. Fortunately the disease has not yet been found in geraniums, poinsettias, or roses, our three major greenhouse crops in Pennsylvania. Prevention of thrips infestation is the only method of control. Since plants already have the disease by the HORSE FENCE CALL OUR 1-800-333-0569 FOR THE REPRESENTATIVE IN YOUR AREA! 2525 Walden Avenue Buffalo, NY 14225 Dealerships Available time you spot the symptoms, early detection is critical. Management of TSWV • Deep seed and vegetatively progagated plants separate. The virus is not seed transmitted, but assume that cuttings from infected plants are infected. • Inspect new material for signs of thrips feeding inujury with TSWV infection. Destroy any infected plants. Individual flowers can be checked by tapping a blos som over a piece of paper and inspecting what falls out Thrips are particularly fond of white and yellow flowers. • Try to break the thrips infesta tion between fall and spring. • Eliminate and discard weeds; most harbor thrips. • Monitor the insect population with sticky cards. • Blue sticky cards seem to be more effective in attracting thrips populations than the standard yel low or white. HORSE FENCE FOR LANCASTER/HARRISBURG/YORK AREAS CALL: QUALITY FENCING - (717) 354-9760 622 N. Shirk Road, New Holland, PA 17557 Potted crops Cut Flowers Bedding Planta Perennials Vegetables African Violet Anemone Agcratum Aster Bean Amaryllis Calendula Begonia Campanula Cauliflower Calceolaria China Aster Calendula Columbine Celery Calla Lily Chrysanthemum Coleus Coreopsis Cowpca Christmas pepper Cosmos Dahlia Dahlia Cucumber Chrysanthemum Dahlia Dusty Miller Delphinium Eggplant Cineraria Delphinium Forget-Me-Not Evening Primrose Endive Cyclamen Gerfoera Impatiens Gaillardia Lettuce Exact im Gladiolus Marigold Lobelia Pepper Geranium Gypsophila Morning Glory Lupine Potato Gerbera Peony Nasturtium Peony Spinach Gloxinia Snapdragon New Guinea Impatiens Ptdox drummondi Tomato Hydrangea Stephanotis Petunia Poppy Nonstop begonia Stock Salvia Tiger lily Primrose Zinnia Snapdragon Ranunculus Verbena Rieger begonia Zinnia Sinningia The Leader In "p -,N - VINYL ♦ FENCING dm. • Placement should be just above the pant canopy at the ends of benches, walls, doors and vents. • Use from 1-3 cards/1000 square feet. • Weekly counting of thrips on each card will aid greatly in timing and distribution of control procedures. • 10 thrips per card per week is the suggested threshold guideline for the application of control. > Chemical control should be monitored carefully. • Rotate materials among chemical classes every 3 weeks. • Repeat applications will prob ably be necessary, consistent with label directions for the chemical use. TSWV symptoms Symptoms vary with species and may also vary with cultivar. Some plants don’t exhibit symp toms. The most common symp toms are yellow or brown rings pots or other line patterns; black VA ” PICKET FENCE YARD FENCE Lancaster Farming Saturday, April 21,1990*023 streaks on petioles or stems; necrotic leaf spots; and tip dieback. These common symptoms may not always occur, and some plants will exhibit symptoms unlike those listed. When you discover plant material with unusual symp- W. Va. Conserves Soil MORGANTOWN, WV West Virginia soil conservation districts approved plans in the last four years to conserve highly erodible soil in crop fields on 3,383 farms, according to Rollin N. Swank, state conservationist at the U.S. Department of Agricul ture’s Soil Conservation Service (SCS). The conservation plans were for 84,214 acres of highly erodible cropland so that farmers could remain eligible few USDA pro grams and benefits. Under the 1985 Food Security Act, they toms isolate the plants immediate ly and, if necessary for positive identification of the problem, con sult your county cooperative extension office or have the plants analyzed by the Penn State Dis ease Clinic, Buckhoul Lab, Uni versity Park, Pa. 16802. were given until Dec. 31,1989, to make the plans. During the fiscal year that ended Sept. 30, 1989, SCS assisted with conservation land treatment on 62,182 acres, 27 per cent more than in 1988. The soil saved from new measures was up by 13 percent to 266,121 tons per year. SCS soil scientists mapped 362. 61S acres in 1989 to extend mod em soil surveys to 13 million acres, or 83 percent of the state. Surveys have been published for 33 counties. 3” PICKET FENCE POOL FENCE
Significant historical Pennsylvania newspapers