http://hdl.handle.net/1813/43314

DISEASES OF PEPPER W@@@U@[ID[L@ Virus Diseases

Fact Sheet ~[j@[¥)~ Page: 736.00 COOPERATIVE EXTENSION • NEW YORK STATE • CORNELL UNIVERSITY Date: 1 0-1984

these viruses reach the northern states is have a general dull appearance (fig. 3). Virus Diseases unclear. They may move north via This difference may be influenced by the of Pepper migrant aphids, which carry the viruses particular CMV strain involved, but progressively northward, passing them more likely reflects the age at which from one susceptible crop to another plants are infected. With early infection, by T. A. Zitter and D. Fiorini along the Atlantic coast. Dissemination both quality and quantity of fruit pro­ Dept. of Plant Pathology from infected transplants produced in duced will be affected. Cornell University southern states has not been demon­ CMV can infect more than 775 plant and R. Provvidenti strated. species including many weed species Dept. of Plant Pathology (chickweed, milkweed, purslane, etc.). Major Pepper Virus CMV is spread by many aphid species New York State Agricultural in a nonpersistent manner, meaning that Experiment Station, Geneva Cucumber mosaic virus (CMV) is one insecticides cannot prevent the spread of of the most important virus diseases of this disease. Strategies to delay early The acreage and value of the New pepper worldwide. The virus exists as a infection should be used to enhance York pepper crop are relatively minor, number of strains, but all are apparently yield and reduce the number of cull but peppers are still an important com­ capable of infecting pepper and differ fruit. Isolate pepper plantings from modity in commercial mixed vegetable only in symptom expression. The age of weedy border areas or grow them next and roadside market operations. Virus a plant at the time of infection strongly to taller border plantings, such as sweet diseases annually reduce yield and qual­ influences what types of symptoms will corn, which can function as a nonsus­ ity of all pepper types including bell, be manifested. CMV symptoms can be ceptible barrier crop. Mineral oil sprays cubanelle, banana, and, occasionally, transitory and often appear on lower, have been used, primarily in the south hot varieties. Cucumber mosaic virus mature leaves as ring-spot or oak-leaf in larger commercial pepper operations, (CMV) is by far the most important necrotic patterns (fig. 1). Ring-spot to interfere with the transmission of all pepper virus in New York although symptoms are more prominent on pepper viruses by aphids. No acceptable tobacco mosaic virus (TMV), tobacco determinate-type peppers. The necrotic level of tolerance to CMV is available in etch virus (TEV), tomato spotted wilt symptoms, whether they occur on the any commercial variety. virus (TSWV), and alfalfa mosaic virus foliage or on the fruit (fig. 2), are basi­ (AMY) appear sporadically. Potato cally a shock reaction attributed to early Minor Pepper Viruses virus Y (PVY), pepper mottle virus virus infection. Sometimes plants adja­ (PeMV), and TEV occur more regularly cent to ring-spotted plants display only Tobacco mosaic virus (TMV) is gen­ in the southern states. How some of a mild to moderate mosaic pattern and erally not a problem for pepper because most varieties are resistant to the com­ inoculum. Because PVY is tuberborne Tomato spotted wilt virus (TSWV) mon strains of the virus. Resistance is in potato, isolation of peppers from can cause disease in a wide variety of conferred by a single dominant gene, potato plantings would be prudent. plants including pepper, tomato, and but two additional factors may be Other controls for PVY include choos­ lettuce. The virus is common in both involved. Resistance operates by allow­ ing resistant varieties, which are pres­ temperate and subtropical areas of the ing infection to occur on inoculated ently limited, but should increase in world. Thrips transmit the virus, but leaves, which develop necrotic local number as more breeding is accom­ only larvae, and not adults, can acquire lesions and abscise prematurely, thus plished; weed control; and other the virus. Thus, only adults that fed on preventing the virus from spreading sys­ methods outlined under CMV. infected plants as larvae can transmit temically. Some strains of TMV, how­ Tobacco etch virus (TEV) normally the virus and then only after a latent ever, can systemically infect pepper and occurs along with PVY. However, spo­ (incubation) period of 4-10 days. This cause a mosaic on the foliage. Those radic occurrence of TEV alone has pre­ type of transmission is much different strains are transmitted through seed, viously been noted in New York. from aphid transmission. The virus and the virus may also be mechanically Typical symptoms consist of broad causes sudden yellowing and browning spread by contact. Growers should be dark-green mosaic bands along the of the young leaves, which later become sure to start with healthy transplants. veins, beginning at the leaf base and necrotic (fig. 8). Fruit formed after Potato virus Y (PVY) is a common often continuing to the tip (fig. 5). The infection develop large necrotic blotches. virus among solanaceous crops, infecting planting of PVY -resistant varieties gen­ Use of insecticides to control the vec­ potato and tomato in addition to erally helps control TEV because resis­ tor reduces disease incidence. Elimina­ pepper. In southern states PVY ranks as tance to both viruses is closely linked; tion of virus reservoirs (weed and one of the more important vegetable however, there are a few strains of TEV ornamental species) near the crop is viruses. The symptom most useful for that can infect PVY-resistant varieties. important but difficult to achieve. diagnosing PVY infection is a mosaic Other control measures have already Alfalfa mosaic virus (AMV), or pattern that develops along the veins, been noted. "calico mosaic" as the disease is called commonly referred to as veinbanding Pepper mottle virus (PeMV) bears when this virus infects potato, can occa­ (fig. 4). With early infection, plants are many characteristics in common with sionally be recovered from pepper. stunted, fruit set is reduced, and fruit PVY and TEV, including symptom AMV is aphid transmitted in a nonper­ express strong mosaic patterns making expression. Veinbanding, as seen with sistent manner and produces spectacular them unmarketable. PVY, is present, but the mottling is white or yellow calico symptoms on sola­ Like CMV, PVY is transmitted by more extensive in interveinal areas and naceous crops, but milder symptoms several aphid species, but the green over the entire leaf surface (fig. 6). Fruit on crop resevoirs like alfalfa and clov­ peach aphid is generally considered to mosaic as noted in figure 7 is common ers. Infection probably causes little be the most important vector. PVY has for TEV, PVY, and PeMV. PeMV is damage to pepper. Isolating peppers a limited host range, so elimination of limited to solanaceous spp., and control several feet from alfalfa and other solanaceous weeds bordering the crop measures are those mentioned for other legumes should diminish the chance for would remove one potential source of pepper viruses. infection.

Quantity discount available.

Cooperative Extension, New York State College of Agriculture and Life Sciences, New York State College of Human Ecology, and New York State College of Veterinary Medicine at Cornell University, and U.S. Department of Agriculture, cooperating. In furtherance of acts of Congress May 8 and June 30, 1914, and providing equal opportunities in employment and programs. Lucinda A. Noble, Director. 11 /84 CRP 4M 9134c