Potatoes are a vegetatively propagated crop, and many disease organisms including several viruses and a viroid are disseminated in tubers. The important role that tubers play in virus spread is recognized by the strict requirements for foundation...

, and the production of unmarketable fruit. Early recognition of the disease, especially in greenhouse crops, is essential if the disease is to be contained. The organism is seedborne and can survive for short periods in soil, greenhouse structures, and equipment...
organism into transplant production fields in southern Georgia originated on commercial seed. If seeds are harvested by either the acetic acid extraction method or by the fermentation process, the threat of seedborne inoculum is greatly reduced...

organisms. Epidemiology and disease development The following comments address pepper Phytophthora blight (P. capsict), and in general also apply for diseases of crops listed in the table. The fungus occurs naturally in most soils and can infect Fig. 5...
(two-tailed) motile zoospores. These spores produce germ tubes that penetrate plant tissue. The cycle is repeated with the production of more sporangiophores and sporangia. When the humidity is high, the sporangia can survive for long periods. During...

rot develops slowly and may not be severe until quite late into the storage period. This decay may allow the entry of secondary organisms such as Fusarium fungi and soft rot bacteria. �CONTROL The following measures will help prevent the occurrence...
. Surface tubers infected by conidia washed from leaves. ~,'~'~:~~"~:,~~:~~,-'".~"~~~~"'~",~",~~~ ~~~~~' ~~"~ "Target" spots Early Blight Disease Cycle Adapted in part from North Dakota State University Extension Bulletin 26, 1976, 'Potato Production...

activities, and may be present in tobacco products. The virus is not spread by insects commonly occurring in the greenhouse or field. The symptoms in tomato vary greatly in intensity depending upon the variety, virus strain, time of infection, light intensity...
by this mycoplasmalike organism (fig. 8), rendering the plant incapable of setting normal fruit. Leafhoppers are generally not difficult to control in temperate climates; thus, vector control should reduce the incidence of this disease. Quantity discount available...