of numerous small, grayish-brown, dead spots which have a thick, paper appearance.Numerous narrow, dark brown streaks develop on the stem and leaf petiole. Fruits are often roughand misshapen and on the surface they have small, irregular, greasy, brown patches which renderthem unfit to market. The virus is transmitted by workers handling the crop. Avoid infection bytobacco mosaic virus, wash hands before starting to work and remove infected Spotted WiltCausal Agent(s): (viral - viral)This disease is similar to streak in that it causes streaking of the leaves, stems and fruits. Numerous small, dark, circular spots appear on younger leaves. Leaves may have a bronzed appearance and later turn dark brown and wither. Fruits show numerous spots about one-half inch in diameter with concentric, circular markings. On ripe fruit these markings are alternate bands of red and yellow. The virus also affects other vegetables and many wild hosts and ornamental plants. Thrips can transmit the disease from the wild hosts. For control, eliminate weeds around field edges and turn rows; remove infected plants when small, and control insects in the field. Curly TopCausal Agent(s): (viral - viral)Pronounced upward rolling and twisting of the leaflets that expose their under surfaces, stiff and leathery foliage, and a peculiar dull yellowing of the entire plant are typical symptoms of the disease. There is also some purpling of the veins and the plant is usually very stunted. Very few fruits are produced after infection. The virus is not transmitted through the seed or soil, nor is it spread by mechanical means. The main vector is the beet leafhopper that becomes infected by feeding on wild or cultivated plants having the disease. The disease is difficult to control. Keep field surroundings free of weeds. Controlling insects may effect some control....
