606 INSECTS AFFECTING VEGETATION 



(a). A trimmed and tied vine that has failed to put out shoots. 

 Such a vine usually splits open longitudinally during hot weather. 



(b) . A vine that has sent forth shoots, the latter dying after a 

 few weeks. 



(c). Vines on which all or part of the shoots and leaves ex- 

 hibit a dwarfing; internodes short and leaves very small and often 

 crimped about the margin. This symptom is observable from a 

 distance. 



(d). Leaves of nearly normal size showing a blanched or 

 chlorotic condition and often crimped about the margin. 



(e). Apparently healthy vines with leaves and fruit shriveling 

 away and dying in the middle of or late in the summer. 



(f). The presence of fleshy or corky excrescences on the stem 

 and arms during the summer; in the autumn these dry down and 

 become reddish brown and the following spring slough off. They 

 have somewhat the appearance of new growth to heal a wound and 

 are in longitudinal ribs, 1-6 inches long; globose, tumorous bodies 

 */2-3 inches in diameter, on one side of the stem, or a gnarled growth 

 encircling the stem near the base. 



(g). The presence of minute black pimples, fruiting bodies of 

 a fungus, on a dead spur, on dead bark or on dead wood under the 

 bark. 



(h). The presence of small reddish brown spots on the green 

 shoots. The spots may be one-eighth of an inch in diameter and 

 distinct; anastomosed to form a continuous diseased area sometimes 

 extending for an inch or more up and down and half-way round the 

 shoot; or in narrow, v-shaped, longitudinal slits. 



(i). Any of the above conditions may refer to one arm only, 

 and any vine may show only a few to nearly all of the conditions 

 named. 



The thorough spraying of the trunks and green shoots of the 

 vines late in May and early June would be of value in preventing 

 new infections from the spores developed at that time. Many vine- 

 yards spray for fungous rots and insect pests, and it would be an easy 

 matter to give the trunks a little more attention. For those who 

 spray for insect pests alone it would not be a great deal more ex- 

 pensive to make up the insect poison in Bordeaux mixture, using 

 the same proportions as though the Bordeaux mixture were water. 



Since a vine once diseased is almost sure to die sooner or later, 

 eradication would seem to be one of the best means of control. A 

 diseased vine left in the vineyard is a menace to its neighbors and 

 may be the center for a general infection. Eradication of this dis- 

 ease means the renewal of the entire vine or of only a part of it. 

 N. Y. [Ithaca] E. S. B. 263.) 



Crown-Gall. This is a disease of somewhat uncertain origin, 

 characterized by the formation of rough outgrowths, or excrescences, 

 on the vines, usually near the surface of the soil. Certain forms 

 at least are known to be contagious. All plants bearing galls should 

 be burned, and great care should be exercised to avoid planting dis- 



