FARMERS' INSTITUTES. 57 



The Strawberry leaf-spot. — The small, rounded spots of a grayish color 

 with purplish centers which appear on strawberry leaves are due to the 

 attack of a parasitic fungus. During the summer the fungus gives off 

 small spores from these spots which spread the disease to healthy leaves 

 and after these die another spore form is produced on them. This 

 spore form lies dormant over winter, starting the disease again in spring. 

 By destroying the old leaves many of the spores will be killed and the lia- 

 bility to attack reduced. This may be accomplished by burning over the 

 rows after fruiting, with a little straw, or the leaves may be mowed off, 

 allowed to dry and then burned. Spraying with the Bordeaux mixture 

 is practiced by large growers. 



Anthracnose of raspberry and blackberry is a common disease of the 

 canes, especially in neglected gardens. Its effects are often very notice- 

 able, the canes being sometimes almost covered with the canker-like 

 spots. Such canes produce a slender, sickly growth, while the fruit pro- 

 duction is much reduced. The disease is least apt to attack plants which 

 are well tended; cultivation, cutting out old and diseased canes are 

 desirable in the way of prevention. Spraying with copper sulphate before 

 the buds start and later with Bordeaux, and with copper carbonate solu- 

 tion when in fruit, is recommended as treatment. 



Black rot of grape. — This disease is probably the most serious with 

 which the vineyardist has to contend. It attacks all parts of the growing 

 portiT)n of the vine, but is especially destructive to the fruit. The berries 

 are affected when about half groAvn and soon rot, assuming a blackish 

 color and eventually drying up, but remaining attached to the stems. 

 These black, shriveled fruits, if left over winter on the vines, or on the 

 ground, serve as agents of infection the next spring; thus they should 

 be gathered and burned or turned under with the plow before growth 

 takes place in the spring. At this time, also, the vines may be sprayed 

 with a solution of copper sulphate and, later, when in leaf, with Bor- 

 deaux mi-xture, and with one of the clear copper compounds when the 

 fruit is about two-thirds grown. 



Brown rot of peach, plum and cherry.— The fungus causing this disease 

 is probably the worst which affects the stone fruits. It is especially 

 bad on early peaches, often causing the entire crop to decay on the 

 trees before they are quite ripe. It also attacks young leaves and tender 

 shoots. The diseased fruit, like that affected with black rot of grape, 

 dries up or becomes mummyfied, often sticking together in clusters. 

 These often remain hanging over winter on the trees to spread the dis- 

 ease the coming season. The diseased fruits which lie on the ground 

 also produce a second spore form in the spring, thus giving the fungous 

 parasite a vigorous start on the new growth of the plants. 



Spraying with Bordeaux mixture has been found only partially effect- 

 ive in checking the disease and along with this should go careful sanitary 

 measures in way of destroying the old diseased^ fruits. 



Black knot of plum. — This is a ver^- common disease of the plum, affect- 

 ing the branches and causing a distorting and enlarging of the diseased 

 part. If allowed to remain these "knots" give rise to spores which spread 

 the disease to other branches and trees. 



It can be greatly checked by cutting out the swollen, diseased parts, 

 as soon as they appear, while spraying with Bordeaux will prevent fur- 

 ther attacks. This fungus also attacks the wild cherry, and these trees 

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