58 The Horticulturisf s Rule- Book. 



Strawberry (Strawberry Leaf -Blight or Sun-Burn), continued. 



as soon as the fruit is picked. Destroy all affected leaves. 

 The leaves are easily destroyed without injury to the plants 

 by quickly burning off a thin layer of straw which is spread 

 over the patch after the fruit is off. 

 Sweet-Potato. Black-Rot (Ceratocystis fimbHata, E. «& Hals.).— 

 A dry-rot of the tuber, and a black rust upon the stems. 

 Upon the tuber it appears in large scab-like patches, and is 

 usually evident at digging time. It may appear upon the 

 young plants in the hotbed and persist upon them through- 

 out the season. 



iJemedies.— Rotation of crops. Spray the young plants, if 

 attack is feared, with some copper fungicides. 

 Drt-Rot {Phoma batatce, E. & Hals.).— The upper end of the 

 tuber becomes dry and wrinkled and bears a multitude of 

 pimples, and its iiesh becomes dry and powdery. 

 Preventive. — Destroy all affected tubers. 

 Leaf-Blight (Phyllosticta bataticola, E. & M.). — Produces 

 white, dead patches upon the leaves, 

 itemed J/.— Spray with some of the copper fungicides. 

 Scurf (Monilochcetes infuscans, E. & Hals.). — The whole sur- 

 face of the potato becomes scurfy, and it causes the tuber to 

 shrink. 

 Preventive. — Use only healthy potatoes for seed. 

 Soft-Rot (Bhizopus nigricans, Ehr.). — The tubers rot with a 

 soft and putrid decay. It is most destructive after the pota- 

 toes are stored. 



Preycntiye.— Store in a well- ventilated, artificially warmed 

 room, at a temperature of about 70°. Store only sound and 

 perfect tubers, and remove at once any which are attacked. 

 Soil-Rot {Acrocystis batatas, E. & Hals.). — The tubers are 

 attacked when young, and the diseased portion ceases to 

 grow, causing the potato to become constricted or variously 

 contorted. 



Preventive. — Rotation. It is probable that the sweet-potato 



cannot be grown again safely on infested soil for a i^umber 



of years. 



Stem-Rot, Black-Shank.— An obscure disease attacking the 



young shoots near the ground and the tops of the j'^oung 



