. Fig. 22.—Spots on blackberry stems caused by leaf-spot fungus. thracnose, and cane blight can be readily distinguished with the aid of a microscope by the spores of the fungi which cause each disease, but the symptoms on the plants are often difficult to distinguish. Practically, however, this is not important, since the treatment is the same as recom- mended for anthracnose (p. 44). Leaf Rust.—In infected plants, small, light-yellow spore pustules of the fungus Phragmidium ruhi-idaei appear on young leaves, and black spores form in the same pustules later in the season. On the variety Raner
. Fig. 22.—Spots on blackberry stems caused by leaf-spot fungus. thracnose, and cane blight can be readily distinguished with the aid of a microscope by the spores of the fungi which cause each disease, but the symptoms on the plants are often difficult to distinguish. Practically, however, this is not important, since the treatment is the same as recom- mended for anthracnose (p. 44). Leaf Rust.—In infected plants, small, light-yellow spore pustules of the fungus Phragmidium ruhi-idaei appear on young leaves, and black spores form in the same pustules later in the season. On the variety Ranere (Ranaree), the attack is usually confined to the older leaves and is not destructive except in coast districts. On Cuthbert, the rust may be very severe; it may attack all leaves and occasionally forms pustules on the canes. There is no practical remedy for leaf rust except the winter cleanup and the spraying recommended for anthracnose (p. 44). Mosaic, Leaf Curl, Yellows.—Several virus diseases of this type
Size: 1983px × 2520px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionamericana, bookl, booksubjectfruit
