50 The Horticulturist' s Rule-Book. 



Peach, continued. 



LEAF-RUST. See under Plum, 



POWDERY MILDEW. See under Apple. 



YELLOWS. The first symptom in bearing trees is usually 

 the premature ripening of the fruit. This fruit contains 

 definite small red spots which extend to the pit. The 

 next stage is indicated by very slender shoots, which branch 

 the first year and which start in clumps from the old 

 limbs, bearing narrow and small yellowish leaves. Later 

 the entire foliage becomes smaller and yellow. In three 

 or four years the tree dies. The disease spreads from 

 tree to tree. It attacks trees of any age. Known at pres- 

 ent only in regions east of the Mississippi, more particu- 

 larly in the north-eastern states. Peculiar to America, 

 so far as known. 



Preventive. -Burn all trees as soon as the disease ap- 

 pears. Laws aiming to suppress the disease should be en- 

 acted in all peach-growing states where it has appeared. 

 Pear. BLIGHT (Micrococcus amylovorus, Burrill). Dis- 

 tinguished by the blackening of the entire leaf, and the 

 blackening of the bark. It may destroy branches or the 

 whole tree. Generally distributed east of the looth 

 meridian. Known only in America. 



Remedy. As soon as the disease is discovered, cut off 

 the affected parts a foot below the point of lowest visible 

 attack, and burn them. 



LEAF-BLIGHT and CRACKING OF THE FRUIT (Entomosporium 

 maculatum, Lev.; Morthiera Mespili is the same). At- 

 tacks nursery stocks of pears, beginning as small and cir- 

 cular brown spots on the leaves ; soon the entire leaf turns 

 brown and falls. Also causes the cracking of the fruit. 

 Remedy. Bordeaux mixture, applied four or five times. 



ROOT- ROT (Polyporus versicolor, Fries). Attacks the roots, 

 the white and felt-like threads of the fungus at length be- 

 coming very abundant and conspicuous. The trees pro- 

 duce a short and thick growth, the new wood being 



