324 THE FRUIT PLANTATION 



to twenty feet each way, but in sections where the sweet 

 cherries reach their full development, twenty-five or thirty 

 feet will be none too much for them. 



After the head has once been formed, sour cherries will 

 require little pruning; but for a number of years it will 

 be well to head back the upright -growing sweet cherries. 

 The injury from the winter spoken of above, as injuring 

 the sweet kinds, can be greatly reduced if the trunks are 

 shortened so that the branches will come out not more 

 than one and one -half feet above the ground. 



VARIETIES OF THE CHERRY. Of the sour varieties, May 

 Duke, Early Richmond, Montmorency, Eeine Hortense, 

 Late Kentish and English Morello are the most valuable. 

 The following sweet varieties are of value where they suc- 

 ceed: Eockport, Yellow Spanish, Elton, Gov. Wood, Coe 

 Transparent, Windsor, Black Tartarian, and Downer. 



INSECTS AND DISEASES OF THE CHERRY. Cherry trees are 

 often nearly defoliated by a s%iall, slimy larva known as- 

 the cherry-tree slug. It eats off the green portions of 

 the leaf, giving them an appearance as if burned with 

 fire. They can be readily destroyed by throwing dry road 

 dust, wood ashes, or air- slaked lime over the trees, but if 

 the trees are large and numerous, it will be easier to 

 spray them with Paris green. The so-called cherry worms 

 are the larva. of the curculio, which also attacks the plum 

 and the peach. (See Plum.) 



Although the foliage of young trees is frequently 

 attacked with powdery mildew, it seldom does much harm, 

 and the only disease to be much feared is brown -rot, 

 mentioned as attacking the plum and peach. If the 

 weather is warm and moist at' the time the trees are in 

 blossom, or just as the fruit is ripening, the injury 

 inflicted will be quite severe, and the fruit must be 

 quickly picked. The disease is most serious on white va- 

 rieties of the sweet cherry type. (Consult bulletins of 

 Cornell and Delaware Experiment Stations.) 



