No. 6. DEPARTMENT OF AGRICULTURE. 591 



This, however, by no means represents the total benefit derived 

 from the control of this pest. For where the insect is controlled 

 by this spray method the foliage continues healthy and a thrifty and 

 hardy cane growth results, which withstands the severity of the 

 winter, and is thus in condition to produce a good, or even increased 

 crop, the following season. 



This is illustrated by the results secured in an experiment cov- 

 ering two consecutive seasons. A portion of a vineyard upon which 

 this experiment was conducted had been badly infested for several 

 years and the vines were much weakened as a result. 



The yield on this block of vineyard was as follows: In 1909, 

 before spraying commenced, 2G2 baskets per acre; 1910, after one 

 spraying, 423 baskets per acre; 1911, after one spraying, 796 baskets 

 I)er acre. 



These results show a yield thi-ee times as great at the end of 

 the experiment as at the beginning. 



The favorable results obtained in this effort to control this pest 

 by the tobacco spray has atti'acted considerable attention in the 

 vicinity of North East, Pa., and should the insect appear in injurious 

 numbers during the coming season a much greater number of vine- 

 yardists are planning to resort to this method of control. 



SOME IMPORTANT DISEASES OF APPLES AND PEACHES 



By H. R. FULTON 



Out of the numerous diseases that affect these two important 

 fruit crops, more or less seriously, we must, because of limited time, 

 S])eak rather briefly of the most important only. Most of them are 

 old and familiar foes. HoAvever. I shall take the risk of reintro- 

 ducing them because they sometimes bob up unexpectedly and we 

 ought to be able to recognize them, as well as know what to do to 

 prevent them. 



Apple Scab is best known on the fniit; but it may be found on 

 upper and lower surfaces of leaves, produ'^'ing indefinite, circular, 

 sooty spots of large size, or on the fruit spurs, or on the flower or 

 fruit stalks, in the latter case interfering with the proper setting of 

 the crop. When leaves are much affected, they curl and dry and 

 fall, and always then is the interference with proper leaf function 

 ing. The fruit is disfigured, or deformed, according to the earliness 

 and amount of scab infection, and is inferior in keeping quality. 



The earliest infection is during a period of several weeks be- 

 ginning at blossoming time, and is caused by a particular type of 

 reproductive body or spore, produced in large numbers at this time 

 of year in fallen leaves that were infested the previous season by 

 the Scab fungus, it having survived the winter in such decaying 

 leaves. These sjiores cause no harm unless they reach susceptible 

 apple parts, and this means a susceptible variety, and usually a young 

 stage in development of leaf or fruit. Furthernrore, th? spores after 

 reaching susceptible parts of the apple do not cause infection unless 

 the weather conditions are favorable to the gei^mination and develop- 

 ment of the scab fungus. Moist and somewhat cool weather favor 

 this, and such conditions prevailing even in midseason may some- 



