DISCUSSION OF PLANT INDUSTRIES 453 



roses are often treated in the same way with striking results. 

 Many of the large and perfect flowers and fruits that are shown 

 in exhibitions are developed in this way. Successful orchard 

 growers prune their trees moderately each year, and thus main- 

 tain the quality and quantity of woody branches from which the 

 largest yield of good fruit may be secured (Fig. 350). Checking 



FIG. 349. Photograph by the New York Agricultural Experiment Station 

 illustrating the results of spraying potatoes to prevent disease 



Those that were not sprayed yielded at the rate of 161 bushels per acre ; those 

 sprayed three times during the season yielded at the rate of 350 bushels per acre ; 

 those sprayed every two weeks yielded at the rate of 380 bushels per acre. In 

 other experiments the results are even better. In this same station, during the 

 year 1904, the average gain per acre in the yield for three sprayings is 191 bushels, 

 and for spraying every two weeks is 233 bushels 



the vegetative growth of the plant at the right time seems to 

 stimulate flower and fruit production. All kinds of orchard 

 trees are more productive when properly pruned. In recent 

 times pruning in order to facilitate proper spraying has become 

 a prominent feature of the work. The various factors that are 

 now involved in the practice of pruning are of such importance 

 that the subject has become almost a specialty in itself. 



