164 STATE HORTICULTURAL SOCIETY. 



ply this want. While it has been possible by the use of certain sprays, 

 such as Bordeaux mixture and Paris green, to effectively reduce these 

 troubles, the sensitiveness of the foliage and fruit of the peach has practi- 

 cally prevented their employment, and the peach grower has been almost 

 helpless against them. A spray effective in the control of these troubles 

 and which at the same time may be used with perfect safety on the trees 

 and fruit has been the most important requirement to place the industry 

 on a reasonably secure foundation. 



Experiments begun by the Bureau of Plant Industry some three or four 

 years ago and carried out under vailing climatic and other conditions 

 in different parts of the eastern United States have established beyond 

 question the effectiveness of the self-boiled lime-sulphur wash for the 

 control of the fungous troubles mentioned. Earlier experiments by the 

 Bureau of Entomology had already shown that by the proper use of 

 arsenate of lead the curculio could be largely controlled, though on ac- 

 count of danger of foliage injury its use had not been unqualifiedly rec- 

 ommended. Cooperative experiments between the two bureaus have 

 shown that the fungicide and arsenical may be used as a combined spray 

 with satisfactory results in controlling these troubles and without injury 

 to the fruit and foliage of the peach. Hence, there is now available a 

 satisfactory method for the control of these three serious obstacles to 

 successful peach culture. 



In the following pages the brown-rot, peach scab, and curculio are 

 treated with reference to their occun^ence on the peach, and results are 

 given of experiments and demonstrations in their control conducted 

 jointly by the Bureau of Plant Industry and the Bureau of Entomology 

 during 1910. The writers were assisted in this work by E. L. Jenne 

 and E. W. Scott, of the Bureau of Entomology, and by Leslie Pierce and 

 G. W. Keitt, of the Bureau of Plant Industry. 



BROWN-ROT. NATURE AND CAUSE OF THE DISEASBl 



Brown-rot is a fungous disease which affects the stone fruits, such as 

 the peach, plum, and cherry, and to a less extent some of the pome fruits, 

 such as the apple, pear, and quince, producing a so-called rot of the fniit 

 and blight of the twigs. It is caused by a fungus known to botanists as 

 Sclef'otinia fructigena (Pers.) Schrot. Brown-rot is the common name 

 usually applied to the disease, but monilia, the generic name of the im- 

 perfect stage of the fungus, is often used by some of the older fruit 

 growers. 



The disease appears on the fruit as a small circular brown spot, which 

 under moist, warm conditions enlarges rapidly, soon involving the entire 

 fruit in decay. The spots do not usually become sunken, and the 

 fruit remains plump until almost entirely decayed. The fungus growing 

 in the tissues of the fruit breaks through the skin, forming small, grayish 

 tufts of spore-bearing threads. These tufts, although few on young spots, 

 soon become so numerous as to give the diseased area a grayish, moldy 

 appearance, which is responsible for the term "peach mold" sometimes 

 applied to the disease. The spores which are produced in great abund- 

 ance by these fungous tufts are blown by the wind and carried by insects 

 and birds from fruit to fruit, tree to tree, and orchard to orchard. Find- 

 ing lodgment on the fruit under favorable conditions of temperature 



