14 CONTROL OF PEACH BROWN-ROT AND SCAB. 



The disease mars the appearance of affected fruit, reducing its 

 market value and often rendering much of it unsalable. The large 

 cracks which occur in severe cases open the way for brown-rot, and 

 in addition the skin under the individual spots is usually broken, 

 exposing the peach to attacks of the fungus. Preventing the scab is 

 therefore an important step in the control of brown-rot. 



The fungus forms brown spots on the twigs where it passes the 

 winter. So far as is known at present, these twig spots are the chief 

 source of infection of the fruit. Fruit infection begins to take place 

 about three to four weeks after the petals fall, although the spots do 

 not show until about three weeks later. Infections continue to take 

 place until about a month before the fruit matures. 



ECONOMIC IMPORTANCE OF THE DISEASE. 



Peach scab has been known in this country for many years, and 

 it occurs to an injurious extent wherever peaches are grown east of 

 the Pocky Mountains. The damage done by this disease is appar- 

 ently not fully realized by peach growers. Scab spots are so com- 

 mon on the peach that most of the eastern growers have come to 

 take the disease as a matter of course and scarcely realize that their 

 fruit is bringing 25 per cent less in the market than the same fruit 

 free from scab would bring. Moreover, the fungus has a tendency 

 to dwarf the fruit and prevent it from attaining full size, so that a 

 considerable loss in 3aeld is thus sustained. 



On the other hand, some growers recognize it as their worst enemy, 

 and in many localities it practically prohibits the growing of certain 

 varieties. Some of the large orchards in the mountains of West Vir- 

 ginia and western Maryland have sustained heavy losses from this 

 disease, and the growers have been obliged to confine their plantings 

 of such late varieties as Bilyeu and Salway to the high ridges in order 

 to avoid scab. The Bilyeu is very valuable commercially, but the 

 scab has restricted its successful production to the higher points. 



It has been known for some years that peach scab could be con- 

 trolled by applications of Bordeaux mixture, but its use for this pur- 

 pose has been discouraged by its injurious effects upon peach foliage. 

 The disease has therefore been practically without a satisfactory 

 remed}^. 



SPRAYING FOR THE CONTROL OF PEACH BROWN-ROT AND SCAB 



IN 1909. 



As stated in the introduction of this paper, peach brown-rot and 

 scab were effectively controlled by spraying with a self-boiled lime- 

 sulphur mixture in experiments conducted during 1907 and 1908. 

 The work of 1907 was confined to small plats in one orchard, while 

 that of 1908 involved several orchards in different localities, aggre- 

 gating about 2,000 trees. 



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