60 BULLETIN 395, U. S. DEPARTMENT OF AGRICULTURE. 



(3) With finely divided wettable sulphur or self-boiled lime-sulphur three to four 

 weeks before the fruit ripens, but not less than four weeks before harvest if self-boiled 

 lime-sulphur is used. This application may be omitted in sections where brown-rot 

 is not seriously injurious. 



Midseason varieties. — ^TJie treatment recommended for early peaches 

 is applicable, likewise, to midseason varieties, such as the Reeves, 

 BeUe, Early Crawford, Elberta, Late Crawford, and Fox. For such 

 varieties, however, the third apphcation is very essential and should 

 not be omitted where brown-rot or scab injury is serious. 



Late varieties. — ^The Salway, Heath, Bilyeu, and varieties with 

 similar ripening periods should be treated as midseason varieties, 

 with the addition of an application of the fungicide alone about a 

 month after the second treatment. 



The following concentrations of spray preparations are recom- 

 mended: Arsenate of lead paste, 1^ pounds (powder, three-fourths 

 pound) in 50 gallons; stone lime, 2 to 3 pounds in 50 gallons; seK- 

 boiled lime-sulphur, 8 pounds of lime and 8 pounds of flour of sulphur 

 in 50 gallons; and finely divided wettable sulphur, 5 pounds in 50 

 gallons in the case of the paste (approximately 50 per cent sulphur) 

 used in the foregoing experiments. Directions concerning the prep- 

 aration and use of these sprays are given by Scott and Quaintance 

 (1911, p. 33-35). 



ORCHARD SANITATION. 



While the disposal of orchard refuse is a highly commendable 

 practice and thoroughly justifiable from the standpoint of the 

 control of other diseases, it appears to be of relatively slight import- 

 ance in peach-scab control, since the lesions on the hving twigs con- 

 stitute the chief source of infectious material. Though it ha-s been 

 recommended that the diseased twigs be pruned out and destroyed, 

 this procedure is manifestly impracticable in view of (1) the great 

 numbers and inconspicuous appearance of the lesions and (2) their 

 occurrence on the fruiting wood. Furthermore, such drastic meas- 

 ures are unnecessary, since the disease is readily and inexpensively 

 controlled by spraying, and httle or no injury is done to the affected 

 twigs. Less directly, however, sanitation may be practiced with 

 profit in pruning and growing the trees in such fashion as to facilitate 

 the free access of air and sunhght and in providing for as good air 

 and surface drainage of the orchard as is feasible. 



RESISTANT VARIETIES. 



Since the severity of scab injury varies materially with varieties, it 

 should be remembered that the disease may be in some degree 

 avoided by growing those varieties which are less severely attacked. 

 However, inasmuch as these are chiefly the earlier peaches, it is not 

 feasible to accomphsh very much with this method in practice. 



