SUMMARY. 203 



The total saving of foliage iiu-reasos with the increase of copper sul- 

 phato Avhoii the aiiioiiiit <>t" limo nMiiaiii.^ constant, hut the average 

 saving per pound of copper sulpiiut<> decreases with the incnnise of 

 copper used. 



(7) In the treatment of peach leaf curl, from 95 to 98 per cent of the 

 spring foliage was saved by spraying. A net gain of GOO per cent in 

 foliage over that retained by adjoining unsprayed trees resulted in the 

 case of several different sprays. Bordeaux mixture when applied to 

 the dormant tree increased the weight and starch-producing power 

 of the leaves, and the sprayed trees showed a great gain over the 

 unsprayed in the num])er and ([uality of the fruit buds they produced 

 for the following year, tlie gain in the luimber of spur ])uds being over 

 100 per cent in some cases. Tiie lower limbs of sprayed trees showed 

 a marked gain over those of unsprayed trees as compared with the 

 upper limbs in both the number of fruit buds and lateral shoots they 

 produced. 



(8) The average value of the fruit per tree in rows treated with the 

 most effective Bordeaux mixture ranged as high as i^G.:20 above that per 

 tree in adjoining untreated rows, or the equivalent of a net gain of 

 $427.80 per acre where trees are planted 2.5 b}^ 25 feet. Over 1,000 per 

 cent net gain in the fruit set has resulted in the use of some of the 

 more effective sprays. 



(9) The trees should be spraj'cd each season, as the experiments 

 proved that treatment one season will not prevent the disease the 

 following year. Spraying should also be done even though the trees 

 may not be expected to bear, as the loss of the crop of leaves is shown 

 to result in as great a drain upon the trees as does the maturing of 

 one-half to two-thirds of a crop of fruit. 



(10) The work demonstrates that peach leaf curl may be cheaply 

 and easily prevented in California, in w^estern Oregon and Washington, 

 and along the east shore of Lake Michigan, where curl causes great 

 loss, as well as in all other peach-growing sections of the United States. 



(11) The copper and lime sprays are less injurious to the trees than 

 those composed of sulphur and lime. The use of lime in winter sprays 

 has proven an advantage in enabling the workmen to see their work 

 and complete it with greater thoroughness than would otherwise be 

 possible. A proportional increase of both lime and copper sulphate 

 is recommended for wet regions, and for very wet localities a second 

 winter spraying is advised. 



(12) Cyclone nozzles with lateral or diagonal discharge are best 

 adapted to the work. 



(13) The proper time for winter spraying and the number of appli- 

 cations depend to some extent on the locality, season, etc., but active 

 sprays are likely to do most good if applied from one to three weeks 

 before the opening of the blossoms in spring. The proper time to 



