626 THE AGRICULTURAL J OUR^ AL. 



the host. For these reasons orchards near 

 large bodies of water and in low or damp 

 situations are more subject to curl than 

 those in dry regions or in elevated situa- 

 tions. 



4. Most of the spring infections of peach 

 leaves ai*e due to the spores of the fungus 

 and not to the perennial mycelium, as 

 formerly held, hence the efficacy of 

 sprays. 



5. Curl was first successfully treated in 

 California during the period from 1880 to 

 1855, the success depending upon the ap- 

 plication of fungicides to the dormant 

 trees. The disease was not successfully 

 treated in Europe for ten years after its 

 prevention in the United States. 



6. The copper sprays are now found to 

 be more elfective than the sulphur or 

 other sprays first used. Of the various 

 sprays experimented with, Bordeaux 

 Mixture, in the proportion of 5 lbs. copper 

 sulphate, 5 lbs. of lime, and 45 gallons of 

 water, gave the best results, the equal 

 weights of the copper sulphate and lime 

 being most effective when the mixture is 

 applied shortly before the opening of the 

 blossom buds. When it is desired to in- 

 crease the durability of a spray by increap- 

 ing the proportion of lime, the application 

 should be made earlier or equal propor- 

 tions of copper and lime should be main- 

 tained. The total saving of foliage 

 increases with the increase of copper 

 sulphate when the amount of lime re- 

 mains constant, but the avei'age saving 

 per pound of copper sulphate' decreases 

 the increase of copper used. 



7. In the treatment of the peach leaf- 

 curl, from 95 to 98 per cent, of the spring 

 foliage was saved bj spraying. A net 

 gain of 600 per cent, in foliage over that 

 retained by adjoining uns])rayed trees re- 

 sulted in the case of several dift'ereiit 

 sprays. Bordeaux Mixture, when ap- 

 plied to the dormant tree, increased the 

 weight and starch-producing powei' of the 

 leaves, and the sprayed trees showed a 

 great gain over the unspraye 1 in- the 

 nuinl)er and quality of the fVuit buds they 

 produced for the following year, the gain 

 in the number of spur buds being over 

 100 per cent, in some cases. The lower 

 limbs of sprayed trees showed a marked 

 gain over those of unB])riiyed trees as com- 



pared 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 Bor- 

 deaux Mixture ranged as high as 6 20 dol. 

 above that per tree in adjoining untreated 

 rows, or the equivalent of a net gain of 

 ■dlr27'80 dol. per acre where trees are planted 

 25 by 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 sprayed each 

 season, as the experiments proved that 

 treatment one season will not prevent the 

 disease the following year. Spraying 

 should 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 pre- 

 vented in California, in Western 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 thorough- 

 ness 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 spray- 

 ing and the number of applications de- 

 pend 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 i)roper time to apply 

 sprays for the prevention of curl is in dry, 

 calm weather, and during the middle of 

 the day, in order to avoid dew or frost 

 upon the limbs as much as possible. 



14. Of nearly two hundred peach and 

 nectarine varieties considered with a view 



