166 PEACH LEAF CURL: ITS NATURE AND TREATMENT. 



Bordeaux mixture could be used upon fruit until a later date in the 

 summer than it could in California, where almost no summer showers 

 occur, and where the lime would remain upon the fruit until the latter 

 was mature. This matter leads us naturally to the consideration of 

 sprays adapted for wet and for dry localities. 



SPEAYS ADAPTED TO USE IN WET AND IN DRY LOCALITIES. 



Little can be said on this subject that has not been previously 

 touched upon in this bulletin. A few general remarks, however, 

 may be of advantage to the grower. The enduring qualities of sprays 

 containing lime increase where the ratio of the other ingredients is 

 maintained, very largely in proportion to the increase of the lime 

 which the formula? contain. For instance, the relative proportions of 

 copper sulphate and lime being maintained, a Bordeaux mixture 

 which contains 10 pounds of lime to 45 gallons of spray will obviously 

 endure much longer upon the trees in a wet climate than a Bordeaux 

 mixture containing but 5 pounds of lime to the same amount of spray. 

 To avoid the loss in activity and effectiveness of a spray containing a 

 large amount of lime, the fungicide, be it copper or sulphur, should 

 be increased so as to maintain the same or nearly the same ratio 

 between the copper and lime which exists in the spray containing less 

 lime. It is advised, therefore, that sprays to be used in a wet climate, 

 especially those intended for winter application, should be made 

 stronger, both in lime and in the essential fungicide they contain, 

 than is found necessary in a dry climate. If two sprayings are neces- 

 sary, both should be given the dormant trees. 



In wet climates the conditions favorable to the development of curl 

 and other fungous diseases are increased. This supplies a further 

 reason for using sprays containing increased amounts of fungicide and 

 having greater enduring qualities than sprays used in dry localities. 

 The soil conditions in wet situations are apt to delay spray work till the 

 last moment compatible with effective work. In such cases the amount 

 of copper should be sufficient, if this class of sprays be used, to act 

 promptly. If the Bordeaux mixture be applied under such circum- 

 stances, it will not be found desirable to reduce the copper below the 

 equivalent of 1 pound of copper for each pound of lime, and a higher 

 proportion may often be used to advantange on dormant trees. 



