168 EXPERIMENT STATION. [Jan. 



less subject to the disease. Trees injured by other agencies, 

 and consequently weakened, seem to be more susceptible to at- 

 tack than healthy, vigorous trees. 



It will be readily seen that it is probably useless to spray the 

 trees after the leaves become infected, but since the spores live 

 over winter on the bark, the trees should be sprayed in the 

 spring, while the spores are still dormant. 



It is generally accepted by all the largest and best growers 

 that the lime sulphur wash, used for the control of San Jose 

 scale, is by far the best remedy for this trouble, although some 

 prefer Bordeaux and others copper sulphate solution, where the 

 scale is not present. Since there is nearly always danger from 

 scale infestation, however, it seems wiser to use the lime and 

 sulphur, which is undoubtedly of great fungicidal value, as well 

 as one of the best remedies for the scale. 



The spray should be ajiplied to the trees from one to two 

 weeks before the buds open, if possible on a quiet day when the 

 atmosphere is free from moisture. 



If the above directions are followed, this treatment should 

 suffice for the leaf curl and the San Jose scale. For this spray 

 mixture use 10 pounds of good fresh stone lime and 15 pounds 

 of sulphur to each 50 gallons of water. Make up the above 

 spray solution as recommended by Quaintance. 



Heat in a cooking barrel or vessel about one-third of the total 

 quantity of water required. When the water is hot, add all the 

 lime and at once add all the sulphur, which previously should 

 have been made into a thick paste with water. After the lime 

 has slaked, about another third of the water should be added, 

 preferably hot, and the cooking should be continued for one 

 hour, when the final dilution may be made, using either hot or 

 cold water, as is most convenient. The boiling due to the slak- 

 ing of the lime thoroughly mixes the ingredients at the start, but 

 subsequent stirring is necessary if the wash is cooked by direct 

 heat in kettles. Tf cooked by steam, no stirring will be neces- 

 sary. After the wash has been prepared it must be well strained 

 as it is being run into the spray pump or tank. The wash may 

 be cooked in large kettles, or, preferably, by steam in barrels or 

 tanks. 



