156 PEACH LEAF CURL! ITS NATURE AND TREATMENT. 



spray should now be strained through a fine wire strainer into the 

 spray tank or barrel, and enough boiling water added to make up the 

 full amount of spray required by the formula. The spray may be 

 boiled to advantage longer than two hours, but should never be boiled 

 for a less time if the best results would be obtained. The sprays should 

 be applied to the trees as hot as possible. The spray is more effective 

 and easier to apply when hot, and contact with the air cools it suffi- 

 ciently so that twigs of dormant trees are not injured by the heat. 



The method of preparing the sulphur sprays here outlined is prac- 

 tically that which has been followed in California for many years. 

 In the series of experiments here described, however, an effort has 

 been made to ascertain if salt is necessary in this spray, and also 

 whether there is any disadvantage in uniting all of the lime and sul- 

 phui" at first. Aftei" a comparison of the results obtained from sprays 

 with and without salt and of those in which the lime was added in two 

 portions and at different times with those prepared by adding all of 

 the lime and sulphur at first, it has not been possible to detect any 

 advantage from the salt nor from the more complex method of pre- 

 paring. This relates, of course, to the use of these sprays for the con- 

 trol of curl, but it is believed that the same will hold true in their use 

 for the control of insect pests. The writer has personally prepared 

 and tested a very large number of these sprays, and recommends the 

 omission of salt, and further, that all of the lime and sulphur be united 

 and reduced with boiling water before the cooking begins in all cases 

 where the spray is to be applied either as a fungicide or insecticide, 

 and where the method of boiling below described is followed. This 

 will both cheapen and simplify the process. 



While many growers may feel obliged to prepare the sulphur sprays 

 in kettles or iron pans, experience has shown that they may be boiled 

 much more uniformly, more easily, and oftentimes better in barrels or 

 wooden tanks by using live steam as the source of heat. These facts 

 are widely recognized on the Pacific coast, and the knowledge is put 

 into practice by some of the leading fruit growers, many of whom 

 have established special steam cooking plants for preparing and hand- 

 ling the sulphur sprays. Some of these spray-cooking appliances are 

 on quite an extensive scale and others more limited, being adapted to 

 the needs or facilities of the growers. As the sulphur sprays have 

 been widely used in California and Oregon, and are likely to become 

 much more generally used throughout the East, especially as they are 

 particularl}' intended for winter application to all deciduous trees and 

 are known to be of marked value both as insecticides and fungicides, the 

 more improved methods of preparing them will be of general interest 

 to orchardists, and several are here given. Three types of cooking 

 plants are described: (1) One adapted to the needs of an orchard of 10 

 acres, (2) one suited to the needs of an orchard of 100 acres, and (3) 



