16 CONTEOL OF PEACH BROWN-ROT AND SCAB. 



to cool the mixture and prevent further cooking. It is then ready 

 to be strained into the spray tank, diluted, and applied. 



The stage at which cold water should be poured on to stop the cook- 

 ing varies with different limes. Some limes are so sluggish in slaking 

 that it is difficult to obtain enough heat from them to cook the mix- 

 ture at all, while other limes become intensely hot on slaking and care 

 must be taken not to allow the boiling to proceed too far. If the 

 mixture is allowed to remain hot fifteen or twenty minutes after the 

 slaking is completed, the sulphur gradually goes into solution, com- 

 bining with the lime to form sulphids, which are injurious to peach 

 foliage. It is therefore very important, especially with hot lime, 

 to cool the mixture quickly by adding a few buckets of water as soon 

 as the lumps of lime have slaked down. The intense heat, violent 

 boiling, and constant stirring result in a uniform mixture of finety 

 divided sulphur and lime, with only a very small percentage of the sul- 

 phur in solution. The mixture should be strained to take out the 

 coarse particles of lime, but the sulphur should be carefully worked 

 through the strainer. 



SELF-BOILED LIME-SULPHUR TREATMENT AND RESULTS. 



Several different varieties of peaches were sprayed with good 

 results. The details of the work were about the same in each case, 

 the following notes on the Waddell variety serving as an example 

 of the treatment given and the results obtained : 



Plat 1, consisting of 568 Waddell trees, was sprayed with self- 

 boiled lime-sulphur (32-32-200) on April 30, about one month after 

 the petals dropped, and again on May 20, three to four weeks before 

 the fruit ripened. At picking time the entire crop, including dropped 

 fruit from five average trees in this plat, was sorted and counted, 

 with the result that 17 per cent was found to be affected with brown- 

 rot. An examination of the rotting fruits showed that 93 per cent 

 of the infections had taken place through curculio punctures and 

 that aside from such infections only 1 per cent of the crop was affected 

 with brown-rot. 



From a commercial standpoint, the scab or black-spot was com- 

 pletely controlled, although 16 per cent of the fruit showed some 

 slight infections. None of the fruit was sufficiently spotted to injure 

 its market value. 



('heck A consisted of 1,357 unsprayed Waddell trees in a block 

 adjacent to plat 1. Of the fruit from five average trees in this block 

 494 per cent was affected with brown-rot and 9H per cent with scab. 

 About one-third of the scabby fruit, or 28^ per cent of the total crop, 

 was so badly spotted and cracked that it had to be discarded as 

 unmerchantable. In this case 81 per cent of the brown-rot infec- 



174 



