JFl-.;Ci' OF LD-E SULi'UK OJM YIZID OF APIr-U^o 



(This articlej prepared by Professor E, J, Rastau £. s ei- , University oF 

 ivew liampsliire, is of timely interest at this seaaon when spray materials are 

 being ordered and plans are being made for the fi^ht against apple scab.) 



L-3-.I-F-D, L-S_M-F-D, Lime-sulfur aeans fever dollars; Lime-sulfur means 

 fewer dollars. Yes, Lime-sulfur, when applied as a spray for scab control on 

 apples definitely reduces j"ields, and consequently means a reduced income to 

 the orche.rdist. In fact, the old Lime-sulfur schedule was responsible to a 

 large extent in some orchards for the biennial bearing of such varieties as 

 Northern 3py. Some experimental work several years ago in New York showed that 

 the apple foli-age spraj^ed with Lime-sulfur was less efficient in the manufacture 

 of carbohydratos for as much as 7 days after the application than unsprayed 

 foliage. Since the carbohydrates are necessary in the gro\-/th of the tree, in 

 blossom formation, and in producing a crop of apples, the Lime-sulfur sprayed 

 trees should produce less fruit since they have less materials from which to 

 develop the fruit. This was found to be tine experimentally in some spraying 

 experiments in Michigan, A block of Northern Spy trees which had been 

 sprayed for a number of years with Lime-sulfur and which had shown low yields, 

 sometimes a crop only once in three years, was divided into three plots. One 

 plot viras sprayed with Lime-sulfur, another v?ith wettable sulfur, and a third 

 with a fixed copper fungicide. The following table shows the effect of the 

 spray treatment on defoliation and yield. _, 



Effect of Spray Treatment on Defoliation and Yield of Northern Spy 



(1939-1943 inclusive) 



Treatment Aver. No. of Leaves Aver, Yield in Percent 



(100 spurs, August 20) bu. per tree Increase in 



1940-44 yield over 



Lime-sulf'-ir 



Lime-sulfur, 2-100 474 39.0 



■Vet table sulfur, 8-100 . 603 51,2 2C.5 



Fixed copper-lime, 2-4-10o' 643 61.2 53,5 



It is seen that there is a definite relation in the amount of foliage 

 and the yield. The Lime-sulfur sprayed trees had smaller mishapen leaves and 

 showed more defoliation and definitely lower yields than did trees sprayed 

 with the other materials. 



Yes, someone will remark after reading this information, "Vifhy this data 

 on Lime-sulfur vdien the material is out of date?" Some folks are going to 

 continue to use Lime-sulfur, especially if 1949 is another favorable year for 

 scab development and they fail to get control of the disease, hoping at least 

 that the failure x.o obtain control was due to the material, and not to poorly 

 timed and inadequate applications. 



