-9- 



with their duties, nor the furnishing of pure drinking water or other sinilar 

 items which would be furnished to civilian workers, 



6. Sentries are not to be used as v/ork supervisors, 



7, In case of any trouble with prisoners of war, including failure or 

 refusal to work, unsatisfactory vifork, insolence, sickness, escapes, etc., 

 telephone to the Provost Marshal, Prisoner of ¥/ar Camp, Ayer 311, Extension 

 7116 or 7248. 



INACTIVATING APPLE SCAB 



Probably never before have Massachusetts fruit growers ex- 

 perienced a combination of events such as have happened this year. Vfithout 

 a crop and an income, growers have been rather reluctant to spend money fight- 

 ing scab as faithfully as in a crop year. 



The eradication of the scab fungus in the trees during the 

 growing season has been an effective method of controlling scab v/hen the 

 more generally accepted method of protection by the eai'ly sprays has failed. 

 This has been the growers' method of attempting to end the disease, much as 

 the atomic bomb has been the means of ending the Japanese war, Yfith an 

 epidemic of foliage scab now existent in many orchards, the writer finds 

 that the grower should have taken advantage of this method of controlling 

 the disease rather than to have allowed it to run its destructive course. 



Heretofore v/e have relied upon lime sulfur to burn out scab 

 and the directions in our apple spraying schedule call for 2 gallons of 

 liquid or 8 pounds of dry lime sulfur in 100 gallons. The application is 

 recommended after the Second Cover spray. At Waltham the writer has been 

 studying the merits of other spray materials for destroying scab by a mid- 

 season application. Some of these nev/ fungicidal materials are as sensa- 

 tional in disease control as DDT is in insect control. It is not too early 

 to predict some striking changes in our apple pest control schedule as we 

 learn more about these new organic . pesticides. 



At Waltham some of our Mcintosh trees were allowed to develop 

 a very heavy infection of foliage scab, and on June 22 the following sprays 

 were compared for killing out scab: 



1. Flotation Sulfur Paste 



2. Lime Sulfur (32° Baum^) 



3. Micronized Dry Vfettable Sulfur 



4 . Fe rmat e 



5. Puritized 



6. Isothan qi5 



A Spreader sticker, l/4 pint, was added to each 100 gallons 

 of spray, except to the Isothan Q15 spray which of itself has good spread- 

 ing properties. Following the treatments, scabby leaves were gathered from 

 the trees, and something like 5,000 scab spores wore tested for spore germin- 

 ation on each day that leaves v;ere gathered. 



