May, 1937] Agricultural Rese.\rch in N. H., 1936 9 



ized milk were selected for detailed study. They were found to be 

 extremely heat resistant, some strains withstanding a temperature of 

 70° C. for 30 minutes. When stained from liquid media, they occur 

 as long-chained streptococci. On blood agar, the colonies usually ap- 

 pear as the alpha-prime or weakly hemolytic type. 



The following biochemical studies were made: fennentation reac- 

 tions; final pH in glucose broth; hydrolysis of sodium hippurate, reduc- 

 tion of methylene blue; formation of soluble hemolysin; and digestion 

 of human fibrin. Precipitin tests with group sera were also carried out. 

 Up to the present time, the hemolytic streptococci isolated have been 

 classified into three different types which do not appear to be identical 

 with the other types of streptococci found in milk and described in the 

 literature. {Hatch Fund) 



Test Sprays for Apple Scab 



Apple scab was more prevalent than for several years past in 1934 

 and a very good test was obtained by 0. Butler of the relative value 

 of fungicides under trial. 



Ascospore discharge first occured May 8; that is, at the mid-period 

 between the pre^pink and pink application. During the period May 1 

 to June 28 there were 17 rains with a mean precipitation of 0.20 inch 

 and a range of .02 inch to 0.72 inch, and 10 spore discharges. In the 

 spraying experiments Cal-mo-sul, sulsol, flotation sulphur, Kolofog and 

 lime-sulphur solution were used. When an arsenical was required in 

 the spray schedule, calcium arsenate was used with Cal-mo-sul, lead 

 arsenate with sulsol and flotation sulphur; in the case of limesulphur 

 solution and Kolofog, calcium arsenate was used exclusively on some 

 plots, lead arsenate on others. In the plots sprayed with lime-sulphur 

 and Kolofog it was impossible to detect any difference in the appear- 

 ance of the foliage of the trees traceable to the arsenical used, and 

 there was no fruit nisseting. A summary of the data obtained is pre- 

 sented below for trees to which the pre-pink, pink, calyx and two cover 

 sprays were applied. 



Method of Treatment Total Scab 



Relative Nos. 



Trees not sprayed 100 



Trees sprayed with Kolofog, 3 lbs. to 50 gallons 74 

 Trees sprayed with Cal-mo-sul, 10 lbs. to 50 gal- 

 lons water 65 



Trees sprayed with Sulsol, 1^/4 lbs. to 50 gallons 60 

 Trees sprayed with Flotation sulphur, 4 lbs. to 



50 gallons 26 



Trees sprayed with lime-sulphur, 1 gal. to 50 gal- 

 lons water 20 



One cover spray did not give as good control as two cover sprays and 

 three cover sprays were more effective than two, but in this connection 

 it should be mentioned that the number of cover sprays required is not 



