16 



UNIV. OF N. H. AGR. EXPERIMENT STATION 



[Bulletin 221 



In another experiment hand spraying was compared with hand dust- 

 ing. An acetate dust containing 4.75 per cent metalHc copper was appHed 

 every two weeks; a Sanders dust containing 8.5 per cent metalhc copper 

 every two weeks on one plot and every week on another; and an 8-4-50 

 Bordeaux mixture was apphed every two weeks. Early blight developed 

 in the field, and on September 5 the plants dusted with acetate of copper 

 were practically dead; the foliage on the plot treated with Sanders dust 

 every two weeks was largely dead, but the plants dusted with Sanders 

 dust weekly, while badly spotted, were still quite green and in very nearly 

 as good condition as those sprayed every two weeks. (See Table IV.) 



Table IV — Effect of hand dusting and hand spraying on the yield of potatoes affected 



loith early blight 



Seed Certification {Miscellaneous Income Fund) 



One hundred and eight acres were inspected for certification, and 104.5 

 acres met requirements. The average yield per acre was 323.7 bushels. 



In order to obtain information regarding the reliability of the certifi- 

 cation records, a plot was established by Dr. Butler at East Kingston 

 in which bushel lots of the certified seed produced by growers in 1923 

 were planted. The results secured are presented in Table V and show 

 that in general the behavior of the certified seed sold was all that could 

 be desired. The total disease count of the majority of the samples came 

 within the requirements for certification. 



Table V — Disease records of certified seed potatoes the year of certification and the year 



following at a foreign station 



Certification records, 1923 



Disease records East Kingston, 1924 



16.7 



4.28 



0.23 



2.45 



1.06 



0.00 



16.7 



2.98 



0.00 



1.8 



0.24 



0.00 



Seed Source Comparison Test {State Fund)* 



In order to give the farmers in every county of the state an opportunity 



to compare New Hampshire Green Mountain certified seed with certified 



*In collaboration with the county agents. The county agents laid out the plots and 

 supervised the planting and harvesting. 



