12 



New Hampshire Experiment Station [Bulletin 239 



TABLE VIII. 

 Relation of Length of Rotation to Yield, to Labor and Costs per Acre and per 



Bushel. 1926-1927. 



which frequently results in a lowered yield. Too late planting- is 

 objectionable because vines grow slowly in hot weather. Occasion- 

 ally early planting in a wet year will allow a crop sufficient time to 

 mature before serious damage may be caused by late blight. Such 

 seasons are rare and, rather than trust to chance, a somewhat 

 later planting and protection by spraying will ordinarily produce 

 a crop enough larger to more than pay material and labor costs for 

 spraying. (See Table IX.) 



One of the facts shown by these data is that higher labor re- 

 quirement, and higher cost per bushel are incurred with late 

 planted potatoes, even, in some cases, with increased yields. 



In 1926 and 1927 in Coos and Grafton Counties a lowered yield 

 resulted from late planting. In Merrimack and Rockingham Coun- 



TABLE IX. 



Relation of Date of Planting to Yield, Labor and Costs per Acre and per 



Bushel. 1926-1927. 



