Agricultural Research in N. H. 27 



Introducing New Potato Varieties for Certified Seed 



In 1946, three relatively new varieties, namely, Mohawk, Ontario, and 

 Pawnee, were tested by the tuber unit method. Pawnee is a high-yielding, 

 mid-season variety and Mohawk is a high-yielding, late variety. Mohawk 

 has proved to be susceptible to leaf-roll but in other respects it seems a high- 

 ly desirable variety. It is a smooth white potato and produces a remarkable 

 high percentage of marketable tubers. It is excellent in cooking quality. The 

 Ontario is resistant to scab. 



All were included in a variety test of 25 strains of potatoes during the 

 1946 season. Three new blight-resistant strains introduced from New York 

 State stood at the head of the list for yield, largely because an uncontrolled 

 severe blight outbreak in August cut the growing season for the rest of the 

 varieties. These blight-resistant varieties proved to be resistant on foliage 

 but not on tubers. Whether or not they will assume any importance, com- 

 m.ercially, is still questionable. Empire was the lowest in respect to tuber 

 infection but it has a higher quality rating. Two other blight-resistant va- 

 rieties, Chenango and Placid, have been added for testing in 1947. Current 

 tests include only 15 varieties because the undesirable varieties have been 

 discarded. Five varieties are being tuber united for foundation stock. 



P. T. Blood, L. T. Kardos, M. C. Richards 

 L. J. HiGGiNS, F. S. Prince 



Proper Construction of Farm and Commercial Potato Storages 



The use of carbon dioxide gas as a sprout retardant in potato storages 

 was continued on a bin scale. Approximately 260 bushels of graded Katah- 

 din table-stock potatoes v/ere loaded into the bin which was of reasonably 

 tight wood construction. 



After several weeks it became apparent that excessive quatities of COo 

 gas had to be supplied to attain adequate COo concentrations in the bin. As 

 the temperature in the bin rose with the passage of the spring season, the 

 tubers themselves supplied an increasing amount of the necessary CO2. At 

 the close of the experimental period, with only moderate additions of CO2 

 from a compressed gas cylinder, a concentration of about 8 per cent CO2 was 

 attained in the bin. 



Upon opening the bin, the degree of sprouting found indicated that the 

 ordinary wood construction employed did not maintain a concentration of 

 10 to 12 per cent CO2 in the bin, and therefore, was not suitable as a sprout 

 retardant bin. The results did indicate, however, that there was adequate gas 

 diffusion within the bin and that with more rigid specifications in construc- 

 tion, an adequate CO2 concentration to prevent sprouting may be maintained. 



P. T. Blood, L. T. Kardos 



Drying Young Grass for Use as a Grain Substitute 



This project was started in the summer of 1946 with the building of a 

 small 9' X 9' house, equipped with 4' x 9' trays for holding grass and a pot- 

 type oil burner installed as the heating unit. This provided maximum capac- 

 ity for 150 pounds of dried grass. The heating unit proved slow and ineffi- 

 cient, the time required to dry the average amount of grass being approxi- 



