ANNUAL REPORT, 1934 15 



Yields of the two crops from the several treatments were rather uniform. 

 The medium application of potassium iodide increased the yield of turnips, but 

 not of spinach, more than any other treatment, but the difference was not great 

 enough to be considered statistically significant. Chemical analysis of these 

 crops is being made. 



In another experiment under the general project of absorption of chemicals, 

 a preliminary pot experiment was conducted with the same type of soil as that 

 used in the tanks mentioned above, for the purpose of determining the limits of 

 tolerance of plants for iron and copper compounds. Ferric oxide, ferric sulfate, 

 ferrous sulfate, and copper sulfate were applied to unlimed and limed soils having 

 reactions of pH 4.4. and 5.4 respectively, at rates of 10, 20, 40, 80, 160, 320, 640, 

 1280, 2560, and 5120 pounds per acre. A marked difference was noted in the 

 concentration of materials causing injury in soils of different reactions, toxic 

 concentrations being lower in the more acid soil; but ferric oxide was not toxic 

 in any concentration used. Spinach and turnips were grown in succession in 

 the same soil. Concentrations at which toxicity definitely appeared were as 

 follows: 



Crop 



Spinach 

 Turnips 



Potato Variety Tests. (E. F. Gaskill, R. W. Donaldson, and W. S. Eisen- 

 menger.) An increased interest in potato production in Massachusetts led to a 

 yield test of several of the varieties considered adaptable to New England condi- 

 tions. The results from plots one-eleventh acre in area showed the following 

 yields calculated on an acre basis: Green Mountain, 635 bushels; Chippewa, 635; 

 Russet Rural, 593; Katahdin, 506; and Golden, 456. 



A compilation of results from quality tests indicates the following: 



Green Mountain: Good flavor, dry and mealy when either boiled or baked, 

 attractive white color. Many of these potatoes were too large for market, a few 

 were hollow hearted, and they had a decided tendency to throw prongs. 



Chippewa: Good flavor, dry and mealy, attractive white color, shallow eyes, 

 smooth, and very even size. 



Katahdin: Good flavor, dry and mealy, attractive white color, very smooth, 

 seem to take a little more time to cook. 



Russet Rural: Good flavor, dry and mealy, seem to require more time to cook 

 than any of the preceding varieties. Too mealy when boiled, but very satisfactory 

 when baked. Skin rough, dark, and not attractive. Size very even, very few large 

 or pig potatoes. 



Golden: Poor flavor, rather flat, the least mealy of the five varieties. Objection- 

 able yellow color. This variety tends to sprout early, several potatoes having 

 started to sprout as early as October 15. 



Annuals as Emergency Hay or Green Manure Crops. (E. F. Gaskill, R. W. 

 Donaldson, and W. S. Eisenmenger.) Plantings of summer annuals were made 

 June 1 to determine their relative yields for emergency hay or green manure 



