June, 1939] Agricultural Research in N. H. 11 



wonder whether our farmers may not be applying too much plant 



food to the potato crop for highest economy. 



An Experiment with Potatoes in a Three-Year Rotation 



On the Jackson farm in Colebrook a rotation of potatoes, oats and 

 hay is in progress with much the same procedure as on the Lane 

 farm. Eighty pounds of elemental nitrogen (the standard applica- 

 tion) appears to be sufficient for optimum potato crops. As on the 

 Lane farm yield data indicate that the 1-3-3 ratio is preferable to the 

 1-2-2 now commonly used by potato growers. On the Jackson farm 

 neither basic slag nor magnesium appear to exert any stimulation to 

 potato yields. 



Lime and phosphorus residues both appear to exert a beneficial 

 influence upon oat yields. Lime especially has resulted in excellent 

 responses in yields of hay. The differences among the plots in the 

 field are noted mainly in the absence or abundance of clover, the 

 unlimed portions of the land being too acid to produce it. 

 Cooking Qualities of Potatoes 



Because of the interest manifested by farmers and others in the 

 cooking quality of potatoes, experiments have been begun by J. L. 

 Haddock and P. T. Blood to try to discover what the causes are of 

 differences in this respect. 



Last fall 23 different samples of potatoes were collected from the 

 fields of farmers in various sections of the state. These samples 

 included several popular varieties grown on the same field and on 

 widely separated fields. In order to make these tests somewhat more 

 significant a sample of Russet Burbanks from Idaho was obtained. 

 The potato samples were boiled, and several more or less experienced 

 persons recorded their best judgment as to the quality, giving most 

 emphasis to texture and flavor, but noting color of flesh and other 

 factors. 



Potatoes with a high specific gravity are more mealy than lighter 

 potatoes, for the more starch a potato contains, the heavier it is. 

 There was a fair rate of agreement in the scores on mealiness that 

 the judges gave the potatoes and the corresponding specific 

 gravities. 



One of the interesting things shown in the tabulated results is the 

 tremendous variation within the same variety, samples of Green 

 Mountain, for instance, ranking both highest and lowest. Obviously, 

 then, it is not possible to select one or two tubers as an adequate 

 sample for a cooking test. Mealiness is widely distributed within a 

 given lot of potatoes, as shown by careful cooking experiments. This 

 work will be continued, especially in regard to the relationship 

 between the specific gravity of a potato and its mealiness. 

 Investigating New Potato Varieties 



New plant varieties developed in the past by plant-breeding scien- 

 tists have contributed so much to present-day agriculture that when- 

 ever new varieties of plants are announced, farmers are keenly inter- 

 ested. This is particularly true of potato-growers who are vitally 

 interested in varieties possessing any combination of superior char- 

 acters such as high yield, good cooking quality, good tuber type, 

 resistance to diseases, etc. 



