18 UNIV. OF N. H. AGR. EXPERIMENT STATION 



The yields obtained are shown in Table VII. 



Table VII — Yield of tests of potato seed 



[Bulletin 221 



Northern New Hampshire seed 



Vermont seed 



Maine seed 



Southern New Hampshire seed. 

 Farmer's own seed* 



Yield per acre in relative numbers 



Min. 



100 

 96 

 92 



77 

 95 



Max. 



INlean 



* Four plots only. 



The figures show that the yields of the northern New Hampshire seed, 

 the Vermont and the ]Maine seed were practically identical. The south- 

 ern New Hampshire seed, as was to be expected from the disease record, 

 yielded less well than the other seed; the lowest yield occurred in a plot 

 in which 8.9 per cent spindling sprout and 1.06 per cent yellow dwarf 

 were found; and the highest yield in a plot where the plants showed 1.5 

 per cent mosaic and 2 per cent leaf-roll. 



Potash Tests on Potatoes {Hatch Fund) 



These tests were begun in 1922 by F. W. Taj'lor and have been con- 

 tinued for four years on quarter-acre plots. Their object was to note the 

 effect on yield of varying amounts of potash applied with fixed amounts 

 of nitrogen and phosphoric acid. Stable manure at the rate of twenty 

 spreader loads per acre was applied to all the plots. The potatoes were 

 planted May 20 and dug October 9. The season was more favorable for 

 potatoes than usual and the yields were above the average. There were 

 practically no diseases except a slight amount of early blight. 



Table VIII shows the yields per acre for each of the several treatments 

 for 1922, '23, '24, and '25, together with the average yield for the four 

 seasons. 



Table VIII — Effects of varying amounts of potash on potatoes 



The seed used in the test this year was Green Mountain produced from 

 certified seed in 1924. The fertilizer was applied at the rate of 1,200 

 pounds per acre of 4-8-0 plus from 96 to 320 pounds of muriate of potash. 

 While the results of these four-year tests are not consistent in every re- 

 spect, they seem to indicate that one year with another where stable 



