173 — 



INFLUENCE OF LATITUDE UPON POTATOES.— A 



CRITICISM. 



During the last year or two a note has gone the rounds of the 

 press to the effect that potatoes giown in the north sprout less in 

 the cellar than those grown in the south. This opinion does not 

 appear to be founded upon experiment, but rather upon a general 

 notion that northern grown seeds and tubers are more tardy in 

 germinating or vegetating, because the northern seasons are 

 more tardy. This is opposed to all the known effects of climate 

 upon plants. Northern .grown plants are more sensitive to heat 

 and cold than southern grown, and start relatively earlier in 

 spring. In 18S9 I attempted to test this point upon the sprouting 

 of potatoes, and the results of the trial were reported in the 

 American Garden for November, 1889, p. 401. Earl}- Rose was 

 grown from Pennsylvania-grown seed and Maine-grown seed. 

 The samples were placed in a moist and light cellar, side by 

 side, and allowed to remain three weeks. When removed, the 

 Maine tubers were so badly sprouted that great difficulty was ex- 

 perienced in removing them from the crate, while the Pennsyl- 

 vania tubers had only begun to sprout. This result was clear 

 and definite, and it appeared to discredit the common notion that 

 northern -grown potatoes sprout less than others. The Maine pota- 

 toes also yielded 4^ more than the others. Experiments made at 

 some other stations have given similar results concerning yields. 



A much larger experiment was planned in the same direction 

 this year, and the results are here given as a criticism upon this 

 method of experimentation, which has been practiced by many 

 others as well as ourselves. Ten lots of potatoes were procured 

 and on April nth they were photographed and placed in identical 

 conditions under a greenhouse bench. The samples were as 

 follows : 



Beauty of Hebron. 



1. Grown by Pennsylvania Experiment Station. 



2. " M. P. Pierson, Ontario Co., N. V. 



3. " S. Frogner, Herman, Minn. 



4. " Geo. \V. P. Jerrard, Caribou, Me. 



