New York Agricultural Experiment Station. 509 



Conclusions. 



Final conclusious cannot be drawn from a single experiment. 

 All we can say is that this experiment teaches the following: 



First: The disease of potatoes known as " internal brown rot " 

 or " internal browning '' is not transmitted from seed to pro- 

 duct; 



Second: The greater the amount of " interior browning " in the 

 seed tubers the smaller the yield. It is therefore not advisable 

 to plant tubers so affected. 



Another Stem-blight of Potatoes. 



In July, 1895, I first noticed at Jamesport, N. Y., a peculiar 

 appearance of potato foliage which was new to me. A few days 

 later potato plants similarly affected were sent to me accom- 

 panied by the information that the disease was doing considerable 

 damage in the vicinity of Farmingdale, N. Y. Pressure of other 

 work prevented a thorough investigation of the trouble. In the 

 later part of August a farmer in Dutchess county, N. Y., reported 

 that the same disease was very destructive in that section. I 

 visited Dutchess county September 4 and found that t5ome fields 

 had been wholly ruined by it. It has also been reported from 

 Orange county, N. Y. 



The disease is characterized as follows: 



First, there is a cessation of growth. The topmost leaves take 

 on a yellowish, or in some varieties a purple color, and roll in- 

 ward from the edges and upwards, exposing the under surfaces. 

 This condition is followed by wilting and complete drying up of 

 the entire foliage, the process taking from one to three weeks. 

 The tubers appear to be sound, but when cut at the stem end 

 blackened fibers are seen penetrating the flesh to a considerable 

 distance materially injuring it for cooking purposes. No rot de- 

 velops in the tubers. The stem just beneath the surface of the 

 soil first shows discolored spots and later becomes dry and 

 shriveled. 



In Dutchess county it was more prevalent on upland soil than 

 on the moister lowlands. No variety appears to be exempt and 



