POTATO DEVELOPMENT WORK IN WISCONSIN. 



The losses from potato diseases in Wisconsin have been so sfig 

 that I expect many growers will have to be shown that a disease 

 problem really exists. A few actual examples are therefore cited. 



1. A carload of seed potatoes was brought to my attention in 

 Virginia. It had been shipped from a point which might have 

 been in Wisconsin, but we may assume for your comfort that it 

 was in a neighboring state. The sacks near the car door were of 

 good quality but the rest of the car was filled with some of the 

 worst scabby tubers I have ever seen, and they had to be thrown 

 a\\ay. Naturally, that town in Virginia now buys its seed pota- 

 toes elsewhere. 



2. Not long ago we recommended Wisconsin potatoes to a Colo- 

 rado grower, who responded that he had tried them and that the 

 varieties were so badly mixed that the stock had to be discarded. 



3. In the South Atlantic States the blackleg disease has become 

 frequent, through the use of infected northern seed, I have seen 

 fields, with 50% to 75% of the plants dead or decaying just be- 

 fore harvest, when a neighbor using healthy seed had none. This 

 blackleg appears to come only from seed infection in this coun- 

 try. It takes a more virulent form in the south than in the north, 

 and can be eliminated by the northern grower by seed selection 

 and disinfection. 



4. The powdery-scab, a new disease to America, though long 

 prevalent in Europe, has been found in a few places in the 

 United States and may develop elsewhere. It will be highly im- 

 portant to pi-event its spread, and consequently whenever a few 

 east -s are found on one farm in Blank county, purchasers of seed 

 potatoes from other farms in that county will require assurance 

 of freedom from powdery-scab. The same would be true of the 

 wart disease or any other new trouble that might crop out and we 

 lack at present any definite means of giving this guarantee. 



5. The Fusarium Wilt is one of the big factors in reducing 

 yields in our wanner districts, particularly in the west. This is 

 carried in the tubers from diseased hills, and has already been 

 widely scattered in this way. Such infected tubers are not fit for 

 seed, and many districts are looking for a source of healthy seed 

 stock. 



6. The potato ell-worm, a dangerous pest in the irrigated val- 

 leys of Nevada and California, in Australia and other warm 

 countries, is spread wholesale by planting affected tubers. 



7. Silver-scurf, a European parasite which disfigures the skin 



