EXPERIMENT STATION REPORTS. 205 



The laboratory room has been built in the grain room above the office, and 

 partially equipped. 



The boarding house has been painted on the outside and kalsomined on 

 the inside. The office building has also been painted. 



Some new machinery has been purchased for the farm, and for experi- 

 mental work. 



The annual round-up put on August 10-11, was quite successful, and 

 approximately 3,000 people were in attendance. Demonstration work along 

 live stock and farm crops lines was a feature, and a speaking program was 

 rendered in the afternoon. Alger county generously donated an excellent 

 barbecue dinner in order to assist in accomodating the crowds. The boys' 

 and girls' club members' camp was put on at the time of the round-up. They 

 received special instructions in live stock and crop lines, and live stock 

 prizes were given to the A\'inners of the final judging contests. 



Respectfully submitted, 



D. L. McMillan, 



Superintendent. 

 Chatham, ^Michigan, June 30, 1921. 



Mr. D. L. ^McMillan, Superintendent, 

 Chatham, ^Michigan. 



Dear Mr. Mc^NIillan: 



I herewith make report of plant disease investigations carried on at the 

 L^pper Peninsula station during the fiscal year ending June 30, 1921. 



POTATO DISEASES. 



These investigations have been a continuation of the projects started in 

 1919, supplemented by the potato leaf-hopper investigations which were 

 started in 1920. The 1919 and 1920 seed treatment experiments having 

 shown that neither formaldehyde nor corrosive sublimate, which are usually 

 recommended for the control of seed-borne diseases such as scab, black scourf 

 and black leg, were effective in the control of scab under conditions existing 

 at this Station. The 1921 seed treatment experiments were supplemented 

 b}' soil treatment experiments for scab control. In these experiments, sul- 

 phur in various forms was applied to the soil as a top dressing before planting 

 the tubers. The importance of scab control in the limestone areas of the 

 Upper Peninsula becomes significant when it is learned that even the first 

 crop of potatoes grown on a given piece of land, bears a high percentage of 

 scab, and succeeding crops on the same ground, even if grown after an interim 

 of 10 years, are largely unmarketable because of this disease. 



Hill selection work for stud^nng the dissemination of jMosaic, Leaf Roll and 

 Streak from diseased to healthy hills has been continued and also the cage 

 experiments to determine whether insects are factors in spreading these 

 diseases. 



Sprajdng experiments for control of hopperburn (tipburn) and leaf diseases 

 which were started in 1920, have been supplemented bv the use of dusts in 

 1921. 



Most of the laboratorj" researches have been devoted to the investigation 

 of the Black Leg disease of potatoes which is very prevalent in the Upper 

 Peninsula potato fields. 



