484 EXPERIMENTAL FARMS 



4 GEORGE V., A. 1914 



The spray solutions were carefully tested by the po'tassium ferro-cyanide method 

 and thus every danger from deficiency of lime and leaf-burning in consequence 

 removed. The spray rows run across the varieties so that each quarter of an acre 

 of each variety received a different kind of spray. 



Spraying began July 6th. It required 50 gallons of spray per acre, and took 

 2£ hours'" time for the four acres. It was arranged to spray once a week, but, owing 

 to incessant rain, the application had to be repeated at shorter intervals, the rain 

 washing off the spray at various times. Up to the end of August, eight applications 

 were given. In September the vines had grown so closely together that too much 

 injury would have resulted from further sprayings. Blight appeared during the first 

 week in September to some extent. On September 29th the vines were cut down by 

 frost. 



It was found that while both solutions (arsenate of lead and arsenite of soda) 

 finally destroyed the potato beetles, their action was too slow to prevent a good deal 

 of defoliation. Arsenate of lead adhered better and longer to the foliage. 



The yield of potatoes was excellent, the quality fair and fairly sound, no scab, 

 but a slight amount of late blight spots in tubers. 



The following is the statement of yields per statute acre: — 



Carman No. 1 444-31 bushels. 



Early Delaware 471-33 " 



Irish Cobbler 455 :83 " 



Gold Coin ;. 411-48 " 



No advantage of any one spray solution over the other could be observed. 



Considerable quantities rotted in storage; insufficient ventilation and injury in 

 digging were thought to account for this. The experiments will be continued for 

 several years', when a more detailed account will be prepared. 



AN EXPERIMENT WITH RHIZOCTONIA DISEASE OF POTATOES. 



A rectangular area of land about ■&> acre in extent had the preceding year borne 

 a crop of peas very badly affected with rhizoctonia. It was decided to see what 

 results would accrue from the planting of this with potatoes and incidentally to try 

 the effect of various treatments against this disease. One-half of the area was given 

 a dressing of lime at the rate of three tons per acre early in the year, and the other 

 half left untreated. Four varieties of potatoes were used, viz. : — Gold Coin, Carman 

 No. 1, Empire State, Rochester Rose. The seed used showed both scab and rhizoc- 

 tonia, and was treated as follows : — 



(1) Check, untreated. 



(2) Soaked in corrosive sublimate %ooo for 3 hours, 



(3) Dipped in gycerine (1:10 in water) and rolled in flowers of sulphur. 



(4) Soaked ten minutes in 2 oz. lime-sulphur concentrate (Niagara 

 Brand) to 6 quarts of water. 



The land was laid out in thirty-two equal plots in such a way that the eight plots 

 of each variety ran the whole length of the area, four being on the limed and four on 

 the unlimed portion, while the tests in seed treatment extended across the four 

 varieties and were duplicated on the limed and unlimed portions. Each plot was 

 planted with sixty uncut tubers May 28th to May 30th. The plants were sprayed 

 three times with arsenicals alone and then six times with Bordeaux mixture plus 

 arsenicals, the season being exceedingly wet. 



