29O MAINS AGRICULTURAL EXPERIMENT STATION. 1907. 



carefully measured and weighed at each application and the 

 yield of the resulting crop determined by weight. 



The experimental field was well drained, sloping slightly to 

 the east, the rows running north and south. The soil was well 

 adapted to potato growing and uniform throughout. The land 

 had been in sod for several years. In September, 1906, a light 

 coat of stable manure was applied with a manure spreader. 

 The field was plowed in May and thoroughly harrowed before 

 planting, which was begun on June 8. On account of a storm, 

 that portion including Plots 8 to 13 was delayed in planting a 

 few days, but the work was all completed within a week from 

 the beginning. One thousand pounds per acre of a commercial 

 fertilizer carrying 3 per cent nitrogen, 6 per cent phosphoric acid, 

 and 10 per cent potash was applied at the time of planting. The 

 plants were very strong and vigorous, and after the first few 

 weeks of growth absolutely no difference could be detected in 

 the appearance of the different plots till the foliage began to 

 show the effects of blight. 



For experimental spraying 13 plots about 39 rods long and 

 containing approximately one-third acre each were laid off on 

 this field beginning on the east side. These plots were all 

 sprayed 6 times, on the following dates, July 17 and 27, August 

 2, 9, 16 and 27. 



Plots 1, 3, 5, 9, 11 and 13 were sprayed with standard wet 

 bordeaux. For the first 3 applications single nozzles were used 

 to each row, applying not over 45 gallons per acre. The last 

 3 times 2 nozzles per row were used, applying 70-75 gallons 

 per acre. 



Plot 2 was dusted with 6 pounds of sal bordeaux per acre, and 

 Plot 4 with 10 pounds of sal bordeaux per acre. 



Plot 6 was an unsprayed check. It was sprayed with paris 

 green only for Colorado beetles. 



Plot 7 was sprayed with sodium benzoate bordeaux,* applied 

 at same rate and the same amount as standard wet bordeaux. 



* This spray was tried at the request of a firm which manufactures 

 sodium benzoate and according to the formula which they furnished as 

 follows : Copper sulphate 1 pound, lime r pound, sodium benzoate % 

 pound, water 50 gallons. "Dissolve the different ingredients separately 

 in about the whole quantity of water required, then combine and add 

 sufficient water to make up to 50 gallons." The manufacturers state 



