224 Report of the Botanical Department of the 



Table XXT. — Yields in the Experiment at Rivebhead in 1911. 



Row. 



Treatment. 



Yield per row.* 



Market- 

 able. 



CuUs. 



Yield per acre 

 (computed) . 



Market- 

 able. 



CuUs. 



1 Sprayed 3 times . 



2 Sprayed 5 times . 



3 Unsprayed 



4 Sprayed 3 times. 



S Sprayed 5 times. 



6 Unsprayed 



7 Sprayed 3 times. 



8 Sprayed 6 times. 



9 Unsprayed 



10 I Sprayed 3 times. 



11 j Sprayed 5 times. 



12 Unsprayed 



13 ' Sprayed 3 tunes. 



14 Sprayed 5 times. 



15 Unsprayed 



Lbs. 

 177 

 168 

 199.5 

 161.5 

 174.5 

 161 

 133.5 

 152.5 

 164.5 

 152 

 151 

 129 

 183 

 157 

 146 



Lbs. 



5 



3 



4 



4 



6.5 



5 



7 



6 



6.5 



8 

 14 



9 

 12 

 14 

 12 



Bu. 

 147 

 140 

 166 

 134 

 145 

 134 

 111 

 127 

 137 

 126 

 125 

 107 

 152 

 130 

 121 



lbs. 

 30 



15 

 35 

 25 

 10 

 15 

 5 

 5 

 40 

 50 

 30 

 30 

 50 

 40 



Bu. 



4 



2 



3 



3 



5 



4 



5 



5 



5 



6 

 11 



7 

 10 

 11 

 10 



lbs. 

 10 

 30 

 20 

 20 

 25 

 10 

 50 



26 

 40 



40 



30 



40 



* Rows 290.4 feet long by 3 feet wide, making the area of each row exactly one-fiftieth acre. 



Table XXII. — Yield by Series at Rivebhead in 1911. 



Increase in yield due to spraying three times, li bu. per acre. 

 Increase in yield due to spraying five times, ^ bu. per acre. 



In all our experience with potato spraying experiments this is 

 the only instance in which five thorough sprayings with bordeaux 

 mixture have failed to increase the yield. What may have been 

 the cause we do not know. Perhaps the severe drought had some- 

 thing to do with it. There is no reason to believe that the un- 

 sprayed rows had any advantage over the sprayed rows. 



