218 Report of the Botanical Department of the 



RESULTS IN 1909. 

 Table XV. — Yield by Series at Geneva in 1909. 



Series. 



I 



n 

 in 



Rows. 



1, 4, 7, 10 and 13.. 



2, 5, 8, 11 and 14.. 



3, 6. 9, 12 and 15.. 



Dates of spraying. 



July 9, 23 and Aug. 11 



July 9. 23. Aug. 11, 27, Sept. 10 and 24 

 Not sprayed 



Yield per acre. 



Bu. 

 162 

 173 

 123 



Ws. 

 20 

 25 

 40 



Increase in yield due to spraying three times, 38f hu. per acre. 

 Increase in yield due to spraying six times, 49'f hu. per acre. 



Early blight, late blight and rot were all absent. Some injury 

 from flea beetles was noticeable throughout the season. After Sep- 

 tember 1 there was considerable tip burn. As late as September 

 24 the difference between sprayed and unsprayed rows appeared 

 slight. The sprayed rows held most of their foliage until killed 

 by frost on October 14. 



Table XVI. — Yield by Series at Rivebhead in 1909. 



* Marketable tubers only. Owing to their small average size it was deemed advisable to make 

 two grades of the marketable tubers; " firsts " which sold for 80 cents per bushel and " seconds " 

 which sold for 40 cents. The increase in yield due to spraying was chiefly in the grade of " firsts." 

 the yields being as follows: 



Rows sprayed three times, 75i bu. " firsts " and 61J bu. " seconds; " rows sprayed six times, 

 100 bu. " firsts " and 60J bu. " seconds; " unsprayed rows, 50 bu. " firsts " and 57| bu. " seconds." 



Increase in yield due to spraying three times, 28f bu. per acre. 

 Increase in yield due to spraying six times, 52^ bu. per acre. 



There was a little early blight, but no late blight and no rot. 

 After July 15 the plants suffered from both drought and flea 

 beetles. From this time until the plants were all dead the sprayed 

 rows were noticeably superior to the unsprayed ones. This differ- 

 ence was more marked during the last week in July than on 

 August 21. 



