﻿COPPER SPRAYS ON IRISH POTATO TUBERS. 



15 



Table 5. — Composition of tubers from sprayed and unsprayed potato plant;;, 

 Maine, Pennsylvania, New Jersey, and New York, HKiO- -Continued. 



Source. 



Variety. 



Treatment. 



Composition of tubers. 



Solids. 



Starch. 



Nitrogen. 





Blight Proof 





Per cent. 



21.92 

 21.79 

 23.36 

 24.42 

 19.80 

 18.20 

 18.33 

 23. 12 

 22.96 

 23.16 

 22.74 

 22.74 

 22.35 



23.80 

 21.72 

 28.16 

 26.42 

 26.62 

 24.03 

 20.34 

 27.61 

 27.37 



Per cent. 

 20. 80 

 17.30 

 10. 75 

 18.53 

 21.04 

 15.20 

 12.73 

 12. 35 

 19.50 

 19.00 

 19.10 

 18.60 

 18.40 

 18.20 



18.90 

 17.30 

 22.30 

 21.00 

 21.40 

 19.60 

 15.40 

 22.75 

 22.80 



Per cent. 

 0. 395 



Do 



do 





.363 



Do 







. 362 



Do 



do.... 







Do 



Blight Proof Union Co . . 

 do 







Do 





. 363 



New Jersey 



Do.... 



American Giants l 



do 1 





. 





.290 





Variety 9 (Wilkes) 





.274 



Do 





.311 



Do 



...do.... 





.297 



Do 



Variety 9 (White) 





.412 



Do 





.403 



Do 



...do.... 





.367 



Do 



Heavyweight (Ed- 









.401 



Do 



do 





.356 



Do 







.455 



Do 



do.... 





.478 



Do 



do.... 





.416 



Do 







.236 



Do 





Check (no copper) » 



.290 



Do 



Dibble Russet (Slayton). 



.348 



Do 





.347 











1 Average of 2 sets. 



For the New York data several varieties of potatoes grown near 

 Bath and one variety from Geneva were analyzed. From the limited 

 number of samples tested it is impossible to state definitely whether 

 Bordeaux dust has the same favorable effect on the potato plant as 

 Bordeaux spray has, although the results in Table 5 are not par- 

 ticularly favorable to the dust, with the exception of those for the 

 Heavyweight variety. Average figures for three sets grown in New 

 York gave 24.67 per cent of solids for tubers from Bordeaux-sprayed 

 plants, 24.04 per cent for tubers from Bordeaux-dusted plants, and 

 24.04 per cent for tubers from unsprayed plants. The average starch 

 results for these three sets are 20.13 per cent for tubers from plants 

 receiving Bordeaux spray, 19.47 per cent for those from plants 

 treated with Bordeaux dust, and 19.57 per cent for those from the 

 check plants. The average nitrogen data for the three sets are: 

 Tubers from Bordeaux-sprayed plants, 0.38 per cent; tubers from 

 Bordeaux-dusted plants, 0.397 per cent; and tubers from unsprayed 

 plants, 0.36 per cent. Comparing all five dusted plots with the five 

 corresponding checks gives an average of 24.71 per cent solids 

 against 24.24 per cent, and comparing all four Bordeaux-sprayed 

 plots an average of 24.51 per cent solids against 23.12 per cent for 

 the checks. In general, the results for the New York tubers were 

 higher when Bordeaux spray was used than when no spray was used. 



Data were secured for four varieties of potatoes grown in Maine, 

 two varieties from Pennsylvania, one variety having been grown in 

 two different places, and one variety from New Jersey. Three of 

 the four samples of tubers from Maine were higher for Bordeaux 

 and they averaged 20.51 per cent solids from the Bordeaux-sprayed 

 plants and 19.84 per cent from the check plants. Two of the three 

 sets of tubers from Pennsylvania were higher for the Bordeaux 



