COPPER SPRAYS ON IRISH POTATO TUBERS. 15 
TABLE 5.—Composition of tubers from sprayed and unsprayed potato plants, 
Maine, Pennsylvania, New Jersey, and New York, 1920—Continued. 
Composition of tubers. 
Source. Variety. Treatment. 
Solids. | Starch. | Nitrogen. 
Per cent. | Per cent. | Per cent. 
Pennsylvania....| Blight Proof ..-.-.....-- 5-5-50 Bordeaux............ .5 20. 0. 395 
1D Tis Soe eee el eee Oe ee ees Check (no copper).......-..- 21. 92 17. 30 . 353 
Gee est | Dibble Russet........... 5-5-50 Bordeaux........-.-- 21.79} 16.75 362 
1) ee ae ee a Ko Geena SE eine tees Check (no copper)....---.--- 23. 36 18. 53 . 334 
Dore es wee Blight Proof Union Co..| 5-5-50 Bordeaux...........- 24, 42 21. 04 . 340 
12a ee OM ee a aie Check (no copper)......--.-- 19. 80 15. 20 . 363 
New Jersey...... American Giants!....-. 44-50 Bordeaux...........- 18. 20 12.73 - 334 
1D Yaya cyie ee Sees 2] 8 EN 6 Voy Dis te one te ky Sema Check (no copper)..........- 18. 33 12: 35 . 290 
New=sY Ork- 22... Variety 9 (Wilkes)...-.. 44-50 Bordeaux.........-.- 23. 12 19. 50 274 
Dip ae ese. 125 2. dows 5 Sarees ee Bordeaux dust...........-.. 22. 96 19. 00 311 
DOr cue as c| ao... -% GOs ee Ae Check (no copper)......--.-- 23. 16 19. 10 . «297 
1) oe ee Variety 9 (White)....... 4-4-50 Bordeaux.........-.- 22.74 18. 60 412 
IDO, Ree er ees Goss) fries Seo se iB Ordeatex GuSit G5. ose cose 22. 74 18. 40 - 403 
WOME nae cc lEe nee don 2 Wate Seen Check (no copper)..........- 22. 35 18. 20 . 367 
1D ace Heavyweight (Kd- 
Wards) 252 eee ase IBOLdealixs GuSteesee acess 23. 80 18. 90 - 401 
IDO as ae GO Ui a: ees aha Check (no copper)........--. PATE 17.30 - 356 
DORSs see << Goldson'e J sseeeek=s 4-4-50 Bordeaux............ 28. 16 22. 30 - 455 
ID) eee et ee ar GOssre see eae IBOLdealxGUSt leet see seen ee 26. 42 21. 00 - 478 
ID On ee eee, Cc fo Me Ce Peer ae Check (no copper).......-..- 26. 62 21.40 - 416 
IDO) oR ee (en i RT UTS EP a a 44-50 Bordeaux...........- 24. 03 19. 60 - 230 
IDO SA cee eee nea a aearcs Ser sty a Check (no copper).-....-..-- 20. 34 15. 40 . 280 
DD Ona sis5 22 =: Dibble Russet (Slayton). Bordeaux dust............-- 27.61 22.75 348 
LD eee ers GOSS see eee Check (no copper)........--- 27.37 22. 80 347 
i 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 tas 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 Berdeaux-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 
recelving 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, 0.88 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 
