﻿14 



BULLETIN 1146, U. S. DEPARTMENT OF AGRICULTURE. 



Table 4. — Yield and composition of tubers from sprayed and unsprayed potato 



plants, etc. — Continued. 



Variety. 



Treiil iiii'iit. 



Yield 



from 



2 rows, 



each 100 



feet long. 



Composition of tubers. 



Solids. 



Starch. 



Nitrogen. 



Late potatoes (October): 

 Spalding Rose 



Do 



Do 



Do 



Gold Coin 



Do 



Do 



Do 



Irish Cobbler ' 



Doi , 



Do 1 



Do* 



Do* 



McCormick l 



Doi 



Do 1 



Doi 



Do' 



0-4-50 spray (no copper) 



Pickering spray 



4-4-50 Bordeaux 



Check (no copper) 



4-4-50 Bordeaux 



0-4-50 spray (no copper) 



Pickering spray 



Check (no copper) 



4-4-50 Bordeaux 



0-1-50 spray (no copper) 



10-10-50 Bordeaux 



Pickering spray 



Check (no copper) 



Check (no copper) 



0-4-50 spray (no copper) 



Pickering spray 



4—4-50 Bordeaux 



10-10-50 Bordeaux 



Pounds. 

 153 

 221 

 250 

 248 

 242 

 232 

 296 

 294 

 303 

 245 

 291 

 261 

 288 

 245 

 237 

 259 

 241 

 226 



Per cent. 

 19.36 

 2L4B 



21. 45 

 19.81 

 22.09 

 21.12 

 23.80 

 19.52 

 22.69 

 20.14 

 22.43 

 21.92 

 20.66 

 21.72 

 21.36 

 21.88 

 21.32 

 21.47 



Per cent. 

 16.80 

 19.20 



17.00 



17.90 

 14. 50 

 17. 20 

 15.13 

 17.15 

 16.73 

 15. 68 

 15.85 

 15.50 

 15.90 

 15.50 

 15.75 



Per cent. 

 0.406 

 .397 

 .430 

 .409 

 .485 

 .461 

 .457 

 .414 

 .4 IS 

 .400 

 .■111 

 .443 

 .429 

 . 430 

 .419 

 .456 

 .436 

 . 157 



i Average of 2 sets. 



2 Average of 3 sets. 



The 10-10-50 Bordeaux spray showed no particular advantages 

 over the 1 1 50 Bordeaux spray or the Pickering spray in either the 

 early or late tests. The vines receiving the 0-4-50 spray, which con- 

 tained no copper but did contain lime, usually showed yield results 

 lower than those of the checks, but the results of the analyses of the 

 tubers usually agreed rather closely with those obtained for tubers 

 from the check plants. The yield data are variable, but on an aver- 

 age are higher for the copper-sprayed than for the check plants. 

 The data for solids, starch, and nitrogen are generally higher for 

 the copper-spiked than for the lime-sprayed or check plants. This 

 indicates that copper is the essential constituent of the spray. 



Maine, Neio York, Neio Jersey, and Pennsylvania. — Thirty-three 

 samples of tubers from Bordeaux-sprayed plants from Maine, Penn- 

 sylvania, and New Jersey and from Bordeaux-sprayed and Bordeaux- 

 dusted and unsprayed potato vines in New York (Table 5) were 

 examined. All of the plants were sprayed with an arsenical. San- 

 der's Bordeaux dust was used. The sprays and dusts were applied 

 five times during the season. 



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

 Maine, Pennsylvania, New Jersey, and Neiv York, 1920. 



Source. 



Variety. 



Treatment. 



Composition of tubers. 



Solids. 



Starch. 



Nitrogen. 









Per cent. 

 20.45 

 18.39 

 18.23 

 18.13 

 21. 70 

 20.91 

 21.65 

 21.93 



Per cent. 

 15.95 

 13.80 

 13.80 

 13.95 

 16.80 

 16.00 

 17.00 

 16.95 



Per cent. 

 0.367 



Do 



do 





.353 



Do 







.356 



Do 



...\.do." 





.319 



Do 







.371 



Do 



do 





.356 



Do 







.316 



Do 



do 





.339 



