13. 



Table 9, - Not off cot qn 19S8 f-rape yields, of each kind of plant food 

 applied to light- and hoaYy-tcztixrod soils, Chautauqua-Erio vineyard! 

 fertilized apprcxiinatoly the same in 1927 and 1928 1/ 



Soil t3rpo 



Light-textured soils 

 (graYclly, or sandy 

 loams ) 



Heavy-textured soils 

 (loam, clay, silt) 



Plant food 



:Und 



Nitrogen 

 Phosphoric acid 

 Potash 



Nitrogen 

 Phosphoric acid 

 Potash 



Quanti- 

 ty J) or 

 acre 



Pounds 



30 



30 



r50 -. 



30 



• .30 



30 



Cost 



per 



acre 



Dollars 



5^02 



2o00 

 1*38 



5.02 

 2.00 

 1.38 



Additional 



grape 



yield 

 per acre, 



1928 2/ 



Pounds: 



812 



555 

 182 



307 

 162 

 203 



Fertilizer 

 cost for 

 additional 



ton of 



grapes 



Dollr.rs 



12.36 



7.21 



15.16 



32.70 

 24.69 

 13.60 



d from the correla- 



1/ The average cooff icioiits and" re:^^ession equations derive 



tion study of fertilizer applications and grapo yields on Chautauqua-Erie vine- 



yards are here given for reference. 



^Increased grapo yields calculated from the: straight-line regression equations 



as given helov/. 



Variables 



Plant food per acre 

 Nitrogen 



Phosphoric acid 

 Potash 

 Dependent variable 



Grape' yields 

 Multiple' correlation 



Avar-: stand--" 

 age : ard 

 per _ :devi- 

 ac ro ; ati_qn_ 

 Pounds rPoimds" 



• 6 



24.6: 16 

 16,5: 17«9: 

 4720: 1340: 



3-ij^. 



soils: 



: 65 vineyards 



, heavy 



soils 



Correlation 



: Aver-^ 



;Stand- 



: Correlation 



coefficients 



: age ^ 

 : per : 



: ard 

 ; devi- 



: coefficients 





Par- : 





; Par- 



Gross: 



tial 



: acre : 



: ation 



:Grc^s : 



: tial 



r : 



r : 



.Pounds: 



; Pounds 



: r : 



r 



4^043: 



+ •37: 



: 12.3: 



: 14.8: 



: 4.25: 



: *,11 



+.47: 



4.30: 



. 16.9: 



; 27.5- 



; +^26: 



. 4*10 



+ .35: 



+ •08: 



; 7.7J 



: -18.3: 



: +.23: 



; *,05 







: 3420 : 



. 1160J 









+ .57: 









; 4.. 30 



Regression oquation, X^" r Grnpe yiolcl in tons; Pounds of plant food applied per 

 aerc, Kitrogen Xg; Phosphoric acid X^; potash X^^.; Light-textured soils X^^ - 

 1.714- * ,01354 XZ^ .00925 X3 •>• .00303 X4, Hoavy-tcxtured soils X-^ = 1.578 -f 

 .00511 Xg f .00270 Xg f .00359 X^. ^ 



