62 INTERNATIONAL CONGRESS OF VITICULTURE 



Any system of training to have merit must be so adapted to the variety, 

 as grown on the particular soil type, that it will conserve the energies of the 

 vine from year to year. Any system can be abused in the hands of the 

 incompetent pruner. 



COMMERCIAL FERTILIZERS FOR AMERICAN GRAPES. 



By F. E. GLADWIN. 

 Vineyard Laboratory, Fredonia, N. Y. 



This paper presents the results of six years' study on the role of com- 

 merical fertilizers in grape growing for New York. The data here presented 

 is not to be considered conclusive but rather suggestive in pointing the 

 way towards a reasonable standard cf production, and at the same time 

 maintaining the vines in good vigor. Fertilization and manuring of vine- 

 yards has been a hit or miss operation, no well-defined plan having been 

 followed out. Vineyardists of New York are generally of the opinion that 

 stable manure or potash in some form are all important. Of the potassium 

 carriers, Kainit is the most popular. Commercial Nitrogen and Phosphorous 

 have generally been applied only in factory-mixed goods and these are 

 usually low in quickly available Nitrogen. 



No long time fertilizer experiments have been conducted with the grape 

 in the United States under commercial conditions. The French and Ger- 

 mans, however, have made numerous tests, yet because of the dissimilarities 

 of species and cultural practices they are of little use to American grape 

 growers. A few are worth brief mention. Sannino2 reports "that he used 

 356 pounds per acre of sulphate of potash and no differences in wood growth 

 were to be seen between the fertilized and the unfertilized. At harvest time, 

 however, the fertilized grapes were seen to be a little larger and sweeter 

 than the unfertilized." No differences in the amounts of fruit are recorded. 



Stoklasa, J.,3 reports the following yields from .08 acre: 

 Plats 



Check 4600 Kg. 



Acid phosphate, 17 per cent, 814 pounds per acre 



Kainit, 1430 pounds per acre 5500 Kg. 



Acid phosphate, 814 pounds per acre 



Ammonium sulphate, 616 pounds per acre 



Kainit, 1430 pounds per acre 7100 Kg. 



This experiment seems to show that nitrogen was the limiting factor. 



Zeissig4 obtained much heavier wood growth from the use of 160 pounds 

 of nitrate of soda put on in three applications than from plats where nitrate 

 was omitted. The development of fruit and the yield were most satisfactory. 

 Nitrate of soda was more effective with some varieties than with others. 



2 Sannino, F. A. (Revista) Conegliano. 



3 Stoklasa, J. Wiener Londw. Ztg. 59.1909. No. 18, p. 182. 



4 Zeissig, Ber. K. Lehranst Wien, Obst. u. Gartenbau, Geisenheim, 1902, 

 pp. 59-64. 



