104 MANUAL OF AMERICAS GRAPE-GROWING 



possible, in which more than a very moderate profit could be 

 credited to manure. The average increase in yield following 

 the application of manure alone was less than a quarter of a 

 ton of grapes to the acre ; while the use of lime with the manure 

 increased the gain to one-third of a ton per acre. The ton of 

 lime to the acre annually would not be paid for by the gain of 

 175 pounds of grapes. Cover-crops were used in five of the 

 six cooperative experiments and proved even less adapted to 

 increasing crop yields than did the manure. There was no ap- 

 preciable gain, on the average, from the use of mammoth clover ; 

 indeed, a slight loss must be recorded for the clover except upon 

 the plats which were also limed, and even with the lime the 

 average yields on check plats and mammoth clover plats 

 differed by only one one-hundredth of a ton. Wheat or barley 

 with cowhorn turnips made a slightly better showing, as the 

 plats on which these crops were turned under, without lime, 

 averaged about one-twentieth of a ton to the acre better than 

 the checks. With these non-legumes, lime was apparently a 

 detriment, as the plants with the lime yielded a tenth of a ton 

 less, on the average, than those without it." 



Practical lessons from the Fredonia experiment. 



From this experiment it becomes clear that the use of fer- 

 tilizers in a vineyard is a local problem. General advice is of 

 little value. It is evident also that the fertilization of vine- 

 yards is so involved with other factors that only carefully 

 planned and long continued work will give reliable information 

 as to the needs of vines. Indeed, field experiments even in 

 carefully selected vineyards, as the cooperative experiments 

 show, may be so contradictory and misleading as to be worse 

 than useless, if deductions are made from the results of a few 

 seasons. The experiment, however, has brought forth informa- 

 tion about fertilizing vineyards that ought to be most helpful 

 to grape-growers. Thus, the results suggest : 



