148 The Principles of Fruit-growing 



and green manures. Hedrick sums up the work thus far 

 (Bull. No. 381) as follows: "From the data obtained in 

 these experiments it is evident that the fertilization of 

 vineyards is so involved with other factors that only long- 

 continued work will give reliable results. From the work^ 

 done, however, several suggestions may be made to grape- 

 growers: 



"First, fertilizers cannot be profitably applied in vine- 

 yards poorly drained, suffering from winter freezes or 

 spring frosts, or in which fungi or insects are uncontrolled, 

 or where good care is lacking. 



"Second, it is probable that most vineyards have a 

 one-sided wear, there being few plantations indeed where 

 more than one or two of the elements of fertility are lack- 

 ing. Nitrogen is probably most frequently the element 

 needed. Each grape-grower should try to discover which 

 of the food elements his particular soil needs, if any. 



"Third, maximum profits cannot be obtained in many 

 vineyards of the Chautauqua belt because of the lack of 

 uniformity in vineyard conditions. Grape-growers should 

 strive by every means possible to secure an equally vigor- 

 ous and healthy growth over the entire area cropped. 



"Fourth, the steps to be taken in restoring a failing 

 vineyard are, in the usual order of importance, (1) give 

 good drainage; (2) control insects and fungi; (3) improve 

 the tillage and general care; (4) apply such fertilizers as 

 may be found lacking." 



Wheeler makes the following general statement: 

 "Grapes may show some gain from the use of lime under 

 certain circumstances, but they do not require it in even 

 approximately the same degree as the cherry, plum, cur- 

 rant, and gooseberry. The chief need of this crop is avail- 

 able phosphoric acid and potash. If nitrogen is used, the 



