INDIANA HORTICULTURAL SOCIETY. 253 



not always remain on the ground around the trees. Ripe leaves may pro- 

 duce some organic matter in the soil, but they contain relatively little fer- 

 tilizing material; for while the leaves evaporate much plant food, most of 

 the plant food itself passes to the fruit and new wood before the leaves 

 ripen. 



The growth of an orchard also differs from that of our common fai-m 

 crops in that the orchard growth is divided into two distinct periods, the 

 period up to the beginning of fruit bearing and the fruit bearing period. 

 During the preliminary period we have to provide only for the growth of 

 the tree, but after the tree comes into bearing we must provide for both 

 the growth of the tree and production of fruit. While a crop of fruit is 

 being produced the tree must also store up material in the buds and 

 young wood for the next year's needs. This requires a constant transfer 

 of plant food throughout the whole gi-owing season. In order to meet this 

 requirement the soil must contain available plant food throughout the 

 season. This means that there must not only be certain chemical elements 

 present in an available form, but that there must also be water enough 

 present at all times to permit these elements to pass from the soil to 

 the trees. 



Proper drainage, deep plowing, subsoiling, mulching, and frequent sur- 

 face cultivation during the summer all aid in storing and retaining the 

 moisture during the season when it is of the most vital importance that 

 both fruit branch and bud should be mailing a continuous growth. With- 

 out a sufficiency of moisture the best fertilization can not produce its 

 desired effect. 



Fruit raising is continuous cropping of one liind and it is well linown 

 that the continual production of one crop on the same land demands bet- 

 ter fertilization than is required when a rotation of crops is used. The pi'o- 

 duction of a rotation of crops in a young orchard is not a rotation so 

 far as the young trees are concerned, but is too often only a means of re- 

 moving plant food that is sorely needed by the trees. 



The chemical elements that malve up trees and fruit are the same that 

 enter into other crops, but the relative amounts of these elements are 

 different. There is a common opinion that the element nitrogen contributes 

 most to the growth of leaf while potash gives color to the fruit. The safer 

 basis on which to proceed is to remember that a suitable supply of all 

 the elements of the plant are necessary for the proper development of tree 

 and fruit. Certain conditions may indicate a lacli of one or more elements. 

 A tree with liglit colored foliage may mean a lack of nitrogen or it may 

 mean a general laclv of plant food. Lack of color in fruit may indicate 

 a lack of potash or it may mean a lack of general vigor due to general 

 starvation. The failure of vigorous young trees to produce fruit is often 

 due to a lack of available phosphoric acid. Late ripening of fruit is often 

 due to the same cause. In the presence of enough of the other plant 

 foods, lime tends to promote a stocky growth of the tree and ripening of 

 the wood. 



