106 SCIENCE AND FRUIT GROWING 



sight be imagined between the requirements of a plantation in 

 full bearing, and of a young plantation in vigorous growth. 



Passing on to the question of the radical difference in behaviour 

 of apples and bush fruits, especially gooseberries, it is clear that 

 this cannot be accounted for by the deeper-rooting habit of the 

 former, for in the Ridgmont soil such deep-rooting does not 

 occur (see p. 309) ; the question arises, therefore, whether the 

 requirements of bush fruits are much greater than those of 

 apple trees. They appear not to be so. Estimates based on the 

 analyses quoted above, and on certain probable values for the 

 crops produced l during 22 years, lead to the following values 

 for the annual production per acre in the case of gooseberries 



Undried wood . . 550 kilos j = potash ^ 



= Dried wood . . 259 ,, J 



Fruit ..... 3000 ,, 5-43 kilos, 



or a total of 6*63 kilos, against 7*52 kilos in the case of apples, 

 so that the cultivation of gooseberries creates a somewhat smaller 

 drain on the mineral resources of the soil than the cultivation 

 of apples. The comparative inefficiency of artificials as a 

 manure for gooseberries harmonises with this conclusion, and it 

 cannot be merely the nitrogen in dung which accounts for the 

 great effect of natural manure, for the artificials applied con- 

 tained ample nitrogen. 



That dung does materially improve the physical character 

 of the soil, rendering it more friable and more retentive of 

 moisture, is, of course, well known, but there is no reason, so 

 far as we know, why such an alteration should be essential to 

 gooseberries, and altogether ineffectual in the case of apples, 



1 Taking two-thirds of the fruit as being gathered when green. It is 

 interesting to note that the difference between the composition of green and 

 ripe fruit is mainly a question of the amount of water present, the actual 

 weight of potash shows very little increase during the ripening, and that 

 of the ash not very much. Thus 



Green. Ripe. 



Weight of berries . . 2-08 grams. 3-33 grams. 



Water content . . . 1-87 ,, 2-81 ,, 



Ash ,, 0-008 o'oi2 ,, 



Potash ,, . . . 0-0041 ,, 0-0047 ,, 



The water increases during ripening by 50 per cent., while the potash 

 increases by only 17 per cent. A similar observation has been made by 

 Clark in respect to apples (Missouri Dep. of Horticulture, Bull. 10, 1890). 



