HORTICULTURAL RESEARCH 411 



interesting. Taking the first period of five years, an increase 

 in the dung from 12 to 30 tons per acre had no effect in 

 increasing the crops but it increased the growth considerably ; 

 with the 12 tons this growth was six times that in the un- 

 manured plot but with 30 tons it was ten times this quantity. 

 In subsequent years, however, this increased growth in the 

 early stages told on the cropping and the crops from the 

 heavily dressed bushes are now, after fifteen years, double to 

 treble those from the lightly dressed ones. 



The effect of artificial manures on growth was similar to that 

 of dung but much less marked. When these artificials were 

 equivalent in supposed manurial value to the 30 tons of dung, 

 the growth was about 80 per cent, more than in the unmanured 

 plot but with artificials equivalent to only 12 tons of dung no 

 increase in growth was obtained. 



Thus dung is essential to the well-being of gooseberries in 

 our soil and probably in all soils ; the same has been found 

 to be the case with black and red currants and with raspberries. 

 With strawberries the results have been somewhat different, 

 for though they were benefited considerably by manuring, the 

 superiority of dung over artificials was not marked and in some 

 seasons was in favour of the one, in others of the other ; but 

 as regards the size of the fruits, there was a distinct balance 

 in favour of the dung. 



The very different manurial requirements of fruit-trees and 

 bushes render it evident that, to obtain the most economical 

 results from this point of view, they should be grown separately 

 and not in mixed plantations ; other considerations, such as 

 economy of space, may often, however, necessitate modifications 

 of such an arrangement. 



Measurement of Results 



The problem as to the measurement of results in the case 

 of fruit-trees is by no means simple and was one of the first 

 which had to be attacked at Woburn. From a fruit grower's 

 point of view it is clear that the fruit borne should be the 

 criterion ; but it would have to be the fruit borne during the 

 whole life of the tree ; as that may extend to fifty years or 

 more, such a method of measurement is hardly practicable. 

 The annual crops, it is true, must always be recorded, not only 



