CONFERENCE ON FEUIT GROWING. 



81 



sometimes, as we have found, be adopted with comparative impunity. But 

 there are circumstances which lead us to believe that we have not yet 

 fathomed the whole problem of grass-action, and that a further investigation 

 of it may bring us to some very interesting observations as to root-action. 

 At any rate, we have sufficiently established the necessity for extreme 

 caution in grassing over trees, even in a well-established orchard. Such a 

 step should never be taken without first making a preliminary trial on 

 a portion of it, to ascertain what the effect is likely to be. 



The effect of manure on fruit-trees is another matter in which our 

 experiments show that we are at present in a state of considerable 



Fig. 5. 



ignorance,?, and that much investigation is still needed. The main 

 feature of these results is to prove that, in the same soil in which manure 

 is of vital importance to one kind of fruit, it may represent so much 

 money thrown away with another kind. With our apple trees, manure, 

 whether artificial or natural, has had practically no effect whatever during 

 the first ten years since planting. The unmanured trees are, as regards 

 growth, vigour and cropping, indistinguishable from those which have 

 been heavily dressed every year ; some slight difference may be noticed 

 when we take the mean results of our numerous experiments, but that 

 difference does not amount to more than a few units per cent., and is 

 therefore of a doubtful character. 



G 



