HORTICULTURAL RESEARCH 401 



been, though the actual thickness of the stem and branches 

 may be less. 



It might be suggested that, though a hard-pruned tree is 

 smaller than an unpruned one, it has really made more growth, 

 where allowance is made for the wood removed in the pruning; 

 but this is not the case, as was proved by comparing the recorded 

 weight of the prunings and the total weights of the trees when 

 some of these came to be removed. This point has also been 

 investigated in another way. Several trees were taken and on 

 each of them a number of straight shoots of exactly the same 

 size were selected, all 36 in. in length ; some of the shoots were 

 left unpruned, whilst others were cut back to a length of 24, 12 

 and 6 in. Fig. 5 shows one set of shoots at the end of the season 

 following this pruning. It is easy to see that the harder the 

 pruning has been the less is the growth which has taken place. 

 On the average the unpruned shoot increased five and a half 

 times more in weight than that which had been cut back to 6 in. 

 and the number and length of side shoots arising from it was 

 three times and twice as great, respectively : so that in no sense 

 had pruning favoured growth. Shoots cut back to intermediate 

 lengths gave intermediate values. 



Effect on Fruiting 



These experiments also afforded evidence on another im- 

 portant point, though this is scarcely visible in the figures : 

 the fruit-buds formed on the twigs were more numerous the 

 less the pruning, so much so that there were on the unpruned 

 twigs five and a half times as many fruit-buds as on those cut 

 back to 6 in. 



The effect of pruning in reducing the fruiting power of trees 

 has been investigated more extensively in other experiments. In 

 one case a record of crops was available for this purpose obtained 

 from a ten years' trial of sixty dwarf apple trees grafted on the 

 paradise stock of each of three different varieties. The general 

 results for the first and second periods of five years are illus- 

 trated by the first two diagrams in fig. 6, from which it will 

 be seen that the weight of fruit obtained from the unpruned 

 trees is about double that obtained from the moderately pruned 

 or " normal " trees, whereas from the hard-pruned trees the 

 yield has been but little more than half of that from these 



