132 The Fruiting of Trees in Consecutive Seasons 



it is capable of doing so, results in its subsequently bearing very heavy 

 crops. From some apple-trees of a precocious variety which had been 

 disblossomed for two years longer than their fellows, the crops obtained 

 during the succeeding five years were, on the average, 3-3 times as 

 heavy as those from their neighbours ; after which time their superiority 

 disappeared {Fifteenth Report, Woburn Experimental Fruit Farm, 1916, 

 p. 2). It may be argued, however, that the delaying of the first coming 

 into bearing of a young tree is not altogether similar to the restriction 

 of the crop of a tree which is already in bearing. 



The difficulties in obtaining exact measurements of the relative 

 behaviour of any two or more trees in consecutive seasons are consider- 

 able. The weight of fruit or the number of fruits may be recorded, 

 but, unless the trees are absolutely similar in size, disposition of branches, 

 situation, etc., which is impossible, the superiority of the one over 

 the other as regards inherent fruiting capabilities may be misleading. 

 On the other hand, the trees under observation may be classified by 

 inspection, grouping them according to the extent which they are 

 loaded with fruit, independent of their size, and then comparing the 

 classification in one year with that in the following year. This method 

 avoids errors due to differences in the size of the trees, but it has the 

 disadvantage of being based on the judgment of the observer, and not 

 on actual weights. This latter method was adopted in the case of 

 one series of observations on trees at Harpenden, and the former in 

 the case of the other series on trees at Richmond. 



Whichever method of observation was adopted the results were 

 treated as follows : two selected trees were numbered 1 or 2, according 

 to which of them bore the heavier crop in consecutive seasons; then, 

 comparing the results in two consecutive seasons, if the order of fruiting 

 had been the same (consecutive fruiting), the difference between the 

 numbers given to the trees would be 0, if the order had been reversed 

 (alternate fruiting) the difference would be 1 ; whereas if neither 

 consecutive nor alternate fruiting prevailed, and the results were 

 dependent solely on chance or on external conditions, the differences 

 would, on the average, be 0-5. An average difference, for instance, of 

 0'75 would be half way between 1 and 0-5, indicating that the results were 

 dependent on the alternating tendency to the extent of 50 per cent., 

 and on chance fruiting to the extent of 50 per cent. 



All the trees compared together were of the same age and had 

 received exactly the same treatment since they had been planted; in 

 some cases they were compared in couples, in other cases, the groups 



