THE MEASUREMENT OF RESULTS 19 



when vigour is decreasing ; this is generally characterised by the 

 spasmodic production of heavy crops of inferior fruit. 



In any measurement of results based on the crops produced, 

 it must be remembered that the point of view of the fruit grower 

 is not identical with that of the tree. A small badly-developed 

 iruit contains a relatively large amount of solid matter compared 

 with a well-developed fruit, and represents nearly the same drain 

 on the resources of the tree (see p. 106) ; but it would rarely 

 happen that the results should be measured from this point of 

 view. In general work, size of fruit must be given as much 

 consideration as quantity, though another factor which is of 

 great importance quality has usually to be left unconsidered. 

 It becomes a question, therefore, how fruit crops may best be 

 dealt with, so as to take into proper consideration weight of crop 

 and the average size of the fruits. In practice, the value of a 

 sample of fruit varies very rapidly with the size of fruits. One 

 sample with fruits half the size of another sample will generally 

 fetch much less than half the money probably only about a 

 quarter as much and such a proportion, i. e. a value varying as 

 the square of the size, or rather weight, of the fruits, has been 

 taken at Woburn as a convenient basis. The total " value " of the 

 crop of a tree, or of a plot of trees, is, therefore, found by multi- 

 plying the square of the average size of the fruits by the number 

 of fruits, or, what comes to the same thing, multiplying the average 

 size of the fruits by the total weight of the crop. 1 Of course, the 

 numbers expressing such " values " have no monetary signifi- 

 cance, but simply give the relative values in different cases, and 

 may, for convenience, be reduced so that the value in the check 

 plots are expressed by 100. The values in the case of apples of 

 different varieties cannot be compared together. In most cases the 

 results have been examined independently from the three points 

 of view of the weight of crop, size of fruits, and value of crops. 



As to what variations may be expected in the cropping of 

 similar trees under the same conditions, or what is the probable 

 experimental error in cropping experiments, no useful estimate 

 can be made, except in cases where the trees are bearing freely ; 

 with young trees, which have come only partially into bearing, 

 with trees which are naturally shy bearers, and with all varieties 

 in a bad season, many trees will be barren, and the variation in 

 cropping will be numerically enormous. To obtain a reasonable 



1 Value = (size) 2 X number : but size = % , or number* = ' 



hence, value = (size) 2 X - = size X weight. 



