336 SCIENCE AND FRUIT GROWING 



best 16 in one series, was amongst the worst 16 in another, whilst 

 the average difference of position of the varieties in the two 

 series was as much as twelve places. 



With such differences in the comparative behaviour of different 

 varieties in the same field, it is obviously impossible to deter- 

 mine their behaviour throughout an extensive district by a trial 

 in one particular spot ; the only way of gaining information on 

 the subject is to make general observations throughout the whole 

 district, and, even then, the conclusions, however carefully drawn, 

 are likely to fail when applied to particular situations. 



CONTINUOUS CROPPING WITH STRAWBERRIES 



The view that the continuous cropping of land with the same 

 plant renders that land " sick," and unfit for the gro\vth of that 

 particular plant, though fertile for other plants, has already been 

 alluded to (p. 302), and shown to be destitute of foundation. 

 Amongst the plants which are supposed to render land " sick," 

 the strawberry must be included, and the results at Woburn 

 showed that in that case, also, such a view could not be main- 

 tained. A plot of ground had been used for growing straw- 

 berries continuously for fifteen years, but at each fresh planting 

 the arrangement had been altered so that various parts of the 

 ground had not carried any plants during five, and others not dur- 

 ing ten years, out of the fifteen. On comparing the weight of 

 the plants grown in these less-continuously cropped sections with 

 those grown where the cropping had been continuous, a balance of 

 8 per cent, was found in their favour : but since of the five 

 different varieties examined, two gave a balance in the opposite 

 direction, and the probable error of the mean result was 9 per 

 cent., it was clear that this average difference of 8 par cent, had 

 no significance, and afforded no evidence of the ground having 

 become " strawberry-sick." 



STRAWBERRY RUNNERS 



Another common tenet relating to strawberries would appear 

 to lack foundation : this is, that the first runners thrown out 

 are much stronger and more prolific than the later ones. This 

 may be so to a certain extent as regards their cropping power 

 during the first year after planting, for the first runners would 

 be appreciably older than the later ones, and would form larger 

 plants : but any advantage of this sort becomes inappreciable 

 in subsequent years, and the later runners then show a con- 



