262 SCIENCE AND FRUIT GROWING 



years the majority of the trees of the weaker varieties were 

 actually dead, as will be seen from Fig. 31. Somewhat similar 

 experiments were made at the same time on the Bramley's 

 standard trees, by grassing them over, either entirely or partially, 

 after they had been established in the ground for eight years, 

 when similar results were obtained (III, 17) ; even a very par- 

 tial grassing of the ground round the trees having a marked 

 effect on them. 



Again, in 1907, two mixed plantations planted in 1894, con- 

 sisting of standard and dwarf apples and pears, were each divided 

 into two similar sections, as to which sections previous records 

 showed that the various trees in the two were closely similar in 

 vigour and bearing. One section in each plantation was then laid 

 down to grass. In spite of the long time which the trees had had 

 to become established, the grass still proved most deleterious : 

 photographs taken three years later of two originally similar trees 

 are reproduced in Fig. 32, and will serve to illustrate the average 

 general effect. The intensity of this effect, however, varied 

 greatly with the different varieties ; 1 in some cases the grassed 

 trees were killed, in others they suffered very little. The extent 

 of the variation maybe judged by the following summary of the 

 relative values of the crops from them during the nine years 

 following the grassing, the values for the trees in the ungrassed 

 sections being represented by 100. In one case, a pear, the 

 effect had been beneficial. 



Apples. Pears. 



Gascoyne . . 100 2 Beurre Hardy . . .165 



Warner's King . . 85 William's 75 



Newton Wonder . 83 Pitmaston ... 58 



Yellow Ingestre . 69 



Golden Noble . . 32 



White transparent . 31 

 New Northern Greening 8 



Bismarck. . . 6 



Peasgood. . . I 



The leaf-weights, which were examined during the four years 

 after the grassing, told a similar tale, those in the grassed section 

 being, on the average, 25 per cent, less than those in the tilled 

 sections. 



1 But is attributable, from recent observations, more to the different 

 drainage in the plots (p. 308). 



2 Probably much too high owing to a very exceptional value in one 



