•20 ''Reversion'' and Resistance to '' Blrj Bud" 



by the comparatively long intcrnodes until 430, the last three internodes 

 being formed without any chance of elongation. It covers therefore a 

 distance of eleven internodes. In the Chelmsford specimen the check 

 begins at 330 and continues strongly, as indicated by the closeness of the 

 internodes, until 460, a distance of eight internodes. The chief difference 

 is therefore that the check at Long Ashton is gradual and weak while 

 that at Chelmsford is sudden and strong. At the other end of the graph 

 it may be noticed that the growth is more vigorous at Chelmsford than 

 Long Ashton as the internodes are rather larger. 



As a general rule the strength of the lateral buds is dependent on the 

 vigour of the bush at the time of their formation and at first sight one 

 would expect the Chelmsford figures to be higher than the Long Ashton 

 ones whereas they tend to be slightly lower. An examination of the 

 number of scale scars on the laterals, however, explains the situation. 

 These numbers (running across the middle of the graph) show that 

 whereas six at Long Ashton run as high as 5, at Chelmsford only two 

 read 4 and it is clear from a superficial view that these average con- 

 siderably less. From these figures one may draw the conclusion that the 

 growth of laterals at Long Ashton continued over an extended period 

 slowly, while that of the laterals at Chelmsford was characterised by a 

 great push and a sudden check. The growth of the laterals therefore 

 closely follows that of the internodes under the two different climatic 

 conditions. These two kinds of growth can be very largely, if not 

 entirely, accounted for by the different rainfall at the two places. Thus 

 for a thirty-five year period the average monthly rainfall for June, July 

 and August are shown in the accompanying table. July and especially 

 August show a markedly increased rainfall at Long Ashton. The soil 

 therefore in these months tends to be wetter and this tendency is in- 

 creased owing to the factors encouraging evaporation, namely sunshine 

 and air dryness, being less marked at Long Ashton than in the east of 

 England. 



Table III. Rainfall in inches. 



35 yr. av. 



Table II shows a similar graph for Boskoop Giant at the two places. 

 In this case also the shoots are fairly comparable with each other and 



