A. H. Lees 13 



a short or a strong growth depending on the vigour of the bush as a 

 whole. Usually they remain dormant or make a short growth. 



The normal growth of the black currant may therefore be said to be 

 terminal and correct pruning and culture ensures a constant supply of 

 long straight young wood. 



Character of abnormal, reverted growth. 



Case 1. Associated with moderate or large numbers of Big Buds. 



Since 1914 it had been noticed that Reversion often occurred amongst 

 mite attacked bushes and frequent cases of such association came under 

 the author's experience in visiting plantations in Worcestershire and 

 Herefordshire. It was natural to suspect that the two were linked to- 

 gether in some way but the case was complicated by the fact that 

 reversion often occurred amongst bushes where there was either no big 

 buds or very few. A year or so after the connection had first been 

 noticed, bushes began to revert at Long Ashton and it was possible to 

 investigate the disease under good conditions. Here it was apparently 

 associated with the Big Bud attack which had been increasing ever since 

 the bushes were planted. 



In order to discover how far the tendency to reversion corresponded 

 with mite attack the bushes were carefully examined in June and marks 

 given for the amount of reversion present. Four classes were recognised, 

 normal bushes, slightly attacked bushes where the leaves tended to the 

 pointed type, but with normal fruit, a worse condition where the fruit 

 had partly run ofE and a still worse where the fruit had completely run off. 



In the following winter the bushes were divided into four classes as 

 regards numbers of big buds present. This was done for two years. In 

 this time there were forty cases of reverted bushes in the two last classes* 

 which were also placed in the last two classes for Big Bud and only 

 twelve such reverted cases that were placed in the second class for Big 

 Bud (namely in the class showing a minimal number of big buds). 



There was no case of definite reversion on bushes that showed no big 

 bud the following winter. The evidence thus pointed to a close con- 

 nection between the two diseases. 



As was previously mentioned, one of the most characteristic signs of 

 a reverted bush is the extensive growth of lateral wood, a condition 

 which is usually associated with a lack of suckers from the base. This 

 lateral growth proceeds largely from the lower buds of a yearly growth 

 and not from the higher as occurs if the terminal be injured or removed 



