124 General Botany 



and the removal of some of the branches forces the development 

 of flower buds which might remain dormant if the terminal and 

 branch buds were allowed to grow uninterruptedly. In grape 

 culture, only four or five branches are allowed to remain on a 

 vine each year, and these branches are shortened. This insures 

 full development for a few of the lateral flowering branches and 

 the production of the best quality of fruit. 



Black raspberry bushes produce fruit only at the ends of 

 branches. Hence the object in pruning is to develop the maxi- 

 mum number of short branches. Each year new shoots develop 

 from the base of the stem. If the tips are cut off when they are 

 1 8 inches high, five or six lateral buds immediately start growth 

 and by the end of the season have formed branches. If these 

 lateral branches are also trimmed back to a length of eight inches 

 the following spring, each will develop several side branches 

 which will be terminated later by flower clusters and fruits. 

 After fruiting, the old much-branched ^' canes " should be re- 

 moved and new shoots should be pruned for the next year's 

 fruit production. 



Leaf scars and bud scars. The leaf scars on some plants are 

 round ; on others they are narrow lines ; on most plants they 

 are crescent-shaped. Usually they are smooth, except for small, 

 dot-like markings. These markings are bundle scars; they show 

 where the bundles of conductive and mechanical tissue extended 

 outward from the stem into the petiole and thus into the veins of 

 the blade. The shape of the leaf scar and the arrangement of 

 the bundle scars are so characteristic for many kinds of trees 

 that they may serve to identify the tree in winter. 



The bud scales also leave scars when they drop. These scars 

 are usually numerous and so closely crowded that they form a 

 roughened ring about the stem. The terminal-bud scars occur 

 at intervals, surrounding the stem or branch. The lateral-bud 

 scars are found only at the bases of the branches and the 

 twigs. 



