No. 1, July, 1920] HORTICULTURE 141 



range of soil may be used but pipe clay within a foot <>f the surface is to be avoided as under 

 such conditions powdery mildew is a permanent and persistant i»;st . Drainage is essential 

 where the soil is water logged. — Apple and pear i rees may be dipped in a red oil solui ion and 

 stone fruit in lime sulphur, each of 1 to 10 strengths. On rich land 20 feet is about the best 

 distance apart. — The young trees are pruned to restore the balance of top and root, and to 

 lay the foundation of the future tree. Three or four branches form the bead of the tree, the 

 lowest one 10 to 12 inches from the ground. They should not be opposite each other and 

 should be cut back so the total height of the tree is about 18 inches. Summer pruning should 

 be practiced to select the permanent branches and keep them within bounds so they may not 

 be broken by the wind. The second season the main branches are cut back to about 8 inches. 

 In the summer strong growths within the tree are removed and if the leaders bend over they are 

 shortened. — J. K. Shaw. 



904. Canedo, Jenaro. La vld. [The vine.] Jalisco Rural [Mexico] 1: 225-228, 236-238; 

 2:24-26. 1919. — A popular account of the cultivation and propagation of the grape. — John 

 A. Stevenson. 



905. Cavanaugh, J. R. Packing and grading. Trans. Indiana Hortic. Soc. 1918: 177— 

 184. 1 pi. 1919. — The benefits to be derived from grading are presented along with a dis- 

 cussion of the grades suggested by the Bureau of Markets. — F. P. Cullinan. 



906. Chandler, W. H. Pollination. Trans. Indiana Hortic. Soc. 1918: 111-120, 173-175. 

 1919. — Cool weather at blooming time caused losses in New York in 1915, 1916 and 1917 be- 

 cause of imperfect pollination. Generally fruit will not grow except through the stimulus of a 

 developing seed. Some varieties are self-fertile, others are self-sterile. This point has been 

 determined for only a few varieties. Bagging the blossoms is one method of testing a variety. 

 Waite's work on pear varieties is reviewed, in which he proved the Bartlett pear self-sterile 

 and the Seckel self-fertile. Peaches and sour cherries are self-fertile. Sweet cherries and 

 American plums are self-sterile. Among apples, Rome Beauty, York Imperial, and Rhode 

 Island Greening are self-sterile, Newtown, Baldwin, and Grimes are self-fertile. The work 

 of Lewis on other varieties is quoted. The remedy for self-sterility is mixed planting and 

 keeping bees. In case of apple and pear, the condition of the tree may influence the set, since 

 on the weak spurs more seeds are necessary to hold the fruit at the time of the June drop. 

 In the discussion are considered the self-sterility of the Delicious, method of interplanting 

 varieties, the June drop, the effect of pollination on flesh color, and the use of Austrian bees. 

 Max W. Gardner. 



907. Chandler, W. H. Pruning — its effect on production. Trans. Indiana Hortic. Soc. 

 1918: 137-145, 156-161. 1919. — This article is a discussion of the subject of pruning based 

 on the author's investigations. The effect of pruning is to reduce the total amount of growth. 

 Pruning during the dormant season increases the vigor of growth during the following season 

 of adjacent twigs that are left. The new shoots will be longer and the growth is generally 

 stockier. In spite of this increase in vigor, the effect of pruning is to reduce the total amount 

 of growth. There are fewer growing points left and not only is the new growth insufficient 

 to replace what has been removed, but in actual fact less growth is made than on the unpruned 

 tree. Pruning by removing buds that would open into leaves, reduces the foliage and, hence, 

 the consequent decrease of elaborated food manifests itself in reduced growth. This is 

 shown in an examination of 15 one-year old apple trees in the nursery row which the author 

 states had their leaves removed to a height of about 20 inches above the ground. At the 

 end of the season the weight of the roots was 38 per cent less and that of the tops 40 per cent 

 less than those of the unpruned trees that were no larger at the beginning of the experiment. 

 Pruning markedly reduces the fruitfulness during the early years of the life of the tree. It 

 was found that even the amount of pruning necessary to secure an open head reduced the 

 amount of fruit borne by the young tree. The author points out that in case of old trees, 

 however, pruning may have the effect of increasing fruitfulness. In an old unpruned tree 

 where most of the growth is in the spur, the effect of pruning would be to increase the vigor and 



