1010] HOKEIOULTUHB. 837 



a considerable portion of the year than >ap from nonbenrlng span. A marked 

 decrease in the sap concentration of hoth hearing and Qonbearlng spurs occurs 

 in late June or early July. Leaf sap from bearing and oonbearing spurs shows 

 considerable variation in concentration. The number of fruit- on a spur affects 

 the concentration of neither spur nor leaf sap. Sugar and starch were found 

 to be present in slightly greater amounts in the bearing spur than in the non- 

 bearing one. 



Counts and measurements were made of the leaves on fruit spurs during 

 three seasons. They indicate that bearing spurs have a smaller total leaf area 

 than nonbearing spurs, the difference being due to the number of leaves devel- 

 oped rather than to the size of the individual leaves. 



To determine the effects of girdling upon the concentration of plant sap a 

 number of nursery trees ranging from 3 to 5 years old were girdled in the two 

 seasons 1915 and 191G. Girdling, regardless of the season, caused an increased 

 concentration of sap in the parts above the girdle and a decreased concentra- 

 tion in the parts below. The most marked effects are in the parts nearest the 

 girdle, the effect being lessened as the distance from the girdle Increased. 



Fertilizer experiments were conducted with dwarf Rome apple trees planted 

 In boxes of sand or soil. Nitrogen, potash, and phosphorus were used both 

 alone and In combination. The results showed that effects upon the size of the 

 tree, the development of its fruiting wood, and the production of blossoms could 

 be attributed only to the use of nitrogen, which was a very decisive factor in 

 both the formation of fruiting parts and the development of blossom buds. 



Tillage experiments have been conducted at the station for a number of year?. 

 Some data are given showing the effect of the tillage method upon depression 

 of twig sap in several varieties. The results, as a whole, show that trees grow- 

 ing in a permanent sod of either grass or a legume had a higher concentration 

 of twig sap than trees growing in plats planted with either annual or biennial 

 cultivated crops. 



A pruning experiment was begun in 1914 with 1-year-old Delicious apple 

 trees to determine the relative influence of different pruning systems upon the 

 size, character of growth, and fruiting age of apple trees. The results thus far 

 secured show that trees headed at 5 or 6 ft. did not produce so many short 

 branches (potential fruiting wood) during the first three years in the orchard, 

 as trees headed at 2 ft. 



In view of the fact that etherization has proved to be a very effective stimu- 

 lant upon the enzym activity of detached parts of woody tissues 12 Jonathan 

 apple trees were etherized, one each month, beginning December, 1014, and con- 

 tinuing until November, 1915. The data given show that etherization has 

 little effect upon the concentration of either twig or leaf sap, and the small 

 differences observed seemed to be only temporary. 



Hardiness in top- worked varieties of the apple, M. J. DORSET {Pfoo. later. 

 Soc. Hort. Sci., 15 (WIS), pp. 88-45, fig. 1). — A discussion of winter injury in 

 Minnesota, including tables showing the degree of wood browning >•( 80 stand- 

 ard apple varieties in 1916-17 and also summarizing the degree of winter in- 

 jury to standard apple varieties growing on different stocks during the winter 

 of 1917-18. 



Spraying apple trees in bloom, W. S. Brock (Pror. Amrr. So<: Eort. 

 15 {1918), pp. 80, 81). — The results of experiments conducted in the three 

 seasons, 1916-1918, are briefly noted. They Indicate that none of our common 

 spraying materials applied at pressures not exceeding 300 lbs. have any dele- 

 terious effects upon the bloom, or cause any appreciable reduction in the 



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