228 HORTICULTURE [BoT. Absts., Vol. IX, 



branched. The same was true of the smaller plants, in which, furthermore, the root systems 

 were greatly restricted. It was noted that comparatively few blossoms formed in the shade, 

 but that the plants in the open bloomed normally. — //. W. Rickey. 



1415. Gray, G. P., and H. J. Ryan. Reduced acidity in oranges caused by certain sprays. 

 Monthly Bull. Dept. Agric. California 10: 11-33. 1921.— The acidity of both Navel and 

 Valencia oranges is greatly reduced when a spray composed of soap, sodium carbonate, sulphur 

 and lead arsenate is applied to the trees, even for 1 season. This reduction in acidity amounts 

 to more than 50 per cent in some cases. The physiological phenomenon involved is not known. 

 The arsenic compound, which seems to be chiefly responsible for the effect, is probably slowly 

 converted, first into a soluble form. The facts do not correlate the reduction of acidity with 

 local absorption of the spray by the fruit, the action of the spray probably being systemic, 

 affecting the whole tree. — E. L. Overholser. 



1416. Greene, L. Orchard soil management studies in Indiana. Proc. Amer. Soc. Hort. 

 Sci. 17: 185-190. 1920 [1921]. — The author believes that soil moisture is one of the limiting 

 factors in orchard production. He suggests that even though nitrates are added to sod or- 

 chards, conservation of soil moisture is still necessary. The differences appearing between 

 plots A and B are attributed to soil moisture conditions rather than to plant food conditions 

 alone. The experiments show that growth and production are very closely coordinated. 

 The author states "Under the conditions of the experiments at Laurel, 2 types of orchard soil 

 management have supplied moisture in sufficient quantities to produce sufficient growth to 

 show profitable production. These 2 are clean cultivation with cover crop, and straw mulch 

 applied at the rate of from seventy-five pounds per tree in the early history of the orchard 

 to one hundred and fifty pounds per tree during the later years." Where cultivation can be 

 practiced without erosion, the writer believes it will undoubtedly prove to be, in most cases, 

 the most economical method of soil management. "Under certain conditions of cheap mulch- 

 ing material the straw mulch will undoubtedly prove more economical than will cultivation. 

 It is altogether probable that a sufficient amount of mulching material can be grown between 

 the trees if the entire orchard is fertilized for grass production as shown by Professor Ballou 

 in southern Ohio." — "One of the dangers which confronts the practical orchardist who adopts 

 the sod mulch method, is that it is very easy to neglect the supply of mulch material necessary 

 to properly conserve moisture, and the trees will suffer accordingly. In other words, sod 

 mulch is the system of the careless orchardist, and while when rightly used it v/ill probably 

 produce as good fruit with better color at very near the same net profit per acre, it is a system 

 which needs careful attention to be made successful." — E. C. Auchter. 



1417. Hardy, F. The application of fertilizers in orchard cultivation. Agric. News 

 [Barbados] 20: 74. 1921. — This paper considers a communication from Mr Keys, Asst. Cura- 

 tor of the Dominica Botanic Station, entitled The Necessity for Clear Statements in Regard 

 to the Rate of Applying Artificial Fertilizers in Orchard Fertilization, in which the author 

 makes a plea for the units of weight mentioned in reports of such experiments to be expressed 

 per tree and not per acre, since very often the number of trees per acre is not stated. — J. S. 

 Dash. 



1418. Hedrick, U. p. Report of the National Research Council Committee. Proc. Amer. 

 Soc. Hort. Sci. 17: 276-279. 1920 [1921].— The committee felt that the American Society for 

 Horticultural Science, through the cooperation of the National Research Council, could well 

 take up the question of establishing arboreal plantings of species of cultivated fruits and nuts 

 in the different parts of the U. S. A. It is planned as a preliminary step to make a survey of 

 living arboreal plant material available for breeding purposes at arboretums and other places 

 in the U. S. A. and Canada. Dr. Galloway was asked to make this survey. The findings 

 will be published either as a government bulletin or as a bulletin from the National Research 

 Council. After this report is secured, future plans for organizing and developing the different 

 arboreal plantings can be made. — E. C. Auchter. 



