Mineral Nutrition of Fruit Trees summarizes the state of knowledge about the mineral nutrition of fruit trees, including peach and apple trees. The discussions are organized around six themes: fruit tree mineral nutrition and crop quality; uptake and transport; effect of soil management and fertilizer applications on nutrient uptake; direct application of nutrients to foliage and fruits; prediction of nutrient requirements; and synthesis. This text consists of 69 chapters and begins with a section dealing with the effects of nutrition on fruit quality. The second section explores the mechanisms of nutrient entry to, and movement within, fruit trees and the means of influencing the nutrition of both the whole tree and the crop by fertilizers and management practices, including irrigation and the use of herbicides. The third section describes methods for predicting the needs of the tree for establishment, growth, and fruit quality. The effects of interactions between nutrition and environment on the mineral composition of fruits are considered, along with an integrated approach to orchard nutrition and bitter pit control, the influence of boron deficiency on fruit quality, and calcium accumulation in apple fruit. This book will be of interest to scientists working in fields such as biochemistry, food technology, agriculture, horticulture, and physiology.

High altitude measurements of the electron density distribution were performed well above the F2 peak of the ionosphere by using the twofrequency rocket-borne propagation experiment of Seddon. An example of a measurement of the electron density profile up to 620 km by means of the CW propagation technique is presented, including the inferred scale height and temperature of the upper ionosphere. For the anticipated measurements up to one earth radius by the CW propagation experiment, the variation of the ionosphere below a vehicle must always be considered to arrive at reliable local electron density data. A correction for this time variation can be made by using recorded information on the ordinary and extraordinary propagation modes at two harmonically related frequencies. This correction procedure is briefly outlined. (Author).

Also available from NASA, Wash. 25, D.C. as NASA Technical note no. D-413AD-262 928Div. 8, 2U (13 Sep 61) OTS price $.50 National Aeronautics and Space Administration, Washington, D.C. ROCKET MEASUREMENT OF A DAYTIME ELECTRON DENSITY PROFILE UP TO 620 KILOMETERS, by J.E. Jackson and S.J. Bauer. Sep 61, 6p. incl. illus. tables (NASA Technical note no. D-413) Unclassified reportAlso available from NASA, Wash. 25, D.C. as NASA Technical note no. D-413. DESCRIPTORS: *Electrons, *Densit, Measure ment, Rockets, Rocket trajectories, Test methods, Ionosphere, Ionospheric propagation, Radio waves. Open-ended Terms: Doppler effect. On April 27, 1961 at 1502 EST a four-stage research rocket was fired from Wallops Island, Virginia, to measure the ionospheric electron density distribution by means of Seddon's CW propagation technique. This experimental technique is based upon the dispersive Doppler effect measured at two harmonically related frequencies, in this case f = 12.267 Mc and 6f = 73.6 Mc. The electron density profile measured above the peak of the F2 region is representative of a diffusive-equilibrium distribution in an isothermal ionosphere having a temperature of 1640 + or - 90 K. This result, when compared with satellite and other data, indicates that the upper ionosphere is in thermodynamic equilibrium. (Author).