California Agriculture, October 1962
Volume 16, Number 10
Root Soil Boundary Zones. As Seen by the Electron Microscope
Pear decline research—Methods of propagating own-rooted old home and Bartlett pears to produce trees resistant to decline
by H. T. Hartmann , W. H. Griggs , C. J. Hansen
Own-rooted Bartlett pear trees and Bartlett on own-rooted Old Home rootstocks are resistant to pear decline, according to observations in Washington, Oregon, and California. These trees are also vigorous and productive. Bartlett pear, top-budded onto own-rooted Old Home stock, has the additional advantage of blight resistance in roots, trunk, and primary scaffold branches. Practical methods now available for propagating such decline-resistant and blight-resistant trees are discussed in this research report.
Soil fumigation found essential for maximum strawberry yields in southern California
by H. Johnson , A. H. Holland , A. O. Paulus , S. Wilhelm
Tests in two southern California counties resulted in similar data offering further proof of the value of soil fumigation for strawberry production. Yield increases as high as 85 per cent were reported following soil treatment. Control of plant pathogens was excellent with full-coverage injections of a mixture of 2 parts of methyl bromide and 1 part chloropicrin applied at 225 pounds per acre.
Root-soil boundary zones as seen by the electron microscope
by H. Jenny , K. Grossenbacher
These micrographs show greatly enlarged views of the outer edges of root cells in contact with the soil. Of particular interest is the mucigel, a jelly-like coating on the outer surface of the roots. Mucigel, produced by the roots and perhaps also by microbes living in it, conforms to the surface contour of the soil particles it touches. Thus, intimate contact is provided for the transfer of soil nutrient ions and water from the soil to the roots.
Wildland value survey shows agreement on fire protection priority
by L. S. Davis , Ann De Bano
A remarkably high degree of agreement exists among public agency land managers and private landowners on the subjects of relative valuation of wildlands and relative priority of wildland fire protection, according to a recent survey. The non-market values of recreation, watershed, and hunting were clearly considered of importance on all classes of land. In many cases these non-market values were rated as more important than known or measurable values. Both timber and grazing interests agreed on the relative value of their activities on the different land classes. The survey revealed a full awareness of the complex structure of land value and its susceptibility to fire damage. This mutual understanding at the ground level should provide a firm basis for policy formulation affecting the wildlands of the central Sierra foothills.
Hot water treatment of hop rhizomes for nematode control
by A. R. Maggenti
Soaking hop rhizomes in hot water—122° F for 10 minutes or 125° F for five minutes—kills nematodes and does not injure the rhizomes, according to tests at Davis. Fumigating hop yards before planting controls root-knot and dagger nematodes more effectively than side-dressing chisel applications. However, stock planted after fumigation must be free of nematodes.
The Economics of farm relocation
by A. D. Reed
Urban and suburban areas are moving closer to many California farms. More people create additional trouble and expense that may cause the farmer to consider selling and either moving to a new location or using the money to invest in other businesses. Any farmer facing such a decision should know the facts about relocation—how much his land is worth, how much actual profit he can make from its sale and how to go about the complicated process of selling.
Ropiness is milk… Psychrophilic bacteria and California milk quality
by B. E. Hubbell , E. B. Collins
Although California's milk supplies, with rare exception, are easily kept well within California Agricultural Code specifications, a few dairy plants have occasionally encountered ropiness in pasteurized milk. This ropiness and some other storage defects such as fruity flavor are attributable to psychrophilic bacteria introduced following pasteurization. Psychrophiles are organisms that grow at refrigerated storage temperatures and can cause noticeable symptoms in milk after about a week. Ropiness in pasteurized milk is likely to become more of a problem for processors as total bacteria counts continue to be lowered by refrigeration and improved sanitation and as storage periods become longer. Under these conditions, a larger fraction of the organisms present in milk will undoubtedly be psychrophiles. Since many of these psychrophiles do not grow at the standard plate count temperature of 35° C used for routine laboratory testing, this study suggests modifications in procedure to allow more accurate determination of the quality of pasteurized milk.