All Issues

Conversion of large acreages of California brushland to grassland—to increase forage for livestock and game—has resulted, in many cases, in an increase in spring and stream flow.

Nitrogen fertilizers applied to range-land in amounts greater than the forage plants require during the first growing season produced increased yields in the second and third seasons in tests in Modoc County.

Ferti-irrigation—injection of water soluble fertilizers into sprinkler systems—has proved to be effective and economical in three years of tests in San Mateo County.

Ponderosa pine has a continuous distribution at medium and lower elevations in the Sierra and inner coast ranges of California but in the middle and south coast ranges it is found only in a few scattered locations.

Even in desert regions of mild climate, frost is often a hazard to specialty vegetables for the winter market.

Earlier field trials indicated that certain plum rootstocks—Marianna 2623, Marianna 2624, and Myrobalan 29—are resistant to the one species of root-knot nematode recognized at the time the work was done. However, since then several species of root-knot nematodes have been classified. Two of these species—Meloidogyne incognita var. acrita and M. javanica—are known to cause serious trouble in California orchards, so additional work was necessary to find out if the rootstocks are resistant to both species.

Laboratory experiments with anhydrous ammonia—for the control of blue-green decay in injured-inoculated fruit—developed a treatment that provided excellent protection for oranges and lemons. However, tests also revealed that the gas must be applied within the first 24-30-hour storage period to be effective, because at 68°F the green mold—Penicillium digitatum—will penetrate approximately one millimeter into the rind, beyond reach of the chemical. Therefore, fruit injured in picking, dumping and loading must be treated promptly to avoid infection.

Leaves of seedling avocado trees grown under glasshouse conditions—in cultures of silica sand or soil—have occasionally shown certain symptoms of nutritional deficiency.