Calag Archive

Early explorers in the Sierra Nevada described the groves of big-trees, Sequoia gigantea (also called Sierra redwood, or giant sequoia) as essentially clean, open, and parklike. The frequent ground fires of primitive times, started by lightning and by Indians, kept the forest floor relatively clean. Today, as a result of fire suppression, many of the groves have a dense understory of shade-tolerant trees, mainly white fir and incense-cedar. The understory of crowded trees has come to be of considerable concern to people interested in park vegetation maintenance because the small trees add to the fire hazard and partially block out the views of the giants.

Hot iron branding was successfully used in these tests as a permanent method of identifying hogs. Branding irons with 6-inch symbols made out of 3/2-inch rake tooth were effective markers. Application of lanolin to the brand decreased susceptibility to fly strike but did not affect legibility. Clipping the hair prior to branding was useful, but not necessary. However, even with good brands and well-defined borders of scar tissue, subsequent growth of long hair often concealed or obscured the brand so that animals had to be clipped after 1 1/2 to 2 years to insure rapid identification. Branding did not affect carcass quality when placed on the carcass where the skin was to be removed.

Guthion gives excellent control of both the Oriental fruit moth and the twig borer in peaches. When used at reduced rates the mortality of beneficial insects and mites is greatly reduced. There are good possibilities for using this chemical in an integrated control program for peach pests.

Rapid cooling after harvest, and continuing protection from heat during transit and marketing, are essential to avoid fruit shriveling and quality deterioration of sweet cherries. Delays of four hours or more between harvesting and cooling were particularly damaging, according to tests at Davis. Rapid cooling by forced air was found superior to slower methods in common use. Cherries exposed to hot, dry air during transit on open trucks lost weight rapidly in comparison to similar fruit protected by a wet canvas cover. Whenever excessive losses of moisture occurred, sweet cherries soon shriveled and became dull and unsightly.

TESTS were conducted at the request of California asparagus growers and canners in 1964 to determine the effect of nonselective mechanical harvesting on white asparagus yields. The harvester used in those tests was similar to one built by Magnuson Engineers in 1951. This machine cuts all spears at a depth of 8 to 9 inches, separates them from most of the dirt and trash, and discharges them onto the top of the asparagus bed. Results from the 1964 tests have been reported. In the 1965 tests reported here, additional comparative-yield tests were undertaken along with the construction and further development of a second harvester, a preliminary study of methods of handling and sorting mechanically harvested asparagus, and investigation of the effects of sprinkler irrigation on peat soil structure, wind erosion, and dust.

ANGULAR LEAF SPOT of cotton (Gossy pium hirsutum L.) was first reported in California in 1912 and again in 1929. It had become an established disease of cotton by 1951 and was finally eradicated 10 years later. Its spread was attributed to (1) the introduction of sprinkler irrigation; (2) a 100% carryover of the bacterial pathogen, Xanthomonas Malvaciarium, each year in affected fields; (3) the use of contaminated seed; and (4) use of a highly susceptible variety (Acala 4-4.2). This report analyzes measures leading to final eradication of the pathogen from California cotton fields and points out procedures to control the disease should it reappear in the future.

ADJUSTABLE NOZZLES are now being used to irrigate large containers. The system is simple, economical, and can be operated manually or automatically. One- and five-gallon container plants have generally been watered by overhead sprinklers. However, because the canopy of larger plants is widespread and the larger fifteen-gallon containers are spaced farther apart, these containers cannot be watered by sprinklers. Hand watering these plants by a drag hose has been the most commonly used method. This method is slow, labor consuming, expensive and often results in poor growth and nonuniformity. Assuming a labor cost of $1.35 an hour, each container costs the nurseryman $1.00 per year in labor alone. The nursery industry has been forced to find ways to reduce production costs, increase profit, or both. This article reports experiments to provide a better, and less expensive, irrigation system for large plant containers.

Dexon controlled damping-off and root rot of zinnia seedlings caused by Pythium ultimum when used as a drench at 27 to 70 ppm in solution (or incorporated in the soil at the rate of 55 to 110 ppm). However, the drench at 70 ppm and soil preparation at 110 ppm controlled the disease for one month under the conditions of the tests reported here. More chemical was needed when incorporated with the soil (110 ppm = 6.2 oz per cubic yard) than when it was used as a drench (2.5 gal of 70 ppm solution per cubic foot = 0.9 oz per cubic yard). If soil is steamed or chemically fumigated, periodic drenches of 70 ppm at one-month intervals are suggested to prevent reinfection by Pythium root rot. Terrazole controlled Pythium damping-off and root rot when incorporated into the soil at the rate of about 55 ppm (3.5 oz per cubic yard). Terrazole is not yet available for use on ornamentals.