Calag Archive

Growers and shippers in the potato industry of California are faced with two important decisions: whether the early-crop area has enough economic advantage in the fresh market to justify continuous production; and whether the expanding use by consumers of processed potatoes will result in a major curtailment in acreage for the fresh market or a partial diversion of production into processed products.

Damage to potatoes during field harvesting and hauling operations often amounts to 40%-50% before the tubers reach the packing shed.

Coarse-textured noncalcareous soils of southern California often require the addition of sulfur to acidify the soil for the control of scab disease of potatoes.

In every water-deficient year, growers are confronted with a series of decisions concerning the utilization of a limited supply of water for crop production.

In southern California peaches frequently are not exposed to winter chilling sufficient to break the rest period. The dormant condition of the flower and leaf buds is prolonged and symptoms sometimes known as delayed foliation appear. Flower and leaf bud growth are late and irregular; the fruit ripens irregularly and, in extreme cases, there is little or no crop. The fall and winter temperatures of the buds and twigs are critical. Pruning has a localized growth-stimulating effect and spraying at the proper time with an oil-in-water emulsion containing DNO—dinitro-o-cyclohexyl phenol—or DNC—3-5-dinitro-o-cresol may be helpful.

The Egyptian alfalfa weevil—Hypera brunneipennis (Boh.)—has become an increasingly serious pest of alfalfa in southern California during recent years. In 1961 weevil populations were the heaviest on record, and in the Imperial Valley alone many thousands of acres of alfalfa required insecticidal treatment. All evidence indicates that the Egyptian alfalfa weevil will continue to pose a serious threat to first and second cutting alfalfa in southern California.

Recent research on fruit harvesting machines in California has centered around two designs.

Previous tests have shown that 75% to 90% of the heat of combustion of the fuel oil burned in an orchard heater goes into producing the hot gases which rise as a plume vertically above the heater. As these hot gases rise, they cool by mixing with the surrounding air. Cooling is rapid until a height is reached where the temperature of the plume is near the temperature of the adjacent air. If the temperature of the air over the crop increases with height at this point—if a temperature inversion exists—continued upward movement of the gases soon brings them to a height where the surrounding air has the same temperature as that of the plume. Above this point, the plume's gases are actually colder than the adjacent air. Thus the gases in the plume are heavier than the surrounding air and their momentum is dissipated. This soon brings the upward motion to a halt. Then the gases fall part way back to the height at which they had the same temperature as the surrounding air and spread out at that level. This height at which the gases spread out and the height at which the upward motion ceases are measures of the depth of the air over the crop being heated.

About one out of every four acres of producing forest land in the north coast counties of California is owned by livestock ranchers and farmers.