Calag Archive

Rapid cooling is one of the most important factors in maintaining initial egg quality. Tests conducted on a poultry ranch in southern California show that the time required for cooling eggs is greatly affected by the container in which they are packed. Best cooling conditions are obtained when the egg has the least packaging or a container that permits maximum exposure to the cooling air. Packages which reduce exposure to the air or insulate the egg increase the cooling time.

The noxious effects of saline irrigation waters on the growth and fruit production of citrus have been recognized for many years. Citrus trees are sensitive to relatively low concentrations of the salts of sodium, chlorine, and sulfur. Boron is toxic to citrus at concentrations of about 0.5 parts per million (ppm) and lithium at about 0.05 ppm. A number of interdependent factors determine the degree of success in the use of a given irrigation water. These include: total soluble salts and specific ion species, soil type and drainage characteristics, amounts of water used and method of application, cultural practices, climate, and the rootstock and associated scion variety.

Foliar absorption of salts from irrigation waters during sprinkler applications can result in accumulation of sufficient sodium and chloride ions to cause leaf burn and defoliation–as directly related to high temperatures, low humidity and water quality. An additional important factor in the accumulation of specific salts in leaves from irrigation waters is that more sodium and chloride are accumulated under intermittent type sprinkling than under continuous sprinkling. Intermittent sprinkling permits evaporation from leaf surfaces, thereby concentrating the salts in water films remaining on the leaves.

A recent estimate of yearly losses in California vegetable crops totaled $57,000,000. This figure included $19,-000,000 used currently for controlling weeds and $38,000,000 for estimated losses due to weed competition. The highest cost per acre was for weed control in onions and peppers. The largest total loss was from weeds in tomatoes, followed by weeds in lettuce and melons.

DDT accumulated over the past 20 years was detected in 22 of 23 pear orchard soils sampled in this Lake County survey. Two-thirds of the DDT was found in the top 6 inches of soil and 94% in the upper 12 inches of soil. Most pear roots in cultivated orchard soils are concentrated between the 1- and 4-ft depths.

The general pattern for optimum tomato production in a single-harvest program appears to favor a high level of soil moisture throughout the vegetative and early bloom phase, followed by a gradual drying-out to a moderate soil moisture level during the fruit development phase, and decreasing to a low level of soil moisture available during the ripening stage—subjecting the plants to a soil moisture tension of at least 5 bars in the zone of greatest root development.

THE SUPPLY OF OXYGEN in the soil is one important factor restricting the parasitism of root rotting fungi on citrus. The relationships of oxygen (in two types of soil) to several citrus root parasites as well as germination and growth of three of the fungi in pure culture were determined in recent experimentation.