All Issues

Approximately 30% of the 450,000 acres of vineyards in California are—necessarily—on rootstock resistant to certain soil pests.

Indio—the first oat variety developed for California by using the backcrossing techniques of plant breeding—has definite advantages over other varieties, and further improvements are under way.

Damage and control experiments in the Sacramento Valley investigated the relationship of the lygus bug—Lygus hesperus Knight—to Red Core Chantenay carrot seed.

When the atmosphere 40′ to 50′ above ground is 13°F or more warmer than it is a few feet above the soil surface, the temperature inversion condition—in frost protection research—is considered to be strong. When the temperature difference is less than about 5°F the inversion is considered weak. The weak inversions usually found in the deciduous orchards on the floor of the Sacramento Valley appear to limit the usefulness of wind machines for frost protection unless additional heat is supplied from orchard heaters.

A caterpillar control program in nine commercial tomato fields—in San Joaquin County in 1956—repeated the successful trials in 1955 because of reports of suspected resistance of the corn ear-worm to DDD and DDT.

Tree structure is the greatest deterrent to the successful mechanical harvest of fruit destined for the cannery.

Flower buds of the common hydrangea—Hydrangea hortensis—are initiated during summer or early fall, but a cold period of 6-8 weeks is required to condition the buds for subsequent flowering.

The orange tortrix—Argyrotaenia citrana (Fernald)—was discovered to be doing a limited amount of damage to avocados in 1949, although it was known to be in California—primarily on citrus—as early as 1885.