Calag Archive

Livestock are frequently blamed for poor regeneration of native oaks in California, but research indicates that other factors are also involved. Conditions favoring natural regeneration may occur only once or twice a century. Artificial regeneration is a practical but currently costly alternative.

The most practical way to dispose of irrigation drainage water in the San Joaquin Valley is to reduce the volume of the water at its source through better irrigation management. Upgrading furrow irrigation systems and cutting run lengths in problem areas reduced drainage 60% to 80%.

Cultural practices that improve biological control of black scale in olive orchards are more common in northern than southern California orchards. A parasite of black scale, recently imported from Spain, has become established in northern orchards and may in time aid in black scale control.

If not controlled with chemicals or by costly hand removal, weeds can cut garlic yields in half and lower the quality of the crop. Field trials comparing chemical and hand removal showed that judicious use of selective herbicides combined with good cultural practices will achieve best results.

Reports that glyphosate, the active ingredient of a post-emergence broad-spectrum herbicide, may inhibit tall fescue germination when applied before seeding were not supported by field experiments. The method of seeding (hydroseeding or overseeding), however, may contribute to poor establishment.

Twig blight of landscape oak trees was reduced to an acceptable level by pruning or by pruning plus treatment with a fungicide.

Natural insecticide resistance of a biological control agent of California red scale was augmented in the laboratory, suggesting that selected strains of the parasitoid, Aphytis melinus, may be able to survive in citrus groves sprayed with carbaryl.

A less attractive investment

Under soil conditions characteristic of the west side of the San Joaquin Valley, subsurface drainlines could recover as much as 90% of potential seepage losses from evaporation ponds.

Research on barley yellow dwarf disease in California small grains is designed to develop cultural controls and cultivars with improved resistance. Recent discovery of BYDV satellite RNA that inhibits replication of the virus offers additional hope of control.

The number of undergraduate student majors in California four-year colleges of agriculture has remained stable but has dropped sharply nationwide. Subject areas in California schools that are not traditionally related to production agriculture have expanded.

Controlled feeding trials at UC Davis found no connection between temperature stress and response to copper supplementation, but confirmed overall effects of heat stress on pigs.

Growers selling at Certified Farmers' Markets include both small and large commercial farms. Many sell at more than one market, traveling over 200 miles each way. Profit was the main reason.

The use of under-tree sprinklers for frost protection is an established practice but the specific mechanisms of the practice aren't well understood. This study of sprinkler spacing showed that best protection depends on placement of lines and air movement within the orchard.