Environmental toxicology University of California, Davis

Also in this issue:

Frustration— agriculture and research

Tillage increases plant diseases

Surfactant longevity and wetting characteristics

Effects of irrigation, crop density on almond trunk growth

Honey bee pollination of alfalfa seed improved by supplemental feeding

Mechanical harvesting for green asparagus

Wood processing residues —disposal and use in Shasta County

Plastic shelters for crop growth experiments in the field

Aphid transmission of nonpersistent plant viruses with special reference to the Brassica nigra virus