Calag Archive

Isolations of Verticillium albo-atrum from olive trees in Tulare County indicated that the T-l strain was most often associated with severe verticillium wilt in Manzaniilo and Sevillano varieties. T-l was also associated with severe wilt in Acala cotton in Tulare and several adjacent counties. The SS-4 strain, which causes only mild symptoms in Acala cotton varieties, was isolated from olive trees and was a relatively mild pathogen in the Manzanillo olive variety. These results indicate that the T-l strain is a major factor in the severe wilt problem in both cotton and olives in Tulare County.

Domestic coturnix, or Japanese quail, have been used for research in several disciplines at the Avian Sciences Department, Davis, since 1957…including investigations in environmental physiology, nutrition, genetics, cancer, environmental toxicology, and embryology. The small, fastmaturing birds allow savings in research time and money. Studies reported here show differences in viability, hatchability, fertility, egg production and weight and age at sexual maturity between the recently imported wild species and the domesticated coturnix…leading to speculation that the bird might still be established as a game bird in this country, despite previous unsuccessful attempts with the domesticated strains.

Sewage sludge and garbage compost were found to be good sources of plant nutrients that increased yields of tomato, barley and lettuce crops. Maximum yields were obtained when the materials were used with the proper rates and combinations of chemical fertilizers. Agricultural utilization of such organic materials may provide a useful outlet for disposal of municipal wastes.

The orange TORTRIX, Argyrotaenia citrana (Fernald), caused considerable damage to grapes in vineyards near Soledad in the Salinas Valley during 1968 and 1969. This insect is morphologically identical to the “apple skin-worm” which is a pest of several deciduous fruit trees and other plants in several northern California coastal counties. So far, it has not been found on grapes in Napa, Sonoma, or Mendocino Counties. In addition to contaminating the grape bunches, the principal damage is caused by the larvae feeding on the berries and stems within the berry clusters. Stem feeding in the cluster causes berry drop and, in some cases, when the stem is cut or girdled, portions of the cluster below the injury are killed. Larval feeding on berry clusters may also provide an avenue for infection by spoilage microorganisms.

Benomyl was significantly better than all other materials tested for control of Cercospora leafspot of sugar beet when applied by ground or aerial application, and was equally effective on a 10-, 18-, or 21-day spray schedule. This is a progress report of research. Benomyl is not registered for use in sugar beets at this time.

Eight oat varieties were tested for tolerance to the nematode ditylenchus dipsaci, the causal agent of tulip root in coastal areas of southern California. The field in which the varieties were to be tested had been planted to oats for several years. A subtreatment of preplant soil fumigation with 1,3 dichloropropene was used for the purpose of better evaluation of varietal tolerance. Field varieties Curt and Moregrain performed well in yields of grain and straw, and the varieties Kanota and Sierra, commonly grown in the area, were severely injured by Ditylenchus dipsaci. The fumigation treatment increased both grain and straw yields of some varieties; however, the increase was not economically significant and cannot be recommended for control of Ditylenchus dipsaci for oats. The variety Curt, which was found to be extremely tolerant in this trial, is now recommended where this nematode has been found in the coastal areas of California.