All Issues

The UC Cooperative Extension's Master Gardener Program has entered into a creative partnership with the Sonoma County Waste Management Agency to help reduce landfill waste by teaching people to how to compost in their back yards. Master Gardener volunteers train approximately 1,000 people each year. A survey was conducted in 1995 and 1996 to evaluate the effectiveness of workshops and clinics. By composting kitchen scraps and yard trimmings, the home composters surveyed were able to reduce their input into the waste stream by 18.3% — about six 32-gallon garbage cans per household per year.

The California greenhouse and nursery industry is the second most important agricultural commodity in the state and the leading producer in the nation. Surveys in 1989 and 1994 collected information from wholesale nurseries regarding basic characteristics and the way they conduct business. Results show that more new nurseries were started between 1983 and 1988 than during the following 5 years. Over that same time period, nurseries employed fewer permanent and more temporary personnel. The surveys reflect the diversity of the California nursery industry, which produced a wide range of landscape plant categories, none of which accounted for more than 18% of overall sales. More than 80% of nursery products are grown in containers, and the majority of California nursery products are sold within the state.

While California consumers are knowledgeable about general dietary recommendations, a recent survey found many are not aware of the recommended daily servings of fruit and vegetables, and do not always follow through on meal-time practices to lower dietary fat and increase fiber. Nutrition education should be targeted to correct misunderstandings about diet, and emphasize the values of eating fruit and vegetables and exercising to maintain good health.

Red color development is an important factor for consumer acceptance of California ‘Fuji’ apples. Several attempts to improve red color development, including delaying harvest, have been unsuccessful in warm production areas. In California, late harvest has been associated with physiological problems such as skin cracking and internal browning. A study conducted under the warm San Joaquin Valley conditions reveals a new approach to economically enhance ‘Fuji’ red color. The use of reflective materials between tree rows enhanced red color development without reducing fruit quality under poor and good orchard conditions.

Deep plowing is unlikely to be a successful disease management strategy for lettuce drop in the high-inoculum-density fields of the Salinas Valley. Research shows that the deep-plowing procedure may change the distribution of soilborne sclerotia, ultimately resulting in higher disease incidence.

Insecticide applications made to Douglas fir Christmas trees vary in their ability to suppress Cooley spruce gall adeigid, a sucking insect that causes needle distortion and discoloration. A field experiment in Napa County showed that organophosphate systemics are ineffective at controlling adelgids, but imidacloprid, a newly registered systemic insecticide, is highly effective. Horticultural oil is effective, but causes slight needle yellowing. This side effect can be mitigated by precisely timing the oil application before bud break when the overwintering adelgids are transforming to adults but before they lay eggs.

Perennial grass stands often face stiff competition from weeds, particularly during the first few years after grass establishment. Field studies were conducted to evaluate the tolerance of several established perennial grasses to preemergence herbicides in order to selectively suppress weeds. Grass vigor was reduced by some herbicides, but most had minimal effects. The herbicides that controlled weeds best also caused the greatest reduction in grass vigor.

Mycorrhizal fungi colonize cotton roots and stimulate plant growth by absorbing minerals from the soil. These beneficial fungi can be adversely affected by metam-sodium, a soil-applied general biocide frequently used for weed control in cotton. Although metam-sodium also kills disease-causing fungi that reduce cotton stands, the advantages of pest control with metam-sodium must be weighed against added fertilizer costs needed to offset the loss of mycorrhizae.

Control of pink bollworm, a serious pest of cotton in southeastern California, is enhanced by knowing when the different stages of its development will occur. Prediction of pink bollworm development requires a phenological model that relates development to a thermal scale. For spring emergence, the study showed that heat unit accumulation starting Feb. 1 was the best predictor of beginning and peak emergence. This research used field-collected data to establish lower and upper temperature thresholds of 57° and 91 °F (13.9° and 32.8°C), respectively; 409° and 918°F-days (227° and 510°C-days) from Feb. 1 to the beginning and the peak of spring emergence, respectively; and 866°F-days (492°C-days) between generations, from adult moth to adult moth.