- Author: Mary Louise Flint
Oils are some of the most useful pesticides available for managing pests on woody ornamentals and fruit trees. They are also widely used on many herbaceous flowers and vegetables. Oils control a range of soft-bodied insects and mites, as well as several foliar diseases including powdery mildew (Table 1). Not only do oils leave no toxic residues, they are safe to use around people, pets, and wildlife; have low impact on beneficial insects; and won’t harm honey bees unless applied directly to flowers during the time of day that bees are foraging.
Oils used for managing pests on plants are most often called horticultural oils. Horticultural oils are derived from petroleum sources, and are sometimes...
Alfalfa farmers are on their second hay cutting in California’s Central Valley. Lush green fields are swathed with new generation rotary disk mowers that are nearly twice as fast as the conventional sickle mowers, cutting about 150 acres of alfalfa a day. Alfalfa hay fields are cut from four to ten times a season, averaging about seven tons per acre per year. It’s a profitable crop these days, with prices for high quality hay frequently reaching $250/ton.
But in addition to its over $1 billion value to the state of California, alfalfa provides a host of environmental benefits that are frequently overlooked. What are these benefits?
Benefits to the soil. In addition to being an important cash...
- Author: Jeannette E. Warnert
Many parts of the Sierra Nevada have not burned in more than 100 years, a significant departure from a natural fire cycle that would characterize a healthy forest, according to Susie Kocher, UC Cooperative Extension advisor in the Central Sierra office.
“The fire interval is completely out of whack compared to pre-settlement conditions,” Kocher said.
In a historical, natural and healthy fire regime, nearly half of Sierra forests would experience fire every 12 years and three-quarters would burn every 20 years. However, only 0.2 percent of Sierra forest land has burned repeatedly at least every 20 years in modern times, while 74 percent has not had a single...
- Contributor: Ann King Filmer
- Author: Robin DeRieux
Ocean waters are warming, sea level is rising, seawater is becoming more acidic, and shoreline erosion is intensifying. The world’s oceans are reacting to increased carbon dioxide and other greenhouse gases in the earth’s atmosphere.
“The physical and chemical environment of the ocean is changing with the climate,” said John Largier of the UC Davis Bodega Marine Laboratory. “This affects ecosystems — like tidal marshes and coral reefs that protect us from storms and flooding.”
The ocean brings stability to the earth’s climate. It heats up and cools down more slowly than the land and the air. With climate...
- Author: Jeannette E. Warnert
Beneath your home, below lawns, under asphalt streets, farms and natural areas there is a complex blend of minerals and organic matter that varies widely in texture, color and structure. Producing food, maintaining landscapes and building structures all depend on this little understood, but critical outermost layer of the Earth’s crust - the soil.
Anyone can learn about the United States’ diversity of soils using SoilWeb, a nationwide database of soil variability first developed in 2004. SoilWeb reached a new milestone this year when it was integrated with Google Maps and designed to scale across any Web-enabled device – desktop computer, tablet...