- Author: Peter B Goodell
The spotted alfalfa aphid (Therioaphis maculate) is a small pale-yellow or grayish aphid with four to six rows of spined spots on its back. It was first detected in California alfalfa in1954 and, although it prefers warmer temperature regions, it quickly spread throughout the state within 2 years. The aphid injects a toxin which stunts and limits regrowth, substantially reducing yield. When it occurs at high population densities, copious of amounts honeydew are produced.
For a time, it was the most destructive pest in California alfalfa. It received a substantial amount of research and extension interest resulting in 9 California Agriculture articles between 1956 and 1963. These covered a wide range...
- Author: Rachael Freeman Long
- Author: Larry Godfrey
Mealybugs are common insect pests of many crops including grapes, citrus, ornamental plants, and various other perennial crops. They feed on trunks, stems, leaves, and roots of plants. At times these infestations can be very obvious on plants due to high mealybug densities, the sticky honeydew that they excrete, and the sooty mold that often grows on the honeydew.
The ground mealybug is an important insect pest of alfalfa, primarily in the Sacramento Valley. This mealybug is a member of a group of species that spend their entire lifecycle below ground. This insect is small (about 1/16" long), whitish, and relatively soft-bodied. Ground mealybugs feed on alfalfa roots by sucking out plant juices, which causes stunting and...
- Author: Steve Orloff
Windrow width has a large influence on several important things: hay quality, irrigation efficiency, plant regrowth and yield. Do we really understand all the reasons that rapid curing is important, and how wide windrows can help?
Growers throughout the Western US are blessed with relatively good hay curing conditions most of the time. The arid, warm weather that occurs during the majority of the hay-making season is truly a blessing compared with the often rainy conditions growers in other parts of the country confront. Other alfalfa production regions, such as the Midwest, generally have much higher relative humidity and summer rains are commonplace. Perhaps for this reason, many California growers are...
- Author: Eric T. Natwick
Alfalfa caterpillar, Colias eurytheme, is a warm weather pest of alfalfa. Six generations of the pest may occur between May and October, in the low desert. The adults are yellow butterflies and are often called alfalfa butterflies. The abundance of alfalfa butterflies is now increasing in the low desert valleys of southern California and in the central valley of California. Alfalfa butterflies that may be flying over tall alfalfa, most likely emerged from the same field. Eggs are football-shaped and are laid singly on the upper surface of leaves in alfalfa re-growth which is up to 6 inches tall. The larvae hatch in 3 to 7 days, grow to about an inch long and pupate in approximately 2...
- Author: Shannon C. Mueller
Mark your calendar for Thursday September 5th and plan to join fellow growers, PCAs, and seed and chemical company reps at our annual Alfalfa and Forage Field Day. Registration begins at 7:30 AM and trams will depart for the field portion of the meeting promptly at 7:50 AM.
In the field, participants will learn about alfalfa variety selection as a tool for managing pests and diseases, using alfalfa-grains rotations to get the most from nitrogen fixation, and how Roundup Ready® and conventional alfalfa hay fields coexist. Three presentations covering nitrogen utilization, variety selection, and irrigation strategies for sorghum are also scheduled.
Once the field visits are finished, we will...