- Author: Shannon C. Mueller
We are approaching our sixth month of alfalfa & forage blog postings and it would be great to receive some feedback. Are you enjoying the blog? Is the information helpful? Do you have suggestions for topics you'd like to see or improvements we could make to increase the effectiveness of this blog? Let us know!
- Author: Michelle Leinfelder-Miles
The Sacramento-San Joaquin River Delta region – for its soil type, climate, and irrigation and groundwater sources – is a unique agricultural region of California. Diverse crops are grown in the Delta region, but alfalfa is a particularly important one as the second most widely grown crop. Border check flood irrigation using surface water is the primary method of irrigating Delta alfalfa.
As a forage crop, the marketed product of alfalfa is the vegetation, or alfalfa hay. Hay yields are directly related to crop evapotranspiration (ET), or the water transpired by the crop plus the water evaporated from the soil. As crop ET increases, so does alfalfa yield; although, agronomic and economic reasons put constraints on...
- Author: Carol A Frate
Walking through an alfalfa field the other day, I saw numerous leaves infected with downy mildew. Because only young leaves are susceptible, symptoms are near the top of the plant and easily visible. Early stage symptoms include a light green blotchy area on the leaf surface (Photo 1). In time the area will turn yellow and eventually may dry out (Photo 2). These diseased areas on leaves are usually localized. In the morning when humidity is high, on the underside of the leaf you can see light gray or violet “fuzz” (Photo 3). Look at the “fuzz” with a hand lens. It is the mycelium and spores of the fungal pathogen Peronospora trifoliorum, the cause of downy mildew in alfalfa. The main...
- Author: Rachael Long
- Author: Daniel H Putnam
This is the time of year that alfalfa fields provide a lush green carpet, outgrowing the damage from 4 months of cold and frost in California’s Central Valley. But not all fields are emerald green-some show the ugly, patchy, stunted evidence of a nasty little invader: stem nematode.
Of course you can’t see the nematodes (ugly or not) with the naked eye but they sure make the alfalfa look ugly.
Stem nematodes (Ditylenchus dipsaci) are causing significant damage to alfalfa fields again this year in the Sacramento and San Joaquin Valleys. These microscopic worm-like pests primarily move through fields in water and infect the above ground portion of the plants (crowns and stems)....
- Author: Rachael Freeman Long
It’s that time of year again when we need to start thinking about controlling weevils in alfalfa hay production. Egyptian alfalfa weevils are the most damaging insect pests of alfalfa in California, as the larvae feed on the foliage, causing yield and quality losses if left untreated.
The life cycle of the Egyptian alfalfa weevil is predictable. Adults spend the summer outside fields in protected areas, such as behind tree bark (for example, eucalyptus trees) and in crevices. In late fall or early winter, adults emerge and migrate into alfalfa stands. Soon after entering fields, they begin laying eggs in new and old or dead alfalfa stems. Hatching larvae make their way to the terminal buds and feed on the developing...