Introduction

Alfalfa (Medicago sativa L.) has been cultivated in California since it was first introduced from Chile in 1850. Alfalfa yields can be reduced by several species of insects, such as leafhoppers in the genus Empoasca. These leafhoppers are highly polyphagous and capable of successful reproduction on over 200 plant species in 25 different families. In alfalfa hay in California there is a complex of three species of Empoasca leafhoppers (ELH) that are nearly identical in appearance and behavior. These include the potato leafhopper, Empoasca fabae (Harris), the garden leafhopper, Empoasca solana DeLong, and the Mexican leafhopper,...

The recent rains were a welcome relief for many parts of our state, but we are still in a serious drought with our reservoirs and snowpack at historical low levels. Ensuring adequate water for crops will be a challenge this year.

In general, perennial crops, such as orchards and vineyards, cannot survive extended periods without irrigation. However, alfalfa is more resilient because it can go into a drought-induced dormancy over the summertime, at least for one year. The tradeoff is that without water there will be little yield, but research has shown that the stand will persist on most soil types and yield will recover the next year once water is applied to the field again.    

In most years hay growers...

At the Alfalfa and Forage Meeting held at the Kearney Agricultural Center in September, we provided a demonstration of the co-existence of Roundup Ready® (RR) and conventional alfalfa hay fields. The demonstration took place between two hay fields – one of them RR and the other conventional – that were in their third year of production and separated only by a one-lane dirt road. The demonstration showed what is meant by “co-existence”; the RR trait has not transferred to the adjacent conventional hay field or to a nearby organic hay field. All of the fields are co-existing in close proximity, and the RR trait is only found in the RR field. We used commercially-available test strips that detect the CP4 EPSPS...

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...