A crop consultant brought in some alfalfa plants and asked if I could help identify the problem. In the field, he was observing stunted plants with shortened internodes and suspected stem nematode (Ditylenchus dipsaci). What seemed different this year is that he was seeing these stunted plants intermingled among healthy plants, and in the past, he was accustomed to seeing stunted plants in groups.

Nematodes are microscopic roundworms that use their stylet, or needle-like mouthpart, to puncture plant cells and suck out their contents. The alfalfa stem nematode lives and feeds in the stems and crown of the plant. Symptoms of infection include plant stunting, shortened...

We are excited to announce that our Alfalfa IPM YouTube video titled, “Identification of parasitized alfalfa caterpillars and armyworms”, was a finalist in the annual national Entomological Society of America YouTube Contest this week in Minneapolis, MN.

This video shows how to monitor alfalfa insect pests and their natural enemies to help make informed management decisions on pest control in alfalfa production. Step-by-step instructions are presented on how to identify parasitized caterpillars under field conditions and how to use this information for managing caterpillar pests, to help reduce pesticide use and production costs in alfalfa.

Take a look at this 2.4-minute Alfalfa IPM video that was produced in...

2015 Western Alfalfa & Forage Symposium will be held in Reno, Nevada on December 2-4 at the Silver Legacy Hotel, with a focus on water, irrigation, pest management and economics.

This is a great opportunity to learn more about alfalfa and other forage crops, and to visit with farmers, scientists, experts in various fields. Eleven Western States have joined forces this year to plan the Symposium. The event will be managed by the California Alfalfa & Forage Association (Sacramento, CA). Typically between 500 and 700 people attend.

Highlights:

• One-Day Alfalfa Irrigation Training Workshop (December 2)
• Economic Trends
• Pest Management...

Basic background and biology of the blue alfalfa aphid:

The blue alfalfa aphid (Acyrthosiphon kondoi Shinji) was first identified by entomologists in the spring of 1975 in the Imperial Valley of California. Since then it has become widespread throughout the state and has become established in Arizona, Nevada, New Mexico, and as far east as Kansas and Oklahoma. Both adults and nymphs feed on photosynthetic fluids from the leaves and stems of the alfalfa plant. Low to moderate populations of blue alfalfa aphid (BAA) may cause little to no visible yellowing of plants. Blue alfalfa aphid feed in the new growth, at the tips and young leaves. After prolonged feeding, leaves will eventually turn yellow,...