Damien Jelen walked into a sun-baked alfalfa field, swinging his sweep net to the left and then to the right. Swoosh. Swoosh. Swoosh. Swoosh.
|Beet arrmyworm. (UC IPM photo)|
Alfalfa pests can significantly reduce yields, stand life and forage quality. Alfalfa serves as an important food for the state’s $6 billion dairy industry.
|Western yellowstriped armyworm butterfliers.|
But with two or more months of harvesting still left in the season, some growers are spending the money to treat their fields. “They had to spray. They can’t wait,” Damien says.The pest counts were above the treatment threshold.
|Alfalfa caterpillar. (UC IPM photo)|
“See if white or green parasitic wasp larvae are inside. Base your population estimates on the average of all sweeps taken in that field, counting only those armyworms collected in sweeps that are at least 0.5 inches in length,” UC IPM says.
- 10 or more nonparasitized alfalfa caterpillars per sweep,
- 15 or more nonparasitized armyworms per sweep, or
- 10 or more nonparasitized alfalfa caterpillars and armyworms combined per sweep.
- Lynn M. Sosnoskie, agronomy and weed science advisor, for the University of California Cooperative Extension in Merced and Madera counties, who will discuss weed control in alfalfa and the chemical, cultural and biological factors that can affect success and failure.
- Tom Casey, pest control operations official for the Fresno County Agricultural Commissioner’s Office, who will cover current pesticide use and regulations.
- Nicolas Clark, agronomy and nutrient management advisor at UCCE Kings, Tulare and Fresno counties, who will offer tips about insect pest management in San Joaquin Valley alfalfa hay.