Several important disease, insect, and weed problems can affect profitability of alfalfa production in New York. The most important pests are alfalfa weevil, potato leafhopper, alfalfa snout beetle, Verticillium wilt, Phytophthora root rot, anthracnose, crown rot, and weeds. Some additional pests may occasionally cause economic losses. Integrated pest management (IPM) methods can be used to help minimize the impact of these pests.
Crop monitoring for pest problems is recommended from early May through early September. In areas where alfalfa snout beetles are known or suspected to occur, field monitoring should begin with the first warm days of April. Weekly field monitoring for alfalfa pests is recommended because populations of alfalfa weevil (first cutting) and potato leafhopper (second and later cuttings) can change dramatically over time. Less frequent field monitoring would miss early pest detection opportunities and allow for otherwise avoidable losses.
Diseases, weeds, and other cropping problems should be assessed during regular field monitoring activities for insect problems. Pre- and postseason weed surveys identify potential problems and current and future weed control needs. Information on significant pest damage, including field location, should be recorded to help improve efficiency of future pest management decisions.
See tables below for suggestions on IPM activities and common pests by crop growth stage and seasonal occurrence.
- BioControl Bytes - a monthly blog from the New York State IPM Program's BioControl Specialist
- NYS IPM videos on YouTube
- Alfalfa Scouting Procedures - Growing Alfalfa the IPM Way
- New York State IPM Program
- IPM for Alfalfa Weevil on Alfalfa - an 8 minute video from NYS IPM on utilizing Integrated Pest Management for alfalfa weevil on alfalfa plants. Includes scouting recommendations and information on natural enemies.