Agriculture: Alfalfa Pest Management Guidelines

Summer

Year-Round IPM Program Pages

Established Stands

This year-round program covers the major pests of established stands of alfalfa hay in California. For planting and establishing stands of alfalfa see Planting and Establishing a Stand.

About Summer

  • Special issues of concern related to water quality: drift, runoff due to irrigation.

What should you be doing during this time?

Time harvests by considering:

  • Alfalfa yield, quality, and stand persistence. Early harvests result in poor stand persistence, encouraging weeds.
  • Pest problems, specifically how close the pest damage is to harvest
  • Irrigation and wheel traffic (avoid wet soils)
  • Alfalfa market and price differential for different quality grades

Survey weeds, especially weedy grasses.

  • Keep records on a weed survey form (PDF) for next spring's weed management decisions.

Monitor cowpea and spotted alfalfa aphids.

Monitor caterpillars and armyworms. Consider early harvest to reduce losses.

Monitor leafhoppers at the first sign of damage. Consider early harvest to reduce losses.

  • Keep records on a monitoring form (PDF).
  • Manage if needed according to the Pest Management Guidelines.

Look for cutworms if damage is apparent. Manage if needed according to the Pest Management Guidelines.

Watch for signs of diseases and disorders (such as nutrient deficiencies, yellowing due to anoxia, or abiotic factors like scald).

Keep records of other invertebrates.

Look for signs of vertebrate pests, such as gophers, meadow voles, or ground squirrels. Manage, if needed, according to the Pest Management Guidelines.

Use proper field sanitation:

  • Harvest disease- and stem nematode-free fields before infested fields.
  • Avoid moving contaminated farm machinery or livestock from a field infested with stem nematodes or disease to a clean field.
  • Be careful when using return water because pathogens and nematodes can be carried in recirculated irrigation water.

Manage irrigation water to prevent standing water, which can kill alfalfa plants through scald, especially at the tail-ends of fields. If possible, avoid watering on hot days (above 104ºF), but if unavoidable: avoid standing water in fields for over 8 hours.

Text Updated: 03/17
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