Lettuce

Year-Round IPM Program

(Reviewed 4/17, updated 4/17)

Use these guidelines for a monitoring-based IPM program to effectively manage pests, while reducing the risks of pesticides on the environment and human health.

When a pesticide application is considered, review the Pesticide Application Checklist at the bottom of this page for information on how to minimize the risks of pesticide use to water and air quality. Water quality can be impaired when pesticides drift into waterways or when they move off-site. Air quality can be impaired when pesticide applications release volatile organic compounds (VOCs) into the atmosphere.

This year-round IPM program covers the major pests of lettuce in the Central Valley, Central Coast, and desert areas (Imperial and Coachella Valleys). Details on carrying out each practice and information on additional pests can be found in the UC IPM Pest Management Guidelines: Lettuce. Track your progress through the year with this annual checklist form. Color photo identification sheets and examples of monitoring forms can be found online at http://ipm.ucanr.edu/FORMS.

Preplant

Mitigate pesticide effects to minimize air and water contamination.
What should you be doing during this time?
Select your field.
  • Consider soil type, cropping and pest history, plantback restrictions from previous crop, and rotational plan for the field.
  • Take a soil sample for nutrient, salinity, and pH analysis to determine field suitability and soil nutrient management.
  • Sample soil for nematodes (Central Valley and desert) and Verticillium (coast).
Survey weeds.
  • Keep records (PDF), noting the presence of problematic weeds.

Manage if needed according to the Pest Management Guidelines.

Clean equipment and tractors to prevent the spread of soilborne diseases before they enter the field.
Prepare the field (in all growing areas):
  • Apply fertilizer based on soil test results.
  • Determine bed size and list (prepare) fall beds.
  • Choose an irrigation system depending on the region.
  • Choose planting configuration (number of seed lines per bed).

In Central Valley and desert areas only:

  • In blocks that will be planted late, plant cover crops appropriate to the planting schedule.
  • In the low desert area, consider the use of solarization in June, July, or August for control of weeds, pathogens, and nematodes.
Preirrigate and cultivate to germinate and destroy the initial flush of weed seedlings.
In coastal organic fields, consider establishing insectary plantings to increase numbers of aphid natural enemies.
Seed selection and treatment:
  • Select an appropriate cultivar based on time of year and disease resistance.
  • Consider using primed seed (soaked in water before planting) in areas where ambient temperatures exceed 90F at planting.

Planting to rosette

Mitigate pesticide effects onto minimize air and water qualitycontamination.
What should you be doing during this time?
Select and apply herbicides at planting based on weed survey taken before planting.
Plant seeds or transplant lettuce into uniform beds to the proper depth with a precision planting system.
Check for stand uniformity and wilted plants, and inspect plants for pests and their damage; manage if needed according to Pest Management Guidelines.
Manage vertebrate pest problems if needed.
Treat fields with a history of severe lettuce drop.
Cultivate as close to seed line as possible.
Use automated thinners or hand thin seedlings and hand weed.
Install drip tape if using drip irrigation.
Apply nitrogen fertilizer as needed based on results of a presidedress soil nitrate quick test (PDF) (PSNT).

Rosette to heading

Mitigate pesticide usage to minimize air and water contamination.
What should you be doing during this time?
Cultivate the field for a second time.
Apply nitrogen if needed based on results of presidedress soil nitrate quick test (PSNT).
Hand or mechanically weed the field. If weeds are producing seed, remove them from the field.
Monitor for pests or pest damage, and manage if needed according to Pest Management Guidelines.

Heading to harvest

Mitigate pesticide effects onto minimize air and water quality contamination.
What should you be doing during this time?
Monitor for pests or pest damage, and manage if needed according to Pest Management Guidelines.
Manage vertebrate pest problems, and take appropriate steps according to industry guidelines for food safety.
Test soil for nitrogen (PDF), and apply as needed based on nitrate quick test results.
Clean harvest equipment and tractors before they enter the field to prevent the spread of diseases.

Harvest and postharvest

Mitigate pesticide effects to minimize air and water contamination.
What should you be doing during this time?
Record the presence and level of soilborne disease at harvest.
Remove drip tape and till soil for subsequent crop or for the fallow season.
Prepare for fallow season and till soil (Central Coast).
Consider planting a cover crop to protect the soil during the winter fallow period (Central Coast).
Disc under crop residue to control leafminers. Destroy plants with thrips and tomato spotted wilt disease.
Plan crop rotation.

Pesticide application checklist

When planning for possible pesticide applications in an IPM program, review and complete this checklist to consider practices that minimize environmental and efficacy problems.
  • Choose a pesticide from the UC IPM Pest Management Guidelines for the target pest considering:
  • Before an application:
    • Ensure that spray equipment is properly calibrated to deliver the desired pesticide amount for optimal coverage.
    • Use appropriate spray nozzles and pressure to minimize off-site movement of pesticides.
    • Choose sprayers and application procedures that keep pesticides on target.
    • Avoid spraying during these conditions to avoid off-site movement of pesticides:
      • Wind speed under 3 mph or over 10 mph
      • Temperature inversions
      • Just prior to rain or irrigation (unless it is an appropriate amount, such as when incorporating a soil-applied pesticide)
      • At tractor speeds over 2 mph
    • Identify and take special care to protect sensitive areas (for example, waterways or riparian areas) surrounding your application site.
    • Review and follow labeling for pesticide handling, personal protection equipment (PPE) requirements, storage, and disposal guidelines.
    • Check and follow restricted entry intervals (REI) and preharvest intervals (PHI).
  • After an application:
    • Record application date, pesticide used, rate, and location of application.
    • Follow up to confirm that treatment was effective.
  • Consider water management practices that reduce pesticide movement off-site.
  • Consider practices that reduce air quality problems.
    • When possible, reduce volatile organic compound (VOC) emissions by decreasing the amount of pesticide applied, choosing low-emission management methods, and avoiding fumigants and emulsifiable concentrate (EC) formulations.
    • Use the Department of Pesticide Regulation calculators to determine VOC emission rates from fumigant and nonfumigant pesticides.
More information about topics mentioned on this checklist is available at the UC IPM website.
For more about mitigating the effects of pesticides, see the Mitigation pages.

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