Agriculture & Natural Resources

IPM – Processing Spinach Scouting Guidelines

I. Pre-planting Decisions

  • Site selection and crop rotation for disease management
  • Use a combination of cultural practices to reduce problems from seed corn maggot: plow down cover crops 3-4 weeks before planting; completely bury cover crops or previous crop residues to reduce adult fly attraction to rotting organic matter; reduce use of heavy manure applications and let it age before incorporating; and attach a set of drag chains behind the planter during seeding to reduce the moisture gradient.

II. Spring Planted Spinach

A. Seed Corn Maggot

  • Sampling and Decision Making: No sampling methods are available for seed corn maggot before planting. During cool, wet conditions, a combination of the above cultural practices and a broadcast application of an insecticide will be needed to achieve effective control.

B. Aphids

  • Sampling: Check 10 plants in 10 locations for the presence of aphids. Be sure to sample the undersurface of leaves.
  • Thresholds: On seedling stage spinach, controls should be applied if you find one aphid per plant. In established fields, apply treatments if you find 4-10 aphids per plant.

C. Flea Beetles

  • Sampling: Monitor newly emerged seedlings for damage which appears as small pits or irregularly shaped holes.
  • Thresholds: A treatment should be considered if you find several damaged rows. Spot treatment of outside rows can be effective.

III. Fall Planted and Overwintered Spinach

A. Garden Webworm and Beet Webworm

  • Sampling: Check for small larvae feeding in the leaves and buds of small plants. Examine 10 plants in 10 locations throughout a field.
  • Thresholds: Treatments should be applied when 5% of the plants are infested with small larvae and before significant webbing has occurred.

B. Beet Armyworm

  • Sampling: Once seedlings emerge, check fields twice a week for small larvae. Check 10 plants in10 locations count the number of larvae per plant.
  • Thresholds: On seedling plants, treatment should be applied if you find one larva for every 10 plants. On established plants, treatment should be applied if you find one larva for every 2 plants.

C. Aphids

  • Sampling: Check 10 plants in 10 locations for the presence of aphids. Be sure to sample the undersurface of leaves.
  • Thresholds: On seedling stage spinach, controls should be applied if you find one aphid per plant. In established fields, apply treatments if you find 4-10 aphids per plant.

D. Leafminers

  • Sampling: Check young seedlings on a weekly basis for mining on the cotyledons and first true leaves. Examine 10 plants in 10 locations. Be sure to examine the undersurface of the leaves where the mines are most obvious.

  • Thresholds: Treatment should be applied when you find eggs or mines on 50% of the plants or if you find an average of one or more mines per leaf. As a field approaches harvest, treatments should be applied so that no more than 5% of the leaves have mines.

 

 

University of Delaware IPM Program
Joanne Whalen – Extension IPM Specialist