NC State Extension Publications

Problem

Herbicide injury caused from natural oils and acids including acetic acid (vinegar), clove oil, d-limonene, long-chain fatty acids, and others.

Symptoms

  • Leaf burn. Amount of necrosis will depend on how much spray solution contacts the plant. Direct exposure will result in overall necrosis. Small amounts of spray drift may result in leaf spotting.
  • Necrotic spots on fruit when spray drift occurs while plants are forming fruit.
  • New, untreated growth will look normal.
Muscadine grape leaf damaged by spray drift from clove oil.

Muscadine grape leaf damaged by spray drift from clove oil, 3 days after treatment.

B. Lassiter  CC BY-NC-SA - 4.0

Necrotic lesions on tomato fruit

Necrotic lesions on tomato fruit caused by spray drift from clove oil, 3 days after treatment.

B. Lassiter  CC BY-NC-SA - 4.0

Strawberry foliage with necrotic margins.

Strawberry foliage with necrotic margins and spots caused by spray drift from clove oil, 3 days after treatment. Note new growth emerging after spray is unaffected.

B. Lassiter  CC BY-NC-SA - 4.0

This strawberry plant treated with a PPO inhibitor herbicide.

Many contact herbicides may produce similar symptoms of leaf necrosis and spotting. This strawberry plant treated with a PPO inhibitor herbicide, flumioxazin.

J. Neal  CC BY-NC-SA - 4.0

Plant Entry and Symptom Expression

Naturally occurring oils or acids can be absorbed by any tender tissue resulting in foliar burn to any plant parts if sprayed at high doses or at times of high heat/drought. Young or older treated foliage will show the same symptomology and at the same time intervals with the exception of tissues with thick cuticles, which may not display any symptoms.

Similar Problems

Injury from natural oils and acids injury may be confused with symptoms from:

  • Other non-selective, postemergence herbicides including glufosinate, paraquat or diquat.
  • Protoporphyrinogen oxidase (PPO) inhibitors including acifluorfen, lactofen, sulfentrazne, oxyflourfen, and others.
  • Organic arsenical herbicides (MSMA, DSMA) causing desiccation within 1-2 days.
  • Salt stress.
  • Prolonged drought stress.

Herbicide Mode of Action Category

No WSSA or HRAC categories specified.

Authors

Professor Emeritus
Cobleskill Univ.
Professor of Weed Science, Extension Specialist & Department Extension Leader
Horticultural Science
Assistant Professor
Horticultural Science
Extension Associate, Horticulture
Horticultural Science

Publication date: Sept. 10, 2015

North Carolina State University and North Carolina A&T State University commit themselves to positive action to secure equal opportunity regardless of race, color, creed, national origin, religion, sex, age, veteran status or disability. In addition, the two Universities welcome all persons without regard to sexual orientation.