Our Gift to You - 20% off online courses Dec. 1-15, 2025 with code HOLIDAY20. Restrictions Apply.

Articles

Herbicide Summary - StalkerĀ®

Used to control individual stems and cut stump resprouting.
Updated:
January 3, 2023

Common Name: Imazapyr-27.7%

Formulation: Emulsifiable concentrate

Signal Word: Caution

Toxicity: Practically nontoxic; oral LD (50): >5,000 mg/kg

Use Classification: General use

Minimum Required Personal Protective Equipment: Long-sleeved shirt, long pants, shoes, and socks

Carriers: Water, diesel oil, or recommended seed oils and penetrating oils

Activity: Absorbed through foliage, bark, cut surface, and root uptake

Mode of Action: Accumulates in plant meristematic regions (growth regions); inhibits the synthesis of any enzyme responsible for the production of certain amino acids found only in plants

Selectivity: Conifers generally resistant

Precautions: Toxic to plants at very low concentrations, do not apply to areas where roots of sensitive desirable plants extend

Application Methods: Frill girdle, stem injection, cut stump, and basal bark

Manufacturer: BASF

David R. Jackson
Former Extension Educator, Renewable Natural Resources
Pennsylvania State University