IMAZETHAPYR
Trade Names: Conquest B, Pursuit
Group 2
Site of Action: Inhibitors of acetolactate synthase (ALS) and also called acetohydroxyacid synthase (AHAS)
Symptoms
Grapevines planted into soil containing imazethapyr residues may show severe stunting, often appearing in a patch in the vineyard (the patch correlates to areas of low soil pH).
Following POST emergent application:
- Within an hour the inhibition of ALS enzyme leads to a rapid cessation of cell division and plant growth
- Within 1- 2 weeks symptoms become visible
- Meristematic regions are the first to experience chlorosis and necrosis followed by general foliar chlorosis and necrosis
Uptake and Translocation
Persistence
- Depends on weather and soil conditions (more persistent under dry conditions)
- Half-life in field: 60- 90 days
- For most vegetable crops, a 22 month recropping interval is recommended
- When soil pH is low (below 6.0), persistance can be many years and residues will only begin to dissipate when lime is applied and pH rises above 6.0.
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