Influence of application volume on herbicide efficacy

Area of Science:

• Agricultural Science
• Weed Science
• Physical Chemistry

Background:

• Farmer herbicide application volumes are often lower than registration standards.
• This practice may increase active ingredient concentration, potentially enhancing efficacy.
• The role of spray volume and formulation on herbicide performance requires investigation.

Purpose of the Study:

• To compare the efficacy of clodinafop-propargyl and fenoxaprop-ethyl on Avena sativa at different application volumes.
• To investigate the impact of spray concentration on herbicide performance.
• To explore the relationship between spray dilution properties and efficacy.

Main Methods:

• Field efficacy trials comparing two graminicides at 75 L ha(-1) and 300 L ha(-1).
• Dynamic surface tension measurements of herbicide spray dilutions.
• Assessment of active ingredient retention on Avena sativa.

Main Results:

• Fenoxaprop-ethyl showed higher efficacy at 75 L ha(-1) compared to 300 L ha(-1).
• Clodinafop-propargyl efficacy remained consistent across both application volumes.
• Surface tension dynamics differed between herbicides, correlating with efficacy variations and application volume.

Conclusions:

• Spray concentration can influence graminicide efficacy, particularly for fenoxaprop-ethyl.
• Herbicide formulation plays a significant role in how application volume affects performance.
• Lower application volumes may enhance efficacy for certain herbicides due to increased concentration.