Ethoprop depletion from soil as influenced by simulated rainfall

Area of Science:

• Agricultural Science
• Environmental Chemistry
• Soil Science

Background:

• Nematicides like ethoprop are crucial for managing plant-parasitic nematodes.
• Understanding pesticide persistence in soil is vital for effective application and environmental protection.

Purpose of the Study:

• To assess the impact of varying simulated rainfall levels on ethoprop retention in sandy soil.
• To determine the relationship between rainfall amount and the degradation rate of ethoprop.

Main Methods:

• Field microplot tests were conducted using sandy soil.
• Ethoprop was applied at 13.5 kg a.i./ha.
• Simulated rainfall was applied at rates of 2.5, 7.5, 15.0, and 22.5 cm over six days.

Main Results:

• Higher rainfall levels led to rapid depletion of ethoprop concentration in the soil.
• 2.5 cm of rain halved ethoprop concentration in the top 15 cm within 10.7 days; 22.5 cm reduced this to 1.7 days.
• 2.5 cm of rain rendered ethoprop ineffective against Meloidogyne javanica 10 days post-application.

Conclusions:

• Simulated rainfall significantly influences ethoprop persistence and efficacy in sandy soils.
• Application timing and expected rainfall are critical factors for effective ethoprop use.
• Reduced nematicidal activity under higher rainfall necessitates careful management strategies.