Influence of Open Alleys in Field Trials Assessing Yield Effects from Fungicides in Corn

Area of Science:

• Agricultural Science
• Agronomy
• Plant Pathology

Background:

• Field trials for corn foliar fungicides commonly use open alleys.
• Open alleys facilitate equipment access but may influence yield estimates due to reduced competition.
• The interaction between open alleys and fungicide efficacy on corn yield has not been previously investigated.

Purpose of the Study:

• To test if open alleys interact with foliar fungicide application to bias corn yield assessments.
• To evaluate the impact of plot design on fungicide efficacy studies in corn.

Main Methods:

• Experiments were conducted over two years using 7.6-m corn plots with 1.5-m open alleys.
• Foliar fungicide (Headline AMP) was applied once during VT/R1 growth stages.
• Yield data were collected from seven subplots within each main plot to analyze position effects.

Main Results:

• Yields were higher in subplots near plot ends compared to central subplots.
• A significant interaction between fungicide and subplot position was observed, indicating position-dependent fungicide response.
• Fungicide-induced yield differences were minimal when comparing full plot data to central subplot data.

Conclusions:

• The open-alley design did not introduce a significant bias in assessing the agronomic effects of foliar fungicides in corn.
• Additional research is warranted to fully understand the complexities of plot design and fungicide efficacy in large-scale field corn production.