White Mold Management in Common Bean by Increasing Within-Row Distance Between Plants

Area of Science:

• Plant Pathology
• Agronomy
• Crop Science

Background:

• White mold, caused by *Sclerotinia sclerotiorum*, significantly limits common bean (*Phaseolus vulgaris*) yield in Brazil's fall-winter season.
• Effective disease management strategies are crucial for improving crop productivity in infested, irrigated agricultural systems.

Purpose of the Study:

• To evaluate the efficacy of reduced within-row plant densities for managing white mold in indeterminate common bean cultivars.
• To assess the impact of modified within-row plant distributions on white mold intensity and common bean yield.
• To determine optimal plant densities for white mold control in sprinkler-irrigated, naturally infested fields.

Main Methods:

• Field experiments were conducted over two growing seasons (2000, 2001) in Viçosa, Minas Gerais, Brazil.
• Treatments involved factorial combinations of within-row plant densities (4-16 plants/m), plant distributions (single vs. grouped), and fluazinam fungicide application.
• Between-row spacing was maintained at 0.5 m; sprinkler irrigation was applied throughout the study.

Main Results:

• White mold incidence and severity decreased, while common bean yield increased, as within-row plant density was reduced.
• Plant distribution in equidistant groups of three did not effectively reduce white mold.
• A density of 4 equidistant plants/m proved to be an effective strategy for managing white mold in infested, irrigated conditions.

Conclusions:

• Reducing within-row plant density is a viable strategy for managing white mold in common beans, independent of fungicide application.
• Optimizing plant density is critical for enhancing crop yield and mitigating disease pressure in susceptible cultivars.
• The use of 4 plants/m offers a promising approach for sustainable white mold management in common bean production systems.