Effects of Silicon Applications on Soybean Rust Development Under Greenhouse and Field Conditions

Area of Science:

• Plant Pathology
• Agronomy
• Soil Science

Background:

• Soybean rust (SBR), caused by Phakopsora pachyrhizi, poses a significant threat to soybean production.
• Silicon (Si) has shown potential in suppressing plant diseases in various host-pathogen systems.
• Exploring Si as a sustainable SBR management strategy is crucial for crop protection.

Purpose of the Study:

• To evaluate the efficacy of silicon amendments in controlling soybean rust.
• To determine the impact of soil and foliar Si applications on disease development.
• To assess the potential of Si for integrated SBR management in soybean.

Main Methods:

• Greenhouse and field experiments were conducted using soybean cultivars inoculated with Phakopsora pachyrhizi.
• Soil applications of wollastonite (calcium silicate) and foliar applications of potassium silicate were applied at varying rates.
• Disease onset, disease progress curve (AUDPC), and severity were monitored and analyzed.

Main Results:

• Silicon treatments significantly delayed soybean rust onset by approximately 3 days in greenhouse trials.
• Both soil and foliar Si applications led to a significant reduction in the area under the disease progress curve (AUDPC).
• Field experiments showed an average 3-day delay in disease onset with soil Si treatments and reductions in AUDPC up to 43%.

Conclusions:

• Silicon amendments represent a promising strategy for managing soybean rust in both organic and conventional farming systems.
• The observed delay in disease onset and reduction in AUDPC suggest Si can mitigate SBR impact.
• Further research into Si application timing and rates could optimize its use for SBR control.