Using microbial seed coating for improving cowpea productivity under a low-input agricultural system

Area of Science:

• Agricultural Science
• Microbiology
• Agronomy

Background:

• Plant-growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal (AM) fungi enhance crop growth and quality.
• Large-scale agricultural applications of these microbes require efficient and cost-effective inoculation methods.
• Microbial seed coating presents a viable strategy for applying reduced inocula amounts in agriculture.

Purpose of the Study:

• To evaluate the impact of seed coating with PGPR (Pseudomonas libanensis TR1) and AM fungi (Rhizophagus irregularis) on cowpea grain yield and nutrient content.
• To assess the effectiveness of single versus multiple AM fungal isolates in combination with PGPR.
• To determine the influence of microbial seed coating on soil properties under low-input field conditions.

Main Methods:

• Cowpea seeds were coated with Pseudomonas libanensis TR1 and single or multiple isolates of Rhizophagus irregularis.
• Field trials were conducted under low-input conditions to assess effects on shoot dry weight, pod and seed number, grain yield, and grain lipid content.
• Soil organic matter and pH were analyzed for the different treatments.

Main Results:

• Seed coating with P. libanensis + multiple R. irregularis isolates (coatPMR) significantly increased shoot dry weight (76%), pods per plant (52%), seeds per plant (56%), and grain yield (56%).
• Grain lipid content was 25% higher in the coatPMR treatment compared to controls.
• The coatPMR treatment also resulted in higher soil organic matter and lower pH.

Conclusions:

• Seed coating with PGPR and multiple AM fungal isolates effectively improves cowpea field productivity.
• This method is suitable for low-input agricultural systems.
• Microbial seed coating is a viable strategy for enhancing crop yield and quality.