Key Differences in Microbial Formulation Applications: Foliar Sprays vs. Seed Treatments

Battelle possesses extensive expertise in developing microbial formulations for both foliar spray and seed treatment applications. The primary distinctions between these approaches lie in the target and method of application. Foliar sprays are applied directly to the aerial parts of growing crops, providing immediate protection against foliar pathogens and pests. Seed treatments, conversely, involve coating seeds with the formulation prior to sowing. This prophylactic approach can provide protection in different ways depending on the formulation including stimulating early formation of a healthy microbiome in the rhizosphere and offering systemic protection against soilborne pathogens and early-season pests to the seeds and seedlings. 

While some microbial formulations can be adapted for both foliar and seed treatment applications, the specific requirements for each differ significantly. 

Foliar Applications 

Foliar applications demand formulations that can withstand environmental stressors such as: 

• UV radiation: Degradation by sunlight is quite critical in formulation success.
• Rain washout: Rainfall can dislodge applied formulations, reducing their efficacy and rain fastness, i.e., the ability of the formulation to stay on the plant (e.g., leaves) is crucial.
• Temperature fluctuations: Formulations must be designed to maintain stability across a range of temperatures that may be experienced to ensure that the active retains efficacy. 

Seed Treatments 

Seed treatments, on the other hand, require formulations that: 

• Adhere effectively to the seed surface: Uniform, stable and robust coating is essential for consistent delivery and retention of the active ingredient.
• Do not impede germination: The formulation must not negatively impact seed viability or germination rates.
• Provide protection in the soil environment: Formulations must protect the microbes from moisture fluctuations, predation and other soilborne stresses. 

Related

Meeting the Demand for Microbial Formulation

Get the White Paper

Related

Meeting the Demand for Microbial Formulation

Get the White Paper

Shelf-Life Considerations for Both Application Types 

Regardless of the application method, maintaining an acceptable shelf life for the active ingredient is paramount. This involves careful selection of formulation components, optimization of manufacturing processes, and rigorous stability testing under various storage conditions. Factors such as water activity, temperature, and packaging play critical roles in preserving microbial viability and product efficacy over time. 

RNAi Technology in Crop Protection: A New Frontier 

RNA interference (RNAi) is a promising technology for targeted gene silencing in pests and pathogens. By delivering double-stranded RNA (dsRNA) molecules that target specific genes, RNAi can disrupt essential biological processes in the target organism, leading to pest or disease control. However, RNA molecules are highly susceptible to degradation by ribonucleases (RNases), enzymes that break down RNA. 

Protecting RNA during formulation, application, and uptake by target organisms is therefore crucial for the success of RNAi-based crop protection products. Key considerations include: 

• Formulation stability: The formulation process and the final formulation should ensure the formulated RNA should have considerable shelf-life.
• Delivery mechanisms: Efficient delivery systems are needed to ensure that RNA reaches its target site within the pest or pathogen after bypassing any possible degradation on the target site and after uptake by the target pest.
• Environmental persistence: Formulations must be designed to protect RNA from degradation in the field environment, including UV radiation, temperature fluctuations, and microbial activity. 

Battelle’s experience in formulating sensitive biological molecules, including peptides and proteins, provides a strong position to address the challenges associated with RNAi formulation.  With broad and deep formulation expertise Battelle is eager to collaborate with partners to develop innovative and effective microbial, RNAi-based or other biological active crop protection solutions, confident of being a key asset in this rapidly evolving field.