An independent efficacy report submitted to the Kenya Plant Health Inspectorate Service (KEPHIS) has confirmed that Terreplenish®, a biofertilizer based on Azotobacter vinelandii and Bacillus subtilis, significantly improves crop performance in maize, tomatoes and roses grown in Kenya. The trials, conducted by Pretac AgResearch and finalized in January 2026, evaluated the product across multiple seasons and agro-ecological zones, including Nairobi, Kiambu, Kirinyaga and Embu counties.
Strong Yield Gains in Maize
Across three seasons, maize plots treated with Terreplenish recorded earlier tasselling and higher yields compared to untreated controls. The report shows tasselling improvements of up to 51% in some seasons, alongside yield increases of up to 42% depending on the dose rate applied. The 25 litres per hectare rate delivered the strongest overall performance in most cases. Treated plots also demonstrated improved crop vigor and higher germination rates compared to untreated plots, pointing to stronger early establishment and stand uniformity.
Tomato Yields Rise by Up to 60%
In tomatoes, the trials recorded significant improvements in early flowering and marketable yield. Early flowering improved by as much as 38% in some seasons, while yield gains reached up to 60% relative to untreated control plots. The treated tomato plots were consistently rated “excellent” in crop vigor assessments, while untreated plots showed weaker performance over time. Improved root and aerial biomass were also observed, suggesting stronger nutrient uptake and overall plant health.
Boost for Kenya’s Floriculture Sector
In greenhouse rose production trials conducted in Nairobi, the application of Terreplenish resulted in up to a 50% increase in stem numbers and up to a 32% increase in stem length across seasons. Stem count and length are key quality parameters for Kenya’s export flower industry, where productivity and uniformity directly influence returns in international markets.
No Phytotoxic Effects Observed
As part of the regulatory requirements, the product was subjected to phytotoxicity testing. The trials confirmed no adverse effects such as wilting, necrosis, stunted growth or chlorosis across maize, tomatoes and roses. This positions the product as suitable for integration into existing production systems without harming crop development.
Registration Recommended
The researchers concluded that Terreplenish demonstrated significant improvements in crop quality and quantity across all tested crops and recommended its registration as a biofertilizer for use in Kenya.
Recommended application rates include:
- Maize: 20–25L per hectare applied before planting and again 14 days after germination
- Tomatoes: 20–25L per hectare applied during transplanting and repeated after 14 days
- Roses: 53L per hectare applied during vegetative growth stages
The findings come at a time when Kenyan farmers are increasingly seeking sustainable solutions to declining soil fertility and rising fertilizer costs.
With measurable gains recorded in staple and high-value crops alike, the report reinforces the growing role of soil-based biological inputs in strengthening Kenya’s agricultural productivity and resilience.
