Stability and shelf life of Metarhizium anisopliae in capsule formulation: Impact of storage conditions

Metarhizium anisopliae is crucial for sustainable pest management as a natural biocontrol agent, effectively targeting harmful insects while being safe for humans, animals and plants. The carrier-based capsule formulations were stored at room temperature for 180 days to assess their shelf life. The carriers used in the experiment were talc, kaolin, charcoal, sorghum grain, maize grain, lignite and fly ash. The month-wise colony-forming unit (CFU) counts of Metarhizium anisopliae in various carrier-based formulations stored at room temperature for six months revealed a gradual decline in spore viability over time. Initial cfu counts (0 days) for all formulations ranged from 17.55 × 10⁶ to 19.40 × 10⁶ cfu/g, indicating good initial viability of the spores. The sorghum grain capsules retained the highest CFU count at 1.33 × 10⁶ CFU/g, while the fly ash capsules showed the greatest decline, dropping to 0.27 × 10⁶ CFU/g.