Do hydraulic pumps and filters of sprayers influence the viability of Beauveria bassiana based mycoinsecticide Botanigard®?

Entomopathogenic fungi are promising biocontrol agents for pest management, but they could be sensitive to application methods. Sprayers, used for both fungal and chemical products, can potentially harm the fungal propagules. This study investigated the impact of common hydraulic pumps (piston and diaphragm) on the viability of Beauveria bassiana Vuillemin (Ascomycota: Hyprocreales) based mycoinsecticide Botanigard® in the spray mixture. It also aimed to determine the optimal filter mesh size for the system to prevent clogging during application. The results showed significant reduction in conidial germination percentages with increasing number of passes through both types of pumps. However, in both cases the decrease was around 4% with a 90% of conidial germination which may be high enough to control the pest. The temperature of the mixture increased with the number of passes through the pumps, but it remained within the suitable range for fungal growth. When it came to filter clogging, the 32-mesh filter did not clog, the 50-mesh had a low clogging percentage, and the 80-mesh filters had higher clogging percentages (18% for suction filter and 56% for impulsion filter) after 30 passes through the system. As a conclusion, hydraulic pumps are suitable to apply B. bassiana based mycoinsecticide Botanigard®, but temperature control should be taken into account to prevent conidia damage. Using 32-mesh filters for both suction and impulsion is recommended to prevent clogging issues when applying this product. [Display omitted] •Hydraulic pumps reduce Botanigard®'s viability 4% at 30 recirculation passes.•At 50 mesh and above, the filters get clogged when Botanigard® is applied.•Maintain optimal temperature for mycoinsecticide with a hydraulic sprayer is crucial.