Application of electrostatically charged sprays ofBacillus thuringiensisusing MicronRMicro‐ulva chargeable spinning disc sprayer was investigated and its efficiency in improving underleaf surface coverage with charged droplets was determined by comparing the total viable spores counts (VSC) from spores washed off the upper and lower leaf surfaces of sprayed Brussels sprouts. Bioassay experiments were also carried out by comparing mortality of third instar larvae of P.xylostellaconfined to upper and lower leaf surfaces of plants sprayed with charged and uncharged droplets. Higher total viable spore counts (P < 0.001) and a higher mortality of P.xylostella(P = 0.029) indicated improved coverage of the lower surfaces of electrostatically sprayed Brussels sprouts plants.