Field evaluation of entomopathogenic fungi and Usher plant Calotropis procera extract for controlling aphids and whiteflies on pepper

Both plant extracts and entomopathogenic fungi play a crucial role in sustainable agriculture as environmentally friendly alternatives to synthetic pesticides. The study aimed to use Calotropis procera extract (PE), and the commercial entomopathogenic fungi; Beauveria bassiana (Bb) and Metarhizium anisopliae (Ma) individually and each one with PE against both aphid and whitefly on pepper plants in two locations. Phenols and flavonoids in leaves of C. procera were detected by HPLC analysis and indicated that there are 14 compounds and some of them are showing insecticide effects. This extract showed LC₅₀ and LC₉₀ on Myzus persicae as 292.24 and 709.7 µg/mL, respectively. Field experiments showed that reduction rates for aphids were increased with significant differences among the treatments in the location-1 to be 100% (PE + Bb), 97.47% (PE + Ma) and 95.53% (pesticide), 87.83% (Bb), and 81.29% (PE) followed by lower rate of 75.98% (Ma). These reduction rates in the location (2) were 96.1% (PE + Bb), and 93.4% (pesticide). Meanwhile, the reduction rate of PE + Ma (86.4%) was significantly lower than that of PE + Bb and pesticide but higher than that of PE (78.23%). Similar trend was recorded) for whitefly in both locations where it was 96% for PE + Bb and pesticide followed by Bb, PE and PE + Ma (86-88%) while the lower rate was 77.48% (Ma). Meanwhile, the reduction rates in the location-2 reached 100% for PE + Bb, PE + Ma and pesticide with significant differences for Bb (96.11%) followed by the lower two treatments (PE = 87.98% and Ma = 89.76%) without a significant difference between both of them. It could be concluded that the using of the commercial EPF especially B. bassiana with C. procera leaf extract achieved the higher reduction rates of aphids and whiteflies than that of using of each one individually. Accordingly, they could be used together in integrated pest management of piercing sucking insect pests due to there are synergistic effects and compatibilities between both of them. Moreover, other isolates of EPFs should be tested with this plant extract to ensure from the compatibility between them due to some EPFs isolates are not compatible with some plant extracts.