The threat of antibiotic-resistance calls for novel antibacterial agents. This study was aimed at screening medicinal plants for their antibacterial properties, phytochemical content and safety. Leaves of Allophylus abyssinicus (Hochst.) Radlk., Dicliptera laxata C.B.Clarke, Ligustrum vulgare L., Solanecio gigas (Vatke) c. Jeffrey and Gymnanthemum myrianthum (Hook.f.) H.Rob.; leaf and stem-bark of Olinia rochetiana A. Juss. and the seed of Cucurbita pepo L. were used. Chloroform and ethanol were used to extract G. myrianthum, D. laxata and O. rochetiana; ethyl acetate and methanol for the rest, and water for all. The extracts were tested against clinical/standard strains of Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Staphylococcus aureus by the agar-diffusion method. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined. Acute toxicity to mice was checked and preliminary phytochemical screening was done. Thirteen extracts, out of 24, were active (inhibition zone >7 mm) at differing levels (9.67±0.33-25.66±0.57 mm) against at least one bacterial strain. The MICs and MBCs were 1.95-15.6 mg/mL and 7.8-125 mg/mL respectively. The aqueous extract of S. gigas, methanol extracts of L. vulgare and A. abyssinicus, and ethanol extract of O. rochetiana leaf were the most active (MIC 1.95mg/ml) against S. aureus. Ethyl acetate extracts of A. abyssinicus, L. vulgare and S. gigas; aqueous of C. pepo, O. rochetiana and G. myrianthum; and all D. laxata had no antibacterial activity. P. aeruginosa was the least susceptible to any extract, although the methanol and aqueous extracts of S. gigas performed better against it. Preliminary phytochemical screening of selected extracts for phenols, flavonoids, tannins, steroids, terpenoids, steroidal glycosides, alkaloids, saponins, resins and glycosides showed positivity at least for four of these phytochemicals with glycoside and terpenoids in nearly all extracts and resin in none. The plants were not toxic to mice at 2000 mg/kg. Further consideration of S. gigas, L. vulgare, A. abyssinicus and O. rochetiana is recommended in light of their promising potential and safety.

Whiteflies are one of the most devastating horticultural pests attacking tomatoes. Although there are several control methods for the control of whitefly pests, the integrated application of entomopathogenic fungi (IPM) with chemical and botanical insecticides has proven more effective than individual control agents. This study was carried out to evaluate individual and combined treatments of entomopathogens B. bassiana, M. anisopliae, B. thuringiensis, Hunter 40 EC, and neem oil for the control of whitefly species on tomato (Solanum lycopersicum) under greenhouse and field condition. The greenhouse study showed that the different treatments resulted in a 58.48 to 100% reduction of nymphs and a 52.06 to 100% reduction of adults on both Galilea and Melkashola tomato varieties under greenhouse conditions. The combined treatments of AAUMB-29 + Neem oil displayed a higher yield (423.3 g fruits/plant) on the Gelilea tomato variety, and AAUDM-43 + Hunter 40 EC displayed a yield of (376.66 g/plant) on the Melkashola tomato variety. Under field conditions, the application of AAUMB-29 + Hunter 40 EC + Neem oil significantly decreased the whitefly population by 91.93% ( P < 0.001 ) after 10 days of the fourth spray. The result of fruit yield of tomato was significantly higher in all treatments (31.17 t to 70.42 t·ha−1) compared to untreated control (25.83 t·ha−1). Among the treatments, AAUMB-29 + Hunter 40 EC + Neem oil gave the highest fruit yield of 70.42 t·ha−1 followed by AAUMB-29 + Hunter 40 EC (64.50 t·ha−1) on the Galilea tomato variety under field conditions. The combined treatment of AAUMB-29 + Hunter 40 EC + Neem oil was the most effective with lower whitefly infestation, higher marketable yields, and less percentage of yield losses. Further investigations are required to determine the optimization and practicability of this integrated application of treatments for the control of both sucking and chewing insect pests under field conditions.

Purpose The biological pest control efficiency of entomopathogenic fungi is improved by the endophytic establishment and combination with agricultural recommended pesticides and plant extracts. This study aimed to evaluate the effects of B. bassiana and M. anisopliae on biological control of T. vaporariorum, endophytic colonization, and compatibility with selected pesticides. Methods The endophytic colonization ability of entomopathogenic fungal isolates was evaluated by using soil drenching and foliar spraying methods under greenhouse condition. Compatibility interaction of potential entomopathogenic fungi with selected pesticides was calculated based on the biological index formula. Results The endophytic colonization pattern of B. bassiana and M. anisopliae isolates using soil drench and foliar spray inoculation methods exhibited significant differences in the different parts of tomato plants. The endophytic B. bassiana and M. anisopliae isolates induced a significant reduction in the number of nymphs and adults of T. vaporariorum (p < 0.001). Thus, the application of B. bassiana AAUMB-29 reduced nymphs by 67% while M. anisopliae AAUDM-43 reduced adults with a percentage reduction of 52% over control. The compatibility study revealed that all tested concentrations of neem extract and chemical pesticides were caused by different levels of inhibition on vegetative growth, germination, and sporulation of M. anisopliae AAUDM-43, B. bassiana AAUMFB-77, and B.bassiana AAUMB-29. The biological index vales indicated that all isolates were compatible with neem oil, neem seed crud extract, and chemical insecticides at both half and recommended doses. Conclusion The tomato endophytic B. bassiana AAUMB-29 and M. anisopliae AAUDM-43 were convinced significant reduction of T. vaporariorum, and highly compatible with selected pesticides. These potential isolates should be used in integrated pest management programs