Dergiler / Türk Tarım - Gıda Bilim ve Teknoloji dergisi / 2020 / Cilt: 8 - Sayı: 0
Management of Erwinia amylovoraby Potential Bio-Pesticides in vitroand in vivo Conditions
- Sayfa
- 38–45
- DOI
- —
Özet
Erwinia amylovora, the causative agent of fire blight disease, threatens a lot of species of the Rosaceae family. Antibiotics and copper compounds in chemical applications are most frequently are applied, but these can be phytotoxic and cause resistant strains of the pathogen. In our experiments, 20 herbal materials were tested for their antimicrobial effectiveness against the fire blight pathogen in vitroand in planta. The air-dried plants ground into fine powder and extraction was performed at room temperature by maceration with 80% (v/v) methanol/distilled water. The minimum inhibitory concentration values were determined by using disc diffusion method and streptomycin was used as control in all experiments. Antimicrobial activity was evaluated by measuring the inhibition zones in reference to the pathogen. Among the tested plants, Szygiumaromaticum,Thymus vulgarisand Rhus cararia showed a good antibacterial activity and they inhibited the growth of E. amylovorawith inhibition zone diameter ranging from 21 to 27 mm at 20% (w/v) in absolute methanol compared to streptomycin (31 mm) in vitroconditions. In vivotests were performed by using highly virulent E. amylovoraisolate (Eak24b, 91%) grown on TSA medium andinoculation on young shoots of 3-year-old Gala variety of apple and Santa Maria variety of pear seedlings at 107CFU ml-1density of the pathogen. Disease severity (%) was assessed by by proportion of blighted shoot length to the whole shoot length and also efficacy of the extracts was determined by using Abbott formula. The highest efficacy was obtained by S. aromaticumand T. vulgarisextracts of reducing shoot blight of cv. Gala and cv. Santa Maria by 67.81% -64-12% and 51.50% -51.04% ratios, respectively. Obtaining results showed that some medicinal and aromatic plant extracts might be used against fire blight disease as potential new generation chemicals on pome fruits within integrated and organic control programs.