Management of faba bean chocolate spot (Botrytis fabae Sard.) using compost tea under in vitro and in vivo conditions

Abstract

The aim of this study was to determine alternative management options against faba bean chocolate spot by applying different concentrations of compost tea. The experiment was conducted at Holeta Agricultural Research Center, during the main cropping season of 2019/20. The compost tea was prepared by mixing mature compost with distilled water. Experiment on antifungal activity was conducted under laboratory conditions. Treatments and experimental design under in vivo conditions were laid out in a randomized complete block design with three replications having 48 total plots. The experiment was repeated twice. The results showed that the highest inhibition rate was recorded at 50% and 35% compost tea concentrations with 5.1 cm and 4.3 cm, respectively. There was a significant difference (P < 0.05) between compost tea concentrations that applied as a foliar spray and soil drench against chocolate spot disease. The compost tea concentrations applied by combining both foliar spray and soil
drench 50% showed less incidence and severity (13.3% and 18.3%, respectively). The maximum severity of 96.3% was recorded on the control (0%) 98 days after planting. Compost tea with high concentrations of 50% provided the highest number of yield per hectare (0.09367 tons/ha) as compared with untreated plots (0%) that showed 0.03453 tons/ha. The combination of compost tea concentrations 50% as a foliar spray and 50% as a soil drench showed promising results both under laboratory and field conditions. Further study is needed on time of application for increasing the efficiency of compost tea.