Inga vivo

Heng, Ming Yuan, Thuerig, Barbara, Danton, Ombeline, Ramseyer, Justine, Gupta, Mahabir P., Tamm, Lucius, Hamburger, Matthias & Potterat, Olivier, 2022, Ingadosides A-C, acacic acid-type saponins from Inga sapindoides with potent inhibitory activity against downy mildew, Phytochemistry (113183) 199, pp. 1-8 : 7

4.7. In vivo Plasmopara viticola assay

Plant pathogen bioassays were performed on grapevine seedlings cv. “Chasselas” grown in the greenhouse as described before ( Thuerig et al., 2016). In short, plants were treated with the product when they had 3-4 fully grown leaves. Leaves were left to dry before inoculation with P. viticola (50 ′ 000 sp/mL). After inoculation, plants were kept at 80–99% relative humidity (RH) (20–21 ◦ C) for 1 d. Then, plants were grown at 60–80% RH and 20 ◦ C for 5 d, before increasing humidity again to 80–99% RH to induce sporulation for disease assessment. The percentage area covered by sporulating lesions (disease severity) was visually assessed for each leaf and a mean calculated for each plant. Each experiment included a non-treated control and a copper reference (copper hydroxide, Kocide® Opti, DuPont, Wilmington, DE, USA) at a standard concentration (0.3 mg /mL copper ions) as used in practice. Dried I. sapindoides extracts were either dissolved in DMSO at 100 mg /mL (small scale EtOH extract), or formulated as a wettable powder to improve solubility and applicability [20% extract (Herbamed extract), 20% solvent, 51% carrier, 6% defoaming agent, 3% surfactant] before adding to water to give extract concentrations of 1, 0.5, and 0.25 mg /mL Each treatment consisted of six replicate plants. Percentage efficacy of the test products was calculated as (1-(mean disease severity in plants treated with product/mean disease severity in non-treated control))*100 for each test product.