In – vitro Evaluation of Some Common Ethnobotanicals to Control the Leaf Spot and Flower blight of Marigold

Abstract

In tropical and subtropical climes, Alternaria zinnia causes leaf spot and blossom blight in marigolds, resulting in yield reductions of 50-60%. Chemical controls can be harmful to ecosystems, and agronomic control methods are difficult to implement. The goal of this study was to examine the efficacy of a variety of botanicals that are easily available in in-vitro situations. Eight plants extracts, including Aloe vera, Azadirachta indica, Allium sativum, Zingiber officinale, Curcuma longa, Phyllanthus emblica, Withania somnifera, and Ocimum tenuiflorum, were evaluated against the pathogen at 10% and 20% concentrations. Allium sativum suppressed mycelial growth the greatest at a 10% concentration, with 80.28 percent, followed by Phyllanthus emblica (64.32 percent), and Curcuma longa (64.32 percent) (54.93 percent). Ocimum tenuiflorum, with a 2.35 percent inhibition, was the least inhibited plant. The results at a concentration of 20% followed the same pattern as the results at a concentration of 15%. The highest level of inhibition was found in Allium sativum (88.26 percent), followed by Phyllanthus emblica (86.85 percent), and Curcuma longa (86.85 percent) (74.65 percent). With 11.74 percent inhibition, Ocimum tenuiflorum was the least inhibited. Although more research is needed, the presence of Allicin in Allium sativum may explain its effectiveness against marigold flower disease. Additionally, the efficacy of phytoextracts against marigold flower blight might be assessed in the field.