Evidences of induced resistance in tomato against Alternaria solani: An investigation

Abstract

Tomato is one of the major solanaceous vegetables, which has a unique place in the global vegetable market. Instead of being a high-value crop, there is still a need to do improvement in its potential against various biotic and abiotic stressors that adequately demolish its real yield. Alternaria solani (causing early blight disease) is designated as one of the fatal organisms that may reduce tomato crop yield by up to 80%. There were lots of methods, viz., chemical, cultural and biological suggested to overcome it. However, chemical strategies are much in vogue, but they have several negative consequences for human health and the ecosystem. Enlightening this issue, the efficacy of various treatments, viz., chemical fungicides (Amistar Top®, Nativo®, and Contaf®), biochar and fungal bioagent (Trichoderma viride) was assessed under both in vivo and in vitro conditions. Induced resistance is mediated by several regulating pathways, like salicylic acid and jasmonic acid. These mediating pathways manipulate different physiological processes like growth and development, stress tolerance, and defence mechanisms of the plant. The assessment of results revealed that among all treatments biochar at 3.25% by weight consistently displayed remarkable effectiveness against the early blight infection by triggering resistance and improving the overall performance of tomato plants. This result is attributed to improved soil health, fastening mineralization as well as absorption processes, and boosting the plant’s immunity with the use of a higher concentration of biochar. Hence, it could be recommended for the overall improvement of tomato crop and its sustainability.