Salicylic Acid and Acetylsalicylic Induced Resistance to Powdery Mildew Disease of Milk thistle (Syllibium marianum)

Abstract

Microscopic examination showed that Erysiphe cichoracaerum is the causal agent of Milk thistle powdery mildew and its symptoms begin to appear in the middle of March. Plants sprayed with Neem (5%) had no effect on the percentage of chlorophyll, but reduced the severity percentage infection to 2.2, 50.0% respectively. The use of different concentrations of salicylic acid (SA) acetylsalicylic acid (ASA) led to an increase in wet and dry weight and higher plants hieght. One spray with 1 mmole ASA increased the wet weight to10.9 g. In the meantime, the dry weight differed significantly from other treatments except of 1 mmole SA once spray.

Methods of Inducing Systemic Resistance in plants by Using Abiotic Agents to Control Powdery Mildew Pathogens

“…The required concentrations of BABA to achieve resistance up to 90% depend on the host, the causative agent, and the method of treatment [21]. A study indicated the use of BABA to induce resistance against powdery mildew in strawberries, as it leads to the accumulation of phenols in strawberry leaves, and a study indicated the use of BABA to induce resistance against powdery mildew in grapes [22]. One study indicated that the effect of BABA on the plant host depends on controlling the directing of the plant's defense mechanisms to respond faster to the attacking pathogen and produce manifestations of conflicting interference such as hypersensitivity reaction [23].…”