Effect of Salicylic Acid on Mycelial Growth and Conidial Germination of <i>Fusarium oxysporum</i>

Fusarium wilt is a significant disease of chilli (Capsicum annuum L.) caused by Fusarium oxysporum f. sp. capsici. Pakistan is known as a major chilli producer; however the chilli industry is suffering from lower yields affected by biotic and abiotic stresses including F. oxysporum. The objective of the study was to evaluate the role of exogenous application of salicylic acid on mycelial growth and conidial germination of the pathogen in controlled lab conditions. Using various concentrations of SA (0-1.5 mM), a clear concentration major effect was observed. At lower concentrations (0.05-0.5 mM) the fungal growth was stimulated, while higher concentrations (0.5–1.5 mM) significantly inhibited fungal growth, being the highest level of inhibition at 1.5 mM where mycelial growth was reduced to 77.8% compared with controls. Moreover, the rate of conidial germination also decreased with increasing levels of SA, with a reduction of 47 % at 1.5 mM indicating its potential as an antifungal agent. The results of this study shows the dual role of SA in regulating plant-pathogen interactions and demonstrate the potential of SA for managing Fusarium wilt in chilli crops, opening avenues for its use as a sustainable agricultural practice to improve the resistance of crops to fungal diseases.