Afraa Mutie Haidar*¹, Mohammad Zakaria Tawil¹ and Essam Allaf¹

1 Faculty of Agricultural Engineering, Lattakia University, Lattakia, Syria.
(*Corresponding author Afraa Mutie Haidar, Email: Afraaafraa485@gmail.com).

Received: 19/ 12/ 2025          Accepted: 4/ 3/ 2026

Abstract

A semi-field experiment was conducted over two consecutive tomato growing seasons in 2024-2025 to study the effect of salicylic acid and the fungicide hymexazole on inducing resistance in the hybrid tomato variety *Pistona* against the fungus Fusarium oxysporum f. sp. radicislycopersici, which causes root and crown rot. Both compounds showed effectiveness in reducing the percentage and severity of infection to 61.1% and 27.8% respectively in infected plants treated with salicylic acid, while the percentage and severity of infection reached 72.2% and 19.4% respectively in infected plants treated with the pesticide, compared to the infected control, which had a percentage and severity of infection of 100% and 65.3% respectively.The stimulatory effect of both the pesticide and salicylic acid on tomato plants was demonstrated by increasing the concentration of methyl jasmonic hormone to more than 170 times and more than 350 times, respectively, compared to the infected control. Treatment of the infected plants with the pesticide and salicylic acid also resulted in the activation of the peroxidase enzyme to (214.2, 238.8) × 10⁻⁵ µmol/mg, respectively in contrast to the infected control, which had an activity of 151.3 × 10⁻⁵ µmol/mg, the total phenolic content increased to 17.5 and 16.5 µmol/g wet weight in infected plants treated with the pesticide or salicylic acid, respectively, compared to the infectious control, which had a total phenolic content of 13.9 µmol/g wet weight.

Keywords: Fusarium oxysporum f. sp. radicislycopersici (FORL), root and crown rot disease, resistance inducer, salicylic acid, fungicide hymexazole.

 Full paper in Arabic: PDF