The effectiveness of the organic fertilizer SALSICO in stimulating acquired systemic resistance of tomato plants in protected agriculture against infection with cucumber mosaic virus
Abstract
The effect of the SALSICO compound containing Salicylic Acid (SA) and Sugar Alcohols was studied in inducing Systemic Acquired Resistance (SAR) in tomato plants protected against infection with Cucumber mosaic virus (CMV). The experimental plants were treated with two irrigation and Spraying methods, with two concentrations of 3 and 6 ml/L of the SALSICO compound, four times at an interval of two weeks, and the first time was three days before mechanical infection with the virus, in the autumn of 2022 in Tartous Governorate, Syria. The incidence of acquired systemic resistance was assessed by determining the timing of infection symptoms, disease severity, free salicylic acid concentration, and peroxidase activity in the experimental plants. The results showed that treatment with the SALSICO compound delayed the appearance of symptoms of viral infection by up to 23 days compared to 12 days for the control, and reduced infection severity to 33.4% in the spray treatment at a concentration of 6 ml/L and it was the best treatment compared to the control infected with the virus and not treated with the SALSICO compound by 81.6%, Compare with the rest of the treatments. The value of free salicylic acid increased to 134.8 µg/g compared to the healthy control (21.54 µg/g) and the infectious control not treated with SALSICO (13.73 µg/g), and the peroxidase enzyme concentration also increased to 0.278 µmol/mg compared to the healthy control
(0.044 µmol /mg) and the infected control not treated with SALSICO (0.112 µmol/mg).
The increase in the content of free salicylic acid and peroxidase enzyme activity, the delay in the onset of mechanical infection symptoms, and the decrease in the severity of the infection are biological and chemical indicators of the induction of systemic acquired resistance as a result of treatment with the SALSICO compound containing salicylic acid and sugar alcohols.