Effect of Salicylic acid and the filtrates of Trichoderma harzianum and Alternaria solani and aqueous extract of Ginger on early blight in hydroponics


The research was conducted on tomatoes to evaluate the effect of Salicylic acid(SA) , Trichoderma harzianum (T.h.), Alternaria solani (ASF and ASS isolates),filtrate and aqueous extract of Ginger treatment (Gr) on the disease severity ofearly blight in inoculated tomato plant by ASF and ASS isolates growing inhydroponics agriculture system. The chlorophyll in leaves was determined ininoculated and non-inoculated leaves (SPAD) , It was found that the SA and T.h.treatments increased the chlorophyll content to 44.86 and 43.68 SPADrespectively compared with 34.92 SPAD in ASS filtrate treatment , While thechlorophyll content decreased to 38.08 SPAD in inoculated plant by ASFcompared with 43.17 SPAD in non-inoculated . The SA treatment reduced thedisease severity to 2.08 , 4.86 and 9.72% after 7,14 and 28 days respectively ,followed by T.h. 3.47,6.25 and 11.11% respectively then Gr treatment 12.50%after 28 days . In addition we found from the results that the disease severity wasincreased significantly in ASF which was 9.37, 13.54 and 34.36% respectivelycompared with 7.29, 11.46 and 26.04% respectively in ASS treatment.