Tomatoes are among the most economical vegetable crops that can be affected by many diseases, for example Fusarium wilt disease, which is caused by the fungus “Fusarium oxysporum f. sp. lycopersici,” which is considered one of the most common diseases affecting tomato plants. Biocontrol and chemical inducers represent an important strategy to stimulate the plant defense system, especially when applied together. In the current study, the efficacy of the following treatments, for example, “Trichoderma viride” and salicylic acid, alone or in combination, was evaluated compared to the effectiveness of the recommended fungicide Topsin-M 70%, which was used in the recommended dose as a new strategy to increase the defense efficiency of tomatoes to combat Fusarium wilt disease under greenhouse and field conditions. The various physiological defensive changes were studied in addition to estimating some enzymes associated with the chemical defense system of tomato plants such as polyphenol oxidase, peroxidase chitinase, and total dissolved phenols). The results obtained confirmed that all the treatments used led to the protection of tomato plants completely from infection, as the risk of disease decreased significantly, the level of all physiological estimates specified changed significantly as a result of the use of anti-fungi and chemical inducers, as many defense compounds were shown, which resulted in the activation of the chemical control in tomato plants against the attack of pathogens. These treatments also led to a significant increase in the growth variables and the total yield.