Effect of Benzothiadiazole (BTH) on Growth of Tomato Plants and on Tomato Yellow Leaf Curl Virus (TYLCV)

Abstract

This research aimed to test the effectiveness of different concentrations of the resistance inducer Benzothiadiazole (BTH) on growth of two tomato varieties (OURJOAN and NEENAR) and protect of Tomato Yellow Leaf Curl Virus (TYLCV). BTH were used at two concentrations 50 and 100 ppm, proved to be effective in promoting the growth indicators of both healthy and infected tomato plants with TYLCV-IL strain. Differences of the average growth indicators were significant for the healthy treatments between the BTH treated plants and the control plants treated with only water in terms of stem diameter, number of flowers, and wet weight of the shoot and root systems. NEENAR variety healthy treated plants with 50 ppm BTH significantly exceeded all other treatments with average values of (68.14, 15.72, 12.20, 72.74, 40,64) respectively for the previously mentioned growth indicators. This indicates the efficiency of using low concentrations of 50 ppm of the BTH in stimulating plant growth. Similarly, plants infected with TYLCV-IL which were treated with the 50 ppm of BTH were significantly superior to positive infected control plants with average values of (58.72, 12.20, 8.40, 59.10, 29.62) respectively for OURJOAN variety and (61.32, 14.12, 9.6, 64.34, 35.92) respectively for NEENAR variety for the previously mentioned growth indicators. By evaluating the disease severity indices TYLCV symptoms decreased in plants treated with BTH, the lowest percentage of infection with TYLCV were for infected plants of NEENAR

variety treated with the 50 ppm of BTH with percentage of (10%, 20%, 35%, 40%, 50%) respectively during the five weeks of experience. BTH helped the tomato plants to have more sustainable resistance to TYLCV by significantly increasing of many growth indices, and by reducing the percentage of viral infection.