Effect of Tomato Yellow Leaf Curl Virus Infection on Some Growth Indicators of Pepper Hybrids Grown Under Plastic House Conditions in Lattakia Governorate, Syria

Hamdan, R.S., I.D. Ismail and I. Akel. 2021. Effect of Tomato Yellow Leaf Curl Virus Infection on Some Growth Indicators of Pepper Hybrids Grown Under Plastic House Conditions in Lattakia Governorate, Syria. Arab Journal of Plant Protection, 39(4): 309-316. https://doi.org/10.22268/AJPP-39.4.309316 This study aimed to evaluate the effect of Tomato yellow leaf curl virus (TYLCV) infection on some growth parameters of several pepper hybrids grown under protected cultivation along the Syrian coast. Four pepper hybrids (Capsicum annum) were tested, two hot (Lahab, Sirad) and two sweet (Nevada, Dallas) peppers. The research was carried out during the 2020-2021 growing season in a plastic house at the Agriculture Scientific Research Center in Lattakia, using a randomized complete block design, with 8 treatments, three replicates and 5 plants per replicate. The results obtained showed that the sweet pepper hybrids (Nevada, Dallas) were more sensitive to infection with Tomato yellow leaf curl virus than the hot pepper hybrids (Lahab, Sirad), without significant differences among them. The pepper hybrid Nevada did not show any apparent symptoms, and the effect of the virus on some growth parameters (number flowers, flower setting, and the leaf surface area) was evident in comparison with other hybrids, but the differences were not significant. The Dallas, Sirad and Lahab pepper hybrids showed visible symptoms in response to infection with infection rate of 93.33%, 80% and 80%, respectively. The effect of virus infection on the growth parameters of these hybrids was variable. The reduction in the flowers number of Nevada, Dallas, Cirad and Lahab after 45 days of infection was 33%, 31.10%, 10.23% and 5.07%, respectively, and also with a reduction in the number of flowers setting of 77.39%, 20.87%, 23.33% and 66.68%, respectively. The same was true for the leaf surface area, where reduction rate for the Nevada, Dallas, Sirad and Lahab hybrids 30 days after infection was 48.17%, 53.06%, 16.45% and 36.6%, respectively. Keywords: Tomato yellow leaf curl virus, pepper hybrids, growth parameter, host resistance, protected agriculture.