Evaluation of Susceptibility to Witches’ Broom of Longan Varieties Grown in Mekong Delta

Abstract

       Longan gall mite, Eriophyes dimocarpi, is a vector of longan witches’ broom disease (LWBD). The causal agent of the disease is very intricate and difficult to control. Management of this disease includes a varietal selection and vector control. The study on management of longan gall mite and LWBD wás conducted at SOFRI and longan growing areas in the Mekong Delta from April 2013 to November 2014. The results showed that Tieu da bo variety of longan was highly susceptible while Edor, Vung Tau and Thach kiet varieties were susceptible and Xuong com trang, Cui, Long Hung Yen varieties and NL1-19 hybrid were moderately susceptible. Giong, Sai Gon and NL1-23 hybrid were moderately resistant. Meanwhile, Xuong com vang, Long and Super varieties were highly resistant to the disease after 11 months treatment. NL1-23 hybrid was moderately susceptible to this disease after 12months planting.