Evaluation of tolerance to Phytophthora capsici-the causal agent of foot rot disease in black pepper

Vietnam is the leading black pepper export country in the world. However, the production of pepper may be affected by natural disasters, pests such as Phytophthora capsici. The Phytophthora capsica disease has caused a significant decline in pepper yields. The disease is characterized with a high mortality rate (up to 100%) and rapid outbreak and thus is very challenging to control. In the present study, eight strains of P. capsici were isolated from 100 samples of leaf, stem, root and soil that were collected from pepper-growing areas of Dong Nai, Binh Duong and Ba Ria - Vung Tau provinces. These isolates' straits had capacity to cause foot rot on pepper leaf after two days of inoculation. Among them, the isolates with the highest pathogenicity are BR-L1, DN-D1 and DN-D2. In order to determine the resistance level to P. capsici of commonly grown pepper varieties (Vinh Linh, Se, Xanh, Trau and Kuching), the pepper leaves were in vitro infected with P. capsici BR-L1 spores in laboratory and greenhouse conditions. Trau variety showed the highest resistance level to P. capsici with the as indicated by (P < 0.01) disease ratio (74.1%) and disease index (73.7%) after 6 days in laboratory condition and the corresponding numbers of 17.3% and 15.8% after 12 days in greenhouse condition.