Resistance to neck blast caused by Pyricularia oryzae in Italian rice cultivars

Abstract

Very little information is available on neck blast resistance in Italian rice varieties under field conditions. In order to provide these data, 105 cultivars were tested under very favourable conditions for the disease development; the cultivars’ response to a single treatment of tricyclazole was also evaluated. Among tested varieties, 15 % showed resistance to the disease, 17 % moderate resistance, 30 % moderate susceptibility and 38 % susceptibility. Generally, recently developed cultivars were more tolerant to neck blast, compared to the oldest ones. Furthermore, cultivars with Long A grain shape are the most susceptible to neck blast, followed by medium grain type, round grain and Long B grain shape. A single spray of tricyclazole (450 a.i. g/ha) was effective in reducing disease incidence (55 % average reduction). It was also observed that there was a reduction in severity of symptoms. The majority of rice Italian cultivars are susceptible to neck blast disease. This study underlines the importance of field tests as useful tool for researchers, breeders and growers, combining scientific value with impact in application, giving valuable information to improve disease control.