Mixed rots of potato tubers in Ukraine

Abstract

The pathogens involved in rotting potato tubers at harvest or in store have been identified in the forest and forest-steppe zones of Ukraine. Fusarium spp., Phytophthora infestans, Erwinia carotovora and Ditylenchus destructor are the most important. Identification of rot pathogens in stored tubersThere is little scientific information on the development and spread of rot of potato tubers in Ukraine, and we now report on our research on this subject in the forest and forest-steppe zones of Ukraine. Our first aim was to identify the pathogens that are involved in tuber rot. Samples of tubers with mixed rot symptoms were selected on farms of the Zhitomir, Kyiv, Cherkasy, Sumy and Rivne regions in autumn (a month after harvest) and in spring (before grading). Pathogens were detected visually (by symptoms) and then diagnosed by inoculation of healthy tubers with the organisms involved, followed by microbiological analysis (Table 1).Thirteen microbial species or subspecies were detected. No tubers were found with symptoms of only one disease. Fungi, bacteria and nematodes were found: Fusarium and Phytophthora spp., Envinia spp. and Ditylenchus destructor. identification of rot pathogens at harvestIn a second series of investigations, we determined the types of mixed rot observed after harvest. Ten Table 1. Main pathogens identified in potato tubers showing mixed rot symptoms Frequency (%)