Study On Seed Rot And Damping Off Of Bean In Ninewah Governorate

Nihal Younis Al-Murad ⁽¹⁾ and Ali Kareem Al-Taae ⁽²⁾.
⁽¹⁾ Department of Biology, College of Science, University of Mosul, Iraq.
⁽²⁾ Department of Plant Protection, College of Agriculture and Forestry, University of Mosul, Iraq.

Abstract

A survey carried out on bean fields in two areas in Ninewah Governorate showed that the incidence percentage of bean seedlings with post emergence damping-off was between 40-49% in spring and 33-43% in autumn. The disease was found to be associated with the fungi Macrophmina phaseolina Tassi, Fusarium solani Mart and Rhizoctonia solani Kuhn. The isolated fungi were found highly pathogenic to the local variety leading to a high incidence of pre-emergence damping off. R solani was highly pathogenic and caused 65% infection. Among the five bean varieties tested, Mosul 36 was the most resistant to the three fungi, with 33.5% infection, and the black bean variety was the most susceptible. The average damping off incidence was 79.5%. When the role of the different pathogens of seedling pre-emergence damping off was compared, it was evident that R. solani is the most important. When the reaction of different varieties to seedlings post emergence damping off was compared, Contender variety was the least susceptible and was not significantly different from black and red bean varieties. M. phaseolina was the most important pathogen causing seedling post-emergence damping off , with 34.4% incidence.