EFFCIENCY OF SOME BIOLOGICAL AND CHEMICAL TREATMENTS AGAINST WHEAT ROOT AND CROWN ROT DISEASE

Document Type : Original Article

Authors

Plant Pathol. Dept., Fac. Agric., Zagazig Univ., Egypt

Abstract

Fusarium culmorum(W.G. Smith) Sacc., Bipolaris sorokiniana (Sacc.) Shoemaker, Rhizoctonia oryzae Kühn and Fusarium spp. were isolated from wheat plants exhibiting typical root and crown rot symptoms from different districts at Sharkia Governorate, Egypt during 2015/ 2016 growing season. Pathogenicity test revealed that B. sorokiniana was the most virulent one causing pre-emergence damping-off followed by Fusarium culmorum. In addition, F. culmorum was the most virulent one responsible for post-emergence damping-off incidence. Rhizoctonia oryzae showed the highest percentage of root rot, Moreover, F. culmorum and B. sorokiniana showed the highest percentage of disease incidence. In the same trend, F. culmorum induce the highest percentage of disease severity. In vitro, Trichoderma sp.  bio-agent and its culture filtrate were the most effective treatment that reduced mycelial growth of the tested fungi. In vivo, it decreased pre and post-emergence damping off, root rot, disease incidence and disease severity compared with the control. In addition, the obtained results indicated a significant increase on healthy survival plants and significantly improved the plant growth parameters i.e. fresh and dry weights of shoots and roots, plant height, spike length and 1000 grain weight. In vitro,Score and Amistar-top fungicides were the most effective in inhibiting the mycelial growth of R. oryzae followed by Amistar-top on B. sorokinana and Score onF. culmorum.Score was the most effective treatment revealed the highest percentage of healthy survival plants followed by Amistar-top and gave the highest protection against root and crown rot disease as shown by disease incidence and severity percentages.

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