Bio Management of Crown Rot and Southern Blight of Carrot by Using Trichoderma Fortified Compost

Hasan, Mahmudul; Jannat, Rayhanur; Briste, Preangka Saha; Hossain, Md. Mofazzal; Bhuiyan, Md. Khurshed Alam

doi:10.21608/ejar.2021.78675.1113

Bio Management of Crown Rot and Southern Blight of Carrot by Using Trichoderma Fortified Compost

Document Type : Original Article

Authors

¹ Department of Plant Pathology, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur-1706, Bangladesh

² Department of plant pathology, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur-1706, Bangladesh

10.21608/ejar.2021.78675.1113

Abstract

Rhizoctonia crown rot and canker caused by Rhizoctonia solani and southern blight caused by Sclerotium rolfsii are the two main devastating diseases that hamper carrot production greatly in Bangladesh. Indiscriminate use of chemical fungicides in controlling the pathogens also pollutes the environment, so an alternative bio-control agent was used to control the diseases. In the pathogenicity test, R-1 isolate of R. solani and S-1 isolate of S. rolfsii were found to be the most virulent against carrot seedlings and harvested carrots. T. harzianum isolate Pb-7 was appeared to be the most effective antagonist in the preliminary screening against both the selected pathogens. The field experiment was laid out following randomized complete block design with five treatments and three replications. In pathogen inoculated fields, 200g and 400g wheat grain colonized Trichoderma fortified compost, composted poultry refuges were mixed in the soil as per treatment before sowing carrot seeds. Pre- and post-emergence seedling mortality, incidence of Rhizoctonia crown rot and canker, and southern blight of carrot reduced significantly in treatments where soil was amended by wheat grain colonized Trichoderma fortified compost. On the contrary, pre- and post-emergence seedling mortality, incidence of Rhizoctonia crown rot and canker and southern blight of carrot was highest in pathogen inoculated fields. Trichoderma fortified compost enhanced germination percentage, growth promoting factors, yield and yield contributing components. The concentration of 400g wheat grain colonized Trichoderma fortified compost can be a suitable alternative to chemical fungicides used against these two devastating diseases of carrot.

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