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Sesame Root Rots of South Texas: A Fresh Look

Kimberly Cochran: Texas A&M University


<div>Sesame is grown throughout the south United States and abroad as an oilseed, seed, and game bird habitat crop. In South Texas, sesame is often grown as a dryland or irrigated crop with both methods generating favorable conditions for soilborne pathogens, which can cause crop loss or failure. Historically, sesame root rot in south Texas was mainly attributed to <em>Phytophthora </em>sp. In recent years, little work has been done in south Texas and the south United States to assess root rot disease challenges and their prevalence. The objective of this work was to determine current disease challenges to sesame production in south Texas. Four sesame fields with suspected root rot in Uvalde Co., Texas were surveyed for root rot symptoms near the end of the production season in September-October 2015-2017. Plant samples were collected and roots and stem tissue from near the soil line were assayed in water agar and fungal isolates identified and transferred to pure culture. All fields had evidence of root rot with <em>Rhizoctonia solani </em>Kuhn and <em>Macrophomina phaseolina </em>(Tassi) Goid. being most commonly isolated. Incidence of <em>R. solani </em>and <em>M. phaseolina</em> were associated with increased lodging near harvest, resulting in dramatically decreased yields in affected areas. A better understanding of the current soilborne pathogen distribution in sesame production will assist producers with management choices and future rotation crop selections.</div>