Experimental Agriculture (2000) 36, 335-342

P.S. Ojiambo, P.O. Ayiecho, R.D. Narla and R.K. Mibey (2000)
Tolerance level of Alternaria sesami and the effect of seed infection on yield of sesame in Kenya
Experimental Agriculture 36 (3), 335-342
Abstract: Field plots of sesame (Sesamum indicum) with six different levels of seed infection with Alternaria sesami were monitored for Alternaria leaf spot severity at Kibwezi, eastern Kenya. The aim of the study was to determine the effect of seed transmission of the pathogen on yield and tolerance level of the fungus in sesame seed. Increase in percentage leaf area diseased and percentage defoliation fitted the Gompertz model more closely than the logistic model. Areas under disease progress curves (AUDPC), infection and defoliation rates varied among the six infection levels. Disease severity increased with increase in seed infection and was least and most severe in plots established with seeds with 0 and 8% infection levels respectively. Yields ranged from 234.9 to 300.1 kg ha^-1 compared with 312.5 kg ha^-1 for the control, and losses due to seed infection ranged from 4% to 25%. Disease severity was negatively correlated with seed yield, 1000-seed weight and seeds per capsule. Alternaria leaf spot severity had a major effect on the seed weight component of yield. Tolerance level of A. sesami in sesame seed was determined to be less than 2%.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Peter Sande Ojiambo

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
damage/losses/economics

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Alternaria sesami	Sesame (Sesamum indicum)	Kenya