Characterisation of Tanzania local sorghmn varieties

Abstract

Many local varieties of sorghum grown in Tanzania have not been characterised in terms of their end uses. This study was conducted to characterise 14 such varieties. Three improved varieties commonly grown in this country were includedfor comparison. Physical analyses that included 100-grain weight, percent dehulling loss and percent water absorption were done. Chemical analysis of the samples to determine protein, crude fibre, fat, ash, and carbohydrate contents was done. Results showed that the 1 00-kernel weight ranged between 1.48 and 3. 18 g. Some of the local varieties had kernel sizes that were greater than those of the improved ones. Dehulling losses for the studied varieties ranged from 4.63 to 29.85%. These losses were generally low for the commonly used local varieties. Water absorption ranged between 6.10 and 28.85%. The flour making varieties showed low water absorption capacity. The protein contents of the studied varieties (8.27-13.52%) differed significantly (P<0.05). However, the crude fibre (1.23-2.30%), fat (3.00-4.30%), ash (1.96-4.25%), and carbohydrate contents (78.84-83.96%) of sorghum varieties did not differ significantly (P>0.05). Studies on endosperm texture revealed that most floury varieties had generally high dehulling losses and were therefore unsuitable for producing dehulled products. Corneous varieties were considered suitable for producing dehulled products due to their low dehulling losses. The intermediate endosperm texture varieties, which also experienced intermediate dehulling losses, need more studies in order to be properly classified Some of these, varieties such as Langalanga are already being used for flour making without prior dehulling. The study, therefore, calls for more screening of the local sorghum varieties not used in this study to identify their potential in relation to end uses for future exploitation and, where possible, to exploit the promising trait for incorporation in breeding programmes.

Keywords: Sorghum varieties, physical and chemical characteristics, Tanzania

Tanzania J. Agric Sc. (2000) Vol. 3 No. 1,69-74