Drought tolerance assessment of cassava genotypes in a semi-arid environment in central Tanzania
Loading...
Date
2014
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Sokoine University of Agricuture
Abstract
Drought tolerance is an increasingly important trait in cassava due to globally dwindling
water resources, a shift in production areas and increasing input costs. This study was
conducted to evaluate eighteen cassava genotypes for drought tolerance to counteract
frequent shortages of rainfall. An experiment was set in Dodoma, Tanzania which is a
drought-stricken environment where cassava genotypes were grown under watered and
water stressed conditions. Identification of drought tolerant genotypes that also had good
yield potential was facilitated by the stress treatments used on farm. Morphological (leaf
length, leaf width, plant height), physiological (leaf retention, chlorophyll content),
biochemical (Catalase and Peroxidase enzymes activities) and yield (number of roots per
plant, yield in tons per hectare, above ground biomass, percentage diy matter content and
harvest index) attributes were used to assess tolerance of the tested genotypes to drought
stress. During harvesting, on farm farmers participatory evaluation and organoleptic test
were also conducted to enable farmers select best genotypes based on consumers criteria.
It was found during the study that water stress had profound effect on growth, physio
chemical and yield performance of cassava genotypes. All attributes measured were
significantly influenced by drought except leaf length atl80 DAP, plant height at 120 and
150 DAP, number of roots per plant, weight of above ground biomass and harvest index
(P<0.05). Generally water stress suppressed both growth and yield of the crop. Through
the study, superior drought promising cassava genotypes identified were 92B/00073, KBH
2006/363, KBH 2006/12 and KBH 2006/18. These genotypes performed well under stress
and well watered conditions and thus may serve as parents for drought stress improvement
and genetic analysis.
Description
Dissertation
Keywords
Drought tolerance, Shift production, Cassava assessment