Browsing by Author "Misangu, R.N."

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Agronomic performance and Heritability of some components of Robusta Coffee (Coffea canephora Pierre ex Froehner) clones
(2003) Reuben, S.O.W.M.; Marandu, E.F.T.; Misangu, R.N.
The present investigation evaluates the performance of newly identified clones in the major coffee growing zones of Kagera region, Tanzania. Five clones namely MS1/95. MS2/95. MS3/95, MS5/95. MS6/95 selected from individual trees in farmers fields and FS a control variety, were grown in farmers fields in March 1998 a four locations representing 3 coffee growing zones of Kagera region. Each chosen farmer's field was a replicate. Plant girth and fruit set percentage differed significantly among the clones tested MS2/95 had the thickest stems while MS3/95 gave the highest percentage of fruit set. Percent fruit set ranged from 13.5% - 31.4% for MS6/95 and MS3/95 respectively. Locations differed on yield % bearing primary branches canopy radius plant girth and plant height. Kabirizi B gave the highest yield of 1853.8 kg/ha while Chanika gave the lowest yield of 358.8 kg/ha. The yield differences between location were associated with performance of clones on plant height, plant girth canopy radius, primary branches and % bearing primary branches. Plant height girth canopy radius, primary branches, % bearing primary branches and yield of clean coffee were positively corrrelated among themselves. Heritability estimates were high (50%) for plant girth, berries per node and fruit set percentage. Heritability ranged from negligible for yield to 125% for plant girth. Expected genetic gain varied with heritability ranging from negligible to 36.5% for fruit set percentage. Yield of clean coffee had appreciable amounts of clone x location interaction and environmental variance in relation to the total phenotypic variance. It should be possible to realize substantial gain from selection and genetic improvement for plant girth, berries per node and fruit set percentage.
Evaluation of maturity characteristics and of yield components of high protein bean (Phoseolus vulgaris L.) varieties in Morogoro, Tanzania
(1998) Mduruma, Z.O.; Nchimbi-Msolla, S.; Reuberi, S.O.W.M.; Misangu, R.N.
Several Bean growing areas in Tqnzania have unreliable and marginal rains necessitating use of short maturing and high yielding varieties. Such varieties however, are not, readily available. This'study was done to evaluate varieties for maturity, yield and its components in the bean growing areas of Morogoro, Tanzania. Sixty four varieties from the Sokoine University of Agriculture (SUA) collection and from a high percentage protein population were grown at two locations, Mgeta (high altitude) and SUA (low altitude) in 8 x 8 partial lattice with 3 replicatiqns during the 1991 season. Yield levels were low, ranging between 0.2 - 0.8 tlha at Mgeta and 0.06 - 2.Otlha atSUA. Earlier varieties were superior in yield due to' a higher yield efficiency. Varieties grown in the cooler higher altitude areas matured late with consequent reduction in yield. Significant G x E interaction effects were observedfor all the variables, except number of seeds per pod. Positive genetic correlations were significant (P ~0.01) at both locations between yield and number of pods per plant, yield efficiency and podjilling period. Yield was genetically and negatively corrected with days to first flower, 50% podfill and 85 % maturity. Path coefficient showed that days to first flower had a consistent negative direct effect o!'l yield. At both locations, the negative genetic relationship between days to 50% podfill with yield was attributed to the negative indirect influence through days to first flower. Earlier flowering anq maturity, longer podfilling with high pod production and yield efficiency are recomme.nded for higher yields of beans in the study area.
Research note on the distribution and relative importance of bean bruchid species aconthoscelides obtectus (say.) and zabrotes subfosciatus (boh.) in Tanzania
(2000) Misangu, R.N.; Nchimbi-Msolla, S.; Reuben, S.O.W. M.
Two bean bruchid species Acanthoscelides·obtectus (Say.) and Zabrotes subfasciatus (Boh.) are known to destroy beans in storage. However, the distribution and relative. importance of these species have not been established in Tanzania. In this study, a bf!an bruchid survey was carried out to find out if the two bean bruchid species occurred in th~ country. The survey was corzduded In 1993 and it was observed that both bean bruchid species were present in all regions surveyed. However, the speCies A. obtectus was more dominant in all. regions except in Ruvuma and therefore' appeared to be relatively more important than Z. subfasciatus. The occurrence of the two species in all surveyed regions indicates that both species are of economic importance in the country. There was no indication that the two species occur in well defined ecological zones.
Resistance of arcelin incorporated bean (Phaseolus vulgaris L.) hybrids and their parental cultivars against the bean bruchid Zabrotes subfasciatus (Boh)
(2001) Misangu, R.N.; Nchimbi-Msolla, S.; Reuben, S.O.W.M.
A hybridization bean breeding programme aimed at breeding beans resistant against the bean bruchid species Z. subfasciatus which destroys beans in storage was carried out at Sokoine University of Agriculture (SUA) Morogoro. Tanzania between 1994-1997. Five potential local bean varieties/lines were crossed to a bruchid resistant bean line RAZ 24-2 which was developed at SUA by selection from ClAT segregating RAZ bean populations. Seeds of RAZ lines contain arcelin a protein which confers resistance against Z. subfasciatus and can be transferred into other varietiess by hybridization. The backcross breeding procedure was adopted and five arcelin containing progenies were developed from this breeding programme. Seed of the developed progenies and those of the parents were then tested for resistance against Z. subfasciatus a randomized complete block design with 5 replications. There were significant difference, (P < 0. 05) in resistance against Z. subfasciatus among the genotypes. Results indicated that arcelin incorporated genotypes were superior over the arcelin deficient parents for resistance against Z. subfasciatus. Generally, the presence of arcelin in bean seeds delayed bruchid development reduced the number of emerged bruchids damage on bean seeds. However, bruchids managed to lay many eggs on seeds of all cultivars tested suggesting that bruchids are not inhibited from laying eggs on archelin containing seeds.