Person: Tadele Tefera
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Tadele Tefera
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Tadele Tefera
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0000-0001-6373-0842 5 results
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- Responses of tropical maize landraces to damage by Chilo partellus stem borer(Academic Journals, 2013) Munyiri, S.W.; Mugo, S.N.; Otim, M.; Tadele Tefera; Beyene, Y.; Mwololo, J.; Okori, P.The potential to manage insect pests using host-plant resistance exists, but has not been exploited adequately. The objective of this study was to determine the resistance of 75 tropical maize landraces through artificial infestation with Chilo partellusSwinhoe. The trial was laid in alpha-lattice design and each seedling was infested with five neonates three weeks after planting, over two seasons in 2009 and 2010. The number of exit holes, tunnel length, ear diameter, ear length, plant height, stem diameter, stem lodging and grain yield were measured and a selection index computed. GUAT 1050 was the most resistant with an index of 0.56, while BRAZ 2179 was the most susceptible with an index of 1.66. Ear characteristics were negatively correlated with damage parameters. The principal component biplot suggested that exit holes, cumulative tunnel length, leaf damage, cob diameter, stem lodging, selection index, ear and plant height contributed 71.2% of the variation in resistance. The mean number of exit holes and tunnel length for resistant landraces and resistant hybrid checks were similar; at 5.5 and 2.48 cm, respectively. The identified resistant landraces (GUAT 1050, GUAT 280, GUAT 1093, GUAT 1082, GUAT 1014, CHIS 114, and GUAN 34) could be used to develop C. partellus stem borer-resistant maize genotypes.
Publication - Yield stability of stem borer resistant maize hybrids evaluated in regional trials in east Africa(Academic Journals, 2012) Beyene, Y.; Mugo, S.N.; Tadele Tefera; Gethi, J.; Gakunga, J.; Ajanga, S.; Karaya, H.; Musila, R.N.; Muasya, W.; Tende, R.; Njoka, S.Twenty-seven stem borer-resistant maize hybrids and three checks were evaluated in 14 locations in Kenya and Ethiopia to study the genotype x environment interaction (GEI) and yield stability. An analysis of variance was conducted for grain yield, number of days to silking, plant height, ear height and grain moisture content, and reaction to turcicum leaf blight, gray leaf spot, maize streak virus diseases and common rust. The yield stability and adaptation pattern of genotypes were examined with genotype plus genotype x environment (GGE) interaction biplot. Variations due to location, genotype and GEI effects were highly significant for all traits. Location variance among the hybrids was the most important source of variation for all traits, accounting for 58 to 90% of the total variance. The genotypic variance was higher than the GEI variance for turcicum leaf blight, plant height and silking date. The GEI variance was higher than the genotypic variance for grain yield, ear height, gray leaf spot, common rust and grain moisture content. The GGE biplot showed that 50% of the entries had positive PC1 scores suggesting above average performance, and 50% of them had negative PC1 scores indicating below average performance. Based on the mean grain yield and stability parameters, hybrid CKIR07003 (5.5 t/ha), CKIR07004 (5.5 t/ha) and CKIR07005 (5.6 t /ha) were identified as high-yielding and stable genotypes, and could be nominated for national performance trials for commercial release in various countries.
Publication - Genotype by environment interactions and yield stability of stem borer resistant maize hybrids in Kenya(Academic Journals, 2011) Beyene, Y.; Mugo, S.N.; Mutinda, C.J.M.; Tadele Tefera; Karaya, H.; Ajanga, S.; Shuma, J.M.; Tende, R.; Kega, V.In a maize breeding program, potential genotypes are usually evaluated in different environments before desirable ones are selected. Genotype x environment (G x E) interaction is associated with the differential performance of genotypes tested at different locations and in different years, and influences selection and recommendation of cultivars. Twenty one stem borer resistance maize hybrids and four commercial checks were evaluated in six environments in Kenya under infestation with Chilo partellus and Busseola fusca to determine the G x E interactions and stability of the hybrids. Analysis of variance was conducted for grain yield, days to flowering and plant and ear height. Stability for grain yield was determined using genotype plus genotype by environment interaction (GGE) biplot analysis. Variances due to genotype, environment and G x E interaction effects were highly significant for all traits. The GGE biplot showed that four experimental hybrids and two commercial checks had positive PC1 score indicating above average performance across environments. However, 10 experimental hybrids and two commercial checks had negative PC1 score, suggesting poor average performance. Experimental hybrids, CKIR07004 and CKIR07013, were highly desirable in terms of grain yield (>7.5 t/ha) and stability across environments. These hybrids could be released in Kenya and similar environments.
Publication - Grain yield, stem borer and disease resistance of new maize hybrids in Kenya(Academic Journals, 2011) Tadele Tefera; Mugo, S.N.; Beyene, Y.; Karaya, H.; Tende, R.Evaluation of 30 maize hybrids for yield and resistance to stem borers and foliar diseases in four agro-ecologies in Kenya was conducted in 2009. There were significant differences among the hybrids in leaf damage, number of exit holes, tunnel length and grain yield in Kiboko. The maize hybrids CKPH08014, CKPH08025, and CKPH08026 showed the least leaf damage, exit holes and tunnel length, similar to the resistant check. Although ten hybrids yielded over 8 t/ha, two hybrids, CKPH09001 and CKPH08033, gave the highest yield of 8.99 and 8.86 t/ha, respectively, in Kiboko. There were significant differences among the hybrids in resistance to leaf rust and maize streak virus in Kakamega. The intensity of foliar diseases was high in Kakamega compared to the other sites. All hybrids appeared resistant to the foliar diseases at Kakamega. On the average, the highest yield of the hybrids was recorded in Kiboko (7.5 t/ha) followed by Kakamega (6.1 t/ha), and the least at Embu (3.5 t/ha), and Mtwapa (3.14 t/ha). The performance of the hybrids varied from site to site, with CKPH09002 and CKPH09003 performing well at Mtwapa, CKPH09001 at Kiboko, CKPH08039 at Embu, CKPH 08002 and CKPH08010 at Kakamega.
Publication - Combining ability of maize (Zea mays L.) inbred lines resistant to stem borers(Academic Journals, 2011) Beyene, Y.; Mugo, S.N.; Gakunga, J.; Karaya, H.; Mutinda, C.J.M.; Tadele Tefera; Njoka, S.; Chepkesis, D.; Shuma, J.M.; Tende, R.Ten inbred parents with varying resistance levels to Chilo partellus and Busseola fusca were crossed in a half diallel mating scheme to generate 45 F1 hybrids. The hybrids and five commercial checks were evaluated across four locations in Kenya under artificial and natural infestation in 2009. Genotype (G) by environment (E) interaction (G x E) was non-significant for stem borer leaf damage, number of exit holes and tunnel length, suggesting that screening for stem borer resistance at one location would be adequate. On the other hand, G x E and general combining ability (GCA) x environment interactions were highly significant for gray leaf spot and turcicum leaf blight, indicating an inbred line resistance to a disease in one location may have a different reaction to the same disease in another location. The results of combining ability analysis showed that GCA effects were significant for stem borer resistance traits (leaf damage scores, number of exit holes, and tunnel length) while the opposite was true for specific combining ability (SCA) effects. Parents 5, 2, 6, 9 and 3, were good sources of genes for higher grain yield while parents 1 and 4 were good sources of resistance genes for stem borers. Hybrid 5 x 9 was the best performing hybrid in grain yield (6.53 t/ha) across the locations, while hybrid 1 x 4 was the least performing in grain yield (3.08 t/ha). The source of stem borer resistance identified in the study may be useful for improving levels of stem borer resistance in maize breeding programs in eastern and southern Africa.
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