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Search Results: 1 - 10 of 332323 matches for " Kabwe C. K. Nkongolo "
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Effect of Gamma Irradiation on Morpho-Agronomic Characteristics of Soybeans (Glycine max L.)  [PDF]
Justin Mudibu, Kabwe K. C. Nkongolo, Adrien Kalonji-Mbuyi, Roger V. Kizungu
American Journal of Plant Sciences (AJPS) , 2012, DOI: 10.4236/ajps.2012.33039
Abstract: Mutation breeding in crop plants is an effective approach in improvement of crop having narrow genetic base such as soybean. The main objective of the present study is to determine the effect of different doses of gamma irradiation on different morpho-agronomic characteristics. Agronomic traits that were analyzed included; grain yield, number of pods/plant, number of seeds/plant and weight of 100 seeds and numbers of days to 50% flowering. Morphometric characterization of the descriptive data included plant height, stem diameter, number of leaves/plant, leaflet length, leaflet width, number of ramifications/plant, and pod length and width at 3 lodge stage. The results of the present study revealed that the two gamma irradiation doses used (0.2 kGy and 0.4 kGy) decreased significantly most of agronomic and morphological traits evaluated in M1 populations. Different effects of 0.2 kGy and 0.4 kGy irradiation were observed in M2 populations with significant increase of grain yields and yield components in all the three soybean varieties. In general, a significant decrease or no changes of morphological traits were observed for the two irradiation doses in M2 populations. The levels of changes varied among varieties. Potential high yielding mutants were identified in progenies of irradiated seeds.
Growth and Leaf Area Index Simulation in Maize (Zea mays L.) Under Small-Scale Farm Conditions in a Sub-Saharan African Region  [PDF]
Jean-Claude Lukombo Lukeba, Roger Kizungu Vumilia, Kabwe C. K. Nkongolo, Mo?se Lufuluabo Mwabila, Mbungu Tsumbu
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.43075
Abstract: Different crop models including MAIZE Ceres, STICS and other approaches have been used to simulate leaf area index (LAI) in maize (Zea mays L.). These modeling tools require genotype-specific calibration procedures. Studies on modeling LAI dynamics under optimal growth conditions with yields close to the yield potential have remained scarce. In the present study, logistic and exponential approaches have been developed and evaluated for the simulation of LAI in maize in a savannah region of the DR-Congo. Data for the development and the evaluation of the model were collected manually by non-destructive method from small farmers’ field. The rate of expansion of the leaf surface and the rate of change of leaf senescence were also simulated. There were measurable variations among sites and varieties for the simulated height of maize plants. At all sites, the varieties with short plants were associated with expected superior performance based on simulation data. In general, the model underestimates the LAI based on observed values. LAI values for the genetically improved maize varieties (Salongo 2, MUS and AK) were greater than those of the unimproved local variety (Local). There were significant differences for K,
Evaluation of Biological Soil Fertility Management Practices for Corn Production in Oxisols  [PDF]
Mupala G. Muyayabantu, Bakach D. Kadiata, Kabwe K. Nkongolo
American Journal of Plant Sciences (AJPS) , 2012, DOI: 10.4236/ajps.2012.311201
Abstract: Field trials on the management of soil biological fertility with aim to increasing corn production were conducted in a savannah region of the DR-Congo. Three organic matters including fresh biomass of Entada abyssinica, Tithonia diversifolia, Stylosanthes gracilis and a mineral combination of nitrogen and phosphorus (NP) (115-63-0) along with a control (without fertilization) were evaluated for corn crop growth and production. The field trial was a completely randomized design with four replicates. Plant height, basal stem diameter, and yield components were assessed. Irrespective of fertilization treatments and variety, maize showed a similar growth up to 20 days after sowing (DAS), and then two distinct trends were observed. At 60 DAS, plant height and basal diameter were significantly bigger in plots treated with NP, T. diversifolia and E. abyssinica compared to S. gracilis treatment and control (NoF). This pattern was also confirmed with agronomic traits such as cob length, number of kernel per cob, and net grain yield. The local variety was the least productive under any treatment. In general, the response of corn crop to organic and inorganic fertilization showed that the mineral combination (NP) increased the most grain yield and other yield components compared to unfertilized trial, followed by T. divessifolia and E. abyssinica. NP and T. diversifolia treatments increased significantly and equally soil potassium content compared to control and other treatments. Application of T. diversifolia appears a more cost effective approach for small farmers to improving fertility of the oxisol prevailing in Central Africa compared to mineral fertilizers.
Simulation of Growth and Leaf Area Index of Quality Protein Maize Varieties in the Southwestern Savannah Region of the DR-Congo  [PDF]
Jean Pierre Kabongo Tshiabukole, Roger Kizungu Vumilia, Gertrude Pongi Khonde, Jean Claude Lukombo Lukeba, Amand Mbuya Kankolongo, Antoine Mumba Djamba, Kabwe K. C. Nkongolo
American Journal of Plant Sciences (AJPS) , 2019, DOI: 10.4236/ajps.2019.106070
Abstract: Logistic and exponential approaches have been used to simulate plant growth and leaf area index (LAI) in different growing conditions. The objective of the present study was to develop and evaluate an approach to simulate maize LAI that expresses key physiological and phonological processes using a minimum entry requirement for Quality Protein maize (QPM) varieties grown in the southwestern region of the DR-Congo. Data for the development and testing of the model were collected manually in experimental plots using a non-destructive method. Simulation results revealed measurable variations between crop seasons (long season A and short season B) and between the two varieties (Mudishi-1 and Mudishi-3) for height, number of visible leaves, and LAI. For both seasons, Mudishi-3, a short stature variety was associated with expected stable yield based on simulation data. In general, the model simulated reliably all the parameters including the LAI. The LAI value for mudishi-1 was higher than that of Mudishi-3. There were significant differences among the model parameters (K, Ti, a, b, Tf) and between the two varieties. In all crop conditions studied and for the two varieties, the senescence rate (a) was higher, while the growth rate (b) was lower compared to the estimates based on the STICS model.
Genetic Variation in Picea mariana × P. rubens Hybrid Populations Assessed with ISSR and RAPD Markers  [PDF]
Ramya Narendrula, Kabwe Nkongolo
American Journal of Plant Sciences (AJPS) , 2012, DOI: 10.4236/ajps.2012.36088
Abstract: Interspecific hybridization can result in significant shifts in allele frequencies. The objective of the present study was to assess the level of genetic variation in populations of P. mariana × P. rubens hybrids derived from artificial crosses. Progenies from backcross populations created through a series of controlled pollinations among P. mariana and P. rubens trees across the hybridization index were analyzed. Several Inter Simple Sequence Repeat (ISSR) and Random Amplified Polymorphic DNA (RAPD) primers were used to amplify genomic DNA samples from each population. ISSR primers produced from 30% to 52% polymorphic loci. The level of polymorphism was higher with RAPD markers, ranging from 57% to 76%. Overall, the two marker systems generated similar levels of polymorphic loci for P. mariana and P. rubens populations. No significant differences were found among the P. mariana × P. rubens populations analyzed and between the hybrids and the parental populations regardless of the molecular marker used. This confirms the genetic closeness of P. mariana and P. rubens species.
Decrease in Lysine and Tryptophan Content in S2 Inbred Lines from a Quality Protein Maize (QPM) Variety in a Breeding Program  [PDF]
Kabwe Nkongolo, Kankolongo Mbuya
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.61021
Abstract: Several countries in Africa, Latin America along with China have incorporated QPM in their Agricultural development plan. A new quality protein maize variety (QPM) was developed by breeders and farmers using the participatory breeding approach in the DR-Congo. It is adapted to all the maize growing regions in the country. Inbred lines from this new variety were produced for further development of maize synthetic populations. The main objective of the present study is to determine the level of amino acid changes in early generations of inbred lines. The results of the study revealed a significant decrease of 33% and 38% of tryptophan in S1 and S2 inbred lines compared to the original parental MUDISHI 3 population, respectively. There was a decrease of 15% of lysine in S2 inbred lines compared to the parental MUDISHI 3. Actually, S2 inbred lines of MUDISHI 3 contain similar level of lysine compared to the genetically improved normal maize (Salongo 2) that is currently released. The development of composite lines is recommended over synthetic populations to maintain the high levels of lysine and tryptophan along with other desirable agronomic characteristics since they involve the intercrossing of open pollinated varieties.
Incidence, Severity and Gravity of Cassava Mosaic Disease in Savannah Agro-Ecological Region of DR-Congo: Analysis of Agro-Environmental Factors  [PDF]
Marcel Muengula-Manyi, Kabwe K. Nkongolo, Claude Bragard, Patrick Tshilenge-Djim, Stephan Winter, Adrien Kalonji-Mbuyi
American Journal of Plant Sciences (AJPS) , 2012, DOI: 10.4236/ajps.2012.34061
Abstract: African Cassava mosaic disease (ACMD) is the most severe and widespread disease caused by viruses limiting production of the crop in sub-Saharan Africa. The objective of the present study was to evaluate CMD incidence, severity, and gravity under different agro-environmental conditions. A total of 222 fields were surveyed in 23 different locations. All the farmers grow only local cassava varieties without applications of fertilizers. Overall, mean CMD incidences for all sites surveyed were 58.2% and 51.7%, in 2009 and 2010, respectively. Disease severity ranged from 2.4 to 3.1 on a scale of 1 to 5. Mean disease gravity varied from 29.7% to 62%, in 2010, and 2009, respectively. Detailed analysis of agronomic and environmental revealed no significant association between cassava stand locations, age, land topography and the development of CMD. Likewise intercropping practices and field topping did not affect the development of CMD in all the fields surveyed. There were significant differences in the number of white flies (Bemisia tabaci) per plant in 2009 and 2010, but no significant correlations between the number of B. tabaci per plant and CMD incidence, severity, and gravity was found. In most fields, CMD appears to originate mostly from unhealthy cassava cuttings used for planting.
Assessing Reactions of Genetically Improved and Local Cassava Varieties to Cassava Mosaic Disease (CMD) Infection in a Savannah Region of the DR-Congo  [PDF]
Marcel Muengula-Manyi, Lyna Mukwa, Kabwe K. Nkongolo, Patrick Tshilenge-Djim, Stephan Winter, Claude Bragard, Adrien Kalonji-Mbuyi
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.44101
Abstract:

The responses of eight genetically improved and eight local cassava varieties to cassava mosaic disease (CMD) were evaluated under field conditions at two sites, in Eastern Kasa?, region of the DR-Congo). The varieties were planted using randomized complete block design with three replications. The rate of cuttings sprouted varied significantly from variety to variety and from location to location. Local varieties were severely infected than improved varieties throughout the trial period. In general, the level of CMD incidence for genetically improved varieties was below 15% while it reached 100% for the local cassava varieties six months after planting (MAP). This trend was also observed for the CMD severity and gravity. The mean scores for CMD severity were 2 and 3.6 for genetically improved and local varieties, respectively at 6 MAP. CMD gravity for improved varieties was below 21% for genetically improved varieties and exceeded 85% for local varieties at the end of trials. Area Under the Severity index Progress Curve (AUSiPC) and Area Under Disease Progress Curve (AUDPC) estimates confirmed that improved varieties were moderately infested comparatively to local varieties. Molecular analysis is being conducted to determine the genetic variability and complexity of the cassava mosaic virus strains involved.

Epidemiology of the Groundnut (Arachis hypogaea L.) Leaf Spot Disease: Genetic Analysis and Developmental Cycles  [PDF]
L. Tshilenge-Lukanda, K. K. C. Nkongolo, A. Kalonji-Mbuyi, R. V. Kizungu
American Journal of Plant Sciences (AJPS) , 2012, DOI: 10.4236/ajps.2012.35070
Abstract: Groundnut leaf spot is one of the important factors limiting groundnut productivity in Africa particularly in the Democratic Republic of Congo (DR Congo). Early and late leaf spot disease of groundnut caused by Cercospora arachidicola Hori and Cercosporidium personatum (Berk & Curt.) Deighton, respectively, can cause considerable yield losses without fungicide management. The main objectives of this research were to analyze plant and disease developmental cycles. Significant differences were observed among the groundnut varieties evaluated for resistance to the leaf spot disease. The results show that plant development cycle can be divided into three developmental stages. A first stage characterized by a low production of leaves, a second stage with a significant leaf development and finally a third stage with a reduction of leaves. Interestingly, the leaf spot disease cycle was also divided in three stages. The disease stage characterized by the highest level of symptom expression was not associated with the plant phase with the highest emerged leaves. Disease symptoms reached the highest pick only after the phase of intense leaf development. The molecular analysis revealed that all the groundnut varieties analyzed were genetically closely related even though they showed different reactions to the leaf spot disease.
Effect of Gamma Irradiation on Morpho-Agronomic Characteristics of Groundnut (Arachis hypogaea L.)  [PDF]
L. Tshilenge-Lukanda, A. Kalonji-Mbuyi, K. K. C. Nkongolo, R. V. Kizungu
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.411271
Abstract:

Induced mutation in plant improvement has been used in several crops to generate new sources of genetic variations. A study was conducted to determine the effect of different doses of gamma irradiation on different morpho-agronomic characteristics. Agronomic traits that were analyzed included: grain yield, number of pods/plant, number of seeds/plant and weight of 100 seeds and numbers of days to 50% flowering. Morphometric characterisation of the descriptive data included plant height, stem diameter, number of leaves/plant, leaflet length, leaflet width and number of ramification/ plant. Groundnut seeds were treated with various doses of gamma rays (100, 200, 400 and 600 Gy). Among the various dose treatments, gamma rays treatment at 100 Gy resulted in a higher increase of grain yield and other morpho-agronomic parameters especially for the JL24 variety. In fact the gamma irradiation at 100 Gy increased significantly grain yield by 14% for JL24, and 4 % for JL12. The number of pods per plant was increased by 2% for JL12 and 37% for JL24. For the number of seeds per plant, there was a significant increase of 8% for JL12, and 62% for JL24 at 100 Gy. A similar trend was observed for the JL24 at 200 Gy dose. Higher doses of gamma rays (400 and 600 Gy) reduced significantly plant growth and grain yield. The usefulness of the mutants identified in a groundnut breeding program is discussed.

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