Theses & Desertations
http://41.89.164.27:8080/xmlui/handle/123456789/303
2024-03-28T18:18:28ZPERFORMANCE EVALUATION OF A PROTOTYPE VARIABLE PITCH IRISH POTATO GRADER
http://41.89.164.27:8080/xmlui/handle/123456789/2055
PERFORMANCE EVALUATION OF A PROTOTYPE VARIABLE PITCH IRISH POTATO GRADER
KIBOR, DAVID TIROP
The manual grading of potatoes in Kenya has resulted in inconsistencies, quality variations and financial losses for small-scale farmers due to low market prices for ungraded products. To mitigate these challenges, this study aimed to develop and evaluate the performance of a cost-effective potato grading machine to enhance uniformity and overall quality of potato tubers. The research involved determining the physical and mechanical properties of Shangi potato variety. The prototype potato grader consisted of a feeding hopper, conveyor belt, grading unit, and collection trays. Grading capacity, grading efficiency, and mechanical damage index were assessed by varying grading unit speeds, angles of inclination and feed rates. The results showed that the grading capacity increased with higher grading unit speeds, inclination angles, and feed rates. The optimal operating conditions were observed at a grading unit speed of 4 rpm, an inclination angle of 0 degrees, and a feed rate of 3400 kg/hr. The prototype potato grader achieved a commendable grading capacity of 3968 kg/hr, with an efficiency of 89.34% and a low mechanical damage index of 2.94%. The results demonstrate that the potato grading machine effectively enhances grading while minimizing mechanical damage. This grading machine offers efficiency a practical and sustainable solution for small-scale farmers to produce high-quality graded potatoes in line with market demands. It is recommended that future research may include further optimization by exploring various grading unit speeds, feed rates, and inclination angles. Implementing padding on the collection trays could further reduce mechanical damage. Additionally, investigating alternative power sources may enhance the grader's versatility and extending testing to other fruits and vegetables would broaden its applicability in the agricultural industry.
2023-10-01T00:00:00ZMORPHO-GENETIC DIVERSITY OF GAMMA IRRADIATED DOLICHOS BEAN (Lablab purpureus (L.) Sweet) GENOTYPES FOR CLIMATE CHANGE ADAPTATION.
http://41.89.164.27:8080/xmlui/handle/123456789/2043
MORPHO-GENETIC DIVERSITY OF GAMMA IRRADIATED DOLICHOS BEAN (Lablab purpureus (L.) Sweet) GENOTYPES FOR CLIMATE CHANGE ADAPTATION.
KIMNO, STEPHEN KIPCHIRCHIR
Dolichos bean (Lablab purpureus (L.) Sweet 2n=22 or 24 is a multipurpose legume mainly grown and used as a pulse, forage feed and in soil amendment for nitrogen fixation and green manure. Practically, it still yields below estimated potential of over 5000 kgha-1. Induced crop mutagenesis is a safer conventional breeding method and has played a major role in increasing global food security. The main objective of the study was to contribute to climate change adaptability through gamma ray irradiation of dolichos bean genotypes and selection of climate smart allelic accessions. Specific objectives were to: evaluate the effect of gamma irradiation doses on morpho-agronomic traits of mutant dolichos bean accessions, assess genetic variability estimates, determine the genetic diversity, and evaluate nutritional and mineral composition and to evaluate the adaptability potential of mutant accessions in north rift Kenya. Four dolichos bean varieties (maridadi, cream, black I and black II) were irradiated with 300 gy and 400 gy gamma rays in 2018 in Austria. The M1 to M4 generations of the accessions of four dolichos bean genotypes were advanced by forward genetics protocol at University of Eldoret in 2019 through 2021.M2 accessions were evaluated for effect of mutation and genetic estimates, 95 M3s for genetic diversity based on 20 SSR markers, 24 M4s were screened for nutritional and mineral composition and yield and adaptability potential. The results showed that dose 300gy and 400gy significantly (p=0.05) increased leaf length, raceme length, dry seed yield per plant and plant height across the accessions. Qualitative phenotypic variations were present in all mutant accessions except black I. There was a higher genetic estimate variability for the yield associated traits measured for eldo maridadi than for eldo black I indicating difference in genotype and impact of mutation. Genetic diversity of 95 accessions based on microsatellite markers produced 20 polymorphic primers mapping an average of 5.25 alleles per locus, polymorphic information content of 0.58 with analysis of molecular variance (AMOVA) among population of 45% and among and within individuals 54% and 1%.The nutritional test showed that accession BF032 (28.86±0.18%), MT076 (74.88±0.59%), BF137 (9.69±0.34%), MT049 (12.55±0.57%) and BT188 (449.69±0.02 kcal) had significantly higher percent crude protein, carbohydrate, crude fat, crude fibre and energy. WT018, BT114 and BT039 had significantly higher phosphorous, potassium, calcium and zinc (0.58±0.21mg/l, 2.81±0.00 mg/l, 175.65±2.27 mg/l and 3.64±2.29 mg/l respectively). Accessions BT188 (3919 kgha-1), MT049 (3315 kgha-1), GT032 (3512 kgha-1) and WT026 (4462 kgha-1) were identified as adaptable and best yielding while Baringo as the best location for dolichos production. The use of gamma irradiation in generating genetic variability in Kenyan dolichos bean genotypes for climate change adaptation was effective. The best accessions on nutrition and yield adaptability are an important genetic resource for building resilience to climate change in Kenya.
2023-10-01T00:00:00ZIDENTIFICATION OF NEW MOLECULAR MARKERS FOR DIVERSITY ANALYSIS AND BREEDING FOR EARLY MATURITY AND DETERMINATE LABLAB (LABLAB PURPUREUS) VARIETIES
http://41.89.164.27:8080/xmlui/handle/123456789/1736
IDENTIFICATION OF NEW MOLECULAR MARKERS FOR DIVERSITY ANALYSIS AND BREEDING FOR EARLY MATURITY AND DETERMINATE LABLAB (LABLAB PURPUREUS) VARIETIES
KAMAU, ELIEZAH MAINA
Lablab (Lablab purpureus (L.) Sweet) is a grain legume crop commonly grown in Africa and India and is used as human food, animal feed, in soil conservation, enhancing soil fertility and in weed management. In Kenya, most farmers grow landraces which are inherently low yielding and have other undesirable attributes like long maturity duration and indeterminate growth habit. The status of genetic diversity of the local lablab germplasm and how it relates to materials from other regions remain unclear. Unavailability of novel breeding selection tools such as molecular markers and lack of adequate information on the inheritance pattern of important traits have also hampered the crop improvement in Kenya. The objectives of the study were therefore: to develop new molecular markers for lablab; to assess the genotypic diversity of local, exotic and wild lablab accessions using simple sequence repeats, diversity array technology (DArT) and single nucleotide polymorphism (SNP) molecular markers; to identify the inheritance pattern of selected lablab qualitative traits and establish the linkage relationship of the genes controlling them; determine the heritability estimates, genetic gain and character association of important traits of determinate lablab. Transcriptome sequencing using 454 Titanium FLX system of mRNA isolated from leaves and shoots of lablab samples, was conducted to discover genic-SSRs and to develop SSR markers. Eight of these new developed SSR markers were used to characterize 189 lablab accessions. SilicoDArT and SNP markers were developed using DArTSeq technology and used to characterize 240 lablab accessions. The genetics of growth habit and other qualitative traits were studied in three generations (F1, F2 F3) of eight lablab populations. Selected F5 lines with determinate growth habit were grown using RCBD design at KALRO Thika and Katumani to determine heritability estimates, genetic gain and character association. Results indicated that there were 446 genic SSRs from 3140 assembled lablab contigs indicating an overall density of 202 SSR per Mbp. SSR primer pairs designed from the contigs sequences amplified on lablab genome. The gene diversity among the 189 accessions based on SSR loci ranged from 0.26 to 0.52 with an average of 0.38, with germplasm collected from Kenya showing a moderate genetic diversity of 0.36. Higher genetic diversity (He<0.5) was detected within the Ethiopian and South Africa populations. A total of 15,601 polymorphic DArT markers and 11,431 SNP markers were identified each with average reproducibility and genotype call rate of more than 90%. Based on both DArT and SNP markers the 240 lablab was of narrow genetic diversity with the expected mean heterozygosity of 0.030 (DArT) and 0.039 (SNP). However, genetic differentiation was most pronounced between the cultivated and the wild accessions. The growth habit in lablab is under control of three genes which could be temperature dependent. The genes controlling stem growth habit and time to flowering in lablab are linked. The study identified, moderate to high heritability, genetic advance estimates and significant positive correlations of pods per plant, raceme per plant, plant height, pod width, racemes per pod and number of flower nodes. The newly developed molecular markers are useful in grouping lablab genotypes into related clusters that breeders can use to enhance lablab productivity. Selection for high number of units of pods per plant, raceme per plant, plant height, pod width, racemes per pod and can be effective when targeting to develop high seed yielding determinate varieties.
2022-02-01T00:00:00ZSOIL EROSION PREDICTION USING MODIFIED UNIVERSAL SOIL LOSS EQUATION (MUSLE) IN TUGEN HILLS, BARINGO, KENYA
http://41.89.164.27:8080/xmlui/handle/123456789/1733
SOIL EROSION PREDICTION USING MODIFIED UNIVERSAL SOIL LOSS EQUATION (MUSLE) IN TUGEN HILLS, BARINGO, KENYA
CHESIRE, ATHANUS KOMEN
Soil erosion by water is one of the primary causes of land degradation and occurs throughout the world. Soil erosion is contributing negatively to the already declining agricultural productivity thereby negatively influencing people’s livelihoods and economic empowerment. Therefore, there is need to understand erosion processes, quantify sediment yield, identify and rank critical sources on spatial domain of sediment. This will help in formulation of prioritized catchment conservation strategies. This study focused on estimation of sediment yield from Tugen Hills particularly Saimo catchment in Baringo County using Modified Universal Soil Loss Equation (MUSLE) model with a view to develop an understanding of inter-relationships between soil erosion and sediment yield. The input model parameters of runoff volume (Q) and peak flow rate (qp) were determined from runoff plots of dimensions 4.8m by 2m set up in the catchment with average slope of 2%. Soil erodibility factor (K) was calculated mathematically based on soil samples collected. Cover management (C) was obtained by percentage cover and support practice (P) factor was determined through observation and use of conversion table. Apart from determination of model parameters, the study calibrated and validated MUSLE for use in future studies within Saimo catchment and other catchments with similar characteristics. The mean bulk densities for top soil and bottom soil are 1.05g/cm2 and 1.07 g/cm3. The total value for fine sand and silt gives 37.1%. The saturated hydraulic conductivity varied from 8.0 μm/s to 41.3 μm/s with a mean value of 24.1 μm/s. There were only two classes high and moderately high translating to code 2 and 3, respectively. The analysis of variance (ANOVA) of the observed data showed that rainfall intensity affected the sediment yield production in the runoff plots and that there was no evidence to suggest that the soil homogeneity in the runoff plots affected the sediment yields. The observed and simulated MUSLE model values for calibration were PBIAS (0.83), R2 (0.75), r (0.87) and KGE (-0.20) and those for validation were NSE (0.96), PBIAS (-0.44), R2 (0.60), r (0.78) and KGE (0.46). Hence it can be concluded that the MUSLE model can be used successfully as an effective tool in soil conservation management. Future work for several seasons is however needed in order to capture different slopes and the varying climatic conditions for the model to be robust and to be used widely.
2022-10-01T00:00:00ZPRODUCTION, STORAGE AND QUALITY CHARACTERISTICS OF SWEET POTATO VARIETIES
http://41.89.164.27:8080/xmlui/handle/123456789/1686
PRODUCTION, STORAGE AND QUALITY CHARACTERISTICS OF SWEET POTATO VARIETIES
YEGO, ROMANA C.
Sweet potato (Ipomeabatatas) is an important subsistence crop in Eastern Africa and is fast becoming an important supplementary staple food in Kenya. It is harvested fresh but the shelf life is short. Little is known in regard to storability of local varieties grown by farmers and its effect on culinary characteristics and nutritional value. The main objective of the study was to evaluate the production, processing, utilization and effect of various storage methods on preservation of nutritional quality (βeta -carotene) of sweet potatoes in Kabras and Kabondo wards. The study adopted a cross sectional survey and experimental research designs using 211 sweet potato farmers who were a stratified random sample. A questionnaire was used to collect data on production, processing and utilization of the sweet potato. The storage experiment involved the use of pit and clamp storage methods. The nutritional quality of the stored sweet potato, particularly the effect of storage on Trans –βeta carotene content cis-isomers, was determined by UV-Spectrophotometer. Data was analyzed using the Statistical Package for Social Sciences (SPSS V.20). T-test and ANOVA for the various variables were determined. The study results showed that 73.3% of the respondents in Kabondo and 86.7% in Kabras; 91.7% were women 64.2% and 39.7 of the farmers in the two study areas preferred the yellow local variety of sweet potatoes and grew sweet potatoes twice a year. There was no significant difference in the mean βeta carotene levels in selected sweet potato varieties stored under pit and clamp methods (p≤ 0.05). The clamp storage method was generally better than the pit storage method as it had fairly higher sensory trait means as compared to the pit storage method, using a five unit hedonic scale. There is need for use of improved storage methods as this will boost food and livelihood security at household, community and national level and also to address nutritional problems.
2022-06-01T00:00:00ZIDENTIFICATION, PREFERENCE AND NUTRITIONAL EVALUATION OF ACACIA SPECIES AS BROWSE FEED FOR GOATS IN ASAL REGION, BARINGO COUNTY - KENYA
http://41.89.164.27:8080/xmlui/handle/123456789/1621
IDENTIFICATION, PREFERENCE AND NUTRITIONAL EVALUATION OF ACACIA SPECIES AS BROWSE FEED FOR GOATS IN ASAL REGION, BARINGO COUNTY - KENYA
KANDIE, HEZEKIAH CHEPTUMO
The pastoralist communities in the ASAL regions of Sub-Saharan Africa face significant constraints arising from insufficient nutritious livestock feeds, which in turn limits livestock productivity. Nonetheless, grass, shrub bushes and fodder trees are primary feed resources for livestock in a wide range of production practices. This study sought to identify and evaluate the nutritive value of five common Acacia browse species; A. brevispica, A. senegal, A. tortilis, A. mellifera and A. nilotica in Marigat sub-county, Baringo County. The study examined the preference rating of Acacia spps, among goats. Their nutritive value was determined by proximate analysis using AOAC (1995) on DM basis of leaves, bark and pods and reported in percentage content as DM, CP, CF, Ash, EE. The In-vitro DM degradability (IVDMD) was also determined and measured by 200 mg dry matter in duplicates at 39.20 C after, 0, 3, 6, 9, 12, 24, 48, 72, 96 and 120h of incubation and fitted to the exponential model, GP(t) = a + b(1 – e-c(t – L)). The statistic, Kruskal-Wallis, H test, (χ2 (4) = 182.6) at 0.05 significance levels indicated significant differences in preferences between the Acacia spps. A. brevispica being ranked the highest in preference while A. senegal ranked the lowest. ANOVA results, F (4, 475) = 62.61, p<0.05 showed significant differences in browsing preference. A. brevispica was highly preferred while A. senegal was least preferred. Results of proximate analysis indicated that DM was high for all samples and ranged from 97.21% in A. nilotica leaves to 94.13% in A. tortilis pods. The CP ranged from 23.9% in A. senegal pods to 2.76% in A. nilotica bark while CF ranged between 43.18 % in A. Senegal bark, to 9.66% in A. nilotica leaves, EE ranged between 5.21% in A. nilotica leaves to 0.31% in A. nilotica bark. Lastly, the IVDMD analysis indicated that A. nilotica leaves had highest gas production followed by A. mellifera and lastly A. brevispica. A. mellifera pods were highly degradable followed by A. nilotica, and lastly, A. tortilis. A. nilotica bark was highly degradable followed by A. senegal, and lastly A. tortilis bark. There were significant differences in the degradability of Acacia spps(p ≤ 0.05) with A. nilotica leaves, A. brevispica pods and A. nilotica bark being highly degradable. Based on the statistical results, the study rejected all the null hypotheses and concluded that some Acacia spps have comparable nutritive value that may meet the feeding requirements of the browsers. The study recommends that A. nilotica A. brevispica and A. tortilis be developed for use in feeding goats in the arid and semi – arid regions. Further studies on anti-nutritional factors and Animal Response Trials for production values needs to be done.
2022-01-01T00:00:00ZBIOLOGICAL MANAGEMENT OF ROOT KNOT NEMATODES (Meloidogyne spp.) USING AFRICAN LEAFY VEGETABLE, Crotalaria spp.
http://41.89.164.27:8080/xmlui/handle/123456789/1587
BIOLOGICAL MANAGEMENT OF ROOT KNOT NEMATODES (Meloidogyne spp.) USING AFRICAN LEAFY VEGETABLE, Crotalaria spp.
CHERUIYOT, HILLARY KIBET
Root knot nematodes are a serious biotic production constraint affecting vegetable production in Kenya. The adoption of sustainable management strategies including the use of antagonistic plants is important in reducing the amount of losses attributed to this soil pest. This study aimed at determining the host suitability of different Crotalaria species against root knot nematodes, assessing different Crotalaria application methods (preplant, aqueous extract and soil amendment) and quantifying nematode infestation at different nematode inoculum threshold levels. A field survey was undertaken in western Kenya to collect root and soil samples as the nematode source. Seven Crotalaria species were screened on pot experiments under green house conditions (23oC). Subsequent in vitro tests were done on extracts under laboratory conditions. Inoculation was done at an equal threshold level of 3000 juveniles while in vitro set up was done at same concentrations (v/v). For the efficacy assessment of the application methods, the most resistant species was applied in two ways under greenhouse. Two vegetables; Solanum nigrum and Cleome gynandra were used during the study. Four different nematode inoculum threshold levels were quantified for the amount of plant infestation. The set ups were arranged in a complete randomized design. Resistance related data based on the reproduction factor (Rf), galling index (GI) and percentage survival of the juveniles, percentage reduction in infestation (galling and nematode population) were then recorded. Data was subjected to analysis of variance and the means separated using Fisher’s protected LSD. There were significant differences in host suitability to the root knot nematodes (P < .001) amongst the seven Crotalaria species tested. The species C. intermedia showed high nematicidal effect and resistance to nematode infestation (low Rf and high galling index) while C. trichotoma was relatively susceptible with a higher Rf value. The aqueous extract application revealed that the different species were significantly different with C. intermedia being the most resistant. Assessment of the two application methods (soil amendment and preplant) indicated that preplant application was a superior method of application as it caused an infestation reduction of 72.13% in root galling and 26.8% in the number of nematodes in the rhizosphere. The different inocula threshold levels showed significant difference in the level of inocula threshold and level of infestation though with a variation in the crop type. The present study’s findings support the use of C. intermedia applied as a preplant and for use at higher than 2000 threshold for Cleome gynandra and at whichever threshold for Solanum nigrum.
Key words: Sustainable
2014-01-01T00:00:00ZEVALUATION OF ADAPTABILITY AND YIELD STABILITY OF SELECTED SWEET CORN VARIETIES GROWN IN RIFT VALLEY PROVINCE IN KENYA
http://41.89.164.27:8080/xmlui/handle/123456789/1586
EVALUATION OF ADAPTABILITY AND YIELD STABILITY OF SELECTED SWEET CORN VARIETIES GROWN IN RIFT VALLEY PROVINCE IN KENYA
KIPNGENO, BENSON LANGAT
Food security has been of a major concern globally. In Kenya the national development Blueprint Vision 2030, envisages the eradication poverty and enhanced food security. Agricultural sector’s economic importance thus cannot be over emphasized. Most research studies have laid focus on the impact of different crop management techniques on crop performance. Sweet corn is an important vegetable and commercial crop in many tropical and sub-tropical countries. It is a relative short season and moderately drought-tolerant crop that is adapted to a wide range of climates and soil characteristics (Bray, 1997). However the study on the adaptation and yield stability of sweet corn varieties grown in selected production areas in Kenya is not evident. A study was carried out using four selected varieties grown in three locations in Kenya for two seasons to assess this. The varieties selected were Chieftain, Star 7717, Pacific Queen Hybrid and a landrace. These varieties were obtained from local seed distributing agents and the farming communities. Bomet, Koibatek FTC and University of Eldoret in the Rift valley province were the selected test sites. The experiment was laid in a Randomized Complete Block Design (RCBD) with three replications. Quantitative traits measured included: the number of days to emergence, flowering and maturity. Other traits were germination percentage, the number of leaves at flowering, the plant heights, the total biomass and the yield. Qualitative traits scored were seedling vigour, leaf colour intensity and pubescence, stand-ability, snapping ease, tolerance to stress, cobs fill, husk cover and sweetness based on IPBGR maize descriptor. ANOVA of quantitative traits showed a significant variation among the varieties, seasons and locations at p ≤ 0.05 level of confidence. It was also observed that qualitative traits varied significantly among varieties; but that variation was not evident with seasons and locations. Early seedling vigour and tolerance to stress varied significantly with both seasons and locations. Variation in both quantitative and qualitative traits indicates the influence of the environment on the performance of a of a variety (GXE). Adaptation and yield stability varied significantly among the varieties at p ≤0.05 level of confidence. The regression coefficients (β) of the tested varieties observed were 0.81, 1.29, 0.302 and 0.04 for the varieties Pacific Queen Hybrid, Landrace, Chieftain and Star 7717 respectively. Pacific Queen Hybrid had a wider adaptation, more stable and high yielding variety across the test locations. Chieftain, Landrace and Star 7717 had lower adaptation, less stable and realized high yields in specific environment (location). Qualitative grading of environment showed Chepkoilel as being superior over Bomet and Ravine. Pacific Queen Hybrid ranked best among the tested varieties in all the test location and thus suitable for production in all the three sites. Chieftain and Star 7717 realized better yields the best Ravine while landrace was in Bomet respectively, hence these varieties can be recommended for each specific location.
2013-01-01T00:00:00ZEFFECTS OF SPRINKLER IRRIGATION ON SOIL PHYSICAL PROPERTIES AND GREEN GRAM CROP YIELD
http://41.89.164.27:8080/xmlui/handle/123456789/1569
EFFECTS OF SPRINKLER IRRIGATION ON SOIL PHYSICAL PROPERTIES AND GREEN GRAM CROP YIELD
SEREM, PAUL KIPKOECH
Kenya’s land area is 582,646 Km2 with 17% suitable for rain-fed agriculture and 83 %
classified as arid and semi-arid and cannot reliably support agricultural activities unless
under irrigation . Insufficient water resources make the selection of an efficient irrigation
system essential. Sprinkler irrigation is one such tool and despite having been proven to
be economical and efficient is known to cause soil compaction leading to reduction in
crop yield. The broad objective of the study was to determine the effect of sprinkler size
on soil compaction and subsequently on green gram crop yield. Field trials were carried
out at Wei Wei Irrigation Development Project in West Pokot County to determine the
impact of sprinkler size on soil physical properties and subsequently on crop yield.
Completely randomized block design was used as a framework for carrying out the trials.
Three different sprinkler size treatments (Jalpari, Taiwan and Naan sprinkler types) with
two replications each in six experimental trial plots were tested under subsoiled plots (B,
D and F) and non subsoiled plots (A, C and F). Green gram crop was planted under four
irrigation schedules of 5 hours each per sprinkler type to harvest. Soil analysis,
penetration resistance, sprinkler characteristics, infiltration rates for the different trial
plots, irrigation water runoff and soil erosion were determined. The experimental trials
plots soils were sandy loam with an average soil bulk density of 1.6 g/cm3
and an
optimum compaction moisture content of 17.53%. This soil can easily be compacted and
suitable moisture range for land preparation with minimal compaction was determined to
be 15.3-17.53% by Proctor compaction test. The soil’s penetration resistance was highest
for non subsoiled plots at a depth of 0-20 cm compared with subsoiled plots by 38 bars.
The penetration resistance values were between 144 and 160 bars against recommended
values of 10-20.68 for crop production. These values were high and indicate that the soil
was prone to compaction. Soil compaction was high for Jalpari Sprinkler type (146 bars)
with more discharge at the end of experiment compared to Taiwan (142.5 bars) and Naan
(145 bars) which had less. Jalpari sprinkler type caused runoff of 0.17 mm/ per irrigation
schedule, soil erosion of 0.27 tons/ha/year against RUSLE modeled value of 0.35
tons/ha/year. The difference between the two values was associated with estimated
RUSLE parameters which were derived from the experimental project’s region’s existing
data. Plots with Taiwan sprinkler having a water application rate of 8.5 mm/hr, DU of
75.88% and CU of 83.2% produced the highest yield with a positive net income of Kshs
80,421.40 per hectare in a subsoiled plot. However yield differences due to sprinkler type
were not significantly different. Statistical analysis on yield and tillage type showed
similar trend except in yield per plant which had an F-ratio value of 26.1 against the
table’s value of 18.51. It could be concluded that sprinklers with high discharge cause
compaction, runoff, soil erosion and lower yield. It was recommended that tillage be
carried out at soil moisture content range of 15.3-17.53% with an effort of 600 KN-m/m3
or less since this did not create compaction. Taiwan sprinkler and sub soiling which gave
the best yields were recommended. Further research on soils, sprinkler types and
machinery were also recommended.
2014-01-01T00:00:00ZEVALUATION OF GENETIC VARIABILITY AND STABILITYOF SELECTED PEARL MILLET GENOTYPES (PENNISETUM GLAUCUM (L.BR.) IN ARID AND SEMI-ARID LANDS OF NORTH RIFT, KEN
http://41.89.164.27:8080/xmlui/handle/123456789/1542
EVALUATION OF GENETIC VARIABILITY AND STABILITYOF SELECTED PEARL MILLET GENOTYPES (PENNISETUM GLAUCUM (L.BR.) IN ARID AND SEMI-ARID LANDS OF NORTH RIFT, KEN
LAGAT, NICHOLAS K
Thirty-six genotypes of pearl millet (Pennisetum glaucum) differing in their
performance from local varieties (OPV) were evaluated in two environments (Marigat
and Koibatek, Kenya) to examine their yield and stability across the two diverse
environment. The main objective is to improve pearl millet production in arid and
semi-arid lands of Kenya. Improvements of hybrids have been made in the past and
yet no yield ceilings have been reached however germplasm provide little genetic
variability for yield and therefore there is need to improve pearl millet in arid and
semi-arid lands of Kenya. The genotypes were laid out in randomized complete block
design in two replication and data collected on yield and yield components. Data
analyses was done using Genstat 12 edition. Data on grain yield was further subjected
to GGE biplot analysis to determine stability and genotype by environment interaction
of the genotypes. The genotypes were grouped into eleven clusters. The clustering
pattern gave indication of classification of genotypes according to the yield and yield
components. The test environments provided improved yields levels from low (600kg
ha-1
) at Koibatek to high (6200kg ha-1
) at Marigat hence there was high significant
variation at P ≤ 0.001 observed among the grain yield in both sites. Performance of
the hybrids showed various pattern of stability to test environments. More genotypes
performed better in Koibatek than Marigat even though Marigat showed good yield
performance. Cluster nine showed good yield performance across the location
because of its characteristic which might have influence the response to the test
environments. Local variety Kat pm 2 appeared to be among the stable genotypes but
among the poor performance than the hybrids. Results indicated that best performing
genotypes were not best adapted in the test environments hence stable hybrids can be
identified through evaluation over diverse environments.
2015-01-01T00:00:00Z