MST-Department of Agricultural Sciences and Technology

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Survey and evaluation of nuclear polyhedrosis virus (NPV) for the control of helicoverpa armigera (hubner) (lepidoptera:nocduidae) on selected vegetable crops in kenya.
(Kenyatta University, 2000-09) Msanzu, Joseph Baya
Samples of Helicoverpa armigera larvae obtained from several sites and crops in Kenya in surveys carried out during June 1998 to October 1999 were examined at ICIPE, Nairobi. They revealed natural infection by nuclear polyhedrosis virus (NPV). Sixteen isolates were collected altogether. In laboratory bioassays on field collected third instar larvae fed on contaminated diet with two local NPV isolates and the Indian (ICRISAT) isolate, the cumulative percent larval mortality did not differ significantly but the local isolates were apparently superior. Percentage larval mortality recorded 9 days after inoculation for the Kenyan isolates were 78.3±7.38% and 68.3±5.68% respectively, compared to 55.9±2.10% for the Indian isolate. Larval mortality was found to be dose-dependent and increased with the larval instars. The Kenyan isolate 1 (Kibwezi isolate) had a higher slope of 0.685±O.1480 compared to 0.0981±O.14680 for the ICRISAT isolate while the LD50 values were 1.59976 x 1010OBs/ml and 3.178 x 1013OBs/ml respectively by probit analysis at 95% fiducial limits. In age-response studies with laboratory reared larvae, mortality was found to decrease with later instars. Cumulative percent mortality of second instar larvae reached 78.3±2.2% by the third day, 93.3±1.36% by day 6 and 100% by day 8. In pot culture tests, when aqueous suspension sprays of native HaNPV were applied on pigeon pea and snow pea potted plants artificially infested with third instar H armigera larvae, significant reduction in larval damage to pods and seeds were obtained. The grain yield per plant was also at par with yields of plants sprayed with two chemical pesticides, Larnbdacyhalothrin (Karate@) and Bifenthrin (Brigade@). Replicated small plots testing on vegetable pigeon pea also confirmed the potential of native HaNPV in providing satisfactory reduction in pest damage leading to grain yield benefits comparable to the chemical pesticide (Larnbdacyhalothrin) spray. Molasses (1%) increased viral activity both in the laboratory, pot-culture and field tests compared to 1% charcoal powder. Further efforts should be made to test the biological potential, characterize, improve and demonstrate the potential of native HaNPV for augmentation biocontrol of H armigera in Kenya.
Assessment of levels of natural radioactivity in surface soils around titanium mines in Kenya
(2011-11-07) Masore, Kefa Osoro
All human beings are exposed to radiation from naturally occurring radionuclides in soil and other environmental materials. Some of these exposures are not amenable to control and they are usually referred to as background radiation. Some work activities such as conventional mining inadvertently produce large quantities of naturally occurring radionuclides, which can result in additional and/or elevated levels of radiation exposure of people in the areas around the mining sites. Such exposures - induced or enhanced by human activities - are subject to control by regulatory authorities. In some instances there may be contributions from the two types of exposures and they must be separated before applying regulatory control. In this study, natural radioactivity levels in surface soils around the proposed titanium mines in Kwale district were determined from measurements of 78 samples of surface soils randomly sampled from two villages within the proposed mining area by using a hyper pure germanium (HpGe) gamma-ray spectrometer. The values of radioactivity concentrations in the soils and the likely radiation doses from contact with these soils were determined and are reported in this thesis. The radiological implication of these levels is discussed with regards to the impending mining operations in the area. The ranges and mean of radioactivity concentrations (Bgkg-l) obtained are. 8.4±0.4-43.6±1.5 (_27.6±1.7) for 232Th; 7.4±0.6-40.6±1.4 .(20.9±1.5) for 226Ra and 31.9±1.3-114.1±1.4 (69.5±3.2) for 40K, respectively. The likely absorbed dose rates in air above these soils were calculated from these radioactivity concentrations and found to be 8.5±0.5-36.9±1.1 nGyh-1 with a mean of 25.2±1.4 nGyh-1. The corresponding effective dose rates are 21.0±1.2-90.8±2.6 mSvy--1 with a mean of 62.0±3.5 uSvy--1, which are lower than the global average of 0.46 mSvy 1 and therefore of little radiological risk to the environment of the study subject.
Effects of soil on pathogenicity of meliodogyne incognita on okra
(2012-06-13) Mbugua, Joyce Waceke
Tests were conducted both in the field and greenhouse to investigate effects of i. chicken and goat manure, sawdust (Cyprerssus governiana L.), kale leaves, bean stems, maize stalks and Nitrogen-Phosphorus-Potassium (20:10:10), (ii) time of incorporation of the organic materials into the soil and (iii) solar heating of soil using 0.07, 0.13 and 0.26 cm-thick polyethylene mulches on pathogenicity of Meloidogyne incorgnita (Kofoid and White) Chitwood on okra (Hibiscus esculentus L cv. pusa sawani). The organic materials and N-P-K (20:10:10) were incorporated into the soil 14 days before planting and at planting time, respectively, at the rate of 20 gms and 4 gms, respectively, per 15 cm diameter plastic pot containing unsterilized soil or per planting hole in tests designed to investigate effects of the materials on pathogenicity of M. incognita. An equal amount of organic material was incorporated into the soil 14, 28 and 42 days prior to inoculation in tests designed to investigate effects of time of incorporation of the organic materials on pathogenicity of M. incognita. Twenty one day old okra seedlings germinated in sterile sand and an inoculum level of 2500 + 50 M. incognita eggs and second stage juveniles (J-2) were used in all tests. A completely randomized block design with four and five replications per treatment was used in tests designed to investigate effects of solar heating of soils and organic materials, respectively, on pathogenicity of M. incognita. A split plot design with three replications per treatment was used in tests designed to investigate effects of time of incorporation of organic materials on pathogenicity of M. incognita. Plant heights and stem diameters were taken 21 days after inoculation and biweekly thereafter for 90 days. In addition, fresh fruit and dry shoot weights and number of fruits per plant were taken at harvesting time, 90 days after inoculation. A 0-4 gall rating scale, where 0 = no galls; 1 = 1-25%; 2 = 26-50%; 3 = 51 - 75% and 4 = 76 - 100% of root system galled was used to assess disease severity. Meloidogyne incognita counts were made 90 days after inoculation. Goat and chicken manure, kale leaves, sawdust and N-P-K suppressed pathogenic effects of M. incognita by up to 79.21%, 75.69%, 67.24%, 22.09% and 90.25%, respectively, as was revealed by the respective coefficients of determination (r2) values of 0.7921, 0.7569, 0.6724, 0.2209 and 0.9025. The effects of maize stalks on pathogenicity of M. incognita varied from one test to another. The suppressive effects of goat manure, chicken manure, kale leaves and sawdust decreased by 24.31%, 20.13%, 20.57% and 98%, respectively, when the materials were incorporated into the soil 42 days prior to inoculation. The suppressive effects of maize stalks, however, increased by 1.97% when the material was incorporated into the soil 42 days prior to inoculation. Although bean stems incorporated into the soil 14 days prior to inoculation did not suppressed by up to 77.44% (r2 = 0.7744) and 76% (r2 = 0.76) when incorporated 28 and 42 days prior to inoculation, respectively. Solar heating of soils using 0.07cm and 0.13cm-thick transparent polyethylene mulches suppressed pathogenic effects of M. incognita by up to 100% (r2 = 1.00) and 59.29% (r2 = 0.5929), respectively. Besides poor plant growth, plants grown in soils mulched with the 0.26cm - thick polyethylene mulch supported low gall indices and numbers of M. incognita.
The influence of nutrients and phenolic componds of cabbage collard green, lettuce and spinach on the biology of cabbage aphid brivicorgbne brassicae(h) and peach potato aphic myzus persicae (SULZ)
(2012-06-13) Mbugi, Jenard Patrick
Defence of plants against pests may depend on texture and composition of the plant surface, absence of nutrients required by the pest and production of toxins or deterrents (Levin, 1971). Majority of toxins or deterrents already identified comprise of plants secondary constituents. One of the most important groups of plants secondary constituents playing a defensive role against insect pests are phenolic compounds. Using Folin-Denis assay, cabbage, collard green, lettuce and spinach were shown to contain a significantly different mean concentration of total phenols, followed by collard green, lettuce and spinach were shown to contain a significantly different mean concentration of total phenols, followed by collard green, cabbage while spinach had the lowest concentration. Experiments on the identification of phenolic compounds using Thin Layer Chromatography (TLC) method revealed that cabbage, collard green, spinach and lettuce contained seven, ten, eight and nine phenolic compounds respectively. Laboratory experiments showed that lettuce and spinach could not successfully support a culture of Brevicoryne brassicae (L.) and all the nymps that were fed on the leaves of the two test cultivars died ten hours after introduction. Further treatment of the spinach and lettuce leaves with cabbage extract had no effect and the two test cultuvars even after treatment with cabbage extract still could not successfully support a culture of B. brassicae. Results on the treatment of cabbage leaves with spinach and lettuce extracts revealed that the extracts had no effect on the survival of B. brassicae. The mean numbers of B brassicae nymps found surviving seven days after introduction to feed on cabbage leaves treated with spinach and lettuce extracts were not significantly different from the mean numbers of the nymphs introduced to feed on untreated cabbage leaves. B. brassicae fed and reproduced successfully on cabbage and collard leaves. The results of this experiment showed that the mean maturity, fecundity and post-reproductive period of B. brassicae on cabbage and collard green were not significantly different. However, the mean longevity and reproductive period of B. brassicae on collard green were significantly longer than on cabbage. Experiments on Myzus persicae (Sulz) reared on cabbage, collard green leaves showed that the mean maturity and longevity of aphid on the three test cultivars were not significantly different. However, the mean fecundity, reproductive periods and post-reproductive periods were significantly different. The highest mean fecundity was recorded on lettuce followed by collard green while cabbage had the lowest. The longest mean reproductive periods and post -reproductive periods were significantly different. The highest mean fecundity was recorded on lettuce followed by collard green while cabbage had the lowest. The longest mean reproductive period was recorded on collard green while cabbage had the shortest. The differences between the mean reproductive period on lettuce and cabbage were not significant and so were those between collard green and lettuce. The mean post reproductive period was longest on lettuce followed by cabbage while the shortest was on collard green. The mean concentration of nitrogen, phosphorous, sulphur, calcium and magnesium in all the four cultivars were not significantly different. However, the mean concentration of potassium, copper, manganese, iron and zinc showed some significant differences. The mean concentration of potassium was highest in lettuce and lowest in cabbage. The differences between the mean concentration of potassium in cabbage, collard green and spinach were not significant and so were those between spinach and lettuce. The mean concentration of copper was highest in spinach and lowest in cabbage. The differences between the mean concentration of copper in cabbage, collard green and lettuce were not significant and as were those between spinach and lettuce. The mean concentration of manganese was highest in spinach followed by lettuce, cabbage while collard green had the lowest. The mean concentration of iron was highest in lettuce followed by spinach and cabbage while collard green had the lowest. The mean concentration of zinc was highest in spinach and lowest in lettuce. The differences between the mean concentration of zinc in cabbage, collard green and lettuce were not significant.
Pesticide use and misuse by small scale farmers in Kiambu, Kenya
(2012-06-13) Karembu, Margaret Gathoni
This study was set to investigate the use of pesticides by small-scale farmers and its implications on the environment. It further sought to find out whether illiteracy causes misuse of pesticides and if provision of information on pesticides reduces their misuse and mishandling. Three divisions in Kiambu district were selected using the cluster sample technique for interviews. The interview schedules contained questions aimed at answering the specific research questions. Data was analysed using descriptive statistics i.e. frequencies, averages and percentages. In some cases, the responses were reported verbatim. The validity of this study relied on the assumption that the interviews were reasonably honest and expressed their true feelings when responding to the interviewer's questions. It was established that some small-scale farmers used a wide range of extremely hazardous pesticides, which were either banned or severely restricted for use in developed countries. These included Dichlorodiphenyltrichloroethane (DDT), dieldrin, heptachlor, cypermethrin and lindane. Factors such as the economic status of the farmers and the prevailing climatic conditions were found to contribute to pesticide misuse and mishandling than illiteracy. In view of the problems of pesticide use, it was recommended that measures be taken to enforce pesticide regulations and legislation. The introduction of laws and regulations concerning disposal of unused pesticides and their containers should be supported while improved methods of packaging would reduce hazards arising from pesticide use. Further, labelling and advertising of pesticides should be monitored. Environmental education should incorporate pesticide safety education in the whole education system to sensitise and increase public awareness on the risks and potential problems of pesticide use and handling.
Molecular characterization sequence variation in the rDNA region of root-knot nematode (Meloidogyne sp.,) in indigenous lefy vegetables
(2012-12-03) Mwangi, John Muturi; Gichuki, Charity; Waceke, J.W.
Indigenous leafy vegetables (IL V s) are plants whose leaves or aerial parts have been integrated in a community's culture for use as food over a large span of time. In the past, traditional societies have exploited edible wild plant resources to obtain their nutritional requirements. Solanum nigrum, Amaranthus hybridus, and Cleome gynandra are the most used ILVs. Root- Knot Nematodes (RKN) belonging to the genus Meloidogyne are the most economically important nematode pests affecting IL V production and have a diverse host range. Plant-parasitic nematodes are responsible for global agricultural losses' amounting to an estimated $157 billion annually. Most IL V crops produced are susceptible to nematode injury, particularly by root knot nematode and sting nematodes. Plant symptoms and yield reductions are often directly related to pre plant infestation levels in soil and to other environmental stresses imposed upon the plant during crop growth. As infestation levels increase so then do the amount of damage and yield loss. Most previous studies on the diversity of Meloidogyne spp. have focused on morphology (for example: perineal patterns, stylet structure, body length), and the response of the populations to differential host test. Morphological differences may be absent or difficult to observe. Identification by these procedures is difficult even for qualified taxonomists. Isoenzyme electrophoresis has also been used to characterize RKN populations. The esterase phenotypes are species-specific and are a good tool for identifying RKN. PCR-based diagnostics offer possibilities for precision, sensitivity and quantification. Ribosomal DNA distinguishes many species of nematodes, investigates intraspecific variation and examines evolutionary relationships. In this study esterase phenotypes (EST), Malate dehydrogenase (MDH) was used. Four esterase phenotypes were recognized on the basis of single bands or combinations of several bands. One Mdh phenotypes (i.e. Nl) and four EST phenotypes (i.e. 12, 13, Al and A2) were detected. Three species were identified from the populations, of which 20 were M incognita (Mdh-Est phenotype NI-I2), 10 were Mjavanica (NI-B), 10 were M arenaria (Nl- A2). All the three species amplified using SSUrRNA produced a single PCR product of 700 bp. The PCR products were then purified and subjected to sequencing. Sequences were aligned with sequence alignment tools (ClustaIW2) to show areas of variability and areas of conserved regions. The obtained sequences were compared with nucleotide sequences in the Gene bank using the BLAST Software to determine similarities. From the blast analysis several sequences of Meloidogyne nematodes (5 S ribosomal RNA) were identified with regions that matched with the obtained sequences. The nearly complete 5S rDNA sequences obtained from the 11 sequences varied from 675 to 692 base pairs. The sequenced products were aligned to investigate sequence diversity and infer phylogenetic relationship among the species. Phylogenetic analysis was done by MEGA (Molecular Evolutionary Genetic Analysis) computer program. The dendrogram of the phylogenetic tree was drawn using a web based program which confirmed the sequences of the most four common Meloidogyne species. The results of the study will be used to design best IPM programs and better understand taxonomy.
Effectiveness of macro propagation technique in production of healthy banana seedlings in Eastern and Central regions, Kenya
(2013-03-20) Njau, Njeri
Banana (Musa spp.) is one of the most important food and cash crops in Kenya. It provides food security. nutrition and income for many smallholder farmers. Bananas are eaten ripe or cooked depending on the variety. Despite its economic importance banana production faces major challenges including scarcity of high quality seedlings insect pests and diseases. Demand for pest free and high quality planting materials has been on the increase. Naturally regenerated suckers that are preferred by farmers are more likely to carry pests and diseases leading to reduced productivity and a short lifetime of new plantations. Tissue Culture has been introduced but its adoption has been low due to the high costs and skills involved. To address this constraint macropropagation has been introduced as an alternative propagation technology. The technology can be implemented with little capital and skill. The study was aimed at assessing whether macropropagation technology can produce healthy banana seedlings. A survey was conducted to identify the current important diseases and insect pests of bananas in Eastern and Central Kenya. Macropropagation nurseries were established at Kenyatta University and in farmers' fields at Mathioya, Kirinyaga, Embu East. Meru Central and Mitunguu and Ntharene in Imenti South District. These sites represent different agroecological zones. including high. mid and low altitudes. Corms obtained in accordance with established quality assurance protocols were propagated and the health of the macropropagated banana seedlings monitored. Macropropagation was done in two cycles. the first in Feb - June 2011. and the second from July - November 2011. The importance of the isolated organisms in banana health was determined through pathogenicity tests carried out under controlled conditions. To determine the effectiveness of macropropagation protocol in eliminating pathogens. corms were artificially inoculated with Radopholus similis, Fusarium oxysporum f. sp. eubense (Foe) andXanthomonas vasieola pv. musaeearum (Xvm) followed by monitoring health of the seedlings from the inoculated corms. Fusarium wilt and Sigatoka were recorded as the most important diseases with 66 and 50% incidence respectively. while nematodes and banana weevil were the most important pests with 21 and 17% incidence. respectively. An average of 98 and 100% healthy seedlings resulted from the first and second cycles of macropropagation. Under simulated infection. macropropagation did not eliminate Foe and Xvm but completely removed plant parasitic nematodes (PPN). The study found that macropropagation technique is an effective method to produce healthy banana seedlings however precaution is needed to ensure quality of the seedlings where Xvm and Foe are present. The key control points for safeguarding health and quality of the macropropagated seedlings is during certification of corm sources to ensure selection of healthy corms the process should be done aseptically and the corms should be treated before planting.
Low Cost Issue Culture of Selected Cassava(Manihot esculenta Crantz)and Sweet Potato(Ipomoea batatas(l)Lam) Varieties
(2013-03-21) Ogero, Kwame Okinyi; Mwangi, M.; Mburungu, G. M.; Ombori, O.
Drought has become a major contributor to food insecurity in sub-Sahara Africa. Drought-tolerant crops such as cassava and sweet potato can help alleviate this situation. However, lack of affordable healthy planting materials of farmer-preferred varieties is a major constraint to sweet potato and cassava production. Conventional tissue culture technology offers an important solution to this but it is very costly, making plantlets out of reach for resource poor farmers. Hence, it is necessary to have low cost options for micropropagation of planting materials. One way of doing this is to substitute the conventional source ofMurashige and Skoog (MS) media salts with alternative sources that are available 10call¥~:'This study sought to compare the cost of regenerating selected cassava and sweet potato "varieties using alternative nutrient sources and the conventional MS nutrient sources. Another objective was to find out if there is any genotypedependent response to regeneration using different media. Two varieties of each crop (KEMB 36 and Tainung for sweet potato and Muchericheri and KME 1 for cassava) were subjected to three treatments with different media composition and replicated nine times. In the first medium (LCM 1), Easygro'" vegetative fertilizer (27:10:16 (N: P: K) + microelements) from Osho Chemical Industries Limited was used as an alternative source for MS basal salts. In the second media (LCM 2), the conventional sources of four MS macronutrients were substituted individually with locally available fertilizers while Stanes Iodized Microfood® was used as the low cost source of micronutrients. Table sugar was used as an alternative source of carbon while the modified conventional MS medium (CM) was used as the control. Growth parameters including numbers of nodes, roots, leaves and plant heigh.t.we.re recorded at 7 and 14 days intervals for cassava and sweet potato, respectively. This was.carried out over a period of five weeks for cassava , and six weeks for sweet potato. The use of LCM 1 for cassava micropropagation led to a reduction of 96.3% in the cost of the ~utrient medium while LCM 2 led to savings of up to 95.5%. For sweet potato a cost reduction of 96.9% was realized with LCM 1 while LCM 2 led to cost reduction of 94.4%. LCM 1 produced better results compared to LCM 2 for cassava regeneration for all the four parameters assessed. The two cassava varieties had regeneration indices of 3-7 nodes per plantlet during initiation and 3.7-6.9 nodes per plantlet during multiplication on all the media. Leaf formation for the two cassava varieties after the sixth week of culture ranged between 2.7 and 7.3 leaves per plantlet on all the media during initiation and 4-7 leaves during multiplication. Muchericheri produced significantly (p:S0.05) higher number of roots on LCM 1. The two cassava varieties had no significant (p2:0.05) differences in root production on LCM 2. Sweet potato varieties produced better results on LCM 2 compared to LCM 1. KEMB 36 had a regeneration index of 7.8 nodes per plantlet on LCM 2 during initiation while Tainung had a mean of 3.8 nodes per plantlet after the sixth week of culture. The two sweet potato varieties recorded regeneration indices of 3.3-7.1 nodes per plantlet during multiplication. The variety KEMB 36 had better leaf production on LCM 2 compared to Tainung and vice versa on LCM 1 during initiation. Acclimatization of cassava was best on vermiculite while for sweet potato it was on a mixture of rice husks and red soil in the ratio 1:2. This study has shown that it is possible to reduce the cost of cassava and sweet potato tissue culture by adopting alternative nutrient sources. However, the differential responses among varieties calls for further investigation.
Etiology, Epidemiology and Management of Dieback Disease of Passion Fruit (Passiflora spp ) in Central and Eastern Regions, Kenya
(2013-10-15) Wangari, Wangungu Carolyne; Mwangi, M.; Kahuthia-Gathu, R.; Muasya, R.
Passion fruit is important in Kenya for nutrition and income. Current production is low and this is largely due to pests and diseases. In Kenya, major passion diseases include Fusarium wilt, Phytophthora canker, Brown spot, Woodiness virus and Dieback. Dieback causes over 80% of tota! produce loss and has negatively affected the passion fruit value chain. The objective of this study was to identify dieback pathogens, determine their aggressiveness, investigate its epidemiology and identify effective management measures. A survey was. carried out in major passion fruit growing areas in Central and Eastern Kenya. Three research sites were set up in the study areas and 1 at Kenyatta University, where epidemiological and disease management trials were done. Passion fruit varieties assessed were Passiflora edulis var Sims and KPF 12 hybrid. Diseased samples were collected for isolation and identification of pathogens in the laboratory. Pathogenicity tests determined aggression of the isolates. Data on disease severity were collected using a dieback scoring chart (with a scale of 1 to 5, subjected to analysis of variance and means separated by LSD at P = 0.05 using the Tukey's test. Results showed that dieback is a disease complex caused by multiple pathogens (Genus Fusarium, Phytophthora, Alternaria and Ascochyta). Disease was most severe when pathogens were inoculated in combinations of 3 and 4. Proper field maintenance practices reduced disease incidence and severity (12% and 1.6 respectively) in Meru B while poor maintenance yielded high levels (55% and 4.0 respectively) in Mathioya. Agronomic practices important in transmission of dieback pathogens on the purple variety were pruning, grafting and wounding (P :::;0.05). Mavuno and TSP fertilizers boosted plant growth leading to lower disease scores of 2.2 and 2.3, respectively, as compared to the control (2.92). None of the fungicides evaluated was curative. Plants treated with Ridomil MZ had a low severity score (2.1), while those treated with Milraz had a higher score (2.7). Water stress increased severity thereby suggesting that the lower the amount of water/rainfall available to a plant, the higher the dieback severity and vice versa. The relationship between rainfall arid severity yielded a negative correlation coefficient (r = -f). 70). Multiple pathogens imply that there should be integrated measures for effective disease control. Positive effect of fertilizers indicates that proper nutrition is crucial to alleviating effects of dieback. This study identified dieback pathogens, showed that proper field maintenance and nutrition are important in disease management and indicated that major fungicides currently in use in production are ineffective. Recommendations were that· although attention is largely on dieback, management of other passion diseases should not be neglected. There is need to strengthen role of nursery operators and training farmers/nursery operators on importance of tool disinfection. Dieback management packages should target multiple pathogens. To boost production there is need for nationwide rotational programs. This information is crucial in dieback disease management programs and will contribute towards reviving the passion fruit industry in Kenya. 1
Economic avaluation of Integrated pest management technology for control of mango fruit flies in Embu County, Kenya
(2014) Kibira, Mary Njeri
Mango is the third most important fruit in Kenya in terms of area and total production. Nutritionally, mango fruit is important for vitamins and mineral provision in the daily diet of Kenyans. As an export crop, mango earns the country foreign exchange, acts as source of food and household income especially for resource poor farmers, contributing to poverty alleviation and achievement of Millennium Development Goal number one. However, mango production and marketing is constrained by several factors, among which pests and disease infestation is major. Among the pests, mango fruit fly present a real challenge to producers and exporters due to losses incurred at the farm level and infested mango rejections at export points. To reduce losses, cost of production and increase the profit at producer level, International Centre of Insect Physiology and Ecology (icipe) developed and implemented an Integrated Pest Management fruit fly control package (IPMFFCP) in Embu County, Kenya. The impact of this intervention, however, had not been evaluated. This study therefore evaluated the impact of this intervention on magnitude of mango rejection due to fruit fly damage, insecticide expenditure and net income from mango production. The study also established households’ perception of the effect of the intervention on human health. The study used survey research design in which a structured questionnaire was administered to 257 randomly selected IPMFFCP participants and non participants from the intervention and control areas. Ordinary Least Square (OLS) regression analysis and Difference-in-difference (DD) method were used to assess the impact of the IPMFFCP on magnitude of mango rejection and insecticide expenditure. Two Stage Least Square (2SLS) analysis and DD were used to evaluate the impact of IPMFFCP on net income from mango production. Descriptive statistics were used to assess the household perception of the effect of IPMFFCP on health. The results indicated that on average IPMFFCP participants had approximately 54.5 percent reduction in magnitude of mango rejection than the non participants. The participants spent approximately 46.3 percent less on insecticide per acre than the non participants and on average received approximately 22.4 percent more net income than the non participants. Results also showed that 78 percent of households perceived the intervention improved human health. The results imply that IPMFFCP participants are better off in terms of magnitude of mango rejection and insecticide expenditure reduction and net income from mango production increment. The study recommends expansion of IPMFFCP intervention to the entire mango growing area in Embu County to improve the farmers’ livelihood through the increased profitability.
Characterization of Virus-Free Sweet Potato (Ipomea Hatata (L) Lam) Landraces Using Morphological and SSR Markers in East Kamagak Location-Homabay County
(Kenyatta University, 2014) onyango, Rosally Anyango
Sweet potato is one of the most important crops for food security and income generation in Kenya. The crop is increasing in importance as adverse climate changes limit crop production in many areas. Understanding the genetic diversity of germplasm of crop species is ofimportance for its rational management and use. Identification of the sweet potato landraces is paramount in addressing food security not only in the study region but elsewhere in the country. Morphological characterization of the accessions facilitates the identification of duplicates and unique traits which is important in the future improvement of the crop having the desired characteristics. The study aimed at identifying sweet potato landraces that have high quality and high consumer acceptance in the area in East Kamagak location of Rachuonyo District, Homabay County .The experiment started with survey and germplasm collection aided by use of questionnaire. The collected germplasm was virus indexed using visual scoring, serological and molecular detection. Six sweet potato landraces from East Kamagak along with six released varieties from Kenya Agricultural Research Institute Njoro were used for the study. The accessions were planted using Randomized Complete Block Design. Planting was done in two sites (Sino and Kachieng). Eighteen qualitative (ground cover, leaf shape, tuber colour.) and Eight quantitative characters (leaf length, vine inter-node length,vineweight, yield of tuber.) were scored one month after planting upto harvesting using the sweet potato descriptors oflnternational Potato Centre (CIP). Harvesting was done at 6 months after planting and tubers dried at 60°C to deterrn ine the dry matter content.The accessions exhibited high morphological diversity in aerial and rootcharacteristics. Analysis of variance showed that out of 24 characters evaluated for morphological characterization, 17 characters were significantly different at p
Influence of one and two node cuttings on rapid vegetatively propagated infilling tea (camellia sinesis) plants
(2014) Mwangi, Simon Mwai
The tea industry in Kenya is rural-based and provides a livelihood to over three million people. Tea is grown in prime agricultural land and can be potentially productive for 100 years if well managed. Peak yields under optimal management are obtained at 20–40 years after planting only if gaps that arise due to factors such as lightening, pests, diseases, unfavorable climatic conditions and incorrect pruning are taken care of through an elaborate infilling program and use of appropriate infilling plants. Infilling in tea farms is however faced with a challenge of lack of suitable infilling plants since commonly used single node cuttings take very long in the nursery and is less robust to compete with established ones. The purpose of this study was therefore to investigate the suitability of vegetatively propagated (VP) tea plants raised from two nodes as opposed to single node cuttings as infilling plants. The study was conducted at tea nurseries of KTDA Kangaita and Kagochi farms in Kirinyaga and Nyeri Counties, respectively. The treatments were two types of cuttings namely single node cutting (SNC) and two node cutting (TNC) from three tea clones (TRFK 31/8, TRFK 6/8 and AHP S15/10). The experimental design was CRD with split arrangements where main plot was the node cutting (2) and subplot was constituted by three clones. The treatment comprised a set of 200 cuttings and was replicated thrice in the two different sites. The parameters measured were survival count, ability to produce two shoots, number of new leaves and size, root and shoot length, and root biomass. All data collected were subjected to analysis of variance (p≤0.05) and where significant differences among treatments were found the means were separated using Least Significant Difference (LSD). The SAS statistical package was employed in all analyses. Results revealed that TNC had superior performance in most parameters measured compared to SNC with clone TRFK 31/8 showing better performance in more parameters than other clones apart from the ability to produce two shoots from TNC. The results showed that apical dominance in tea is not absolute and therefore a good number of cuttings grown as two node cutting (TNC) were capable of producing two shoots, a characteristic desirable for an infilling plant. The outcome of the study shows that tea farm productivity can be increased through faster development of healthy and robust infilling plants using TNC than through the conventional method employing SNC. It is therefore recommended that tea growers requiring faster infilling plants can use TNC in the tea nurseries. A further research to explore suitability of cuttings with more than two nodes needs to be undertaken.
Efficiency of Macropropagation in Relation to Other Banana Seedling Production Methods in Different Agro-ecologies in Central and Eastern Kenya
(2014-02-19) Kasyoka, Martha Rhoda; Mwangi, M.; Gitonga, Nkanata Mburugu
Bananas and plantains (Musa spp.) are amongst the most important tropical fruit crops and are staple foods in most parts of the humid tropics and important sources of income to small scale holders in rural areas. In Kenya, banana is grown as an important food and cash crop. However, its cultivation has largely remained small scale. A common limiting factor to large scale production and expansion of existing plantations is the difficulty in obtaining high quality planting materials. Natural regeneration relied on by most farmers is slow and could be a source of pests and diseases in new plantations. In addition, the numbers of seedlings generated are inadequate. Although tissue culture (TC) can produce a large quantity of high quality planting materials, it is not a viable option to small scale farmers due to the high cost of seedlings. To increase banana production, there is need for an easy-to-implement and affordable method of producing seedlings among small scale holders. This study investigated macro-propagation as an alternative low cost method for producing banana seedlings. In the present research, farmers showed preference for certain banana cultivars in five agro ecological zones namely LH1, UM1, UM3, UM4 and LM3. Cavendish, Gros Mitchel, Uganda green and Sweet banana were identified as the most popular varieties with percentage preferences of 70, 60, 15 and 15% respectively. Macropropagation nurseries were established in the five agro ecological zones. Efficiency of macropropagation as affected by genotype and ecology was then determined. Seedling production through macropropagation was also compared to micro-propagation and natural regeneration over a period of six months. Evaluations were done on the number of seedlings produced, costs of production and requisite skills. Growth characteristics such as height, number of leaves and diameter of the suckers from each technique were evaluated and compared under field conditions. Data was analyzed to form the basis for recommending the best cultivars in relation to the macropropagation technique and agro-ecological zones. Macropropagated seedlings were not significantly different from TC seedlings in terms of growth four months after transplanting (p>0.05). Seedlings produced through TC and MP reached average heights of 66.6± 2.58 cm and 62.56± 1.99 cm; and average diameters of 7.90± 0.37 cm and 7.43± 0.21 cm respectively four months after planting. However, macropropagation was significantly different (p>0.05) from TC and natural regeneration. It required less skills and capital investment compared to TC; Seedling production through macropropagation was easy and required a lower level of education compared to TC hence can be easily adopted among small scale farmers albeit with proper training. This can greatly increase banana production which will uplift the livelihoods of many Kenyans who depend on the crop.
Effects of water stress on antioxidant activity and phenolic contents of African nightshades and their distribution in Kisii and Siaya Counties of Kenya
(2014-07-25) Odhiambo Peter Okello; Mildred Pauline Nawiri; Winfred Musila
Over the last decade, African nightshades have featured increasingly in both formal and informal markets in different parts of Kenya. African nightshades were to be found only in the backstreets and in a few open-air markets but since then, they have become a common occurrence in most supermarkets, where they are sold in increasing quantities on a daily basis. However, consumption pattern seems to change as more consumers are becoming aware of the importance of health promoting phytochemicals with antioxidants properties present in African nightshades. This observed upward trend in consumption has been attributed partly to the benefits construed to accrue from their consumption. There is scantly scientific report point on the role of the vegetables in alleviation of diseases due to their richness in antioxidants. The study aims to characterize the different African nightshades in different agro-ecologies of Kenya (Kisii, Siaya and Kakamega counties) and assess the effects of water stress on the relative concentration of the antioxidants. The findings will help assign relative significance of the secondary metabolites to abiotic factor (water) and genetic (nightshade accession). The Participatory Rural appraisal will be employed to gather information from farmers on agronomic practices and the various African nightshades being grown. Water stress treatments will be carried out in farmers fields in the selected regions, however a control will be set up in a greenhouse. The treatments will be subjected to randomized complete block design. Different methods will be used in identification and quantification of the main phytochemicals. The researcher proposes to make use of Analysis of variance, data analysis approach to determine the correlations between subjecting the plants of different genotypes to water stress and the accumulation of phytochemicals in different plant
Genetic Diversity of Arabusta Coffee (Coffea arabica L. x Coffea canephora Pierre) and their Parental Genotypes
(2014-08-22) Gimase, James Mwita
Coffee ranks second after petroleum in international trade. In Kenya, it supports over 600,000 households, contributes up to12% of export revenue and employs 30% of the total workforce in Agriculture. Arabica (Coffea arabica L.) and Robusta (Coffea canephora Pierre) are the two species under commercial cultivation. Arabica coffee has low genetic diversity and susceptible to Coffee Berry Disease (CBD) and Coffee Leaf Rust (CLR) while Robusta Coffee has considerable diversity and tolerant to CBD and CLR. Interspecific hybrids between the two species have been utilized as sources of resistance to CBD and CLR. Induced tetraploid Robusta genotypes were introduced to Coffee Research Foundation (CRF), Kenya from Uganda and crossed with four varieties of Arabica as female parents to obtain interspecific F 1 hybrids (Arabusta) that are resistant to CBD and CLR. This study was carried out at CRF to characterize the genetic diversity of 12 interspecific F 1 Arabusta hybrids, 3 induced tetraploid Robusta, 4 Arabica varieties, Hibrido de Timor and a diploid Robusta using 13 SSR and 10 RAPD molecular markers. Bean biochemical components and beverage quality were also analyzed. RAPD and SSR PCR products were electrophoresed in 2.3% (w/v) agarose gel with 1x TBE buffer system and visualized in a UV light after staining with ethium bromide solution. The SSR and RAPD data were scored for presence (1) or absence (0) of bands, analyzed for polymorphic rate, subjected to cluster analysis using XLSTAT software and a dendrogram constructed using Un-weighted Pair Group Method with Arithmetic Averages. Coffee oils were extracted by Soxhlet method while caffeine, trigonelline, chlogenic acids (CGA) and sucrose were detected by high performance liquid chromatography system. Sensory analysis was carried by a panel of six judges as per the Specialty Coffee Association of America (SCAA). Biochemical and sensory data were subjected to Analysis of Variance using COSTAT software, means separated by Student- Newman - Keuls (SNK, p≤0.05) and Principle components analysis (PCA) plotted using XLSTAT software. SSR data revealed polymorphism of 51.5%, 50% and 6.9% for induced tetraploid Robusta, interspecific F1 Arabusta hybrids and Arabica genotypes respectively. RAPD data revealed polymorphism of 51.6%, 47.4% and 3.5% for induced tetraploid Robusta, interspecific F1 Arabusta hybrids and Arabica genotypes respectively. Cluster dendrogram separated the genotypes into various group revealing variations and indicating their relatedness. Biochemical data revealed significant (p≤0.05) differences among the genotypes for Caffeine, oils and sucrose but was not significantly different for CGA and trigonelline. Sensory data revealed highly significant (p≤0.05) differences for all the attributes. All the F1 hybrids scored above 80 points for total score, values that were similar to SL28 and SL34. This study revealed high genetic diversity and good cup quality for F 1 hybrids hence recommended for conservation, utilization in breeding programs, further study for adaptability and selection for release as coffee varieties.
Effects of Varietal Differences, Plant Spacing and Weeding Regimes on Weed Density and Yields of Upland Rice in Uganda
(Kenyatta University, 2015) Tabot, Anyang R.
Rice is relatively new to Uganda, yet consumption is outstripping production; and with a growing population, demand is likely to increase. NERICA (New Rice for Africa) rice – with high yields and ability to withstand dry conditions is being planted in most part of the country. However, weed infestation is becoming one of the biggest hindrances affecting rice production. The objective of the current work was therefore to investigate the effects of varietal differences, plant spacing and weeding regime on weed density and yields of upland rice in Uganda. A study was carried out during the 2013 cropping season in Mukono agricultural research station and a farmer’s field in Amuru District to evaluate the effects of varietal differences, plant spacing and weeding regimes on weed density and yields of upland rice. The experiment was laid in a Randomized Complete Block Design (RCBD) with Split-split plot arrangement and replicated three times. The weeding regime was the main plot treatment; row spacing constituted the sub-plot while varieties were sub–sub plot. In both sites, the average weed coverage was higher in NERICA-10 (87.8%) followed by NERICA-1 (58.2%) and lowest in NERICA -4 (22.5%). At both sites weed competition reduced rice plant height in NERICA-10 (52%) while, NERICA-1 and NERICA-4 had 27% and 15% reduction respectively. Integration of row spacing and weeding reduced weed biomass, with NERICA-4 having highest weed reduction of 89.2% under row spacing of 25cm by 10 cm and 2 hoe-weeding regime(2 and 3 weeks interval), while NERICA-1 and NERICA-10 under same treatment had weed reduction of (67%) and (48%) respectively. Weed competition significantly reduced productive tillers of rice varieties. NERICA-4 produced higher number of productive tiller (84.5%) under row spacing 30 cm by 10 cm and 2 hoe-weeding followed by NERICA-1 (68%) under 25cm and 2 hoe weeding and NERICA-10 (65%) under row spacing of 15 cm by 10 cm and 2 hoe weeding. The data showed that NERICA 4 was more tolerant to weed pressure than the other varieties. Spacing of 25 cm x 10 cm had less weed biomass though 15cm X 10 cm also reduce the weed biomass but had negative result in terms of yield. If farmers were to explore one hoe weeding to control weeds in rice; NERICA-1 should be recommend at a spacing of 30cm x 10 cm to attain an average yield of (2.93tha1) which is still above the national average of 1.7t ha-1. NERICA -4 at single hoe weeding out-yielded other varieties and its yield at two hoe weeding regimes tended to approach optimum.. Its superior yield advantage at single hoe weeding was consistent across locations and is of importance since most farmers are known to avoid a second weeding due to insufficient time and high cost of labor.
Effectiveness of macro propagation technique in production of healthy Banana seedlings in Eastern and Central regions, Kenya
(Kenyatta University, 2015-06) Njau, Njeri
Banana (Musa spp.) is one of the most important food and cash crops in Kenya. It provides food security, nutrition and income for many smallholder farmers. Bananas are eaten ripe or cooked depending on the variety. Despite its economic importance, banana production faces major challenges including scarcity of high quality seedlings, insect pests and diseases. Demand for pest free and high quality planting materials has been on the increase. Naturally regenerated suckers that are preferred by farmers are more likely to carry pests and diseases leading to reduced productivity and a short lifetime of new plantations. Tissue Culture has been introduced but its adoption has been low due to the high costs and skills involved. To address this constraint, macropropagation has been introduced as an alternative propagation technology. The technology can be implemented with little capital and skill. The study was aimed at assessing whether macropropagation technology can produce healthy banana seedlings. A survey was conducted to identify the current important diseases and insect pests of bananas in Eastern and Central Kenya. Macro propagation nurseries were established at Kenyatta University and in farmers' fields at Mathioya, Kirinyaga, Embu East, Meru Central and Mitunguu and Ntharene in Imenti South District. These sites represent different agroecological zones, including high, mid and low altitudes. Corms obtained in accordance with established quality assurance protocols were propagated and the health of the macro propagated banana seedlings monitored. Macropropagation was done in two cycles, the first in Feb - June 2011, and the second from July November 2011. The importance of the isolated organisms in banana health was determined through pathogenicity tests carried out under controlled conditions. To determine the effectiveness of macropropagation protocol in eliminating pathogens, corms were artificially inoculated with Radopholus similis, Fusarium oxysporum f. sp. eubense (Foe) andXanthomonas vasicola pv. musacearum (Xvm) followed by monitoring health of the seedlings from the inoculated corms. Fusarium wilt and Sigatoka were recorded as the most important diseases with 66 and 50% incidence respectively, while nematodes and banana weevil were the most important pests with 21 and 17% incidence, respectively. An average of 98 and 100% healthy seedlings resulted from the first and second cycles of macropropagation. Under simulated infection, macropropagation did not eliminate Foe and Xvm but completely removed plant parasitic nematodes (PPN). The study found that macropropagation technique is an effective method to produce healthy banana seedlings however precaution is needed to ensure quality of the seedlings where Xvm and Foe are present. The key control points for safeguarding health and quality of the macropropagated seedlings is during certification of corm sources to ensure selection of healthy corms, the process should be done aseptically and the corms should be treated before planting.
Effects of Phosphorus Deficiency on Secondary Metabolites and Distribution of African Nightshade in Siaya and Kisii Counties, Kenya
(Kenyatta University, 2015-08) Ogembo, Joel Oyaro
African Indigenous Vegetables form an integral part of the Kenyan diets, among the most commonly consumed being the African nightshade. These vegetables contain important phenolics that have medicinal values and good health attributes. The abundance of these phenolic substances has strongly been associated with phosphorus use efficiency. In order to investigate the effect of phosphorus stress on African nightshade distribution, a purposive research was done from February 2014 on 70 random farmers growing African nightshade using semi-structured questionnaires in Siaya and Kisii Counties, Kenya. The coordinates, plant and soil samples for the surveyed regions were taken and later on used to map the vegetables according to plant and soil phosphorus, total phenolic content (TPC), total antioxidant activities (TAA) and the two dominant varieties. Solanum scabrum had 69% distribution whereas Solanum villosum had 21% hence chosen for greenhouse and field experiments. The two varieties were planted in greenhouse and two field cropping seasons (long and short rain seasons) at Kenyatta University farm as split plot arrangements with two varieties being the main plot and phosphorus levels (0, 20, 40 and 60 kg/ha) constituting the subplot in Randomized Complete Block Design. The treatments were replicated four times. Data on plant height, fresh weight, number of secondary buds, leaf and root area was recorded and later the effects resulting from these treatments analysed using ANOVA. In greenhouse and field experiments, plant height, fresh weight, number of secondary buds, leaf and root area, TPC and TAA were significantly (p≤0.05) affected by the level of phosphorus. TPC and TAA decreased with increase in P, whereas all the growth parameters increased with increase of Phosphorus levels apart from height and weight of plants treated with 60kgP/ha that showed either stagnation or a slight decline. The decline was attributed to zinc and copper deficiency. The highest fresh weight was recorded at 40 kgP/ha, where Solanum villosum yielded 6.1t/ha and Solanum scabrum yielded 6.35t/ha. Solanum villosum had higher TPC and TAA (6.09mg/g and 38.58%) respectively as compared to Solanum scabrum that had 5.49mg/g (TPC) and 35.92% (TAA). Solanum villosum had more secondary metabolites in the shoots as compared to the roots, the converse was reported for Solanum scabrum. Results obtained will be used to educate farmers and extension personnel on ways of improving productivity of African nightshade and will also help develop product labels highlighting their phenolic and antioxidant contents. Farmers are therefore advised to apply phosphorus at the rate 40 kg/ha as it had the highest biomass production. Solanum villosum is recommended for soils with limited phosphorus. Further research to be done on other important nutrients for instance anthraquinones and how different levels of macronutrients affect their production.
Xenia effect on resistance to maize weevil and larger grain in maize
(Kenyatta University, 2015-11) Munyao, William Muthui
Maize (Zea mays) is a preferred staple as well as a cash crop in Sub-Sahara Africa, contributing to 34-36% of the daily caloric intake in Kenya. Maize production is constrained by several factors among them biotic factors. The key biotic factors leading to post-harvest losses are the maize weevil and the larger grain borer both of which cause grain weight losses in the range of 21-35%. Maize is an open pollinated crop and pollen from other sources influences grain characteristics in the year of crossing, an effect known as xenia. The xenia effect on resistance to maize weevil and larger grain borer is not known. The objective of this study was to determine the occurrence and level of xenia effect on resistance of F2 grain to maize weevil and larger grain borer. Fourteen genotypes (4 resistant and 4 susceptible to maize weevil) and 6 commercial genotypes, were used. The 14 genotypes were grown in 12 crossing nurseries using un-replicated nursery design. Crossing was done using maize weevil and larger grain borer resistant and susceptible genotypes as pollen parents in addition to sib, self, grouped-sib and open pollination treatments to generate F2 grain for evaluating xenia effect. Protein, oil and starch contents, hardness and 100 grain weight of the F2 grain were determined. Shelled and unshelled F2 grained were screened for maize weevil and larger grain borer resistance. Xenia effects were calculated by subtracting sib-mating treatment means from other treatment means for maize weevil and larger grain borer resistance traits evaluated. Xenia effect on F2 grain to maize weevil in cross pollination was a decrease in grain weight loss of 8.41%. Self and sib-pollination treatments xenia effects on resistance of F2 grain to maize weevil and larger grain borer were not significantly different which suggests that these treatments had no xenia effect on F2 grain resistance to these pests. Open pollination increased the starch content of F2 grain by 0.9% but reduced the oil and protein content by 0.16% and 1.03%, respectively. Group-sib pollination increased the oil and protein content by 0.14% and 0.34% respectively but reduced starch content by 0.41%. There was a decrease in F2 grain hardness in all treatments that ranged from 9.96% in cross pollination to 19.19% in open pollination. The decrease in hardness in cross pollination meant that the percent weight loss should have increased. But in contrary the percent weight loss decreased, suggesting that xenia effect in cross pollination influenced other factors that contributed resistance to maize weevil. The protein content of F2 grain was negatively correlated with percent dust weight, and percent grain weight loss and number of live insects. This means that percent grain weight loss, percent dust and number of live insects may be the best traits for determining xenia effect of F2 grain. The percent grain weight in the crosses between resistance and resistant and resistance with susceptible were not significantly different suggesting that xenia effects are as a result of dominance gene. It is evident from the results that xenia has effect on F2 grain resistance to maize weevil and larger grain borer and therefore screening for these pests should take into account this effect.
Evaluation of Chickpea (Cicer Arietinum L.) Genotypes for Host Plant Resistance to Ascochyta Blight (Ascochyta Rabiei) in Elgeyo-Marakwet, Uasin-Gishu and Baringo Counties of Kenya
(Kenyatta University, 2016) Chemweno, Jacob Kiprop
In Kenya, the counties of Elgeyo-Marakwet, Uasin-Gishu and Baringo, where maize, wheat and barley are normally grown, can be used to produce a second crop during the off-season (October-February) before the next cropping season or as a rotation crop during the main season (April-August). Introduction of drought tolerant leguminous crops such as chickpea in these counties is ideal in order to provide an alternative source of income to farmers. However Ascochyta blight (AB) disease which causes a lot of yield loss in chickpea could hinder this effort. Although the disease can be controlled by application of fungicides, host plant resistance is the most ideal as it is cheaper and ecologically sustainable. The objectives of this study were; to determine Ascochyta blight disease incidence and severity levels among selected chickpea genotypes in Elgeyo-Marakwet, Uasin-Gishu and Baringo counties, to determine the effect of Ascochyta blight disease on grain yields of selected chickpea genotypes in the three counties and to determine resistance levels to Ascochyta blight disease among selected chickpea genotypes. The study was carried out in three field sites; at Eldoret (LH4) in Uasin-Gishu county, Kaptagat (UH4) in Elgeyo-Marakwet county and ATC-Koibatek (UM4) in Baringo county. Greenhouse screening was carried out at Egerton University. Twenty five genotypes were obtained from Egerton University’s Seed Unit for evaluation in the three field sites and in the greenhouse. In the field, each genotype was sown in 2 m × 2 m plots, while in the greenhouse the genotypes were sown in 2 kg plastic containers. Each experiment was replicated 3 times in a randomized complete block design (RCBD). Data on disease incidence, severity and resistance levels to Ascochyta blight disease was obtained. Also data on grain yield and yield loss due to Ascochyta blight disease together with yield components such as plant height, number of pods, hundred seed weight, biomass and days to physiological maturity were collected. Collected data was subjected to Analysis of Variance (ANOVA) using PROC GLM of the SAS software. Correlation analysis was done using the PROC CORR procedures of the SAS (Version 9.3) and means were separated using Duncan’s Multiple Range Test (DMRT) at α = 0.05. There was very high (> 85 %) Ascochyta blight disease incidence in the three field experimental sites. Analysis of variance showed significant difference (P ≤ 0.0001) in resistance levels among the test genotypes; with mean resistance level of 5.68, coefficient of variation C.V = 12.55 and R2 = 0.88. There was a negative correlation (r = -0.84) between resistance levels of the test genotypes and their grain yield performance. Yield performance had a positive correlation with yield parameters such as number of pods (r = 0.85), biomass (r = 0.51) and hundred seed weight (r = 0.39), and a negative correlation with plant height (r = -0.09). Genotypes ICCV92318, ICCV07308, ICCV07304, ICCV00302 and ICCV6571 found to be both high yielding and moderately resistant to Ascochyta blight disease, are recommended for adoption in the three counties. Genotype ICCV05315 which was moderately resistant but low yielding is recommended for further breeding aimed at improving its yield. Similarly genotypes ICCV 96329, ICCV92944 and ICCV93954 which were high yielding but more susceptible to Ascochyta blight disease are recommended for further breeding aimed at improving their resistance.

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