Agronomy

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Effect of phytase application on micronutrient status of plant-based foods
(ios journals, 2022) Anuro J.B; Ogutu F.O; Okumu T.M
Abstract Plant-based foods constitute an important source of carbohydrates, protein, dietary fiber and vitamins. They are also associated with anti-nutrients, whose presence result in low bioavailabity of several micronutrients causing metabolic disorders related to the nutritional factors. Of prime concern for human nutrition and health management is phytic acid. In this review the effect of phytase application on micronutrient content and bioavailability of plant-based foods was critically analyzed. PubMed and Google scholar databases were searched for articles using phytase, phytase application in cereals, plant-based foods, micronutrients and deficiency as keywords. A total of 105 articles were obtained out of which 39 were included in the review. Results indicate that application of exogenous phytase to plant-b
Utilization of fruit waste substrates in mushroom production and manipulation of chemical composition
(Science Direct, 2020-01) Ojwang D. Otieno; Francis J. Mulaa; George Obiero; Jacob Midiwo
The current study evaluated the effect of mushroom cultivation using fruit waste substrates on yield performance and antioxidant activities. The total phenolic content and the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of the mushroom extracts were determined using colorimetric method. Mushroom P. eryngii had the highest yield of 87.2 ± 2.4 g/100 g dry substrate when grown on pineapple peels, while P.ostreatus yielded the least fruiting bodies 53.1 ± 1.8 g/100 g dry substrate when grown on orange peels. Similarly, P. eryngii grown on pineapple peels and P. ostreatus grown on orange peels had the highest and lowest biological efficiencies of 94.2 ± 3.5% and 69 ± 4.3%, respectively. The total phenolic content of P.ostreatus grown on avocado peels was 26.4 ± 3.8 mg GAE/g dry extract, while P.eryngii grown on avocado peels had the lowest at 9.3 ± 0.2 mg GAE/g dry extract. Mushrooms cultivated on fruit wastes generally exhibited higher DPPH activities than those grown on wheat straw (control) substrate. This study provided baseline information on the potential role of fruit waste substrates in mushroom growth and chemical composition.
Recent Limnological Changes and Their Implication on Fisheries in Lake Baringo, Kenya.
(Academic Journals, 2014) Omondi R.; Kembenya E.; Nyamweya C.; Ouma H.; Machua S. K.; Ogari Z.
Water samples for physico-chemical analysis for this study were collected monthly for five years between April 2008 and March 2013. Conductivity, temperature, dissolved oxygen and pH was measured in situ using a Surveyor II model hydrolab. Chlorophyll-a concentration was determined using a Genesys 10S Vis spectrophotomer. Nutrients were determined using standard methods and procedures. Analysis of Variance (ANOVA) was used to determine spatial and temporal variation in physico-chemical and biological factors. Principal component analysis (PCA) was performed to establish the correlation of the physico-chemical and biological parameters among sampling stations and to group stations with similar physico-chemical parameters. Both spatial and temporal significant variations (P<0.05) were detected in the concentrations of the nutrients measured during the study.
Reactive Oxygen Species (ROS) Generation, Impacts on Tissue Oxidation and Dietary Management of Non-Communicable Diseases: A Review
(African Journal of Biochemistry Research, 2017-12-31) Wanjala George Wafula; Onyango Arnold; Onyango Calvin; Makayoto Moses
Generation of reactive oxygen species (ROS) in biological systems has been reported to be a significant cause of inflammatory and metabolic diseases. More recently, ROS and in a particular ozone has also been implicated in the conversion of cholesterol to atherogenic compounds, secosterol A, and upon aldolization to secosterol-B. Secosterol-A is uniquely produced by cholesterol ozonolysis, while secosterol-B can also be generated through the reaction of cholesterol with singlet oxygen. On the other hand, lipid oxidation reactions generate hydroperoxides, which upon catalytic and/or enzymatic decomposition yields lipid peroxide products of significant importance to tissue health. The mechanism of formation of potent oxidants like ozone in biological systems has not been clearly demonstrated, with only a theory: That antibodies catalyze oxidation of water by singlet oxygen to yield a trioxidic species, like hydrogen trioxide, as an intermediate in hydrogen peroxide formation while a recent hypothesis indicates that ozone could also be an intermediate in the aforementioned pathway and could be generated from biological molecules in the presence of singlet oxygen. Similarly, there is new information being generated concerning the involvement of antioxidants and amino acids in either termination or propagation of oxidative processes in mammalian systems. This review explores mechanisms of ROS/ozone generation in tissues, lipid peroxidation, cholesterol oxidation and highlight dietary management of non-communicable diseases with a focus on the roles of antioxidants and amino acids.
Quality of Porridge rom Sub-Saharan Africa Evaluated Using Instrumental Techniques and Descriptive Sensory Lexicon - Part 1: Thick (Stiff) Porridge
(Academic Journals of Food Science, 2018-04-30) Onyango Calvin; Wanjala George W.
The sensory attributes of thick porridges made from different composite flours in neutral, citric acid or sodium bicarbonate media was identified using instrumental methods and modified quantitative descriptive analysis. The results showed that composite flours with high cassava concentrations had lower pasting temperatures but higher peak, breakdown, final and setback viscosities than the cereal-rich flours. The onset pasting temperatures of alkali-treated slurries were higher (p < 0.05) than for the neutral- or acid-treated slurries. Acid-treated slurries had higher (p < 0.05) peak viscosities than neutral- or alkali-treated slurries. Acid-treated slurries had higher (p < 0.05) breakdown viscosities as compared to the neutral slurries. The toughness and work of shear of thick porridge ranged between 0.21 - 0.58 kg and 0.83 - 5.95 kg·mm, respectively. Thick porridge cooked in alkaline media was significantly darker (p < 0.05) than that made in neutral or acid media. Principal component analysis identified four major principal components (PCs) that accounted for 87.6% of the total variance in the sensory attribute data. The principal component scores indicated that the location of each porridge along each of the four scales corresponded with attributes associated with sodium bicarbonate aroma and taste (PC1); cassava aroma and hardness (PC2); colour of thick porridge (PC3); and finger millet/sorghum aroma (PC4). Thick porridges targeting specific consumer groups in sub-Saharan Africa can be developed by appropriate choice of flours and pH thereby forming the basis for commercial production of thick porridges for different population categories in sub-Saharan Africa with diverse sensory expectations of the product.
Quality of Porridge from Sub-Saharan Africa Evaluated Using Instrumental Techniques and Descriptive Sensory Lexicon - Part 1: Thick (Stiff) Porridge
(Academic Journals, 2018-04-30) Onyango Calvin; Wanjala George W.
The sensory attributes of thick porridges made from different composite flours in neutral, citric acid or sodium bicarbonate media was identified using instrumental methods and modified quantitative descriptive analysis. The results showed that composite flours with high cassava concentrations had lower pasting temperatures but higher peak, breakdown, final and setback viscosities than the cereal-rich flours. The onset pasting temperatures of alkali-treated slurries were higher (p < 0.05) than for the neutral- or acid-treated slurries. Acid-treated slurries had higher (p < 0.05) peak viscosities than neutral- or alkali-treated slurries. Acid-treated slurries had higher (p < 0.05) breakdown viscosities as compared to the neutral slurries. The toughness and work of shear of thick porridge ranged between 0.21 - 0.58 kg and 0.83 - 5.95 kg·mm, respectively. Thick porridge cooked in alkaline media was significantly darker (p < 0.05) than that made in neutral or acid media. Principal component analysis identified four major principal components (PCs) that accounted for 87.6% of the total variance in the sensory attribute data. The principal component scores indicated that the location of each porridge along each of the four scales corresponded with attributes associated with sodium bicarbonate aroma and taste (PC1); cassava aroma and hardness (PC2); colour of thick porridge (PC3); and finger millet/sorghum aroma (PC4). Thick porridges targeting specific consumer groups in sub-Saharan Africa can be developed by appropriate choice of flours and pH thereby forming the basis for commercial production of thick porridges for different population categories in sub-Saharan Africa with diverse sensory expectations of the product.
Macrolepiota Aberdarense, A New Edible Mushroom from Kenya
(Current Research in Environmental & Applied Mycology, 2018) Mbaluto C; Runo S; Wanyoike W; Onyango C; Kimani W; Jagger H; Otieno DO
A new Macrolepiota species from the Aberdare Forest in Kenya is described and illustrated. The larger basidiomata with yellow brownish to brownish granular squamules, distinct umbo, larger basidia and smaller ellipsoid basidiospores form remarkable features that separate this species from previously published members belonging to the genus Macrolepiota. The phylogenetic analyses based on ITS-rDNA sequences further supported this distinction.
Strategies for Improving Hydrolytic Efficiency of Crude Multienzyme Extracts in Mushroom Processing
(Elsevier Inc, 2022-11) Ojwang D. Otieno; Mulaa F. Jakim; Obiero George; Midiwo Jacob
The current study investigated and optimized key process parameters affecting mushroom hydrolysis with crude enzymatic extract. The crude enzyme was prepared by solid-state fermentation of pineapple peels using Aspergillus niger. The reaction parameters viz. time, temperature, pH and enzyme concentration were optimized using the central composite design of the response surface methodology. The model predicted glucose yield of 1.49 mg/mL at optimal pH of 6.5, temperature of 50 °C, enzyme loading of 5 % (v/v), and reaction time of 12 h. Mushroom hydrolysis at the same optimal model conditions, increased glucose yield by 10%. More so supplementing SSF media with 0.2% (w/v) Tween-80 and 0.08% (w/v) yeast extract at moisture level of 70–75% significantly (p value < 0.05) improved hydrolytic efficiency of the crude enzyme extract by 2.2-fold. This study provides baseline data that will be useful in developing a low-cost enzyme-based process for hydrolyzing mushrooms to recover high-value products.
Utilization of Fruit Waste Substrates in Mushroom Production and Manipulation of Chemical Composition
(Elsevier B.V, 2022-01) Ojwang D. Otieno; Mulaa Francis J.; Obiero George; Midiwo Jacob
The current study evaluated the effect of mushroom cultivation using fruit waste substrates on yield performance and antioxidant activities. The total phenolic content and the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of the mushroom extracts were determined using colorimetric method. Mushroom P. eryngii had the highest yield of 87.2 ± 2.4 g/100 g dry substrate when grown on pineapple peels, while P.ostreatus yielded the least fruiting bodies 53.1 ± 1.8 g/100 g dry substrate when grown on orange peels. Similarly, P. eryngii grown on pineapple peels and P. ostreatus grown on orange peels had the highest and lowest biological efficiencies of 94.2 ± 3.5% and 69 ± 4.3%, respectively. The total phenolic content of P.ostreatus grown on avocado peels was 26.4 ± 3.8 mg GAE/g dry extract, while P.eryngii grown on avocado peels had the lowest at 9.3 ± 0.2 mg GAE/g dry extract. Mushrooms cultivated on fruit wastes generally exhibited higher DPPH activities than those grown on wheat straw (control) substrate. This study provided baseline information on the potential role of fruit waste substrates in mushroom growth and chemical composition.
Utilization of Fruit Waste Substrates in Mushroom Production and Manipulation of Chemical Composition
(Elsevier B.V, 2022-01) Ojwang D. Otieno; Mulaa Francis J.; Obiero George; Midiwo Jacob
The current study evaluated the effect of mushroom cultivation using fruit waste substrates on yield performance and antioxidant activities. The total phenolic content and the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of the mushroom extracts were determined using colorimetric method. Mushroom P. eryngii had the highest yield of 87.2 ± 2.4 g/100 g dry substrate when grown on pineapple peels, while P.ostreatus yielded the least fruiting bodies 53.1 ± 1.8 g/100 g dry substrate when grown on orange peels. Similarly, P. eryngii grown on pineapple peels and P. ostreatus grown on orange peels had the highest and lowest biological efficiencies of 94.2 ± 3.5% and 69 ± 4.3%, respectively. The total phenolic content of P.ostreatus grown on avocado peels was 26.4 ± 3.8 mg GAE/g dry extract, while P.eryngii grown on avocado peels had the lowest at 9.3 ± 0.2 mg GAE/g dry extract. Mushrooms cultivated on fruit wastes generally exhibited higher DPPH activities than those grown on wheat straw (control) substrate. This study provided baseline information on the potential role of fruit waste substrates in mushroom growth and chemical composition.
Lactic Acid Bacteria from African Fermented Cereal-Based Products: Potential Biological Control Agents for Mycotoxins in Kenya
(Journal of toxicology, 2022-02-22) Wafula E. N; Muhonja C. N; Kuja J. O; Owaga E. E; Makonde H. X; Mathara J. M
Abstract Cereals play an important role in global food security. Data from the UN Food and Agriculture Organization projects increased consumption of cereals from 2.6 billion tonnes in 2017 to approximately 2.9 billion tonnes by 2027. However, cereals are prone to contamination by toxigenic fungi, which lead to mycotoxicosis. The current methods for mycotoxin control involve the use of chemical preservatives. However, there are concerns about the use of chemicals in food preservation due to their effects on the health, nutritional quality, and organoleptic properties of food. Therefore, alternative methods are needed that are affordable and simple to use. The fermentation technique is based on the use of microorganisms mainly to impart desirable sensory properties and shelf-life extension. The lactic acid bacteria (LAB) are generally regarded as safe (GRAS) due to their long history of application in food fermentation systems and ability to produce antimicrobial compounds (hydroxyl fatty acids, organic acids, phenyllactic acid, hydrogen peroxide, bacteriocins, and carbon dioxide) with a broad range of antifungal activity. Hence, LAB can inhibit the growth of mycotoxin-producing fungi, thereby preventing the production of mycotoxins. Fermentation is also an efficient technique for improving nutrient bioavailability and other functional properties of cereal-based products. This review seeks to provide evidence of the potential of LAB from African fermented cereal-based products as potential biological agents against mycotoxin-producing fungi.
The Utilization of Cassava (Manihot Esculenta) and Quality Characteristics of Improved Varieties. A Case of Marigat, Baringo County.
(University of Eldoret, 2015-05) Yabann Eunice
Cassava provides vital nutrients to its consumers and is considered a food security crop for poor rural communities, particularly in arid and semi-arid regions of developing countries. The nutritional value of this crop is normally affected by many factors. In the central Rift Valley of Kenya, scientists have introduced new varieties. However, little is known about utilization and quality characteristics of new varieties, thus the need for this study. The objective of this study was to evaluate the utilization of cassava roots among the study group and to study culinary characteristics and nutritional values of the newly introduced cassava root variety. A total of 51 introduced cassava varieties were grown and all harvested at 16 months of age by Kenya Agricultural Research Institute (KARI)-Marigat. External preference mapping resulted in sensory panelists rejecting some of the cassava roots (n = 26) from further processing owing to the fact that they were woody, rotten, dark colored and fibrous. The remaining samples (n = 25), plus one sample (n = 1) picked from the local market were prepared and evaluated to determine ease of cooking. The panelists evaluated each sample and recorded their opinion in terms of surface appearance, taste, texture and overall acceptability. The attributes were scored using a hedonic scale ranging from 1-5 (where 1 = worst and 5 = very good). The varieties with a mean score of three (m = 3.0) and above in the given attribute(s) were considered acceptable. The surface appearance scored the highest means (3.80 ± 0.63) and least mean score was texture (3.20 ± 0.42). ANOVA results showed a significant mean difference in their sensory characteristics. The final test eliminated some of the cassava samples (n = 16). The remaining accepted cassava samples (n = 10) were further processed for nutritional quality determination. Proximate composition and mineral elements were measured using AOAC and HPLC. The results obtained were compared with U.S.D.A-21 reference standards. Protein levels of cassava variety R252m recorded the highest with 2.05% per 100g lower than the 3% USDA-21 reference standards. Fats ranged from 0.17% to 1.24% with only P12m cassava sample having value above the reference standards (1%). Carbohydrate (CHO) values were high in POROs with the value of 93.51% per 100gm, higher than the recommended U.S.D.A 21 standards (78%). Calcium (Ca) recorded highest in the variety P15 at 6.92% per 100g while P117o had the highest Fe content with 1.56 % per 100g. Phosphorus (P) was found in large amounts with P15m leading with 96% per 100gm. Iron (Fe), Fat, Potassium (K), and Protein had significant positive correlation with sensory qualities.
Quality Evaluation of Oil from Seeds of Wild Plant Tylosema fassoglensis in Kenya
(Journal of Food Processing, 2015-07-15) Ojwang D. Otieno; Okewo B. Awuor; Wanjala G. Wafula
Tylosema fassoglensis is a plant species that is native to Sub-Saharan Africa. The aim of this study was to evaluate the physicochemical properties of oil from T. fassoglensis in Kenya. Seeds of T. fassoglensis were collected from Mombasa, Taita Taveta, Homa Bay, and Siaya regions. Counts of T. fassoglensis in each region were recorded during the entire survey period. The highest distribution was recorded in Homa Bay followed by Siaya region. Distribution was the least in Taita Taveta and Mombasa regions. The analysis of the physicochemical characteristics of the oil was performed according to the official methods of analysis and the recommended practices of the American Oil Chemists Society. Oil content of 36.4% was obtained. The oil had refractive index 1.47 at 40°C, peroxide value 6.34 meq O2/kg, iodine value 94.06 g of I2/100 g, saponification value 145.93 mg KOH/g of oil, acid value 2.49 ± 0.56 mg KOH/g of oil, and unsaponifiable matter 5.87 g/kg. The oil had Lovibond color index of 2.0Y+28.0R. Oil content of T. fassoglensis is comparable with those of most oil crop under commercial production. The physicochemical properties of oil from T. fassoglensis are within the range recommended by FAO/WHO and hence suitable for human consumption.
Molecular Characterization of Wood Ear Mushrooms (Auricularia Sp.) from Kakamega Forest in Western Kenya
(Current Research in Environmental & Applied Mycology, 2016-03-30) Onyango B.O.; Mbaluto C. M.; Otieno D. O.
Mushrooms of the genus Auricularia, generally termed wood ear mushrooms are in high demand in Western Kenya due to their numerous medicinal and nutritional properties. Interventions to characterize and conserve the native wood ear mushrooms are necessary to mitigate possible extinction of this valuable bio-resource. Currently, the species richness and bio-geographical relatedness of the Kenyan native wood ears is not fully elucidated. This study used molecular sequence analysis of the internal transcribed spacer (ITS) and the 28S nuclear ribosomal large subunit (nLSU) genes in species delimitation of six strains of wood ear mushrooms native to Kakamega Forest. Phylogeny of both the ITS and nLSU gene regions showed that three strains clustered with Auricularia delicata while the other three strains clustered with Auricularia polytricha at bootstrap support values of above 97%. An intragenomic dichotomy appeared to occur in the Auricularia delicata strains based on the genetic distance of the nLSU gene sequences. The wood ear mushrooms identified from the Kakamega Forest strains were Auricularia delicata and Auricularia polytricha and not Auricularia auricula as previously reported. This rich biodiversity needs further exploration to widen the nutritional and medicinal base of the rural populace who depend on the mushrooms through conservation, cultivation and commercialization activities.
Storage Conditions and Postharvest Practices Lead to Aflatoxin Contamination in Maize in Two Counties (Makueni And Baringo) in Kenya
(De Gruyter Open Access, 2022-11-30) Kamano Hannah Mugure; Okoth Michael Wandayi; Makau Wambui-Kogi; Kuloba Patrick; Gitahi Nduhiu
Aflatoxins are known to cause devastating acute and chronic effects in humans and animals. The objective of the study was to determine the influence of postharvest practices and storage conditions on aflatoxin contamination in maize in two counties. Aflatoxin levels in 144 maize samples from different maize storage conditions were determined. While sampling, a structured questionnaire was also administered to evaluate farmer’s postharvest practices. Makueni County had the highest percentage of aflatoxin positive samples with up to 174 ppb attributed to the long storage under unfavourable conditions. On the other hand, Baringo County had lower positivity associated with the harvesting season at the time of sample collection. The type of storage condition had a significant effect on the extent of contamination and accounted for 11% of the variation (R 2 = 0.11). Gunny bags were the most common type of storage condition and had the highest level of contamination in both the counties. Metallic bins had the lowest level of contamination. Aflatoxin G1 and G2 were predominant in samples from Baringo County, while aflatoxin B1 and B2 were predominant in samples from Makueni County. The study concluded that the type of storage condition significantly contributes to the aflatoxin contamination in the stored maize. Proper drying of maize to the recommended moisture content and subsequent storage in hermetic structures will reduce the cases of aflatoxin contamination.
Survival and Avoidance Response of the Freshwater Gastropod Melanoides Tuberculatus (Muller) to Different Concentrations of Tobacco Waste.
(Wiley online library, 2011-11) Ochieng Eric; Omondi Reuben; Opiyo Mary A.; Charo-karisa Harrison; Muguti Jonathan; Aura christopher Mulanda
The Gastropod Melanoides tuberculatus plays a significant role in hampering fish larval production in earthen ponds. This study investigated use of tobacco waste to assess behavioural and survival responses of M. tuberculatus at different concentrations of tobacco waste solution of 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75 and 2 g L−1. Mean escape time varied significantly among concentrations (P < 0.05). Escape time decreased in 1-, 2- and 3-day-old solutions. Percentage survival decreased significantly with increasing concentrations of tobacco waste solution and exposure time (P < 0.05). Concentrations of 1.75 g L −1 and 2.0 g L−1 had high hazard ratios and low survival rates of gastropods and were the most effective in eradication of M. tuberculatus, hence recommended dose for preparing ponds for stocking. We conclude that tobacco waste solution can be used for control of M. tuberculatus.
The Fate of Afiatoxins During Processing of Maize into Muthokoi - A Traditional Kenyan Food
(ScienceDirect, 2008-07) Mutungi Christopher; Lamuka Peter; Arimi Samuel; Gathumbi James; Onyango Calvin
The effect of processing muthokoi, (a traditional dehulled maize dish in Kenya) on aflatoxin content of naturally contaminated maize was investigated. Dehulling decreased aflatoxin levels by 46.6% (5.5-70%) in maize samples containing 10.7-270 ngjg aflatoxin levels. Soaking muthokoi in 0.2%, 0.5% and 1.0% solutions iati, sodium hypochlorite or ammonium persulphate for 6 or 14 h further decreased aflatoxin contents by 28-72% in maize samples containing 107-363 ng/g aflatoxin levels, and boiling muthokoi at 98°C for 150 min in 0.2-1.0% w/v iati decreased aflatoxin contents by 80-93% in samples having 101 ng/g aflatoxin contamination. Findings imply that expo¬sure to acute aflatoxin levels in maize is minimised during processing and preparation of muthokoi.
Relationship between Level of Participation of Researchers, Extension Agents and Farmers in On-Farm Research Trials and Adoption of Technologies Case Study: Maize and Beans Producers, Kenya
(Institute of Development Studies, 2014) Ochola W.A.; Basweti E.A.; Ogendi G.M.; Onyango C.A.; Ochola W.O.
This study was conducted to determine the relationship between level of participation of researchers, extension agents and farmers in on-farm research trial activities and level of adoption of technologies developed through that process. The study was based on technologies used to improve the productivity of maize and beans in southwest Kenya. The study used an ex-post facto research design with a survey methodology. It was designed to use three sets of questionnaires directly administered to farmers, extension agents and researchers to collect data from the researchers, farmers and government extension agents. Stratified random sampling technique was used to select 104 respondents. The study established that; there was a significant relationship between occupation of respondents and their level of participation; there was a significant difference between the level of involvement of farmers, extension agents and researchers with the mean participation of the extension agents being relatively high compared to the researchers and farmers in on-farm related activities. However, there was low level of interaction between the researchers, extension agents and farmers; and there was a significant relationship between agro-ecological zones (AEZs) and level of participation of farmers with farmers at higher AEZs having higher participation levels compared to the farmers at the lower zones. The study finally concluded that, there was a strong positive relationship between the level of participation and level of adoption. The study therefore recommends that extension agents and researchers should consider improving their level of participation in joint activities.
Effect of Ridging and Intercropping on Sorghum Productivity in Arid and Semi-Arid Lands of Eastern Kenya
(African Crop Science Journal, 2022) D. Musyimi
Sorghum is a staple food crop and essential for food security in Arid and Semi-Arid Lands (ASALs). The crop is one of the major sources of livelihood in Kenya’s Eastern, Western and Rift Valley regions. Sorghum productivity has however been on a decline due to soil moisture deficit owing to erratic and erratically distributed rainfall and elevated temperatures experienced in the ASALs. It was therefore critical to explore the effects of moisture conservation practises and intercropping of sorghum with common beans on sorghum productivity, an area that has received limited research attention. The objective of this study was to evaluate the effect of ridging and intercropping on soil moisture conservation, sorghum productivity and land productivity in ASALs. The study was carried out at Agricultural Mechanization Research Institute, Kiboko sub-centre, under controlled irrigation. The experimental design was a randomized complete block design in split plot arrangement. The treatment structure constituted ridging techniques; 1) no ridging, 2) open ridging 3) tie ridging under the main plot and intercropping; sole sorghum and sorghum-bean intercropping with two bean varieties KAT Bean 1 and KAT X56 under the subplot. Soil moisture content was monitored gravimetrically. Moisture data, sorghum yield and bean yield data were collected and subjected to analysis of variance (ANOVA) using GENSTAT (version 20.1) and means were separated by fisher’s protected LSD. Soil moisture content was found to increase by 25-26% and 11-13% due to tie-ridging and open-ridging respectively relative to no ridging. On the other hand, moisture content decreased by 10%-11% due to Sorghum-KAT B1 intercropping and 5-8% due to sorghum Kat X56 intercropping relative to sole sorghum. Sorghum grain yield was found to increase by 29-33% due to tie ridging and 0-28% due to open ridging relative to no ridges. Sorghum-bean intercropping was found to decrease sorghum grain yield by 34% due to sorghum-KAT B1 and 36% due to sorghum-KAT X56 intercropping. There was no significant interaction between ridging and intercropping. Ridging exhibited increase in soil moisture content, sorghum yield and sorghum equivalent yield. Intercropping sorghum and bean (additive system) exhibited a decrease in soil moisture content and component sorghum yield. Interestingly, intercropping exhibited an increase in sorghum equivalent yield (p≤0.05). The study recommends 1. the use of tie ridging for improved soil moisture content and sorghum yield. 2. Integration of ridging and sorghum-bean intercropping (additive system) for increased water use efficiency and land productivity.
Response of Tea (Camellia Sinensis) to Rainfall and Temperature Patterns in Kenya
(African Journal of Agriculture and Utilisation of Natural Resources for Sustainable, 2022-04) Kimutai Langat Joseph
Tea (Camellia sinensis [L.]) is cultivated in diverse climatic conditions, latitudes ranging from the equator to 33O S (Natal, South Africa) and 49ON (Georgia, USA), altitude varying between sea level (Bangladesh) to 2600 MASL (Mt. Kenya). The climates in these altitudes and latitudes range from Mediterranean to hot, humid tropics of Africa and Asia. Growth and productivity of tea are influenced by air temperature, soil temperature, soil moisture and solar radiation, all other factors not limiting. Seasonal differences in rainfall and temperature exist in the tea growing areas. This study was undertaken to investigate the response of tea genotypes to rainfall and temperature patterns in the Kenya’s tea growing sites. A study was conducted in three sites (Kangaita (0O 30’S, 37O 16’E, 2100 m a.s.l.), Kipkebe (0O 17’S, 35O 3’E, 1740 m a.s.l.) and Timbilil (0O 22'S, 35O 21'E, 2200 m a.s.l.) with variations in weather conditions in Kenya using a split-plot design laid in RCBD to investigate the effect of temperature and rainfall to seasonal patterns among four tea clones (AHP-SC31/37, EPK-TN14-3, TRFK-301/5 and TRFK-31/8) of scientific and commercial importance to the country. Season 1 (mid-December to March) experienced clear skies, where highest temperature values and lowest rainfall amounts were realized. In season 2 (April to August), highest amount of rainfall and lowest temperature were measured. Moderate temperature and rainfall were recorded in season 3. Two-way ANOVA (P=0.05) for split-plot design indicated rainfall and temperature were significantly different between seasons and locations. This study conformed to the seasonal patterns experienced in the tea growing regions of Kenya.

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