Department of Agricultural Resources and Economics

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EFFECTS OF WEATHER ON THRIPS POPULATION DYNAMICS AND ITS IMPLICATIONS ON THE THRIPS PEST MANAGEMENT
(Karatina University, 2008-06-30) Waiganjo, M.M.; Gitonga, L.M.; Mueke, J.M.
Onion thrips, Thrips tabaci Lindeman, is the most destructive insect pest of the onion crop, Allium cepa L. worldwide. Both larvae and adults attack the onion crop at all stages of its growth, resulting in reduction of yield and quality. Despite the heavy losses incurred as a result of damage by the onion thrips, very little efforts have been made to develop an integrated pest management strategy for the control of the pest in many African countries. Field trials were conducted in four seasons at the Kenya Agricultural Research Institute (KARI) Mwea-Tebere farm in Kirinyaga District. Onion plants were planted periodically and thrips populations monitored weekly from onion plant samples and blue sticky traps for a full year under natural field conditions. The purpose of the trials was to assess the effect of weather on thrips population in onions with the aim of predicting thrips control requirements for a given climatic trend. Weather variables monitored included: rainfall, temperature, relative humidity and wind. Thrips occurred in the onion field and infested onions in all the crop seasons. However, there was significant (P=0.05) variation in thrips numbers between the crop seasons. Dry weather (30.3 mm rainfall) with moderately high temperatures (15.6-28.2oC) increased seasonal thrips numbers, while wet season (391mm rainfall) with moderately high relative humidity was negatively correlated with thrips numbers. Regression analysis (step-wise selection model) showed that minimum relative humidity was the only significant weather factor for predicting thrips infestation in the onion crop (R2 =0.15; y = 60.342-0.1022x). The results suggest that climatic trends can be used to determine the potential thrips control needs in onion production.
The polyphenolic composition and radical scavenging properties of Kenyan tea cultivars
(2015) Karori, S.M; Wachira, F.N; Ngure, R.M; Mireji, P.O.; Koech, R.K
Interest in medicinal and health enhancing properties of functional components in foods continues to arouse a lot of interest. Polyphenolic fractions in tea are potent bioactive molecules. In this study, the polyphenolic composition of 25 different types of Kenyan tea cultivars was determined using the HPLC and the Folins Ciocalteus spectrophotometric methods. Total polyphenols, total catechins, individual catechins and antioxidant activity were significantly (P < 0.05) different among tea varieties, with green tea having the highest levels of total polyphenols ranging from 19.70% to 26.12%, TC (8.51% to 17.60%), individual catechins, and AA (86.65% to 94.50%). In vitro bioassay carried out using 2, 2'-diphenyl picryl hydrazyl radical showed epigallocatechin gallate was the most potent catechin and the most potent in antioxidant activity (r = 0.968***). Epigallocatechin (r = 0.659***, P < 0.001), epicatechigallate (r = 0.454*, P < 0.001), and epicatechin (EC) (r = 0.780***, P < 0.001), showed significant (P < 0.05) antioxidant activity. Black tea contained high levels of theaflavins and thearubigins (2.072% to 17.12%), respectively which accounted for its antioxidant activity (r = 0.803*** and r = 0.859***, respectively). Gallic acid also showed significant (r = 0.530*) contribution to the antioxidant activity in black tea. Data obtained from this study reveals that different Kenyan tea cultivars have different polyphenolic composition which imparts on their unique biochemical qualities. Cultivar type is therefore a critical factor in determining the antioxidant potency of tea product and that black tea processed from suitable cultivars could be potent in antioxidant activity when compared to green tea. Green and white tea products are rich in catechins, black tea products are rich in TFs and TRs while purple tea is rich in anthocyanins.
Factors influencing adoption potential of purple tea in Nyeri County: A geographic perspective
(2015) Huho, J.M.
Kenya is the world’s third largest producer of tea after China and India. Tea plays a major role in Kenya’s economy as it is the third major foreign exchange earner, behind tourism and horticulture and employs approximately four million people. Over 96% of the tea is produced and exported as black tea; largely for blending lower quality tea from other countries, leading to low market prices. Coupled with the effects of changing climate, the low prices have been threatening tea production. As a result, Tea Research Foundation of Kenya (TRFK) has developed the purple tea clone (TRFK306/1) which is not only high quality and high yielding but also drought, frost and diseases resistant. The release of purple tea clone to farmers in 2011 was in response to the Vision 2030 and MediumTerm Plan (MTP) 2008-2012 which targeted new tea products diversification and value addition so as to enhance tea productivity and to boost agricultural economic growth. Unfortunately, the adoption of the purple tea by farmers has remained relatively low with the awareness standing at 30%. To a large extent, this has been attributed to poor marketing of the purple tea and inadequate processing plants for the product. The need to enhance adoption potential on purple tea has therefore, led to emergence of researches largely focusing on economic aspects such as marketing and establishment of processing plants. However, other important factors influencing adoption potential such as climate change and demographic characteristics of the farmers have received less attention. This study investigated the socio-demographic factors affecting adoption potential of purple tea in Nyeri County from a geographical perspective.
Addressing the education and training needs of the tea sector in Kenya: The case of the School of Agriculture and Biotechnology at Karatina University
(2015) Kamotho, G.N.; Mathenge, P.W.; Kamiri, H.W
In Kenya, personnel working in the tea sector are drawn from various fields of specialization such as general agriculture, horticulture, engineering and economics. There are no special training programmes to train personnel at degree, diploma and certificate levels on tea in the country. The training needs assessment carried out by Tetralink Taylor and Associates East Africa in 2010, observed that there are training needs for each segment along the tea value chain. It is against this background that the School of Agriculture and Biotechnology, Karatina University recognized the training gap in tea value chain and decided to design and mount specialized programmes in tea. The paper was informed by the Training Needs Report of 2010 by the Tetralink Taylor and Associates East Africa and other secondary data from published articles on tea. From the documentary analysis, it was established that training of personnel for tea sector was long overdue. Karatina University has taken the right direction towards this crucial aspect of human resource capacity building. It is recommended that Karatina University be a centre of excellence for tea information resource and develop more tea academic programmes for manpower training at bachelors, master and doctorate degree levels.
Tea and biofertilizers: A below ground biodiversity sustainable approach
(2015) Kavoo, A.; Kamiri, H.; Jefwa, J.
Tea is produced in the humid tropical and sub-tropical regions, which are home to rich biodiversity. The tea plantation environments have the potential to conserve a rich biodiversity which could serve as a source of biofertilizers. The natural abundance of microorganisms within the tea agro-ecosystems are expected to play a key role in sustainability of environment and increase tea performance and quality. However, agricultural and anthropogenic practices interfere with the tea agro-ecosystems and reduce the potential of the below ground biodiversity in sustainable tea production. The extent of this interference differs agro-ecologically and mapping of the biodiversities could provide a guide into the rich sampling sites which can be characterized, isolated, bulked and packaged into biofertilizers. Biofertilizers often double as efficient plant-aids in nutrient uptake and biopesticides, and offer an alternative to inorganic fertilizers and chemical pesticides which are a threat to humans and environments. Currently, the biotechnological manipulation of the tea rich biodiversities is very limited despite the opportunity it offers in biofertilizer production and utilization.
Emerging issues in the Tea Industry
(2015) Kimenyi, E.
Impact of innovation on the financial performance of KTDA managed tea factories: A case of Meru and Kirinyaga counties
(2015) Kiai, R.M.; Wambui, J.W.
Kenya is a key player in global tea industry and especially through Kenya Tea Development Agency (KTDA). However, KTDA has been facing the challenges of increasing cost of production in the recent past. The higher processing cost translates to low returns to the farmers resulting in conflict between the management and the farmers. To address the issue of increasing cost, a number of innovations have been undertaken with the aim of reducing the operational cost. This paper looks at the organizational innovation and process innovations and the effect they have in the reduction of operation costs in KTDA factories in Meru and Kirinyaga counties. The study used both primary and secondary data from sampled respondents. A self-administered questionnaire was used for collecting primary data and financial reports by the companies for the secondary data. Data analysis was by use of SPSS, where descriptive and inferential statistics, t-statistic, were used in assessing the relationship between the variables in the study. The study found out that the innovations adopted by KTDA have had a positive impact on the financial performance of the factories by reducing the operational cost. The paper recommends that KTDA managed factories continue adopting innovations in their operations to lower operational cost and higher returns to the farmers.
The role of Tea Industry in the achievement of the Kenya Vision 2030
(2015) Wainaina, G.
ICT and technological development in advancing tea research in Kenya
(2015) Oluoch, J.; Osida, J.
Agriculture is the backbone of the Kenyan economy and it is constantly influenced by changes in technology. Because of the rapid development of ICT in the world, each organization or person has to concern their products and services more towards modernized and ICT related manner. This research contribute to understand the technological development and use of ICT in advancing tea research, identify the constraints associated with ICT use and propose recommendations with managerial implications towards the improvement of present ICT system in agriculture sector of Kenya. Tea producers and farmers in Kericho County were selected for the survey. A scoring system was used to develop continuous dependent variables which were used in regression models to identify the variables most significantly influencing ICT use. Least significant difference technique was used to identify comparisons of constraints in ICT use in advancing tea research. There were 60.6% of the participants who used ICT related equipment or facilities for their tea production and tea related business and 76.1% of the participants had ICT uptake problems, where telecommunication and internet reported higher impact on tea sector. The participants stressed the cost of technology, lack of training, trust level in the ICT system, lack of ICT proficiency and lack of technological infrastructure as challenges for ICT use in advancing tea research. Managers can use these results to promote ICT use in tea research that can lead to more efficient communication and increased demand for the firm’s products and services. The usage of different ICT applications was comparatively high in tea sector and in general the usage of mobile communication was common among all participants. This survey results provide insights which suggest corrective steps to expedite ICT and technological development in advancing tea research and prioritize the necessary research in the sector.
Recent advances in tea research
(2015) Bore, J.K.
Origin, discovery of tea, wild tea and early development of tea in Assam, indigenous tea and tea drinking habit among the tribes in Assam of India
(2015) Baruah, P.
Tea is the most popular beverage in the world and its consumption is next only to water. The scientific findings on its health beneficial properties and as a drink of general wellbeing are contributing to make it even more popular and accepted as a beverage of goodness and for a healthy life style. Tea drinking originated in China about 5,000 years ago and gradually the world took to drinking tea. India is a major producer of tea in the world and the State of Assam is the largest tea growing belt in the world. Tea was discovered growing wild in Assam by the British in early 1800. The local population of Assam, some of the tribal people, were in the habit of drinking tea in their indigenous method of preparation. The practice is still continuing. Subsequent tea cultivation in Assam has made it a major agro-industry of the state and the finest liquoring quality of black tea in the world are produced here and consumed all over the world. Tea drinking has rather been gaining further acceptance now due to its natural health benefiting properties. The heritage drink has withstood the test of time and it may well be the drink of the future. The journey of the beverage through the passage of time has been glorious and fascinating. The origin of tea in China, myths associated with it, spread across the world, perceptions, culture and habits, discovery in wild forests of Assam, and tea drinking habit of the tribes of the state are all amazing like the mystic brew itself.
Tea trade in Kenyan markets: Effects of marketing strategies on sustainable domestic market and return to the smallholder tea enterprise
(2015) Wanjiru, M.E.; Wangare, W.T.; Muchina, S.; Kimani, P.
Kenya is the third largest tea producer and the leading producer of black tea in the world. It exports over 99% of her tea as black CTC of which 88% is exported in bulk form while the rest as value added tea. Kenyan tea is acclaimed globally as a high quality product, available all year round. It is primarily used for blending tea from other origins hence lacks visibility in the world market. Kenya's domestic market is limited and accounts for about 5% of her total production. A drop in demand in any of her exporting market can lead to a major impact on her revenues from tea as well as the return to the smallholder enterprises. The processed tea is traded through three marketing channels namely; direct sales, factory door sales, and the tea auction in Mombasa. The Mombasa Tea Auction serves as a regional auction centre for the tea producing countries namely; Uganda, Tanzania, Rwanda, Burundi, Congo and Malawi thereby positioning Kenya as a major tea trade centre. However, the Mombasa Auction faces competition from the Dubai Tea Trading Centre (DTTC) posing a challenge for the Kenyan tea industry. It is because of this glaring competition that the Tea Industry needs to have plan B. This paper explores the effect of the marketing strategies on creating sustainable domestic markets and on the return to the smallholder tea enterprise in Kenya. The paper is guided by secondary tea sector data, field data obtained from smallholder tea farmers sampled from KTDA managed factories in the Nyeri and Kirinyaga counties. Interview reports from key tea sector stakeholders in Kenya were used as well. The paper indicates that the domestic market of the Kenyan tea is shrinking due to unfavourable marketing strategies. Brand awareness locally is ignored and all the efforts are geared towards foreign markets which are not sustainable. Promotion of the domestic markets would increase the brand ownership creating a competitive platform for tea and other beverages in the shop floors. This in turn would increase the smallholder earnings through increased sales volumes and improved prices. The paper recommends strategies that would increase awareness of tea locally to the advantage and benefit of the smallholder tea enterprise and ensure sustainability of domestic Kenyan market.
Genetic mapping and identification of quantitative trait loci for yield and drought tolerance in tea
(2015) Kamunya, S.M.; Kireger, E.K.; Wachira, F.N.; Sharma, R.S.; Korir, R.; Maritim, T; Kiplang’at, J.; Sharma, V.; Chalo, R.; Ahuja, P.S.
Accelerated breeding and selection of improved tea (Camellia sinensis (L.) O. Kuntze) cultivars requires sound knowledge and understanding of genetics associated with desirable attributes.Quantitative trait loci (QTL) mapping for yield and drought tolerance in tea was performed using 42 F1 clonal progeny derived from a cross between tea cultivars TRFCA SFS150 and AHP S15/10 that had been established at two distinct tea growing regions in Kenya. The 100 informative markers identified in the cross that exhibited 1:1 segregation ratio were used to construct a linkage map of tea. The map consisted of 30 (19 maternal and 11 paternal) linkage groups that spanned 1411.5 cM with mean interval of 14.7 cM between loci. QTL analysis was carried out for yield and drought tolerance produced nine putative yieldQTLs and 13QTLs for drought tolerance. None of theQTLs was congruently detected in the two sites owing to G x E interactions. Markers OPT-18- 2500 and OPO-02-900 had pleiotropic effects in that they were significantly associated with yield at Timbilil (YLD-T; P = 0.007) and drought tolerance at Kangaita (DT-K; P = 0.003). The implications of the current study with respect to mapping population, G x E and marker-assisted selection are discussed.
Environmental issues in the tea value chain
(2015) Macharia, A.
The Director EEIPP's presentation pointed out that tea production is important for Kenya’s economy in several ways. These include: direct and indirect contribution to GDP and exports dependency; Source of employment; and, Food security. However, there are environmental concerns in the tea sector. The Environmental Concerns can be summarized into three: i) Concerns during construction of tea factories and associated infrastructure; ii) Concerns during tea manufacturing process; and iii) Concerns in tea agriculture.
Quality assurance in Tea Industry
(2015) Imong’i, F.K.
Prospects for organic tea farming in Kenya: Two case studies
(2015) Kamau, D.M.; Kekana, V.; Sitienei, K.; Wanyoko, J.K.; Nyabundi, K.
Organic tea farming entails non-use of pesticides and inorganic fertilizers, including the processing and packaging of the tea. This implies that documents must be filed which prove all requirements are met throughout the growing, processing, packaging, and which can be traced by the organic certification organization. Today, almost all kinds of tea grown in Kenya are non-organic. This is despite the fact that only NPK fertilizers are used in tea farms. It is difficult just to make an organic tea farm because of the many non-organic tea farms around it. Dispersals of chemical fertilizers or herbicides and other chemical agents interfused through the soil from surrounding farms can enter the organic farm. Therefore, it is necessary to make a buffer zone or shelterbelt between an organic tea farm and nonorganic tea farm or to embrace organic tea cultivation together with the neighbouring farmers. However, the starting point is to establish that organic tea can indeed be grown economically. Two long term studies comparing different sources of organic manures in Kericho and Kangaita were assessed for yield, some soil properties and tea quality chemical parameters. The results reveal that although the organic manures do not give as high yields as the enriched manure treatments from inorganic sources, rates of 120-150 kgN/ha would suffice to replenish the lost nutrients thus maintaining tea bush health and also optimal yields. The soil pH, available K and Ca results also demonstrated that the organic manures can maintain the acidity levels of the soils thus addressing the often controversial land sustainability problem arising from use of external inputs in tea agroecosystems. Organic manures and enriched manures increased the TF and TR content while caffeine increased with increase in nitrogen rates. This was more pronounced when using inorganic fertilizers and enriched manures. The study suggests that development and promotion of organic and low carbon in the Tea Industry is key to the attainment of ecological health and environment protection by both the tea producers and consumers. Tea growers have to be compensated by benefiting from premium organic tea prices due to the loss in yields as seen by the higher yields arising from the enriched manures.
The use of modern information and communication technologies in smallholder agriculture: Examples from Kenya and Tanzania
(Information Development, 2015-09) Krone, M.; Dannenberg, P.; Nduru, G.
Through examining the example of commercial small-scale horticultural farmers in Mt. Kenya region and Mwanza region, this empirical study aims to provide an explanation for why different perspectives on the impact of information and communication technologies (ICT) in the Global South exist. A mixed methods approach was used to show that ICT usage can lead to significant improvements, including access to simple and complex knowledge and the development of business linkages. However, the influence of ICT depends on the different ICT usage types and the capabilities of farmers to use them. This paper gives a differentiated view on factors influencing the effects of ICT on small-scale farming. It provides a typology of ICT that helps to explains some of the potential effects of ICT usage in the Global South. The results contribute to the current applied and conceptual debate on market access for smallholders and Information and Communication Technologies for Development.
Optimization of manufacturing conditions of the new purple leafed Kenyan teas (TRFK 306) – maceration style and withering duration
(2018) Kilel, E.C.; Wanyoko, J.K.; Faraj, A.K.; Ngoda, P.
Purple tea in Kenya, TRFK 306, has received great attention due to its perceived health benefits though how it should be optimally manufactured has not been researched on exhaustively. The current study investigated on the two possible methods of manufacture – Cut Tear and Curl (CTC) and orthodox manufacture - with varying withering time of 0, 5, 10, 15 and 20 hours. Catechins, gallic acid, caffeine, total polyphenols and antioxidant activity were assayed as quality indicators. If gallic acid and caffeine are the main chemicals targeted, then orthodox type with longer withering, 15 – 20 hours, is usually recommended. When targeting catechins especially epigallocatechin gallate and high total polyphenols, orthodox type of manufacture whichever the withering time is proposed. CTC with withering hours of 15-20 produces teas with high antioxidant activity. It was concluded that TRFK 306 is best processed by orthodox or CTC but with longer withering time.
Effects of Blended Fertilizers on Leaf Nutrients Content of Mature Clonal Tea in Kenya. Journal of Experimental Research. Volume 6 (2).
(Enugu State University of Science & Technology, 2018-06) itienei, Kibet S; Kamiri, Hellen W.; Kamau, David M.; Nyabundi, Wilson K.; Morogo, Maureen
Fertilizer studies in Kenya tea industry have focused predominantly on compound NPK. These fertilizers cannot be easily manipulated for specific soils and tea clones. In this respect, Athi River Mining limited has produced Mavuno blended NPK fertilizers with calcium (Ca) and magnesium (Mg). However, their application rates that would result in optimal nutrients uptake are lacking. This is the knowledge gap that this study sought to address. Therefore, the fertilizer blends were assessed for their effects on nutrients uptake at different rate in two sites. The sites were selected purposefully, one in the eastern and the other in the western tea growing areas. Randomized complete block design (RCBD) were used to select 36 trial plots in the two areas which were treated with three fertilizer types where one type was control, and four fertilizer application rates with one rate being a control. The trial was replicated three times Leaf samples were collected and analyzed for nutrients content. The data were then subjected to the analysis of variance (ANOVA) using Mstat C computer software package. Two leaves and a bud had higher nitrogen content (Timbilil 4.84%; Kagochi 4.53%) compared to deficient levels in mature leaf (Timbilil 2.26%; Kagochi 2.95%). This study has shown that supplementing the soil applied NPK fertilizers with calcium, magnesium and micronutrients resulted in better nutrients uptake.
Influence of Vegetation Cover and Topographic Position on Water Infiltration, Organic Matter Content and Aggregate Stability of Grassland Soils in Semi-Arid Kenya
(Advances in Agricultural Science, 2019) Mutuku, Daisy; Kamiri, Hellen; Ndufa, James; Kiama, Stephen; Mware, Mugo
A study was conducted in Mpala and Ilmotiok ranches in Laikipia County, Kenya, to investigate the influence of vegetation cover and topographic position on soil organic matter, bulk density, aggregate stability and water infiltration rate. Three vegetation cover types; (Tree, Grass and Bare) and four topographic positions (Hillslope, Headwater, Riparian, and Plateau) were evaluated. Soil samples were collected along the topographic positions and within the vegetation cover types at five levels of depth; 0-10, 10-20, 20-30, 30-40, 40-50 cm during the dry season May to August 2016. The samples were analyzed for soil organic matter, bulk density and soil aggregate stability. Water infiltration rate was measured in situ on the soil surface using a mini-disk Infiltrometer. Soil aggregate stability varied significantly between topographic zones (p=0.0124) but not between the vegetation cover types and soil depth in Ilmotiok site. Mpala site showed a significant difference in aggregate stability between the topographic zones (p=0.0152). However, no significant difference was observed in variation of aggregate stability between the vegetation cover types and soil depth (p=0.8998; p=0.8284) respectively. In Ilmotiok site, the highest infiltration rate was recorded in the Tree covered fields (73.3 mm/hr) and decreased in Grass fields and Bare grounds at 25 and 17 mm/hr, respectively. The Headwater zones had the highest infiltration rates (73.3 mm/hr) while the lowest infiltration rates were (0 mm/hr) in the Hillslope zones. The infiltration rates in Mpala site were highest in Bare grounds (37.8 mm/hr) and lowest in Tree fields with 5.7 mm/hr. The Headwater zones had the highest infiltration rates followed by Hillslope zones with (8.9 mm/hr) while the Riparian zones had the lowest infiltration rates (0.00 mm/hr). Soil organic matter (SOM) differed significantly at P (<0.0001) among the vegetation cover types, topographic zones and soil depth for both sites. In Ilmotiok site, the mean soil organic matter was highest (1.96%) in Hillslopes zones and lowest in Grass covered fields (0.30%). In Mpala, SOM content was highest in Tree covered fields at 2.28%, and lowest in Grass covered fields at 0.38%, for RIP and PLA zones respectively. Topographic positions and grazing management influenced soil properties in the semi-arid grasslands, hence the need for strategies in grazing management that will promote restoration of these degraded areas.