Discussion Papers

Physiological and biochemical response of tea [Camellia sinensis (L.) O. Kuntze] to water-deficit stress

Physiological and biochemical response of tea [Camellia sinensis (L.) O. Kuntze] to water-deficit stress

A study to determine the physiological and biochemical responses of eight tea [Camellia sinensis (L.) O. Kuntze] cultivars to water-deficit stress was conducted in a ‘rain-out shelter’ using potted plants. Three levels of soil moisture content [34, 26, or 18% (v/v) water] were applied to three plants of each cultivar in a complete randomised design, and the whole experiment was replicated three-times. The treatments were applied for 12 weeks, during which time plant water status, shoot extension rates, changes in gas exchange parameters, and leaf proline and glycinebetaine concentrations were determined. The imposition of severe water-deficit conditions [18% (v/v) soil water content] caused a significant (P ≤ 0.05) decline in the relative water content of leaves, shoot water potentials, and shoot extension rates from mean values of 84.8% to 50.6%, –0.80 to –1.15MPa, and 1.87 to 0.29 mm d–1, respectively, compared to plants grown in a well-watered soil [34% (v/v) soil water content]. The three gas exchange parameters measured (stomatal conductance, evapotranspiration rate, and rate of net photosynthesis) also declined significantly (P ≤ 0.05) with decreasing soil moisture content. In contrast, water-deficit stress increased the accumulation of leaf proline and glycinebetaine from mean values of 0.104 to 0.244 μmol g–1 FW, and from 1.567 to 2.025 μmol g–1 DW,
respectively. The eight tea cultivars differed significantly (P ≤ 0.05) in their responses to water-deficit stress. Proline
accumulation was significantly (P ≤ 0.05) higher in the drought-tolerant cultivars, ‘TRFK 306’, ‘TRFCA SFS150’, and
‘EPK TN14/3’, suggesting that proline concentration could be used as a marker for drought-tolerance in tea.

Payment for environmental services: Laying the ground work

Between 2009-2011 ASARECA supported a consortium of five institutions in three countries, namely, the School of Environmental Studies (Moi University), Kenya Agricultural Research Institute (KARI), and VIRED International – all of Kenya; University of Kinshasa & INERA of D. R. Congo; Nature Harness Initiatives and the Environmental Conservation Trust both of Uganda, to conduct research to develop methods for Valuation, Attribution and Compensation for Payments for Environmental Services (VAC-PES) in Eastern and Central Africa. The target research landscapes were the Mt. Elgon Region (Cross boundary between Uganda and Kenya) and the Albertine Rift (between Uganda and DRC). Many other institutions have carried out studies and undertaken PES related activities in other landscapes in Eastern and Central Africa, but the information on these activities occurs in a disjointed manner.

The papers presented in this book are an attempt to pool some of this information into one volume. The papers cut across different aspects of Environmental Services (watershed management, carbon sequestration, and biodiversity management), as well as policy and institutional issues related to PES. It is envisaged that this publication will provide information necessary to spur PES programmess in the region.

The Role of Mainstreaming Gender in Agricultural Research and Development

This paper seeks to highlight one of the major contradictions bedeviling efforts to feed the ECA region in the present times; whereas the gendered management system of food production in particular and agricultural production in general has not changed much over the last century, the bio-physical production system has undergone tremendous change. As a result, there has been increasing demand for food without commensurate increases in food production. Unfortunately, while the deteriorating bio-physical production system that has depressed food production has evidently received research and policy attention, the static gendered management system has received scanty attention. This is because the gendered management system is part of the broader structure of gender relations that are so entrenched in the formal and informal institutions in society that they are treated as givens or “natural”. Hence, agricultural and social scientists and policy makers rarely recognize the challenges posed by the gendered management system to food production.

How ASARECA’s climbing bean project has improved livelihoods in Rwanda, Burundi and eastern DR Congo

“Intensification of Climbing Bean Agro-systems” is one of the projects the Association for Strengthening Agricultural Research in Eastern and Central Africa (ASARECA) is funding in Rwanda, Burundi, and eastern DR Congo. This project is crucial because of the importance of beans in the diets of the populations of the three countries. The common bean (Phaseolus vulgaris L) is their primary source of proteins (21%), carbohydrates (60%), minerals (iron, zinc) and vitamins (19%) and other nutrients. The consumption of beans in the project area is estimated to be more than 60 kg per person per year.

Celebrating the International Day of Biodiversity

Realizing the strategic importance of this day to the attainment of ASARECA’s ultimate objective to Improve Livelihoods, ASARECA member countries celebrate the Worlds Biodiversity Day by organizing various forums including national discourse, workshops, public discussions and exhibitions, among other activities. The activities highlight the role of biodiversity in ensuring that people have sustainable access to adequate and nutritive food to lead active and healthy lives and sustain ecosystem goods and services and promote socio-economic development.

Annex to the Paper: Responding to the Food Price Crisis in Eastern and Southern Africa

This is the Annex to the paper entitled "Responding to the Food Price Crisis in Eastern and Southern Africa"

Responding to the Food Price Crisis in Eastern and Southern Africa

This paper addresses the magnitude and implications of food price changes in national and regional markets in Eastern and Southern Africa with a view to provide the evidence base for effective policy action.

Impacts of an improved seed policy environment in Eastern and Central Africa

Impacts of an improved seed policy environment in Eastern and Central Africa

This discussion paper assesses the impacts of an improved seed policy environment in the Eastern and Central Africa (ECA) region using a case study of formal trade in seed maize in Kenya, Uganda and Tanzania that employs a spatial equilibrium model (SEM). The data used in this study was derived from a regional survey of key informants undertaken in August 2009. It is complimented by secondary data on seed production, consumption, prices and elasticity parameter estimates that were derived from various sources. The quantification of the trade and welfare impacts of seed policy harmonization involved a before and after comparative analysis. The paper commences by reviewing the progress made in the harmonization of seed policies in ECA region with regard to five thematic areas agreed for harmonization.


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