Selian Agricultural Research Institute SARI

Arusha, Tanzania

Selian Agricultural Research Institute SARI

Arusha, Tanzania
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Kihara J.,International Center for Tropical Agriculture | Tamene L.D.,International Center for Tropical Agriculture | Massawe P.,Selian Agricultural Research Institute SARI | Bekunda M.,International Institute Of Tropical Agriculture
Nutrient Cycling in Agroecosystems | Year: 2015

Improved agronomic management is important to reduce yield gaps and enhance food security in sub-Saharan Africa. This study was undertaken to understand contributing factors to observed yield gaps for maize in farmer fields and to demonstrate appropriate agronomic survey methods. The study aimed to (1) demonstrate an approach for farm-level agronomic survey, (2) identify key crop production constraints and (3) define the nutrient input and output balances of different fields. Agronomic survey was conducted in 117 farmer fields randomly distributed in a 10 km by 10 km block in Babati, northern Tanzania. A semi-structured questionnaire and production measurements were used to collect data which were analyzed with regression classification and mixed effect models. The exploitable maize yield gap at farm-level reaches up to 7.4 t ha−1, and only <5 % of fields achieve maize grain yield of 5 t ha−1. Slope, plant density, distance from homestead, crop variety, timing of planting and period since conversion significantly influenced maize yields. For example, fields on flat land had up to 1.6 t ha−1 more maize grain yield than those on steep slopes while fields with plant density >24,000 plants ha−1 had 900 kg ha−1 more yield than those with less density. At least 52 % of the fields had negative nutrient balances. We conclude that cropping systems used in Babati should be preferentially supplemented with mineral fertilizers while optimizing plant density, increasing manure application and appropriate varietal choice in order to reduce the yield gaps. © 2014, The Author(s).

Kassie M.,International Maize and Wheat Improvement Center | Jaleta M.,International Maize and Wheat Improvement Center | Shiferaw B.,International Maize and Wheat Improvement Center | Mmbando F.,Selian Agricultural Research Institute SARI | Mekuria M.,International Maize and Wheat Improvement Center
Technological Forecasting and Social Change | Year: 2013

Soil fertility depletion is considered one of the main biophysical limiting factors for increasing per capita food production for smallholder farmers in Sub-Saharan Africa. The adoption and diffusion of sustainable agricultural practices (SAPs), as a way to tackle this challenge, has become an important issue in the development policy agenda in the region. This paper examines the adoption decisions for SAPs, using recent primary data of multiple plot-level observations collected in 4 districts and 60 villages of rural Tanzania. The paper employs a multivariate probit technique to model simultaneous interdependent adoption decisions by farm households. The analysis reveals that rainfall, insects and disease shocks, government effectiveness in provision of extension services, tenure status of plot, social capital, plot location and size, and household assets, all influence farmer investment in SAPs. Policies that target SAPs and are aimed at organizing farmers into associations, improving land tenure security, and enhancing skills of civil servants can increase uptake of SAPs in smallholder systems. © 2012 Elsevier Inc.

Mmbando F.E.,University of KwaZulu - Natal | Mmbando F.E.,Selian Agricultural Research Institute SARI | Wale E.Z.,University of KwaZulu - Natal | Baiyegunhi L.J.S.,University of KwaZulu - Natal
Food Security | Year: 2015

This paper evaluates the impact of maize and pigeonpea market participation and the level of participation on household welfare measured by consumption expenditure in rural Tanzania. The study used cross-sectional farm household level data collected in 2010 from 700 randomly selected households in northern and eastern zones of Tanzania. Propensity score matching and endogenous switching regression techniques were employed to address the welfare impacts of market participation for binary treatment, while linear regression was employed to address the welfare impacts of the level of market participation. Maize and pigeonpea market participation and the level of participation had positive and significant impacts on the welfare of rural households. On average, maize and pigeonpea market participation increased consumption expenditure per capita in the range of 19.2–20.4 % and 28.3–29.4 %, respectively. Similarly, a one unit increase in the predicted level of market participation increased per capita consumption expenditure by 0.5 and 0.3 %, for both maize and pigeonpea, respectively. This confirms the potential role of market participation and the level of participation in improving rural household welfare, as higher consumption expenditures from market participation also mean improved food security and reduced poverty. Policies aimed at reducing the transaction costs of accessing markets such as improved market information, rural infrastructure and household capacity to produce surplus production are critical to the improvement of household welfare. © 2015 Springer Science+Business Media Dordrecht and International Society for Plant Pathology

Nyaligwa L.,University of KwaZulu - Natal | Nyaligwa L.,Selian Agricultural Research Institute SARI | Hussein S.,University of KwaZulu - Natal | Amelework B.,University of KwaZulu - Natal | Ghebrehiwot H.,University of KwaZulu - Natal
Maydica | Year: 2015

Genetically diverse and complementary elite inbred lines are fundamental for hybrid maize breeding or for strategic conservation. The objectives of this study were to determine the genetic diversity present among 79 elite maize inbred lines collected from five different sources using 30 SSR markers and to identify unique genotypes for breeding. The mean numbers of observed and effective alleles were 4.7 and 2.4 per marker, respectively. The polymorphic information content (PIC) of the 30 SSR markers ranged from 0.01 to 0.92, with a mean of 0.51. Six markers: Phi 031, phi 308707, phi 96100, phi 114, phi 299852 and phi 063 revealed the highest PIC values greater than 0.70 suggesting the potential of these loci for genetic diversity analysis. The mean value of total gene diversity was 0.51 which partitioned 72% among inbred lines, 26% within inbred lines and 7% was attributed to variation between the five sources. Cluster analysis allocated the inbred lines into three main genetic groups. The principal coordinate analysis explained 67% of the total genetic variation detected among inbred lines and separated them into two main clusters. The study identified elite maize inbred lines such as TL2012-2, TL2012-14, TL2012-20, TL2012-31, TL2012-54 and TL2012-55 from Cluster I; TL2012-6, TL2012-35, TL2012-53 and TL2012-75 from cluster II; TL2012-12, TL2012-27, TL2012-29 and TL2012-58 from cluster III with marked genetic differences for hybrid breeding to exploit heterosis. © 2015, Consiglio per la Ricercame la sperimentazione in Agrcoltura. All rights reserved.

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