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Modern Varieties (modern + variety)

Distribution by Scientific Domains

Life Sciences	40%

Selected Abstracts

The economic and poverty impacts of maize research in West and Central Africa

AGRICULTURAL ECONOMICS, Issue 5 2009
Arega D. Alene
Maize research; Economic surplus; Poverty reduction; West Africa Abstract This article assembles the results of three multicountry surveys on variety performance and adoption patterns to measure the impacts of maize research in West and Central Africa from 1981 to 2005, and uses cost data since 1971 to compute social rates of return on public investments in maize research in the region. Adoption of modern varieties increased from less than 5% of the maize area in the 1970s to about 60% in 2005, yielding an aggregate rate of return on research and development (R&D) investment of 43%. The estimated number of people moved out of poverty through adoption of new maize varieties rose gradually in the 1980s to more than one million people per year since the mid 1990s. Over half of these impacts can be attributed to international maize research at IITA and CIMMYT. The article concludes with a discussion of strategic options to enhance the impacts of maize research in the region. [source]

Barley adaptation and improvement in the Mediterranean basin

PLANT BREEDING, Issue 6 2008
A. Pswarayi
Abstract To study barley adaptation and improvement in the Mediterranean basin, a collection of 188 entries comprising landraces and old genotypes and current modern varieties from the Mediterranean basin and elsewhere was tested on moisture-contrasted environments in seven Mediterranean countries, during 2004 and 2005 harvest seasons. The experimental design consisted of an unreplicated trial for all entries, augmented by four repeated checks to which a partial replicate containing a quarter of the entries was added. Best Linear Unbiased Predictions (BLUPs) representing adjusted genotypic means were generated for individual trials using a mixed model. BLUPs were used for genotype by environment interaction analysis using main effect plus genotype by environment interaction (GGE) biplots of yield ranked data and for comparisons of landraces, old and modern genotypes using analysis of variance. Mean yields ranged from near crop failure to 6 t/ha. Local landraces were better adapted to environments yielding below 2 t/ha, thus breeding has mostly benefited environments yielding above 2 t/ha where modern genotypes out yielded landraces and old cultivars by 15%. Current barley selection is leading to specifically adapted genotypes. [source]

LESSONS FROM THREE DECADES OF GREEN REVOLUTION IN THE PHILIPPINES

THE DEVELOPING ECONOMIES, Issue 2 2006
Jonna P. ESTUDILLO
O13; O33; O53 The purpose of the current paper is to assess the changing contributions of successive generations of modern varieties of rice (MV) to yield increase and stability and the changes in total factor productivity (TFP) in irrigated, rainfed, and upland ecosystems in the Philippines. We found that the yield increase in irrigated ecosystem has been by far the highest, which can be attributed to the diffusion of pest- and disease-resistant MV. The contribution of MV to yield increase in the rainfed ecosystem has been less significant, but much more compared with that of upland ecosystem. The rainfed and upland ecosystems have experienced an upward trend in yield, albeit slowly, because of the diffusion of improved traditional varieties and MV suitable to adverse production environments. The contribution of MV cum irrigation has accounted for approximately 50% of the growth of TFP in Central Luzon. [source]

ADOPTION AND PRODUCTIVITY IMPACT OF MODERN RICE VARIETIES IN BANGLADESH

THE DEVELOPING ECONOMIES, Issue 2 2006
Mahabub HOSSAIN
O13; O33 Technological progress has helped Bangladesh to achieve self-sufficiency in rice production in 2001 from a heavy import-dependence, despite doubling of population and a reduction in arable land since its independence in 1971. As the adoption of modern varieties (MV) of rice is reaching a plateau, particularly for the irrigated ecosystem, an important issue is whether the research system will be able to sustain the growth of production. The present paper addresses the following questions: (i) to what extent farmers have been replacing the old MV with the new MV, and (ii) what has been the impact of the variety replacement on productivity and profitability. How crucial is the continuous research and release of improved rice varieties toward improving farm production and income for farmers comes out as a clear message to policymakers from the current paper. [source]

Diversity in commercial varieties and landraces of black eggplants and implications for broadening the breeders' gene pool

ANNALS OF APPLIED BIOLOGY, Issue 3 2009
J.E. Muñoz-Falcón
Abstract Black-coloured eggplants (Solanum melongena) represent the commercially most important group of eggplants in Europe and North America. Most of the modern varieties of black eggplants correspond to F1 hybrids, which at the same time constitute an elite gene pool for the development of new varieties. However, there are many black landraces and old varieties, which could be useful as sources of variation for black eggplant breeding programmes as well as for the broadening of the genetic diversity of the breeders' gene pool. We have studied the morphological and molecular [amplified fragment length polymorphism and simple sequence repeat (SSR)] diversity in a collection of 38 black eggplant accessions, including commercial (modern F1 hybrid and old nonhybrid) varieties and landraces as well as in six nonblack control eggplants, from different origins. The results show that black eggplants contain a considerable morphological and molecular diversity, but commercial varieties, and in particular F1 hybrids, display a reduced morphological and molecular diversity when compared with landraces. The principal components analysis morphological and principal coordinates analysis molecular analyses show that commercial F1 hybrids group together, indicating that they share a common and narrow gene pool. Commercial F1 hybrids present a series of productive advantages, like early production, intense black colour (low L*, a* and b*) values and absence of fruit calyx prickles. However, several of the landraces and old nonhybrid varieties studied present a high yield as well as other traits of interest for eggplant breeding. Furthermore, given the low genetic diversity of F1 hybrids and the moderate level of SSR heterozygosity found in these materials (0.382), introduction of black landraces and old varieties in the present breeding programmes could contribute to broadening the gene pool used by breeders and this could help increase the heterosis for yield of F1 hybrids, which is greatly favoured by high heterozygosity levels. [source]