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Chand R.,Banaras Hindu University | Joshi A.K.,CIMMYT South Asia Regional Office
Indian Journal of Genetics and Plant Breeding | Year: 2012

Two hundred twenty five isolates of B. sorokiniana of barley were studied for their morpho-pathological characterization and were grouped in to four categories (1) dull white to slight black, gel type cottony growth (DW), (2) white fluffy growth (WE), (3) suppressed white growth (SW) and (4) black fluffy growth (BF).The frequency of BE isolate was highest (39.6 %) whereas SW isolates displayed lowest frequency (7.1 %). The group IV (BE) isolate was most aggressive. Sixty four purified isolates, sixteen from each of the four groups, were taken for RAPD analysis. Twenty RAPD primers were tested to detect the variability among these four identified groups. A total of 204 bands were amplified with 100% polymorphism using 20 primers. Dendrogram based on molecular polymorphism displayed considerable diversity within and between groups of 64 isolates which displayed four morpho-pathological groups into seven clusters. Specific DNA bands were identified for the selected isolates. The distinct markers may potentially be employed as genetic fingerprints for specific strain identification and classification in future.


Schulthess U.,Centro Internacional Of Mejoramiento Of Maiz Y Trigo | Timsina J.,University of Melbourne | Herrera J.M.,Centro Internacional Of Mejoramiento Of Maiz Y Trigo | McDonald A.,CIMMYT South Asia Regional Office
Field Crops Research | Year: 2013

Accurate estimation of the size and spatial distribution of the yield gap has many practical applications, including relevance to precision agriculture and technology targeting. The objectives of this study were to illustrate a methodology to create a yield gap map and to discuss its potential uses to provide optimal crop management recommendations to the farmers. We used the HybridMaize crop simulation model to estimate potential yield for maize grown in the winter season in northwestern Bangladesh. This is a high yielding environment, where farmers achieve yields as high as 12. Mg/ha. The model predicted a mean potential yield of 12.87. Mg/ha. We used a RapidEye satellite image acquired around tasseling to identify the maize fields, calculate ground cover and its regression to actual yield from farmers' fields. Next, the regression was applied to all the maize pixels in the image to calculate actual yield. In the last step, we created a yield gap map based on the difference between potential and actual yield. Yield gap maps will enable agronomists to identify production constraints on farmers' fields with large yield gaps. Alternatively, by learning from the farmers with the highest actual yields and analyzing their data, it will be possible to generate region or field specific, optimized crop management recommendations. © 2012 Elsevier B.V.


Tiwari T.P.,CIMMYT Office Bangladesh | Ortiz-Ferrara G.,CIMMYT South Asia Regional Office | Gurung D.B.,Nepal Agriculture Research Council | Dhakal R.,Nepal Agriculture Research Council | And 4 more authors.
Food Security | Year: 2010

This is a follow-up study of two previous papers in this series in which we discussed the effectiveness of participatory varietal selection (PVS) and community-based seed production (CBSP). In this paper we present from survey results the impact of new, improved varieties on food security of farmers who had previously participated in PVS or CBSP, or both. A total of 230 households from eight locations, representing different social classes (A, B, C), castes (Dalit, Janajati, BCTN; referring to Bahun, Chhetry, Thakuri and Newar) and gender (male- or female-headed households) were randomly surveyed to assess changes in household food security after the adoption of improved varieties. Use of improved varieties, on average, increased production by 50%, compared to the existing local cultivars (2. 4 t ha-1) and this was reflected in the improvement of food security by 1. 6 months (24% increase) in the year for all farmers. Food security for male-headed households increased from 7. 4 to 9. 1 months and for female-headed households from 6. 4 to 7. 9 months (by 23% in both). The average food security of all castes improved by 23%-31% but the increased food availability of the underprivileged castes of Dalits (from 5. 1 to 6. 4 months) and Janjati (from 5. 8 to 7. 6 months) from lower food security levels is more important than that for BCTN (from 7. 5 to 9. 2 months). Similarly, food deficit households (C and B) had higher food availability over the food surplus households (A). The results indicate that the targeted participatory approach can reverse the findings of past maize research and development efforts which benefited only the elite farmers. © 2010 Springer Science + Business Media B.V. & International Society for Plant Pathology.


Chapagain T.,Nepal Agricultural Research Council | Khatri B.,Nepal Agricultural Research Council | Bhattarai P.,Nepal Agricultural Research Council | Luitel B.,Nepal Agricultural Research Council | And 2 more authors.
Acta Agronomica Hungarica | Year: 2012

Intercropping potato with quality protein maize (QPM) could improve the livelihood and nutritional status of the resource-poor farmers who produce and consume them. A study was conducted from 2008 to 2010 to assess the performance of three improved potato varieties in an intercropping system with an improved QPM in the high hills of Nepal. The QPM was sown for four consecutive weeks following potato planting. The commercial potato varieties Janak Dev, Kufri Jyoti and Khumal Seto-1 were used, while the improved QPM was Poshilo Makai-1. Delayed intercropping caused a reduction in the maize yield, but an increase in the potato yield. The highest potato yield was obtained from maize intercropping after four weeks. The grain yield of maize was significantly reduced by late planting beyond the second week. The average weekly rate of increase due to maize intercropping was better for Janak Dev and Kufri Jyoti, while Khumal Seto-1 was less suitable for intercropping. The land equivalent ratio for potato-maize intercropping was 2.23. The results suggest that Poshilo Makai-1 could be incorporated in potato-maize intercropping, leading to higher returns and nutritional benefits. The findings underline the importance of variety and date of intercropping to maximize production. The findings have implications for harnessing higher productivity on resource-poor farms, and could contribute to food and nutritional security for resource-poor farmers.


Pask A.,CIMMYT Int. Apdo. Postal 6 641 | Joshi A.K.,CIMMYT South Asia Regional Office | Manes Y.,CIMMYT Int. Apdo. Postal 6 641 | Sharma I.,Directorate of Wheat Research | And 16 more authors.
Field Crops Research | Year: 2014

South Asia, which is already home to more than one fifth of the world's population and rapidly growing, will require wheat yields to rise annually by 2.0 to 2.5% to meet demand and maintain food security. To address these challenges, a wheat phenotyping network was established in the region in 2009 to support national breeding programs by applying practical phenotyping techniques to increase selection success using a cooperative multi-location testing network. A number of trials have been grown to introduce new genetic diversity for stress adaptive traits, to establish their genetic bases, and to test a new generation of lines developed using physiological approaches. The 17th Semi-Arid Wheat Yield Trial (SAWYT), consisting of a group of 50 elite spring bread wheat advanced lines, bred in Mexico using both conventional (CON) and physiological trait (PT) approaches, was grown for two seasons 2009/10 and 2010/11. Data showed that PT lines gave superior yields overall, associated with higher grain weight, and with cooler vegetative and grain-filling canopy temperatures (CT); the CT trait is considered indicative of increased gas exchange, a likely consequence in these environments of superior vascular capacity including deeper rooting to access subsoil water. Local check genotypes, which were generally well adapted to the stressed environments tended to be 3-5 days earlier to heading than CIMMYT cultivars. Results demonstrate the potential to integrate physiological breeding approaches into genetic improvement for the region, particularly as future wheat production will take place under increasing water scarcity. © 2014 Elsevier B.V..


Pask A.,CIMMYT Int. | Joshi A.K.,CIMMYT South Asia Regional Office | Manes Y.,CIMMYT Int. | Sharma I.,Directorate of Wheat Research | And 16 more authors.
Field Crops Research | Year: 2015

South Asia, which is already home to more than one-fifth of the world's population and rapidly growing, will require wheat yields to rise annually by 2.0-2.5% to meet demand and maintain food security. To address these challenges, a wheat phenotyping network was established in the region in 2009 to support national breeding programs by applying practical phenotyping techniques to increase selection success using a cooperative multi-location testing network. A number of trials have been grown to introduce new genetic diversity for stress adaptive traits, to establish their genetic bases, and to test a new generation of lines developed using physiological approaches. The 17th Semi-Arid Wheat Yield Trial (SAWYT), consisting of a group of 50 elite spring bread wheat advanced lines, bred in Mexico using both conventional (CON) and physiological trait (PT) approaches, was grown for two seasons 2009/10 and 2010/11. Data showed that PT lines gave superior yields overall, associated with higher grain weight, and with cooler vegetative and grain-filling canopy temperatures (CT); the CT trait is considered indicative of increased gas exchange, a likely consequence in these environments of superior vascular capacity including deeper rooting to access subsoil water. Local check genotypes, which were generally well adapted to the stressed environments tended to be 3-5 days earlier to heading than CIMMYT cultivars. Results demonstrate the potential to integrate physiological breeding approaches into genetic improvement for the region, particularly as future wheat production will take place under increasing water scarcity. © 2014 Elsevier B.V.

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