Posts Tagged ‘Asia’

Mining centuries old In situ conserved turkish wheat landraces for grain yield and stripe rust resistance genes

Posted by gabrielamartinez on , in Journal Articles

58094Authors: Sehgal, D.; Dreisigacker, S.; Belen, S.; Kucukozdemir, U.; Mert, Z.; Ozer, E.; Morgounov, A.I.

Published in: Frontiers in genetics, 2016, vol.7, no.201.


Wheat landraces in Turkey are an important genetic resource for wheat improvement. An exhaustive 5-year (2009–2014) effort made by the International Winter Wheat Improvement Programme (IWWIP), a cooperative program between the Ministry of Food, Agriculture and Livestock of Turkey, the International Center for Maize and Wheat Improvement (CIMMYT) and the International Center for Agricultural Research in the Dry Areas (ICARDA), led to the collection and documentation of around 2000 landrace populations from 55 provinces throughout Turkey. This study reports the genetic characterization of a subset of bread wheat landraces collected in 2010 from 11 diverse provinces using genotyping-by-sequencing (GBS) technology. The potential of this collection to identify loci determining grain yield and stripe rust resistance via genome-wide association (GWA) analysis was explored. A high genetic diversity (diversity index = 0.260) and a moderate population structure based on highly inherited spike traits was revealed in the panel. The linkage disequilibrium decayed at 10 cM across the whole genome and was slower as compared to other landrace collections. In addition to previously reported QTL, GWA analysis also identified new candidate genomic regions for stripe rust resistance, grain yield, and spike productivity components. New candidate genomic regions reflect the potential of this landrace collection to further increase genetic diversity in elite germplasm.

Factors associated with small-scale agricultural machinery adoption in Bangladesh : census findings

Posted by gabrielamartinez on , in Journal Articles

57968Authors: Mottaleb, K.A.; Krupnik, T.J.; Erenstein, O.

Published in: Journal of Rural Studies, 2016, vol.46, p.155-168.


There is strong advocacy for agricultural machinery appropriate for smallholder farmers in South Asia. Such ‘scale-appropriate’ machinery can increase returns to land and labour, although the still substantial capital investment required can preclude smallholder ownership. Increasing machinery demand has resulted in relatively well-developed markets for rental services for tillage, irrigation, and post-harvest operations. Many smallholders thereby access agricultural machinery that may have otherwise been cost prohibitive to purchase through fee-for-service arrangements, though opportunity for expansion remains. To more effectively facilitate the development and investment in scale-appropriate machinery, there is a need to better understand the factors associated with agricultural machinery purchases and service provision. This paper first reviews Bangladesh’s historical policy environment that facilitated the development of agricultural machinery markets. It then uses recent Bangladesh census data from 814,058 farm households to identify variables associated with the adoption of the most common smallholder agricultural machinery – irrigation pumps, threshers, and power tillers (mainly driven by two-wheel tractors). Multinomial probit model results indicate that machinery ownership is positively associated with household assets, credit availability, electrification, and road density. These findings suggest that donors and policy makers should focus not only on short-term projects to boost machinery adoption. Rather, sustained emphasis on improving physical and civil infrastructure and services, as well as assuring credit availability, is also necessary to create an enabling environment in which the adoption of scale-appropriate farm machinery is most likely.

13C Natural Abundance of Serum Retinol Is a Novel Biomarker for Evaluating Provitamin A Carotenoid-Biofortified Maize Consumption in Male Mongolian Gerbils

Posted by gabrielamartinez on , in Journal Articles

57971Authors: Gannon, B.; Pungarcher, I.; Mourao, L.; Davis, C.R.; Simon, P.; Pixley, K.V.; Tanumihardjo, S.A.

Published in: The Journal of Nutrition, July 2016, vol. 146, p. 1290-1297


Background: Crops such as maize, sorghum, and millet are being biofortified with provitamin A carotenoids to ensure adequate vitamin A (VA) intakes. VA assessment can be challenging because serum retinol concentrations are homeostatically controlled and more sensitive techniques are resource-intensive.
Objectives: We investigated changes in serum retinol relative differences of isotope amount ratios of 13C/12C (d13C) caused by natural 13C fractionation in C3 compared with C4 plants as a biomarker to detect provitamin A efficacy from biofortified (orange) maize and high-carotene carrots.
Methods: The design was a 2 3 2 3 2 maize (orange compared with white) by carrot (orange compared with white) by a VA fortificant (VA+ compared with VA2) in weanling male Mongolian gerbils (n = 55), which included a 14-d VA depletion period and a 62-d treatment period (1 baseline and 8 treatment groups; n = 527/group). Liver VA and serum retinol were quantified, purified by HPLC, and analyzed by GC combustion isotope ratio mass spectrometry for 13C.
Results: Treatments affected liver VA concentrations (0.048 6 0.039 to 0.79 6 0.24 mmol/g; P < 0.0001) but not overall serum retinol concentrations (1.3860.22 mmol/L). Serum retinol and liver VA d13C were significantly correlated (R2 = 0.92; P < 0.0001). Serum retinol d13C differentiated control groups that consumed white maize and white carrots (227.1 6 1.2 d13C&) from treated groups that consumed orange maize and white carrots (221.6 6 1.4 d13C&; P < 0.0001) and white maize and orange carrots (230.6 6 0.7 d13C&; P < 0.0001). A prediction model demonstrated the relative contribution of orange maize to total dietary VA for groups that consumed VA from mixed sources.
Conclusions: Provitamin A efficacy and quantitative estimation of the relative contribution to dietary VA were demonstrated with the use of serum retinol d13C. This method could be used for maize efficacy or effectiveness studies and with other C4 crops biofortified with provitamin A carotenoids (e.g., millet, sorghum). Advantages include no extrinsic tracer dose, 1 blood sample, and higher sensitivity than serum retinol concentrations alone.

Linkage analysis and map construction in genetic populations of clonal F1 and double cross

Posted by gabrielamartinez on , in Journal Articles

57985Authors: Manickavelu, A.; Joukhadar, R.; Jighly, A.; Caixia Lan; Huerta-Espino, J.; Ahmad Shah Stanikzai; Kilian, A.; Singh, R.P.; Ban, T.

Published in: Plant Science, 2016, vol.252, p.222-229


Mining of new genetic resources is of paramount importance to combat the alarming spread of stripe rustdisease and breakdown of major resistance genes in wheat. We conducted a genome wide associationstudy on 352 un-utilized Afghan wheat landraces against stripe rust resistance in eight locations. Highlevel of disease variation was observed among locations and a core-set of germplasm showed consis-tence performance. Linkage disequilibrium (LD) decayed rapidly (R2≈ 0.16 at 0 cM) due to germplasmpeerless diversity. The mixed linear model resulted in ten marker-trait associations (MTAs) across allenvironments representing five QTL. The extensively short LD blocks required us to repeat the analysiswith less diverse subset of 220 landraces in which R2decayed below 0.2 at 0.3 cM. The subset GWASresulted in 36 MTAs clustered in nine QTL. The subset analysis validated three QTL previously detectedin the full list analysis. Overall, the study revealed that stripe rust epidemics in the geographical originof this germplasm through time have permitted for selecting novel resistance loci.

Quantifying changes to the global warming potential of rice wheat systems with the adoption of conservation agriculture in northwestern India

Posted by gabrielamartinez on , in Journal Articles

57504Authors: Tirol Padre, A.; Munmun Rai; Kumar, V; Gathala, M.K; Sharma, P.C; Sharma, S; Rakesh Kumar Nagar; Deshwal, S; Singh, L.K; Jat, H.S; Sharma, D.K; Wassmann, R; Jagdish Kumar Ladha.

Published in: Agriculture, Ecosystems and Environment, 2016, vol. 219, p.125-137


 

Field trials were conducted in Haryana representing the northwestern Indo-Gangetic Plains (IGP) to assess the changes brought about by management, including conservation agriculture (CA) practices, in the global warming potential (GWP) of conventional rice–wheat systems. Conservation agriculture is an approach to managing agro-ecosystems for improved and sustained productivity, by way of minimal soil disturbance, permanent soil cover with organic matter or cover crops and crop rotation. Methane (CH4) and nitrous oxide (N2O) fluxes were measured using static chambers. Experiments involved four cropping system scenarios with different CA components, and different N rates. In addition, emissions of CH4 and N2O fluxes were measured in farmers’ fields to establish baselines. The dynamics of CH4 emissions were controlled by floodwater levels, and fertilizer N had no effect. On the other hand, N application rates and timing in relation to soil water status determined the N2O emissions in rice fields. Nitrous oxide fluxes could be avoided by applying N fertilizer to wet soil or by irrigating the field not later than 1 day after N application. Applying crop residues on soil surface had no significant effect on the seasonal CH4 and N2O emissions. It was estimated that switching rice crop establishment method from conventional to CA-based practices in Haryana could reduce GWP for rice by 23% or by 1.26 Tg CO2 eq yr−1. An intensive CA-based rice–wheat and maize–wheat system reduced GWP by 16–26% or by 1.3–2.0 Tg CO2 eq yr−1 compared with the conventional rice–wheat system. However, this reduction in GWP would be from a decrease in diesel and electricity consumption and not from direct emissions of CH4 and N2O, which were higher in the maize–wheat system than in the rice–wheat system.

Agronomic improvements can make future cereal systems in South Asia far more productive and result in a lower environmental footprint

Posted by gabrielamartinez on , in Journal Articles

57503Authors: Jagdish Kumar Ladha; Adusumilli Narayana Rao; Raman, A.K; Tirol Padre, A; Dobermann, A; Gathala, M.K; Kumar, V; Saharawat, Y.S; Sharma, S; Piepho, H.P; Md Mursedul Alam; Liak, R; Rajendran, R; Chinnagangannagari Kesava Reddy; Parsad, R; Sharma, P.C; Singh, S.S; Saha, A; Shamsoon Noor.

Published in: Global Change Biology In press


South Asian countries will have to double their food production by 2050 while using resources more efficiently and minimizing environmental problems. Transformative management approaches and technology solutions will be required in the major grain-producing areas that provide the basis for future food and nutrition security. This study was conducted in four locations representing major food production systems of densely populated regions of South Asia. Novel production-scale research platforms were established to assess and optimize three futuristic cropping systems and management scenarios (S2, S3, S4) in comparison with current management (S1). With best agronomic management practices (BMPs), including conservation agriculture (CA) and cropping system diversification, the productivity of rice- and wheat-based cropping systems of South Asia increased substantially, whereas the global warming potential intensity (GWPi) decreased. Positive economic returns and less use of water, labor, nitrogen, and fossil fuel energy per unit food produced were achieved. In comparison with S1, S4, in which BMPs, CA and crop diversification were implemented in the most integrated manner, achieved 54% higher grain energy yield with a 104% increase in economic returns, 35% lower total water input, and a 43% lower GWPi. Conservation agriculture practices were most suitable for intensifying as well as diversifying wheat–rice rotations, but less so for rice–rice systems. This finding also highlights the need for characterizing areas suitable for CA and subsequent technology targeting. A comprehensive baseline dataset generated in this study will allow the prediction of extending benefits to a larger scale.

Conservation agriculture and weed management in south Asia: perspective and development

Posted by gabrielamartinez on , in Journal Articles

56834Authors: Malik, R.; Kumar, V.; Yadav, A.; McDonald, A.

Published in: Indian Journal of Weed Science, 46(1): 31–35, 2014.


 

It was 20 years ago which marked the beginning of conservation agriculture (CA) with introduction of zerotillage (ZT) in wheat to (1) reduce cultivation cost so that farmers can afford to purchase new but expensive alternate herbicides for the control of herbicide-resistant population of Phalaris minor Retz., the most troublesome weed of wheat, and (2) reduce land preparation period for timely wheat planting. Worldwide, CA has spread mostly in the rain-fed agriculture but India witnessed its success more in irrigated rice-wheat cropping systems (RWCS) of the Indo-Gangetic Plains (IGP). High input based crop culture in the North West IGP has enabled weeds such as P. minor in wheat and Echinochloa crusgalli (L.) Beauv. in rice to dominate the weed flora. In wheat, zero tillage (ZT) is widely adopted by farmers in North West India and recently it is widely accepted by farmers in the eastern IGP also. In North West India, under ZT wheat, emergence and biomass of P. minor was reduced, but weed flora shifted toward more broad-leaf weeds such as Rumex dentatus (L.). In the Eastern IGP, perennial weeds such as Cynodon dactylon L. Pers. and Cyperus rotundus L. are also problematic weeds in some cases under ZT. In rice, the focus now is on dry direct-seeded rice (DSR) and machine transplanting of non-puddled rice (MTNPR) as an alternate option to puddled transplanted rice (PTR). Shifting from PTR to DSR results in changes in tillage, crop establishment method, water and weed management which often results in changes in weed composition and diversity. Weedy rice has emerged as a major threat for DSR in countries where DSR is widely adopted. In the eastern IGP, Physallis minima and Cyperus rotundus are also becoming major problematic weeds in DSR. Increased net profit for farmers by using this new technology was the main reason for rapid adoption of ZT. Since 2009, the Cereal Systems Initiatives for South Asia (CSISA), project funded by Gates Foundation and USAID and implemented by four consultative group on International Agricultural Research (CGIAR) (CG) Centers (CIMMYT, IRRI, IFPRI and ILRI) in collaboration with national partners, has explored options for sustainable intensification across the IGP, including CA-based crop management. This paper highlights the weed management scenario in conservation agriculture in India.

Improving water productivity of wheat-based cropping systems in South Asia for sustained productivity

Posted by Carelia Juarez on , in Journal Articles

Published in Advances in Agronomy 127 157-258, 2014

Kukal, S.S.;Yadvinder-SinghJat, M.L.Sidhu, H.S.

Serious water deficits are threatening agricultural sustainability in many regions of the South Asia (SA). While the increase in crop production of irrigated rice–wheat system in SA has been impressive since the 1970s, the low water productivity (WP) has led to the depletion of surface water and groundwaters. In this chapter we have discussed the availability of water resources in SA, identified the positive effects of soil and water management and crop genetic improvement on WP, and then described knowledge gaps and research priorities to further improve the WP with special emphasis on wheat-based cropping systems in irrigated and rainfed regions of SA. A single approach would not be able to tackle the forthcoming challenge of producing more food and fiber with limited or even reduced available water. Integrating irrigation water-saving techniques (water-saving irrigation methods, deficit irrigation, modernization of irrigation system, etc.) with agronomic and soil manipulations viz., optimum irrigation scheduling, direct-seeded rice, alternate wetting and drying in puddle transplanted rice, raised bed planting, crop diversification, conservation tillage, crop residue management, and conjunctive use of good quality (canal) water. Improved soil water management practices for rainfed regions include reducing runoff, rainwater harvesting and recycling, conserving rainwater in the root zone by reducing evaporation losses, and optimal nutrient management. The low WP in farmer’s fields compared with well-managed experimental sites indicates the need for more efforts to transfer water-saving technologies to the farmers. In future we need to increase scientific understanding of the effects of agronomic management on WP across various soil and climate conditions; improve irrigation practices (timing and amounts) and methods (drip and sprinkler) based on real-time monitoring of water status in soil-crop systems; and maximize WP by managing water resources and allocation at regional scales in wheat-based cropping systems.

Nutrient management and use efficiency in wheat systems of South Asia

Posted by Carelia Juarez on , in Journal Articles

Published in Advances in Agronomy  125 : 171-259, 2014

Jat, M.L.; Bijay-Singh; Gerard, B.

With the advent of Green Revolution era in the mid-1960s, high-yielding wheat (Triticum aestivum L.) varieties and chemical fertilizers were introduced in South Asia. Fertilizer consumption is continuously increasing since then, but the productivity of wheat is relatively stagnant during the last decade. In South Asia, fertilizers have been applied to wheat as blanket recommendations for regions with similar climate and landform. There exists a large variation in nutrient use efficiencies in wheat because of following blanket recommendations for nitrogen, phosphorus, and potassium in fields differing greatly in nutrient-supplying capacity of the soil. Research carried out in South Asia suggests that further improvement in nutrient use efficiency will become possible by balanced use of nitrogen, phosphorus, and potassium fertilizers, and by rational use of organic manures in wheat systems. Long-term fertility experiments also confirm the need of balanced use of nutrients to produce high sustainable yield levels of wheat. In saline alkali soils, wheat needs to be supplied with higher amounts of nutrients, particularly N, than in normal soils. Band placement of fertilizers, particularly phosphorus, leads to improved fertilizer use efficiency, but appropriate machinery is lacking. Recently introduced site-specific nutrient management strategies for wheat take into account field-to-field variability and can help increase fertilizer use efficiency more than that achieved by following blanket fertilizer recommendations. Conservation agricultural practices consisting of reduced tillage and residue retention in wheat fields have already been introduced in South Asia. Nutrient management strategies for these wheat-growing environments are also being actively worked out. Yield gap analysis shows that productivity of wheat as well as nutrient use efficiencies can be further improved.

Earliness in wheat: A key to adaptation under terminal and continual high temperature stress in South Asia

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research 151 : 19-26, 2013

S. Mondal, R.P. Singh, J. Crossa, J. Huerta-Espino,  I. Sharmac, R. Chatrath, G.P. Singh, V.S. Sohu, G.S. Mavi, V.S.P. Sukaru, I.K. Kalappanavarg, V.K. Mishra, M. Hussain, N.R. Gautam, J. Uddin, N.C.D. Barma, A. Hakim and  A.K. Joshi

High temperatures are a primary concern for wheat production in South Asia. A trial was conducted to evaluate the grain yield performance of high yielding, early maturing heat tolerant CIMMYT wheat lines, developed recently in Mexico for adaptation to high temperature stresses in South Asia. The trial, comprised of 28 entries and two checks, was grown in 13 locations across South Asia and two environments in Mexico. Each location was classified by mega environment (ME); ME1 being the temperate irrigated locations with terminal high temperature stress, and ME5 as warm, tropical, irrigated locations. Grain yield (GY), thousand kernel weight (TKW), days to heading (DH) and plant height (PH) were recorded at each location. Canopy temperature (CT) was also measured at some locations. Significant differences were observed between ME for DH, PH, GY, and TKW. The cooler ME1 locations had a mean DH of 83 days, compared to 68 days mean DH in ME5. The ME1 locations had higher mean GY of 5.26 t/ha and TKW of 41.8 g compared to 3.63 t/ha and 37.4 g, respectively, for ME5. Early heading entries (<79 days, mean DH) performed better across all locations, with GY of 2–11% above the local checks and 40–44 g TKW. Across all locations the top five highest yielding entries had 5–11% higher GY than the local checks. The early maturing CIMMYT check ‘Baj’ also performed well across all locations. In the Mexico location, CT was associated with GY, thereby suggesting that cooler canopies may contribute to higher GY under normal as well as high temperature stress conditions. Our results suggest that the early maturing, high yielding, and heat tolerant wheat lines developed in Mexico can adapt to the diverse heat stressed areas of South Asia.