Breeding crops for reduced-tillage management in the intensive, rice–wheat systems of South Asia |
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Authors: | A K Joshi R Chand B Arun R P Singh Rodomiro Ortiz |
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Institution: | (1) Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi , 221 005, India;(2) Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi , 221 005, India;(3) Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT), Apdo. Postal 6-641, C.P. 06600 Mexico D.F., Mexico |
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Abstract: | The importance of reduced tillage in sustainable agriculture is well recognized. Reduced-tillage practices (which may or may
not involve retention of crop residues) and their effects differ from those of conventional tillage in several ways: soil
physical properties; shifts in host–weed competition; soil moisture availability (especially when sowing deeply or under stubble);
and the emergence of pathogen populations that survive on crop residues. There may be a need for genotypes suited to special
forms of mechanization (e.g. direct seeding into residues) and to agronomic conditions such as allelopathy, as well as specific
issues relating to problem soils. This article examines issues and breeding targets for researchers who seek to improve crops
for reduced-tillage systems. Most of the examples used pertain to wheat, but we also refer to other crops. Our primary claim
is that new breeding initiatives are needed to introgress favourable traits into wheat and other crops in areas where reduced
or zero-tillage is being adopted. Key traits include faster emergence, faster decomposition, and the ability to germinate
when deep seeded (so that crops compete with weeds and use available moisture more efficiently). Enhancement of resistance
to new pathogens and insect pests surviving on crop residues must also be given attention. In addition to focusing on new
traits, breeders need to assess germplasm and breeding populations under reduced tillage. Farmer participatory approaches
can also enhance the effectiveness of cultivar development and selection in environments where farmers’ links with technology
providers are weak. Finally, modern breeding tools may also play a substantial role in future efforts to develop adapted crop
genotypes for reduced tillage. |
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Keywords: | Conservation agriculture Reduced tillage Zero-tillage Wheat improvement Wheat breeding Participatory varietal selection |
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