Agriculture Reference
In-Depth Information
maintain yield stability. Improvement in germplasm of important crops
for heat-stress tolerance should be one of the targets of breeding program.
Similarly, it is essential to develop tolerance to multiple abiotic stresses
as they occur in nature. The abiotic stress tolerance mechanisms are
quantitative traits in plants. Germplasm with greater oxidative stress
tolerance may be exploited as oxidative stress tolerance is one example
where plant's defense mechanism targets several abiotic stresses. Similar
to the research efforts on conversion of C3 to C4 crop for improvement
in radiation-use efficiency.
Improvement in water-use and nitrogen-use efficiencies is being at-
tempted since long. These efforts assume more relevance in the climate
change scenarios as water resources for agriculture are likely to dwindle
in future. Nitrogen-use efficiency may be reduced under the climate
change scenarios because of high temperatures and heavy precipitation
events causing volatilization and leaching losses. Apart from this, for
exploiting the beneficial effects of elevated CO
2
concentrations, crop
demand for nitrogen is likely to increase. Thus, it is important to improve
the root efficiency for mining the water and absorption of nutrients.
Exploitation of genetic engineering for 'gene pyramiding' has become es-
sential to pool all the desirable traits in one plant to get the 'ideal plant
type' which may also be 'adverse climate-tolerant' genotype.
Farmers need to be provided with cultivars with a broad genetic base.
Their adaptation process could be strengthened with availability of new va-
rieties having tolerance to drought, heat and salinity and thus, minimize
the risks of climatic aberrations. Similarly, development of varieties is
required to offset the emerging problems of shortening of growing sea-
son and other vagaries of production environment. Farmers could better
stabilize their production system with basket of technological options.
8.3.10.2 CROP DIVERSIFICATION
Diversification of crop, including replacement of plant types, culti-
vars and hybrids intended for higher drought or heat tolerance, are being
advocated as having the potential to increase productivity in the face of
temperature and moisture stresses. Diversity in the seed genetic struc-
ture and composition has been recognized as an effective defense against
disease and pest outbreak and climatic hazards. Moreover, demand for
