Agriculture Reference
In-Depth Information
private vegetable breeding programs. This germplasm will include both
cultivated and wild accessions possessing genetic variation unavailable in
extensively grown cultivars. Genetic populations are being developed to
introgression and identify genes conferring tolerance to stresses and at the
same time generate tools for gene isolation, characterization, and genetic
engineering. Furthermore, agronomic practices that conserve water and
protect vegetable crops from suboptimal environmental conditions must
be continuously enhanced and made easily accessible to farmers in the
developing world.
8.1 INTRODUCTION
Global climate system warmed up by 0.74 °C between 1906 and 2005 due to
increased concentration of greenhouse gases (GHGs). The trends of rise in
temperature, heat waves, droughts and floods, and sea level observed by the
Indian scientists are in line with the Inter-Governmental Panel on Climate
Change (IPCC), though the magnitude of changes varies. Agriculture in
India, where nearly 60% of area is rain fed, has been a highly risky venture
with vagaries of monsoon besides the interplay of other abiotic and bi-
otic factors. Climate change is further compounding the daunting complex
challenges already being faced by agriculture. C oncerted efforts are,
therefore, required for mitigation and adaptation to counter the adverse
impacts of climate change and making it more resilient.
A significant change has been observed in the gaseous composition
of earth's atmosphere during the last few decades which is attributable
to the increased emissions from energy, industry and agriculture sectors
widespread deforestation as well as fast changes in land use and land
management practices mainly active gases, viz. carbon dioxide (CO
2
),
methane (CH
4
) and nitrous oxide (N
2
O), popularly known as the
'greenhouse gases' (GHGs). These GHGs trap the outgoing infrared
radiations from the earth's surface and, thus, raise the temperature
of the atmosphere. The global mean annual temperature at the end of the
twentieth century, as a result of GHG accumulation in the atmosphere,
has increased by 0.4-0.7ºC above that recorded at the end of the nine-
teenth century. An increasing trend in temperature at 0.13 °C/decade
has been observed during the past 50 years, however the rise has been
much higher d u r i n g the past one and half decades.
