Agriculture Reference
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grown under the influence of typical forest and agricultural ecosystems.
Deforestation, shift in cropping systems, decline in wetlands, and deple-
tion of surface and groundwater resources may aggravate the adverse ef-
fects of floods and drought on crops.
Many studies have shown that the primary climatic elements (temper-
ature and rainfall) have a profound influence on the phenology of crop
plants. In the case of cardamom, the seasonal flowering habit has changed.
Up to early1990s, June to December was the main flowering season and
now cardamom has been flowering throughout the year. Accordingly, the
number of harvests also has been increased from five to nine per year.
This has resulted in manifold increase in productivity of cardamom. More
harvests in recent years (since late 1990s) indicate the impact of climate
change on cardamom phenology (Murugan et al., 2012). Cardamom pro-
ductivity increased in the cardamom hills irrespective of the variety dur-
ing the study period (1987 to 2007) indicating that warming may have
positive influence on cardamom productivity (Murugan et al., 2012). But
apart from warming, crop management practices may also have influence
on productivity.
The spatial and temporal distribution and proliferation of pests is de-
termined, largely, by climate, because temperature, light, and water are the
major factors controlling the growth and development of pests (Rosenz-
weig et al., 2001). In cardamom hills, since 2000, the number of pesticide
sprays has been significantly increased, and at present, 15-18 rounds of
pesticide sprays are given (as against 7-8 rounds until 1990). But there
was no great increase in the frequency of cardamom damage by major in-
sect pests like thrips and borers indicating the involvement of more num-
ber of insect pests and diseases in damaging the crops. The incidence of
many minor pest insects and disease pathogens has increased in the recent
years along with warming. Increased frequency of break period during
monsoon seasons (wet and dry spells) as observed in Pampadumpara sta-
tion might favor the development of dry rot during dry spell and wet rot
during wet spell (Murugan et al., 2012). Such situations necessitated the
use of pesticides to manage these rot diseases in cardamom, otherwise the
crop loss would reach up to 70% (DaMatta et al., 2006).
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