Geoscience Reference
In-Depth Information
Philippines). Two weather generators, WGEN and WMAK,
from the Decision Support System for Agrotechnology Transfer,
were utilised to produce estimated daily weather data for each
location. Thirty years of daily weather data produced by one of
the generators for each location were used as input to the com-
bined model to simulate blast epidemics for each temperature
change. Maximum blast severity and the area under the disease
progress curve caused by leaf blast which resulted from 30-year
simulations were statistically analysed for each temperature
change and for each location. Simulations suggest that tempera-
ture changes had significant effects on disease development at
most locations. However, the effect varied in different agro-eco-
logical zones. In the cool subtropics such as Japan and north-
ern China, elevation of temperature above normal temperature
resulted in more severe blast epidemics. In warm/cool humid
subtropics, elevation of temperature caused significantly less
blast epidemics. However, lower temperature caused insignifi-
cant difference in disease epidemics compared with that in nor-
mal temperature. Conditions in the humid tropics were opposite
to those in cool areas, where daily temperature changes by −1°C
and −3°C resulted in significantly more severe blast epidemics,
and temperature changes by +1°C and +3°C caused less severe
blast. Scenarios showing blast intensity affected by temperature
change in different agro-ecological zones were generated with a
geographic information system (GIS) (Luo et al., 1998).
8.8
Strategies for mitigating effects of global
warming on rice production
The paddy experiments carried out at UC Davis and Trinity
College Dublin indicated that increased carbon dioxide in the
atmosphere boosted rice yields by 24.5% and methane emis-
sions by 42.2%, increasing the amount of methane emitted per
kilo of rice (Soos, 2012). There are several options available to
reduce methane emissions from rice agriculture. The manage-
ment practices such as mid-season drainage and using alterna-
tive fertilisers as well as switching to more heat-tolerant rice
varieties and adjusting sowing dates are some of the measures
suggested to reduce the methane emissions (NAU, 2013).
The following are few of the strategies which may be adopted
to counter the effect of global warming on rice:
1. To breed and release new rice cultivars with better adap-
tation to high temperature and other climatic stresses
