Agriculture Reference
In-Depth Information
Plant pests, which include insects, pathogens and weeds, continue to be
one of the biggest constraints to food and agricultural production. Despite
of continued release of high yielding disease and pest resistant varieties
and introduction of new pesticides 12-15% yield losses were observed
which is caused by pest and diseases. In spite of that they not only reduce
the crop yield but they also contaminate the agricultural produce by secret-
ing toxins, which creates several health hazards. Climate change and plant
disease development rising concern of agricultural producers and scien-
tists how is climate change going to affect agriculture as a whole Plant
pathology is one of the agricultural disciplines that is directly affected by
the climate change. Garret et al. (2006) established the connection in the
climate change and plant pathogens by empirical and modeling experi-
ments. According to them the first direct impact of climate change on plant
disease would be the balance of the encounter rate between pathogen and
host by changing rates of the two species.
15.3 EFFECT OF ELEVATED TEMPERATURE ON PLANT
PATHOGENS
Temperature has potential impacts on plant disease affecting the host and
pathogen. Rise in temperatures caused by increasing green house gases
is likely to affect crops differently from region to region. For example,
moderate warming (increase of 1 to 3°C in mean temperature) is expected
to benefit crop yields in temperate regions, while in lower latitudes espe-
cially seasonally dry tropics, even moderate temperature increases (1 to
2°C) are likely to have negative impacts for major cereal crops. Warming
of more than 3°C is expected to have negative effect on production in all
regions (IPCC, 2011). The Third Assessment Report of the IPCC, 2001
concluded that climate change would hit the poorest countries severely
in terms of reducing the agricultural products. The Report claimed that
crop yield would be reduced in most tropical and subtropical regions due
to decreased water availability, and new or changed insect/pest incidence.
Fungi that cause plant disease grow best in moderate temperature ranges.
Temperate climate zones that include seasons with cold average tempera-
tures are likely to experience longer periods of temperatures suitable for
pathogen growth and reproduction if climates warm. It has been predicted
that the expansion of geographic area of
Phytophthora
in response to in-
