Agriculture Reference
In-Depth Information
Increased fecundity and growth of some fungal pathogens under elevated
CO
2
has also been reported (Singh, 2004). However, it has been reported
that greater plant canopy size, especially in combination with humidity
and increased host abundance, can increase pathogen load. Temperature
Changes in environmental conditions are likely to result in the northward
extension of certain diseases and pests, more generations of pathogens per
season, and a better capacity to survive the winter, thus increasing their
prevalence and range. The favorable temperature range for the infestation
of the rice gundhi bug is 13°C-35°C. If the temperature exceeds the upper
threshold of the favorable range, the development rate and the survival
capacity of the bugs get reduced. Moisture also plays an important role in
the activities of the pathogens as optimal breeding conditions are usually
created when moisture is high. The increase in temperature and moisture
creates especially favorable conditions and affects both hosts and patho-
gens in various ways.
19.2.9 FUNGAL INFECTION
Another aspect is that the occurrence of plant-based toxic contaminants
can be influenced by changes in climate. For example, aflatoxin a me-
tabolite of the fungal species Aspergillus is a dangerous contaminant that
infects food grains and is harmful for human and animal health. Climatic
changes including increased prevalence of drought and unseasonal rains,
changes in relative humidity and shift in temperature may favor the popu-
lation and spread of aflatoxin-producing fungi. Compounding this prob-
lem is the fact that changes in climate may allow the increased population
of fungal pathogens to have increased opportunities to attack food grain
crops. For example, dry conditions during grain filling and maturity en-
hance the probability of cracked grains, which can get more easily infected
by this fungal pathogen. Heavy rains during or after the harvest may lead
incomplete drying of grains before storage and causes proliferation of the
fungus during the storage period.
19.2.10 POULTRY AND LIVESTOCK
Poultry, livestock and other farm animals will suffer due to climate chang-
es because higher temperatures will increase the number of new diseases
