Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
rainfed crops, it is necessary to use the knowledge of climate variability to tailor the innovative
cropping patterns and the disease management practices for location specific agro-climate zone.
It is well established that temperature, moisture and greenhouse gases are the major elements
of climate change. Current estimates of changes in climate indicate an increase in global mean
annual temperatures of 1ºC by 2025 and 3ºC by the 2100. Variability in rainfall pattern and
intensity is expected to be high. Greenhouse gases (CO 2 and O 3 ) would result inincrease in global
precipitation of 2 ± 0.5ºC per 1ºC warming. Overall, changes in these elements will result in i)
warmer and more frequent hot days and nights ii) erratic rainfall distribution pattern leading to
drought or high precipitation and iii) drying of rainfed tropics (specifically semi-arid tropics) in Asia
and Africa. Temperature increaseassociated with climatic changes could result in following
changes in plant diseases:
Extension of geographical range of pathogens
Changes in population growth ratesof pathogens
Changes in relative abundance and effectiveness of biocontrol agents
Changes in pathogen×host×environment interactions
Loss of resistance in cultivars containing temperature-sensitive genes
Emergence of new diseases/and pathogen forms
Increased risk of invasion by migrant diseases
Reduced efficacy of integrated disease management practices
These changes will have major implications for food and nutritional security, particularly in
the developing countries of the dry-tropics, where the need to increase and sustain food
production is most urgent. In this commentary an attempt has been made to introduce climate
change to plant pathologists, update knowledge on its potential impacts on host–pathogen
interactions, critically review progress, and initiatives taken by ICRISATon research needs to
better manage legume (pulse) diseases under a changing climateas a case-study.It is sincerely
hoped that this effort may sensitize the pathologists and researchers to initiate location specific
multidisciplinary researchto device sustainable management options ofplant diseases as impacted
by climate change in India.
Current Knowledge
The current knowledge on the main potential effects of climate change on plant
pathosystems has been recently summarized by Pautasso et al. (2012). Their overview suggests
that maintaining plant health across diversified environments is a key requirement for climate
change mitigation as well as the conservation of biodiversity and provisions of ecosystem services
under global change. Environmental influences on plant diseases have always been considered by
plant pathologists: the classic disease triangle emphasizes the interactions between plant hosts,
pathogen and environment in causing disease (Garrett et al. 2011; Grulke 2011). Climate change
is one of the many ways in which the environment can move in long term from disease–
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