Abiotic factors in horticultural crops.

Abstract

Abstract Abiotic disorders in horticultural crops are those caused by non-living or non-infectious factors, which may also be referred to as abiotic disease or physiological disorders. Abiotic factors refer to a wide range of plant and crop problems with varied symptoms and differing degrees of damage. Abiotic disorders are often associated with causal factors such as temperature/weather, soils, water, chemicals, mechanical injuries, cultural practices and, in some cases, a genetic predisposition within the plant itself (Schutzki and Cregg, 2007). It has been suggested that the environmental abiotic factors alone can limit crop production by as much as 70% (Boyer, 1982). The yields of major food crops are expected to decline in many areas in the future due to the continued reduction in arable land, reduction of water resources, increased global warming and climate change (Lobell et al., 2011). An FAO report published in 2007 stated that 96.5% of global rural land area is affected in some way by abiotic stress (van Velthuizen et al., 2007), with factors such as temperature, mineral deficiency, drought, flooding and salinity being the most significant issues. While abiotic factors that have a negative effect on plant growth primarily reduce yields and productivity, they also influence produce quality, postharvest shelf life, susceptibility to pathogens, and marketability of a wide range of food and ornamental plants. There is also a complex relationship between many abiotic factors with light, temperature, moisture and nutrient levels all interacting to create multiple plant stresses. Plant responses to abiotic stresses are dynamic and complex; they are both elastic (reversible) and plastic (irreversible), (Cramer et al., 2011), and many responses are heavily dependent on genetic susceptibility or tolerance.