Flooding: Abiotic Constraint Limiting Vegetable Productivity

Abstract

Physico-chemical events during flooding Change rhizosphere chemistryExcess water causes a sharp decrease in soil redox potential, AbstractFlooding is a major environmental stress that severely limits crop productivity and it has become a major problem worldwide. More than one third of the world's irrigated area suffers due to flooding, frequently or otherwise. It may result due to heavy rainfall, faulty irrigation, unleveled land, poor drainage or heavy soil texture. Various morpho-physiological, biochemical and anatomical changes induced in root system during flooding, for example reduction in the shoot-root relative growth, Formation of thicker adventitious roots or air roots, arenchyma formation and cuboidal packing of cells enhances the longitudinal transport of gases, the major shift occurs in the carbohydrate metabolism of the plants, which move towards lactate and ethanolic fermentation to provide the required ATP. Oxygen diffusion is 10,000 times slower in waterlogged soil as compared to air. Continued flooded conditions lead to lack of oxygen in the soil, restricting respiration of the growing roots and other living organisms. Soil chemical properties also change when anaerobic conditions persist for several days. This is followed by loss of chlorophyll of the lower leaves, arrest of crop growth and proliferation of surface root growth with the retreat of water level. Plant transpiration is affected under anaerobic conditions and extended water logging results in root death due to inadequate oxygen supply.

A physiology‐based Earth observation model indicates stagnation in the global gross primary production during recent decades

“…Drought stress causes stomatal closure, reduces leaf size, stem extension and root proliferation, and disturbs plant water relations (Farooq et al, 2009). Waterlogging leads to reduced oxygen availability, lower root growth, reduced respiration rates, lower nutrient availability and thereby reduced plant growth (Patel et al, 2014;Tewari & Mishra, 2018). Most Earth observation-based GPP models do not include the waterlogging effect, and assume that drought stress is sufficiently captured by the FAPAR and the VPD signals (Stocker et al, 2019).…”

Mangrove root: adaptations and ecological importance

“…It is reported that lenticel formation is associated with ethylene and auxin accumulation due to stress caused by O 2 deficiency in flooded soil (Bruna et al 2012;Patel et al 2014). Flooded roots contain more amount of ethylene and its precursor (acid-1 aminocyclopropane-1-carboxylic acid-ACC), and high activity of ACC synthase and ACC oxidase compared with normal roots (He et al 1996;Rieu et al 2005;Vidoz et al 2010).…”

Genetic Variation Based on RAPD Profiling and Production Loss of Cayenne Pepper due to Periodic Flooding

“…Lack of oxygen disrupts energy supply, ion transport, and membrane integrity, giving rise to nutritional deficiencies in roots and in shoots [38], and plant death occurs due to this lack of oxygen, which results in an energy crisis in the root. Flooding causes increasing severity of diseases [39], and due to the inability of plants to handle the severity and duration of stress, it leads to plant death [6]. Furthermore, death response in periodic flooding causes multiple stress in plants, not only by submergence (flooding) followed by de-submergence (drainage) but also by the presence of more pest and disease infection in high humidity environments post-flooding [28].…”