Flood stress and its effects on fruit crops: A critical review

Growth, development, yield, and even normal functioning of the tropical and subtropical fruit crops are affected by flood stress due to unpredictable climate change. Flooding-induced anerobic respiration affects the cell integrity by the excess intake of Reactive Oxygen Species and other phytotoxic components, which affects both vegetative and reproductive growth and leads to yield loss or complete crop loss. These anerobic condition favors the growth of microbes which cause Phytophthora root rot. Wilting, necrosis, leaf yellowing, shedding of leaves, and stunted growth are the symptoms shown by flooded plants due to the reduced photosynthetic activity. Due to flood-induced oxidative stress, a plant undergoes morphological, physiological, and biochemical adaptations for survival. Formation of aerenchyma, adventitious root, hypertrophic lenticels, pneumatophores, and leaf epinasty are the morphological adaptations observed in fruit crops. Some of the preventive measures which increase the tolerance toward flood stress are the selection of flood-tolerant rootstocks, pruning to maintain the aerial part/root ratio, application of fertilizers to improve the redox potential, plant recovery, and improved mycorrhizal colonization in the roots.