A synoptic review of deficit irrigation methods: sustainable water-saving strategies in vegetable cultivation

It is elusive and highly challenging to sustain the productivity of vegetable commodities under limited available natural resources and anticipated future climatic scenarios. Amongst available natural resources, water remains the most limiting factor. Present vegetable cultivation practices involve the utilization of excessive quantities of water, thereby leading to the wastage of precious water resources. Therefore, sustainable management of irrigation water is crucial for future vegetable cultivation, as most vegetable crops are vulnerable to water scarcity at different growth stages, which can result in yield and post-harvest quality losses. Adoption of deficit irrigation (DI) is one of the sustainable irrigation water management approaches. DI is a sustainable water-saving approach, as irrigation water is applied in limited or lower quantities than the actual evapotranspiration-based crop water requirement. Strategic application of water at the right time and quantity with the right technique can greatly improve water use efficiency and water productivity. It could also enhance the post-harvest quality with marginal yield loss. Yield losses whatsoever could be compensated by expanding agricultural areas in water-scarce zones by adopting the DI strategy. This review discusses the concept and types of DI and examines its implications for the morpho-physiology and productivity of commercially important vegetable crops.