Potential Foliar Chemicals for Enhancing Yield and Drought Tolerance in Leguminous Crops: A Review

In pulse crops, synchronized flowering altered the source-sink relationship due to the rapid translocation of nutrients from leaves to the developing pods. Additional nutrition through foliar feeding plays a vital role in pulse production by stimulating root development, nodulation, energy transformation, various metabolic processes and increasing pod setting, thereby increasing the yield. Many researchers are trying to reduce transpiration losses, flower shedding and maximizing productivity, foliar application of nutrient formulations and growth regulators in pulses. Thus, the foliar application of macro and micronutrients and growth regulators is considered an efficient and economical method of supplementing part of the nutrient requirements and moisture stress tolerance at critical stages. The PPFM (Pink pigmented facultative methylobacteria), when used as a foliar spray, it releases osmoprotectants (sugars and alcohols) on the surface of the plants and it increases chlorophyll content, thereby increasing the photosynthetic efficiency and makes drought tolerance ability of plants. This matrix helped to protect the plants from desiccation and high temperatures. Whereas potassium as spray also enhances drought tolerance in plants by mitigating harmful effects by increasing translocation, maintaining water balance and increasing pod filling. Further, salicylic acid is an endogenous growth regulator of phenolic nature, which regulates physiological processes to mitigate stress, acts as a chelate for phosphorous uptake, increases pod setting, flowering and grain yield. Pulse wonder decreases flower shedding, increases yield by up to 20% and offers moisture stress tolerance.