Occurrence of combined salinity and waterlogging stress is increasing throughout the world. According to the FAO, about 60-80 million hectares of land are affected to some extent by combined waterlogging and salinity stress. Waterlogging and salinity impair and effects the growth and development of pigoen pea, and reduces its productivity significantly. When water and salt exceed their optimum levels, it leads to waterlogging and salinity stress, respectively. The combination of waterlogging and salinity exacerbates the effects of salinity and vice versa. In this study, we examined the impact of waterlogging (W), salinity (S), and their combination (W+S) on plant survival percentage, shoot dry weight, total plant biomass, and total chlorophyll content in pigeonpea. The pot experiment was conducted during the rainy season of 2018-19, involving three genotypes (Bahar, UPAS-120 and Asha). Stress was imposed 40 days after sowing, and observations were taken at 6th and 10th day after the imposition of stress. Waterlogging + salinity was found to be more deleterious to plants, although the effect was less pronounced with salinity (30 mM NaCl) treatment alone. In terms of survival percentage, shoot dry weight, total plant biomass, and total chlorophyll content, the Bahar genotype demonstrated relatively higher tolerance compared to other genotypes in all treatments (waterlogging, salinity, and salinity + waterlogging). The order of performance among genotypes was found to be Bahar, UPAS-120, and Asha. These findings can contribute to the development of stress-tolerant pigeonpea genotypes or selection of a relatively tolerant genotype aimed at mitigating the negative effects of waterlogging and salinity stresses on crop productivity.

Pigeonpea, Salinity, Waterlogging, Plant biomass, Chlorophyll content

In conclusion, the study investigated the effects of waterlogging, salinity, and their combination on morpho-physiological parameter revealed that the genotypes exhibited varying degrees of tolerance to the imposed stresses. Survival percentages under combined waterlogging (W)+ Salinity(S) was more deleterious to pigeonpea compared to individual stresses. With respect to morphological parameters, plant height, shoot dry weight and total plant biomass were reduced under stress conditions compared to the control. The combined stress of salinity and waterlogging had the most detrimental effect on plant height, shoot dry weight and total plant biomass. Further, total chlorophyll content, was also significantly reduced under stress conditions compared to control. Among individual stress given alone, waterlogging stress was found to be more detrimental as compared to 30 mM NaCl salinity for recorded observations. Overall, Bahar genotype showed comparatively higher level of tolerance under the stress conditions, followed by UPAS-120 and Asha respectively. The findings can contribute to the development of stress-tolerant pigeonpea varieties and to select appropriate genotypes aimed at mitigating the negative effects of these stresses on crop productivity.

Uday Pratap Singh, J. P. Srivastava, Pravin Prakash and Krishna Kumar (2023). Independent and Combined Effects of Waterlogging and Salinity on Morpho-Physiological Parameters in Pigeonpea Genotypes at Early Growth Stages. Biological Forum – An International Journal, 15(12): 29-33.