R.K. YADAVTARAMANI YADAV2023-11-142023-11-142019https://krishikosh.egranth.ac.in/handle/1/5810201101The study entitled “Role of plant bioregulators in mitigating matric and osmotic stress in pearl millet-wheat cropping system” was undertaken for two consecutive years (2016- 2018) in salty sandy loam soil ECe (7.61±2.32 dS m-1), pH1:2 (8.38±0.77) at ICAR-CSSRI experimental farm, Nain, Panipat (Haryana). Subsequent laboratory analysis was completed at ICAR-CSSRI and ICAR-NDRI, Karnal. In triple replicated split-split plot design experiment, matric stress i.e. irrigations~@60 (I1), 80 (I2) and 100% (I3) of crop ET (ETc) was imposed in main plot treatments at critical growth stages. Four levels of saline irrigation water i.e. EC 2, 4, 8 and 12 dS m-1 (S0, S1, S2 and S3) were applied in sub plots. In sub-sub plots two plant bioregulators (PBRs); salicylic acid (SA) and thiourea (TU) along with control [G0, G1 and G2), were applied as seed priming and foliar spray at critical growth stages. Deficit irrigation regimes (I2 and I1) significantly reduced wheat grain yield. Growth, yield, many quality and physiological parameters of wheat were reduced significantly with matric stress (I1 and I2). There were significant reductions in grain yield, RWC (at flowering stage), crude protein yield (total) and B:C ratio of pearl millet and wheat, wheat straw yield beyond 4 dS m-1. Stover and biological yield of pearl millet was not changed significantly upto 8 dS m-1. Dry matter (DM) content of wheat straw and, ash, ADF, ADL (grain and stover) and NDF (stover) content of pearl millet were significantly higher in S2 and S3. Higher irrigation volume (100% ETc) with higher osmotic stress (12 dS m-1) significantly reduced wheat and pearl millet grain yields. Both salicylic acid and thiourea had improved growth, yield, nutritional quality, biochemical activities and benefit:cost ratio of pearl millet and wheat. However, SA was superior for alleviating the stresses in pearl millet and TU in wheat. SA was more effective in mitigating mild osmotic stress (4 dS m-1), but TU performed significantly better at severe osmotic stress (12 dS m-1) in both crops. Soil ECe at harvest increased significantly with application of 8 dS m-1 and 12 dS m-1 irrigation water. Net return and B:C ratio did not influence significantly upto 4 and 8 dS m-1 by application of SA and TU, respectively in wheat.EnglishThesis