A field experiment was conducted during rabi 2021-22, to study the influence of zinc sulphate and potassium nitrate on morpho-physiological parameters, yield and yield contributes of lathyrus cv. Ratan. The experiment was laid down in randomized block design with nine treatments and three replications at research farm of Botany Section College of Agriculture, Nagpur. The aim of this work was to study the effect of foliar application of zinc sulphate at 0.25, 0.50, 0.75 and 1% and potassium nitrate at 0.20, 0.40, 0.60 and 0.80% on biochemical parameters and yield in lathyrus. Spraying of zinc suphate and potassium nitrate was done two times i.e. on 20 and 40 DAS. Observations about morpho-physiological parameters like plant height, number of branches, total dry matter production and leaf area were also estimated. Observation on yield contributing parameters like 100 seed weight (g), number of pods plant-1, grain yield plant-1, plot-1, ha-1, harvest index recorded. Foliar sprays of 0.80% KNO3 followed by 0.60% KNO3 significantly enhanced biochemical parameters and yield contributing parameters when compared with control and rest of the treatments under study.