Quality Seeds are the critical determinant of different agro-climatic zones for sustainable planning in agricultural production. It is necessary to raise the supply of quality seeds of different crops in sufficient quantity at reasonable prices for farmers at the right time in the state. New seeds are either Certified Seeds (CS) or Hybrid Seeds. A better Seed Replacement Rate (SRR) presents a better application of Certified or Quality Seed or Hybrid Varieties Seeds (HYV). It plays a major role in agriculture to raise the production of crops. In this research paper, we have analysed the impact of Seed Replacement Rate on the production of Mustard Seeds during the period 2022-23 in the Jarur Gram Panchayat (GP) of Block Raghunathganj-I, Murshidabad District, West Bengal. The data have been collected by the stratified random sampling procedure. With the help of collected data, we have formed a Coob-Douglas Type of production function and which is estimated by the Ordinary Least Square Method. From the collected data, it has been observed that the average Seed Replacement Rate is 38.52 percent which is below the state average (53.2%). We have also noticed that 30.43 percent farmers have used farm-saved seeds and only 17.4 percent farmers have used hundred percent new seeds. The estimated result has proved that Seed Replacement Rate is a key determinant to raise both production, productivity and economic benefits. If Seed Replacement increases production also will increase and thereby there would be economic leverage. It has also been found that farm size with Seed Replacement Rate is not a significant factor in increasing the production of Mustard Seeds. Another interesting finding is that seventy percent of farmers have used inorganic fertilizers. They have applied excessive chemical fertilizers which is greater than the government’s prescribed norm. However, from the estimated result we have observed that the

Seed Replacement Rate according to different farm sizes with excessive application of fertilizers does not influence both the production and productivity of Mustard Seeds. From an economic standpoint of view, new seeds are better than farm-saved seeds (old seeds) as their gross income increases.