During monsoon, the rice crop of eastern states of India shows lesser yield due to limiting factor of

According to law of limiting factors given by Blackman, when a process depends upon a number of factors which are separate, the rate of the process is limited by the pace of the slowest factor. Rate of yield is dependent on light as photosynthesis is dependent on light. During monsoon, the light is dim and so this reduces rate of photosynthesis and hence yield.