Indian Journal of Ecology

Rice (Oryza sativa L.) wheat (Triticum aestivum L.) cropping system (RWCS) is the largest grain production system in the world, including India. In India, with the introduction of high-yielding varieties of rice and wheat, RWCS emerged as the principal cropping system, ushering in the Green Revolution. However, the widespread adoption of higher-yielding varieties led to the loss of genetic diversity. A farm survey was conducted to analyse the on-farm varietal diversity of rice and wheat crops in the Jammu & Kashmir subtropics and Punjab. A multistage random sampling technique was applied to select a sample of 480 rice-wheat-cultivating farmers. In Punjab, 23 rice and 20 wheat varieties, and in Jammu, 17 rice and 19 wheat varieties were grown by the farmers. Ten and seven rice varieties were dominant varieties cultivated in Jammu and Punjab, respectively, covering a crop acreage of 76.40 and 46.86 per cent with a varietal diversity index of 0.131 and 0.106. In wheat, 88.75 per cent of wheat acreage was under two varieties with a varietal diversity index of 0.066 in the Jammu subtropics, and 82.02 per cent of total wheat acreage in Punjab was under five varieties with a mean varietal diversity index of 0.080.