Nitrate reductase activity (NRA) in vivo was more in the leaf laminae of plant crop than in the respective ratoons of sugarcane cultivars. This could be due to efficient reduction of nitrate and its utilization by the plant crop as compared to ratoon. Protein and total nitrogen content was more in the plant crop than in the ratoon. At all the levels of nitrate applied in the soil, plant crop recorded consistently higher NRA than that in ratoon. For a similar level of induction of NRA, ratoons need more nitrate nitrogen than do plant crop.
