Indian Institute of Horticultural Research, Hessaraghatta, Bangalore 560 089
The experiment was conducted to select banana leaf part as an index tissue of N at a physiological stage of crop growth which can give best possible relationship between N of index tissue with yield, as well as to work out N requirement for optimum yield of banana Robusta. Leaf tissues were collected up to bloom stage from leaf lamina, midrib and petiole when plants had 8, 12, 16, 20, 24, 28 and 32 leaves. Petiole of third fuly opened leaf was the best index tissue for nutritional diaposis. However, midrib from the same leaf also was equally indicative in bringing out the variation in N of index tissue due to its differential supply rate. Index tissue can be collected at 24th leaf stage. The optimum N level at this stage can be related to potential yield. Index tissue norm for N was 0.98% in petiole at 24th leaf stage on application of 200g N/plant at 4,444 plants/ha population. Nitrogen norms for midrib and leaf lamina would be 0.80 and 2.57% respectively.
