Nutrient requirement and DRIS indices for Sunflower Genotypes

Different crops have unlike nutrient requirements and different soil types vary in their capacity to provide nutrients. Therefore, we need to study the optimum requirement of nutrients for particular crops on different soil types and in different agro climatic conditions. Several methods of fertility management have been proposed from time to time to maintain the soil fertility and improve the crop productivity. Of late, the close association between the nutrient status of leaves and yield of crop is considered as one of the most important factor. Nutrient indices are worked out in many crops to monitor the adequate and balanced fertilization. DRIS not only helps to identify the nutrient(s) that are deficient but also the order of their severity and requirement is prioritized. This helps the farmer to know which nutrient should be corrected first before attempting to correct the next deficient nutrient through its application. Such an identification of multiple nutrient deficiencies or imbalances is not possible through the conventional methods. The present work will help to understand and identify the nutritional imbalances in sunflower through DRIS and work out the schedule.