| Abstract: | Abstract The Diagnosis and Recommendation Integrated System, previously applied successfully to many other crops, is shown to be an appropriate foliar diagnostic tool for sorghum (Sorghum bicolor L.) with respect to N, P, K, Ca and Mg. The norms were developed from a data bank comprising 907 observations of tissue composition and yield gathered from the literature and investigators’ files. The total population of observations is divided into a high and low subpopulation on the basis of yield. Those forms of expressing tissue composition which discriminate best between the two subpopulations are used to compute DRIS indices which measure the extent of the deviation from the established norm. An independent set of data from two field experiments is used to show that the norms can validly diagnose nutrient insufficiences which when, corrected result, in yield increases. |
