PRELIMINARY COMPOSITIONAL NUTRIENT DIAGNOSIS NORMS AND CORRELATIONS AMONG NUTRIENTS AND YIELD IN PEPPER (Capsicum annuum L.)

Abstract

Pepper is one of the most important crops in Mexico. It is known that healthy plants may resist in a better way to pests and diseases. Thus, balanced nutrient quantity must be provided to the plants. In this context, it is important to account with nutrient norms and to be able to perform correct nutrient diagnosis. Therefore, the aims of this study were to determine compositional nutrient diagnosis (CND) standards and to identify important correlations between nutrients and between nutrients and yield. Thus, one experiment under greenhouse conditions was carried out taking into account three concentration levels of the Steiner nutrient solution. Fruit fresh matter was considered as yield when three cuts were performed. Tissues (mature leaves) from plants were sampled to quantify nutrient (N, P, K, Ca, Mg, Fe, Cu and Mn) concentrations. CND norms were computed using such a database. Pearson correlations were computed in order to identify those significant. Row–centered log ratios (CND norms, mean ± 1 standard deviation) for d = 8 nutrients under the basis of high–yield subpopulation (n = 19, yield > 1333.33 g Plant–1) are: = 2.51 ± 0.17, = 0.09 ± 0.14, = 2.57 ± 0.25, = 1.66 ± 0.16, = 0.56 ± 0.13, = –3.76 ± 0.11, = –5.96 ± 0.25, = –3.13 ± 0.14 y = 5.46 ± 0.12. And their corresponding sufficiency ranges (mean ± 1 standard deviation, g Kg–1) are: 45.88 ± 6.64 for N, 4.16 ± 0.96 for P, 49.69 ± 12.2 for K, 19.98 ± 4.65 for Ca, 6.59 ± 1.21 for Mg, 0.09 ± 0.01 fore Fe, 0.01 ± 0.003 for Cu and 0.16 ± 0.04 fore Mn. Yield depended significantly (p≤0.05) on P concentration, in a negative way. However, it appears N was the most limitating nutrient under greenhouse conditions. Optimum N concentration was at a different level when compared with that of the same species grown under field conditions.