Preliminary diagnosis of the nutrient status of cotton (Gossypium hirsutum L) in Benin (West Africa)

Critical leaf nutrient concentrations have often been used to diagnose the nutritional causes of crop under performance. The Diagnosis and Recommendation Integrated System (DRIS), however, provides a reliable means of linking leaf nutrient concentrations to the yield of cotton, and may be developed for this crop using existing experiment data. In the present study, carried out in the Upper Catchment of Benin, fiber yield and leaf nutrient concentration data from an organic and inorganic trials were used to establish Diagnosis and Recommendation Integrated System norms for nitrogen (N), phosphorus (P), potassium K, magnesium (Mg), calcium (Ca), sulphur (S) and zinc (Zn) and statistical parameters for cotton. The Diagnosis and Recommendation Integrated System norms provided by this study were as followings: N/P = 9.65; K/N = 0.59; N/Mg = 10.55; S/N = 0.08; P/K = 0.19; Ca/P = 5.79; Mg/P = 0.96; Zn/P = 0.01; Ca/K = 1.08; Mg/K = 0.18; Zn/K = 0.001; Ca/Mg = 5.77; S/Ca = 0.14; Mg/Zn = 143.84. Although the database was relatively small, the norms derived for nutrient ratios of key biological significance, i.e. N/S and K/N, were within the expected narrow ranges for higher plants, giving credibility to both the database and the Diagnosis and Recommendation Integrated System model. Data from future surveys and field experiments may subsequently be used to enlarge the database allowing the refinement of model parameters and hopefully an expansion of diagnostic scope to include other micro-nutrients. As it stands, this preliminary Diagnosis and Recommendation Integrated System model for cotton is a good diagnostic tool currently available for evaluating the N, P, K, Mg, Ca, S and Zn status for cotton crops in Benin.

Source de publication: Bulletin de la Recherche Agronomique du Bénin 2010, 64: 32-45

Contacts du ou des auteurs: G. D. Dagbénonbakin, Emile C. Agbangba, R. L. Glèlè Kakaï (glele.romain@gmail.com), H. Goldbach