Potassium concentration in leaf‐blades and petioles as affected by potassium fertilization and stage of maturity of cotton

Abstract

Abstract Analysis of data obtained from samples collected in the Delta area of Mississippi showed that the potassium concentration of young mature and old mature cotton leaf‐blades correlated better with soil test potassium than did that of the apical immature leaf‐blades. Results from field studies indicated that the old mature petiole was the most sensitive indicator of the potassium status of the cotton plants. The potassium concentration in both leaf‐blades and petioles decreased with stage of maturity from early square to early half‐grown boll. Potassium concentration did not fluctuate with sampling at different times of the day. The rate of decline of potassium concentration was greater in petioles of mature cotton leaves than in the leaf‐blades. For mature leaves, the potassium concentration of leaf‐blades was highly correlated with that in petioles, but for immature leaves, the correlation was poor. The rate of decline of potassium concentration in both cotton leaf‐blades and petioles was not affected by potassium fertilization but was a function of maturity stage. Key words: PotassiumPlant AnalysisCotton Notes Contribution from the Agronomy Dept., Mississippi State Univ., Mississippi State. Graduate Research Assistant, Professor, and Assistant Professor of Agronomy, Agronomy Dept., Mississippi State Univ., Mississippi State.