Cotton (Gossypium hirsutum L.) uptake of potassium parallels dry matter accumulation. Early crop growth rate is generally not affected by K supply, however, total K accumulation is closely related to soil K supply. Although potassium is mobile in the plant, deficiency symptoms frequently appear on new leaves. Apparently developing fruit are a stronger sink for plant K than are new leaves. A three bale crop, set in a four week flowering cycle, accumulates about 1.5 lbs K/A/ day in the fruit during the period from 20 to 70 days after first bloom. Ultimately about 65 percent of the total plant K is found in fruit, with about 45 percent of the total boll K found in lint and seed. Demand for K by fruit during this period generally exceeds the plant uptake rate which requires redistribution from vegetative growth. Typical petiole potassium concentrations decline about 1 percent every 16 days beginning at first bloom until boll development is complete or plant K is exhausted. To make proper potassium management decisions at least three factors must be considered: The soil K supply rate; demand by fruit (yield level); and the quantity of K stored in the plant for redistribution (tissue concentrations and quantity of vegetative growth).