Differential absorption of anions by varieties of cotton.

Abstract

Earlier studies 1 have shown that the Egyptian and Upland types of cotton are differentiated with respect to certain physico-chemical properties of the leaf tissue fluids, such as osmotic concentration, specific electrical conductivity and hydrogen-ion concentration. 2 The higher specific electrical conductivity of the tissue fluids of the Egyptian, as compared with the Upland type of cotton, evidences for the absorption from the soil and the retention in solution of electrolytes as an important factor in the determination of the higher osmotic concentration of the Egyptian type. Analyses have shown 3 that the chloride content is far higher in the Egyptian type.

We now note that these two types (closely enough related that at least first, second and third generation hybrids may be secured) are also characterized by differential absorption of sulphates.

Table I shows the mean chloride and sulphate contents of two series of about seventy analyses each on plants of Lone Star

Upland and Pima Egyptian cotton growing in immediate association, and hence under identical environmental conditions. 4 The values are given in terms of grams per liter. The probable errors of the means have been calculated with due regard to the correlation between associated plants due to the influence of environmental conditions.

The differences between both chloride and sulphate content in Egyptian and Upland cotton are many times (18.2 to 41.7) as large as their probable errors, thus leaving no possible doubt as to the differentiation of these two varieties with respect to their absorption of both of these anions.

The point to be emphasized here is that the behavior of these two types with respect to these anions is not merely quantitative in the sense that the tissue fluids of one of the two varieties contains larger quantities of electrolytes.