A nutrient applied to a soil favourably or adversely affects the plant availability of other nutrients present in the soil. Such interaction my occur within the soil, within the plant or at the root surface. Nutrients acting synergistically or antagonistically may imbalance the nutrition of crop plants. Therefore, the effect of potassium (K) nutrition [0, 62.5, 125.0, 250.0 1Eg K ha" of KISO4 or KCl] on interaction of different ions in four cultivars i.e., CIM-448, C1M-l 100, Karishma, S-12 of irrigated cotton (Gossypium hirsutum L.) was quantified in silt loam soil. Various plant parts i.e., leaves, stems, burs, seed, lint were analyzed for their ionic composition, i.e., nitrogm (N), phosphorus (P), K, calcium (Ca), magnesium (Mg), sodium (Na), chloride (Cl), and sulphur (S) at maturity. The K concentration in different plant parts increased with an increase in soil K-level. Averaged across cultivars and K·doses, K concentration in different plant parts was in the order of leaves > burs > stems > seed > lint. As N concentration increased with increasing levels of K-fertilizer, the relationship between K and N concentration in cotton plant partswas positive (r 0.87** to 0.98**). However, the relationships between K and P, Ca, or Na concentration in leaf tissues werenegative i.e. (r -0.64** to - 0.75**; -0.78** to -0.96**; - 0.65** to -0.91**) respectively. Application of K25,.] in the form of KCl raised Cl content by 175.0, 138.1, 136.4, 111.0 and 33.3 percent in burs, stems, seed, leaves and lint, respectively. There was highly significant r = (0.77** to 0.99**) relationship between K and Cl under KC1 treated plots. However, addition of K;SO4 produced non-significant effect (r 0.03 to 0.50) by addition of KzSOi between K and C1 content. Thus, findings suggest that soil K supply influences ionic relations in cotton plant. Hence, sufficiency levels of N, P, K., Ca, Mg, Na, Cl and S in cotton plant may be considered with respect to K-dose and form of K-fertilizer applied.
H PERVEZ ,M ASHRAF ,M I MAKHDUM ,