Screening of cotton genotypes for potassium use and response efficiencies through cluster analysis

Some cotton genotypes take up potassium more potentially from the growth media and they are also different in response to K fertilizer application. Identification of these genotypes represents a very effective strategy for best cotton production in K deficient soils and optimum K fertilizer application. A hydroponically experiment was carried out to compare and rank 25 cotton genotypes through cluster analysis for K use and response efficiencies in deficient and sufficient K conditions. The results showed that potassium deficiency resulted in significant decrease in root and shoot dry weights of cotton genotypes. Also, by supplying sufficient potassium for the plant, its concentration and uptake increased in the root and shoots of cotton. Cluster analysis categorized cotton genotypes into four non-efficient, moderately efficient, efficient and highly efficient groups in terms of potassium use efficiency (deficiency conditions), in which the SKT133, Sepid and Mehr genotypes were stood in efficient cluster and Shayan, N2G80, Golestan and Sajjadi genotypes were found in the highly efficient cluster. Other genotypes were in non-efficient or moderately efficient groups. Also, in response to potassium application (sufficiency conditions), cotton genotypes were classified into four non-responsive, low responsive, moderately responsive, and responsive clusters. Accordingly, the genotypes of the Sahel, M13, Sajjadi, Tabladilla and Latif were identified as responsive genotypes. Sajid genotype, which is both highly efficient and responsive to potassium, is therefore recommended for use in any state of available soil potassium (deficiency or sufficiency).