EVALUATING POTASSIUM-USE-EFFICIENT COTTON GENOTYPES USING DIFFERENT RANKING METHODS

Abstract

Identification of cotton (Gossypium hirsutum L.) genotypes efficient in potassium (K) uptake and utilization, under K-deficient conditions represents a cost-effective and environmentally friendly approach for low-K-input agriculture. It would reduce the costly input of K-fertilizers and manage K resources in agro-ecosystems. We ranked 25 cotton genotypes for their K use efficiency under deficient and adequate K regimes in hydroponics, using two different methods. K deficiency generally reduced cotton growth; however, K-efficient genotypes accumulated more biomass due to higher K uptake. Genotype NIBGE-2 exhibited excellent adaptation potential in terms of high shoot dry weight under both K regimes and ranked as the only most desirable, “efficient-responsive” genotype. Genotype CIM-506 produced low shoot dry weight under low K condition and ranked as “non-efficient.” Genotype Desi okra produced low shoot dry weight at adequate K level and ranked as “non-responsive.” Genotype ranking using two different methods ensured the validity of results.

Keywords:

• Gossypium hirsutum
• genotypic variation
• K use efficiency
• K uptake
• K utilization
• ranking methods

ACKNOWLEDGMENTS

We dedicate this work to the loving memories of the late Dr. Maqsood Ahmad Gill. Our gratitude goes to Dr. Sergey Shabala, University of Tasmania, Australia and Dr. Scott Chang, University of Alberta, Canada for their useful suggestions in improving this manuscript. This study was a part of the PhD dissertation research of the first author, funded by the Higher Education Commission of Pakistan.