Variation in growth, dry matter production, nitrogen and potassium uptake by six Musa genotypes in a soilless culture

Abstract: Six genotypes comprising a landrace and a hybrid from each of the three Musa major genomic groups were evaluated in a soilless potting mix. Effect of genotype on most of the growth parameters was non-significant. But the uptake (total quantity accumulated, distribution pattern and tissue concentration) of N and K was significantly (P < 0.05) influenced by genotype (G), age of plant at sampling (AP) and G x AP interaction. Dessert bananas had higher N uptake while 'PITA 22' (a plantain hybrid) demonstrated an exceptional propensity for K uptake. Nitrogen and potassium concentration varied with tissue, genotype and age of plant at sampling. Nitrogen concentration in roots and leaves decreased with plant age while it increased in the corm. Potassium concentration in roots, corm and leaves increased progressively with plant age in all the genotypes. Significant differences in the quantity of N and K accumulated per plant, even though all the genotypes were planted in the same potting mix, suggested differential nutrient mining capacity of the genotypes. Implying that nutrient uptake and consequently nutrient demand varies with genotype, supplemental application would vary accordingly. The study suggested that genotype that had higher nutrient uptake will impoverish the soil faster, and thus require more external nutrient inputs to maintain/restore soil productivity.