Evaluation of White yam (Dioscorea rotundata) genotypes for arbuscular mycorrhizal colonization, leaf nutrient concentrations and tuber yield under NPK fertilizer application
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Date
2014
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Taylor & Francis
Abstract
Yield decline in yam may not only be due to soil nutrient depletion but also to the activity of soil
microflora. Arbuscular mycorrhizal (AM) symbiosis helps in plant nutrition but may be affected by
the application of fertilizer. The effects of nitrogen (N), phosphorus (P), and potassium (K) fertilizer
rates on the AM colonization, leaf nutrient concentrations, and tuber yields of eleven genotypes of
Dioscorea rotundata were investigated at Ibadan, Nigeria. The soil was ferric luvisol. Eleven
genotypes were selected from the previously conducted screening of 75 genotypes of D. rotundata for
fertilizer response. Four application rates: 0, 200, 400, and 600 kg ha−1 of NPK 15-15-15 were
applied in a split plot design with four replications. Fertilizer rate was the main plot and variety
was the sub plot. Percentage AM colonization was significantly reduced at 600 kg ha−1 but not at
lower rates when compared to zero rate and it was negatively correlated with leaf N, P, and zinc (Zn)
concentrations. Leaf N concentrations were significantly increased at 200 kg ha−1 in five genotypes
and at 600 kg ha−1 in two genotypes compared to zero application. Leaf P and K concentrations
were decreased with the application of fertilizer in most of the genotypes. The NPK fertilizer of 15-
15-15 at the rate of 200–400 kg ha−1 gave yield response in eight genotypes of D. rotundata, with
minimal or no effect on their AM colonization when compared to zero application. Long term study
on the effect of fertilizer application on AM symbiosis in yam is recommended.
Description
This article is Published by Taylor & Francis 2014, and is also available at 10.1080/01904167.2013.867988
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Citation
Journal of Plant Nutrition, 37:658–673, 2014