Multiple nutrient imbalances in ear leaves of on-farm
unfertilized maize in eastern and southern Africa
H. Høgh-Jensen1, 2*,
D. Kamalongo3, F. A. Myaka4 and J. J.
Adu-Gyanfi5
1Department
of Policy Analysis, National Environmental Research
Institute, Aarhus University, Frederiksborgvej 399, DK-4000
Roskilde, Denmark.
2Department
of Agriculture and Ecology, Faculty of Life Sciences,
University of Copenhagen, Højbakkegaard Allé 9, DK-2630
Taastrup, Denmark.
3Chitedze
Agricultural Research Station, P.O.Box 158 Lilongwe, Malawi.
4Ilonga
Agricultural Research Institute, P.O.Box 33, Kilosa,
Morogoro, Tanzania.
5International
Atomic Energy Agency (IAEA), Wagramer Strasse 5, A-1400,
Vienna, Austria.
*Corresponding author: E-mail:
hhj@dmu.dk.
Accepted 14 January, 2009
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Maize is a major food crop in eastern and southern Africa
and is often cultivated with insufficient supplies of
nutrients. The current studies are aimed at diagnosing any
potential nutrient limitation in maize under farmers’
conditions using the nutrient content in ear leaf tissue at
tasseling stage. The majority of the maize crops were
considered below the critical nitrogen (N) content in the
ear leaves with mean N content of 1.84%. Phosphorus (P), B
and Cu content appeared critically low at three of the four
sites. Unique fingerprinting by multivariate statistics was
possible for each site when using the proportion of
nutrients in the leaf tissue. The content of six macro
elements (N, P, K, S, Mg, Ca) at the tasseling stage were
found to be able to predict 83% of the variation in the
grain yield at maturity whereas the inclusion of
micronutrients only improved this prediction with an
additional 3%. N alone predicted 50% of the variation in
grain yield and the N
supply of the maize crops in eastern and southern Africa
must thus be the first priority before yields can be
improved.
Key words: Maize ear leaves, foliar tissue diagnosis,
nutrient deficiencies, element interactions.
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