The influence of nitrogen source and aluminum on growth and elemental composition of nemaguard peach seedlings
2001
Graham, C.J.
A greenhouse sand culture experiment was conducted to determine the effects of aluminum (Al) and nitrogen source on vegetative growth, biomass production, and nutrient concentration of Nemaguard peach. Seedlings were treated with 3 mM N using NO3-N:NH4-N ratios of 100:0, 75:25, 50:50, 25:75, and 0:100 supplemented with 0 or 1 mM Al. Aluminum decreased the number of laterals and lateral length, total vegetative growth, leaf number, and plant leaf area. Root, stem, and leaf dry weight were similar in controls and Al-treated seedlings. Aluminum decreased P, Ca, Mg, Fe, and Mo concentration in roots and leaves, decreased P and Mg concentration in the stem tissue, and decreased Mn concentration in the leaves only. Increasing the proportion of NH4-N in the irrigation solution reduced all vegetative parameters measured. The root:shoot ratio increased, suggesting that shoot growth is more sensitive to NH4-N toxicity than roots. Leaf chlorophyll concentration increased on an area basis as NH4-N increased in the irrigation solution. Increasing NH4-N increased N, P, and Cu concentrations in roots, stems, and leaves, but only increased Fe concentrations in the roots and leaves and Mn in the stems. The concentration of Ca, Mg, Mn, and Mo in the roots, Ca and Mo in the stems, and Ca, Mg, and Mo in the leaves decreased as the proportion of NH4-N increased.
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