Articles
Soil pH and apple rootstock genotype affect apple tree growth and absorption of mineral nutrients
Article number
1432_11
Pages
79 – 86
Language
English
Abstract
Soil pH is one of the properties that determines the levels of bioavailability of macro- and micronutrients for plant roots.
Apple rootstocks are the interface by which these nutrients are absorbed and shuttled to grafted scions.
Our experiment was aimed at understanding the phenotypic and underlying genotypic variation of apple roots interacting with the same soil amended to five pH levels (4.5, 5.5, 6.5, 7.5 and 8.5) by monitoring growth and leaf nutrient concentrations (Ca, Cu, Fe, K, Mg, Mn, Na, P, S, Zn, and Ni) of one-year-old ‘Golden Delicious’ trees grafted on 28 different apple rootstocks.
Data were analyzed as a full factorial of pH and rootstock type.
Soil pH amendment was successful as least squares means for the pH main effect displayed expected nutrient content curves for Mo (increasing with higher pH) and for Mn (decreasing with higher pH). ANOVA showed significance for main effects (pH and rootstock type) while the interaction (pH × rootstock type) was significant only for Mo.
Both main effects were significant for Mn, P, and Ca whereas pH was significant for Fe and rootstock type was significant for Cu, Zn, and S. No significant effects were observed for Na, Ni and K. Multivariate analyses using rootstock genotype LS means revealed diverse correlation (pairwise Pearson) patterns when the data were analyzed as a whole or split by pH treatment levels.
For example, the genotypic similarity (Pearson pairwise) between K and Mo was not significant at pH level 4.5 (r=-0.342 and p=0.109) whereas at pH 8.5 such relationship was highly correlated (r=-0.547 and p=0.006). Similar results were observed among other nutrients.
Dual hierarchical clustering (Ward) displayed different number and composition of clusters according to pH where two main clusters were observed for pH 4.5 and three main clusters for the other pH levels.
Rootstocks G.41, G.890, MM.111 and G.935 were tightly clustered at pH 7.5 whereas at pH 5.5 they all fell into different clusters.
These results suggest the individuality of the interaction of each rootstock with pH levels with implications on fertilizer management practices and optimum pH and planting amendments specific for rootstock type.
Apple rootstocks are the interface by which these nutrients are absorbed and shuttled to grafted scions.
Our experiment was aimed at understanding the phenotypic and underlying genotypic variation of apple roots interacting with the same soil amended to five pH levels (4.5, 5.5, 6.5, 7.5 and 8.5) by monitoring growth and leaf nutrient concentrations (Ca, Cu, Fe, K, Mg, Mn, Na, P, S, Zn, and Ni) of one-year-old ‘Golden Delicious’ trees grafted on 28 different apple rootstocks.
Data were analyzed as a full factorial of pH and rootstock type.
Soil pH amendment was successful as least squares means for the pH main effect displayed expected nutrient content curves for Mo (increasing with higher pH) and for Mn (decreasing with higher pH). ANOVA showed significance for main effects (pH and rootstock type) while the interaction (pH × rootstock type) was significant only for Mo.
Both main effects were significant for Mn, P, and Ca whereas pH was significant for Fe and rootstock type was significant for Cu, Zn, and S. No significant effects were observed for Na, Ni and K. Multivariate analyses using rootstock genotype LS means revealed diverse correlation (pairwise Pearson) patterns when the data were analyzed as a whole or split by pH treatment levels.
For example, the genotypic similarity (Pearson pairwise) between K and Mo was not significant at pH level 4.5 (r=-0.342 and p=0.109) whereas at pH 8.5 such relationship was highly correlated (r=-0.547 and p=0.006). Similar results were observed among other nutrients.
Dual hierarchical clustering (Ward) displayed different number and composition of clusters according to pH where two main clusters were observed for pH 4.5 and three main clusters for the other pH levels.
Rootstocks G.41, G.890, MM.111 and G.935 were tightly clustered at pH 7.5 whereas at pH 5.5 they all fell into different clusters.
These results suggest the individuality of the interaction of each rootstock with pH levels with implications on fertilizer management practices and optimum pH and planting amendments specific for rootstock type.
Authors
G. Fazio, D. Kviklys, M.A. Grusak, T. Robinson
Keywords
Malus × domestica, manganese, phosphorus, calcium, iron, copper, zinc, sulfur
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