Tissue Macro Nutrient Contents and Their Relationship with Growth in Two Dominant Eucalyptus Cultivars Across Three Selected Districts of Uganda

Abstract

Analyzing nutrient levels in plant tissues and comprehending how they are distributed among different parts is essential for implementing efficient nutrient management strategies across various crops. This study aimed to assess the levels of macro nutrients in different tissues of two prevalent Eucalyptus cultivars and their correlation with growth parameters in Kabarole, Mpigi, and Rakai districts. Two dominant Eucalyptus cultivars, E. grandis (local) and GU7 (Improved), were examined for nitrogen, phosphorus, potassium, calcium, and magnesium levels in leaves, bark, branches, and wood. Plant growth was evaluated by measuring diameter at breast height, total tree height, tree volume, and biomass per plot. Results revealed that the GU7 cultivar exhibited a higher accumulation of major nutrients in all plant parts compared to E. grandis across the three districts, with a descending order of Leaves > Branches > Bark > Wood for N, P, and K. Whereas, Ca and Mg were predominantly stored in the bark for both cultivars, although more significantly in GU7, in the order of Bark > Branches > Wood > Leaves. Furthermore, a positive significant correlation was observed between most nutrient contents in leaves and growth parameters of Eucalyptus cultivars, although no significant relation was found with phosphorus.