Micronutrients Content in Guava Seedlings after Variations in Phosphorus Sources, Liming, and Soil Types.

Guava is one of the most important fruits in the Brazilian export market. The objective of this work was to evaluate the effects of liming and phosphorus (P) sources on micronutrients content in guava seedlings. The experimental design was completely randomized in a factorial scheme (2 × 3 × 3) comprising two dolomite limestone rates (0 and 5 Mg ha−1), three soil types (Typical Red Oxisol, Typical Yellow Oxisol, and Typical Yellow Ultisol), and three P sources (Arad rock phosphate, thermophosphate 'Yoorin,' and triple superphosphate) at 150 mg kg−1, with three replicates. Boron [B], copper [Cu], zinc [Zn], iron [Fe], and manganese [Mn] concentrations in guava seedling leaves and stems were affected by liming, by the P source, and by the soil type. Limestone and P sources altered the B, Cu, Zn, Fe, and Mn concentrations in leaves and stems of guava seedlings in each of the three evaluated soil types. Due to its low solubility, and regardless of soil type and liming, Arad rock phosphate was less effective than triple super phosphate as a P source for guava seedlings. [ABSTRACT FROM AUTHOR]