| 【Objective】The effects of magnesium fertilizer and its combined application with calcium and boron
fertilizers on the leaves and fruit quality of ‘Yongjiazaoxiangyou’ pomelo were studied based on magnesium deficiency of
‘Yongjiazaoxiangyou’ pomelo.【Method】 The experiments about applying different amount of magnesium fertilizer and its combined application of calcium and boron fertilizers were carried out in the bud stage of ‘Yongjiazaoxiangyou’ pomelo.
In mid-July, the spring leaves were collected from different azimuths of the tree and the contents of Mg, Ca, B and chlorophyll
of ‘Yongjiazaoxiangyou’ pomelo leaves were measured. Fruits of the same size were harvested when ripe and the contents of
fruit soluble solids, soluble sugar, and total acids were determined. Then the data was analyzed by SPSS software.【Result】The
contents of chlorophyll and Mg of ‘Yongjiazaoxiangyou’ pomelo leaves were significantly increased by adding magnesium
fertilizer. The contents of chlorophyll a, chlorophyll b and Mg of the leaves treated with 0.5 kg magnesium fertilizer per plant
reached 1.64 g/kg, 0.69 g/kg and 0.32% respectively, with the increase of 22.4%, 11.3% and 0.11 %, respectively compared
with those of control,group and the content of Mg reached the appropriate standard for Citrus leaves. The contents of soluble
solids and soluble sugar of ‘Yongjiazaoxiangyou’ pomelo fruit were also increased by applying magnesium fertilizer, and the
highest contents of fruit soluble solids and soluble sugar were obtained when treated with 0.5 kg magnesium fertilizer per plant
and the highest contents of which were 1.07% and 1.08% higher than those of the control group. The contents of Mg, Ca and B of
the leaves treated with the combination of magnesium fertilizer, calcium fertilizer and boron fertilizer could be increased at the
same time, especially when treated with the combination of magnesium sulfate, quicklime and borax, the contents of Mg, Ca and
B in the leaves being 0.31%, 2.83% and 48.2 mg/kg, respectively.【Conclusion】The contents of chlorophyll and magnesium
of‘Yongjiazaoxiangyou’ leaves, soluble solids and soluble sugar of fruit were increased, and the contents of total acid of
fruit were reduced by adding magnesium fertilizer. The contents of Mg, Ca and B of leaves were significantly increased by the
combined application of magnesium, calcium and boron fertilizers, and the promotion effect was stronger than that of single
application of magnesium fertilizer. |
