The frostbitten pomelo tree should be heavily fattened before flowering

Frozen grapefruit must be in the minor cold?During the big cold period, the pre-flowering fertilizers were mainly organic fertilizers with high quality and complete nitrogen-phosphor and potassium fertilizers, with increased application of phosphor and potassium fertilizers and biological bacterial fertilizers.The results of more than five years of the tree, each of the human and livestock manure 15~20 kg, nitrogen, phosphorus and potassium (15:15:15) potassium sulfate compound fertilizer 0.75~1 kg, calcium superphosphate or calcium magnesium phosphate fertilizer 1~1.5 kg, potassium sulfate 0.25~0.5 kg, compound biological fertilizer 0.5~0.75 kg.

All the fertilizer fully mixing evenly mixed, and around the canopy drip line, dig deep, each 25 ~ 30 cm wide ring groove, the mixer mixing fertilizer broadcasting within the annular groove, cover soil, covering all the fertilizers, then each tree Lin shi 40 ~ 50 kg water or biogas slurry or retting rotten people and livestock manure, to water infiltration into the soil completely not to drain is advisable.

In addition, but also timely root topdressing.Spray 0.1% borax, 0.1% magnesium sulfate, 0.1% zinc sulfate, 0.2% urea, 0.3% potassium dihydrogen phosphate, 600-fold amino acid complex microfertilizer, 1000-fold trialkanol, and 1500-fold 0.001% natural brassin-mixed solution on the leaf surface every 7 to 10 days for continuous 2-3 times.