Growth promoter special for banana planting and preparation method and application thereof

The invention discloses a growth promoter special for banana planting and a preparation method and application thereof. The growth promoter comprises a yield-increasing and quality-improving agent anda nitrogen-phosphorus-potassium base fertilizer. The yield-increasing and quality-improving agent is composed of 8.4-9.6 parts by weight of potassium fulvate and 2.8-3.4 parts by weight of lauric acid, and the mass of the nitrogen-phosphorus-potassium base fertilizer is 1.2-2.8 times of the mass of the yield-increasing and quality-improving agent. Experimental results show that the lauric-acid-containing growth promoter special for banana planting can effectively inhibit infection of root-knot nematodes on banana root systems, improve the relative abundance of beneficial bacteria Bacillus insoil, obviously improve the single-plant yield and single-fruit weight of bananas, and obviously improve the soluble solids and soluble proteins of bananas. The growth promoter is safe and non-toxic,and does not bring negative