During the mid-growth stage of sweet potatoes, foliar fertilization is a critical practice for enhancing yield and quality. Selecting the appropriate foliar fertilizer is essential to ensure healthy plant development. Below are recommended foliar fertilizers and usage guidelines:

I. Selection of Foliar Fertilizers

1. Seaweed Extract Seaweed extract contains natural minerals and microelements, providing essential nutrients for sweet potato plants while promoting robust root and stem growth. When using seaweed extract, adhere to recommended dilution ratios, as excessive concentration may harm the plants.

2. Amino Acid Complex Solution Amino acids are key nutrients for plant growth, improving photosynthetic efficiency and stress resistance. Amino acid solutions often contain nitrogen (N), phosphorus (P), and potassium (K), meeting the nutritional demands of sweet potatoes during mid-growth.

3. Humic Acid-Based Foliar Fertilizer Humic acid-rich fertilizers improve soil structure, enhance water and nutrient retention, and boost root development and disease resistance.

4. Trace Element Water-Soluble Fertilizer These fertilizers supply essential micronutrients like zinc (Zn), iron (Fe), and copper (Cu), promoting healthy growth. Avoid overapplication to prevent toxicity.

5. Bio-Bacterial Agents Beneficial microbes in bio-bacterial agents decompose soil organic matter, enriching soil fertility and stimulating root growth. Use alongside conventional fertilizers to avoid interference.

6. High-Phosphorus, High-Potassium Foliar Fertilizer Provides rapid replenishment of phosphorus and potassium, supporting plant growth and fruit development. Control dosage to prevent excessive vegetative growth.

7. Multi-Effect Compound Foliar Fertilizer A hybrid formula containing diverse nutrients, addressing multiple growth needs. Follow product instructions to avoid waste or damage.

8. Chelated Trace Element Foliar Fertilizer Micronutrients in chelated form enhance absorption. Choose reputable brands and follow dilution guidelines.

9. Seaweed Glycol Calcium Combines seaweed extract with calcium to support cell wall development and overall growth. Avoid overuse to prevent excessive speed of growth.

10. Seaweed Glycol Magnesium Provides magnesium via seaweed extract, aiding chlorophyll synthesis and growth. Monitor dosage to avoid overstimulation.

II. Application Methods

1. Dilution Ratio Dilute fertilizers according to packaging instructions, typically using a 1000:1 water solution. Spray evenly on both sides of leaves.

2. Timing Apply in early morning or late afternoon when temperatures are cooler, maximizing absorption. Clean leaves of dirt or residues before spraying.

3. Frequency Initial applications every 7–10 days, adjusted based on growth stages and soil fertility. Over-application can burden plants.

4. Dosage Limit to 2–3 kg per mu (0.5–0.75 lbs per acre) per application. Excessive use may hinder normal growth.

5. Precautions Monitor plants for adverse reactions and discontinue use if issues arise. Consult professionals for guidance. Coordinate with other fertilizers to ensure balanced nutrition.

By selecting suitable foliar fertilizers and following proper application methods, mid-growth sweet potato yields and quality can be significantly improved. Prioritize product reliability and adherence to guidelines for optimal results.