Apple

1. Stress Resistance (Enzyme Activity Across Various Tissues, Phenotypic Characteristics of Different Organs)

Treatment: Two treatments were set up in the experiment, namely CK (0 g/L) and FA-K (1.5 g/L). Both were applied to two batches of apple seedlings with similar basic conditions to subject them to drought and low-temperature stress. After observing the occurrence of stress, irrigation and foliar fertilization were applied, while other operations followed standard procedures.

Figure8. Plant growth under different treatments of drought and low-temperature stress.

Result: Compared to the control, fulvic acid-treated apple seedlings showed better growth under both types of stress, with significantly increased survival rates.

3. Biomass (Growth of Different Organs)

Treatment: Two treatments were set up, namely CK (0g/L) and FA-K (1.5g/L), applied to two batches of apple seedlings with similar basic conditions, while other operations followed regular procedures.

Figure9. Plant growth under various treatment conditions.

Results: Compared with the control, fulvic acid treatment significantly increased the height, stem diameter, and number of lateral roots of apple seedlings, while leaf area was larger but not significantly.

4. Fruit (Yield, Coloration, Internal Quality (Nutritional Composition))

Treatment: Two treatments were set up, namely CK (0 g/L) and FA-K (1.5 g/L), applied to two basically identical batches of apple trees. During the fruit enlargement period, spraying was done once a week, while other operations followed conventional practices.

Figure10. Fruit growth under different treatment conditions.

Result: Compared with the control, potassium humate can reduce acidity and increase sugar, promoting fruit coloring.