1、Effects of Foliar Fertilization: a Review of Current Status and Future

Foliar fertilizer application after soil fertilization is an effective method to increase the contents of trace elements in crops and crop yield, and to improve the soil environment. However, the application of inorganic foliar fertilizer results in difficulties in nutrient absorption and migration in plants.

2、Foliar nutrition: Potential and challenges under multifaceted

The potential of foliar fertilization in improving crop yield and quality under environmental stresses has been evaluated based on a meta-analysis. Foliar-applied fertilizers showed higher crop plants yield and quality traits by 15–19% and 9–29%, respectively, under different environmental stresses.

3、Frontiers

Excess application of foliar fertilizers can result in nutrient toxicity then limit crop growth (Al-Juthery et al., 2021). Moreover, soil and foliar application of fertilizers can disturb plant N 2 O emission.

4、Foliar Fertilization for Vegetable Crops

All other nutrients may take several days of wetting and rewetting to be absorbed. Therefore, it is recommended that foliar fertilizers be applied at dusk or early evening when dew is on the leaves, in high volume water, and using smaller droplets to cover more of the leaf.

5、Foliar Fertilization

It is not advisable to spray leaves during the heat of the day. The combined effects of fertilizer and sunlight on the foliage could cause tissue damage. Any time a new foliar product is applied, it makes sense to test it on a small portion of leaves before spraying the entire plant or crop.

EFFECT OF FOLIAR

The relative re-greening effect of organic acids applied with Fe III -sulphate, particularly in case of moderately chlorotic leaves, is likely due to an increased availability of Fe to leaf FCR.

The Ultimate Guide to Foliar Fertilizer

Under some circumstances (low soil fertility), when plants can’t easily take up nutrients through the soil, farmers resort to spreading fertilizer on the surface of leaves. This process is called foliar fertilization.

Foliar Fertilizer Overview and Analysis

Most times, the symptoms of nutrient deficiencies that require quick action are visible: If your plants turn pale green or have yellowish-green leaves, and you notice poor growth and limited tiller development is a sign of nitrogen shortage.

Foliar Feeding Vegetables

When applying any foliar nutrient, always follow the label directions and never exceed the recommended rate, otherwise you will likely cause a “burning” (called a phytotoxic reaction) of leaf tissue.

Mastering Foliar Feeding: The Essential Dos and Don'ts for Optimal

High Humidity or Rainy Weather: Applying foliar sprays during periods of high humidity or rainy weather can hinder nutrient absorption and promote the growth of fungal diseases. Stressed or Unhealthy Plants: Foliar feeding should be avoided on plants experiencing stress or suffering from diseases.

The greening of leaves several days after foliar fertilizer application is typically due to chemical reactions between certain components of the fertilizer and the plant leaves, resulting in a green discoloration. This phenomenon may stem from the following reasons:

1. Chemical Reactions Between Fertilizer Components and Leaves: Foliar fertilizers often contain essential nutrients such as nitrogen (N), phosphorus (P), potassium (K), and trace elements. When these nutrients interact with plant leaves, chemical reactions may occur, leading to greening. For example, nitrogen sources in some fertilizers might react with amino acids in leaves, forming green compounds.

2. Absorption of Nutrients by Leaves: Nutrients in foliar fertilizers can be absorbed by plant leaves, contributing to their green color. Plant leaves contain cells (e.g., chloroplasts) capable of absorbing nutrients. Once absorbed, these nutrients are converted into other substances within the plant, while excess nutrients may temporarily remain in the leaves in a green form.

3. Stimulant Effects of Fertilizer Components: Certain components in foliar fertilizers, such as hormone-like substances, may stimulate plant growth and metabolic processes, indirectly causing leaves to appear greener.

4. Improper Application Methods: Incorrect use of foliar fertilizers can lead to greening. For instance, excessive application may overwhelm plants with nutrients, triggering stress responses. Additionally, failing to clean leaf surfaces before spraying or applying fertilizer during unsuitable conditions (e.g., high temperatures) can exacerbate this issue.

Solutions to Prevent Greening:

1. Select Appropriate Fertilizers: Choose foliar fertilizers tailored to the plant’s growth stage, soil conditions, and climate. Proper formulations ensure efficient nutrient absorption and reduce the risk of greening.

2. Control Dosage: Follow the recommended dosage on product labels strictly. Overapplication can overload plants with nutrients, leading to stress and greening.

3. Proper Application Techniques:

   • Uniform Spraying: Ensure even coverage to avoid missed or over-sprayed areas.
   • Avoid High-Temperature Periods: Apply fertilizers during cooler parts of the day (e.g., morning or evening) to prevent rapid evaporation and nutrient loss.
   • Protect Leaves: Minimize leaf contamination or damage during application.

4. Monitor Plant Responses: After application, closely observe plants. If greening occurs, adjust strategies by reducing dosage or modifying the fertilization schedule.

5. Regular Growth Checks: Routinely inspect plants for signs of stress, abnormal color, or texture changes. Address issues promptly by refining fertilization practices.

In Summary:

Greening of leaves after foliar fertilizer application results from chemical reactions, nutrient absorption, stimulant effects, or improper use. To mitigate this, select suitable fertilizers, apply appropriate dosages, follow correct techniques, and monitor plant health closely. Adjusting practices based on observations ensures optimal results while minimizing adverse effects.