1、Nurturing Citrus Blooms: The Optimal Fertilization Guide

Fertilizing citrus trees during the blooming period is a common practice to support their growth and fruit production. However, it's essential to understand the specific needs of citrus trees and the potential risks associated with fertilizing during bloom.

2、Foliar Feed Your Trees

Currently, with citrus greening in Florida, many growers and production managers consider foliar fertilization a key factor to stimulate the natural defense mechanisms of their trees, to induce pest and disease tolerance, and to improve fruit yield and fruit quality.

3、Optimizing Citrus Production: Practical Guidelines for Effective Foliar

Post-bloom foliar applications are performed immediately after petals fall and may extend through June. During this period, citrus trees experience rapid cell division and active fruit development. The demand for N remains high, driven by simultaneous fruit set and vegetative growth.

4、Foliar application of bioorganic fertilizer enhances plant nutrients

Foliar Bio-organic fertilizer (BIOF) enhanced soil properties including soil enzymes, except soil P and pH. The foliar application has mitigated the uptake of the cadmium and iron to the plants. Foliar organic fertilizer increased yield parameters, including fruit size and numbers.

CMG14/CG092: 2026–2026 Florida Citrus Production Guide: Fertilizer

For over five decades, foliar fertilization of citrus has been recommended to correct zinc, manganese, boron, copper, and magnesium deficiencies. It is now common knowledge in agriculture that properly nourished crops may better tolerate insect pests and diseases.

Should I fertilize my citrus trees and if so, with what and when?

First application should be in January or February, just prior to bloom. Additional applications should be made in early May and in June. Late season fertilization should be avoided as it may affect fruit quality, delay fruit coloring, and make the rind rough. Nitrogen is the chief nutrient required by citrus and should be applied each year.

Zinc fertilizers for Citrus production: assessing nutrient supply via

Field studies were carried out with sweet orange trees for four growing seasons, testing Zn (nitrate, sulfate or EDTA) applied either via fertigation or foliar spray compared to a control without Zn. The Zn concentrations in the soil increased with nutrient supply by both application methods.

(PDF) Foliar fertilization in citrus; A review

Fertilizer programs for citrus are determined by many approaches. ... ... Some of the difficulties in developing sound recommendation for fertilizer program may be traced in the history of...

(PDF) Foliar fertilization in citrus – A Review

Foliar fertilization improves citrus nutrition, with historical roots dating back to 1844. Optimal timing and environmental conditions enhance foliar nutrient absorption and plant growth. Application of low-biuret urea significantly influences nitrogen metabolism and flowering in citrus.

Citrus Fertilizer Management: Nutrient Requirements and Application

Citrus fertilizers can be applied in various forms and methods, such as granular, liquid, and foliar. The timing and frequency of fertilizer application depend on the nutrient demand of the citrus trees, with the highest demand during spring and summer and the lowest during winter.

Foliar fertilization is a common method for supplementing nutrients during plant growth. Foliar fertilizers are directly absorbed by plant leaves, rapidly improving their nutritional status. For citrus trees, appropriate foliar fertilization can effectively promote growth and enhance fruit quality. whether foliar fertilization is advisable during the blooming period and how to use it correctly requires detailed analysis based on specific conditions.

I. Nutrient Requirements During the Citrus Blooming Period

1. Nitrogen (N) Nitrogen is a key nutrient for plant growth, particularly critical for citrus trees. It promotes leaf development and differentiation while enhancing photosynthetic efficiency, providing adequate energy and nutrients. During blooming, insufficient soil nitrogen may lead to poor flower bud differentiation, affecting flower quality and yield. Thus, proper nitrogen application during this stage supports healthy flower bud formation.

2. Phosphorus (P) Phosphorus is vital for root development and fruit maturation. It strengthens root systems, improves disease resistance, and enhances fruit flavor. A phosphorus deficiency during blooming may cause weak roots, stunting growth, and reducing yields. Proper phosphorus application during this period fosters robust roots and superior fruit quality.

3. Potassium (K) Potassium plays a crucial role in fruit maturation. It regulates water balance, boosts drought and disease resistance, and improves fruit texture and taste. Insufficient potassium during blooming can degrade fruit quality, impacting market value. Timely potassium supplementation enhances fruit ripening and quality.

4. Microelements Besides macronutrients, citrus trees require microelements like calcium, magnesium, and iron for normal physiological functions. Though needed in small amounts, deficiencies can harm growth and fruit quality. Balanced micronutrient application during blooming ensures healthy tree development.

II. Methods for Foliar Fertilization During Blooming

1. Select Appropriate Fertilizer Choose fertilizers containing balanced nitrogen, phosphorus, and potassium, along with essential microelements. Opt for reputable brands to ensure safety and efficacy.

2. Dilution Ratio Follow product instructions or expert guidance to dilute the fertilizer. Adjust concentrations based on growth stages and soil conditions. During blooming, slightly increase dilution to support flower bud development.

3. Spraying Technique

   • Use appropriate nozzle sizes to cover all plant parts.
   • Start spraying from a distance, gradually moving closer.
   • Maintain even speed and distance to avoid over-application or omissions.

4. Precautions

   • Avoid spraying during hot weather to prevent leaf burn.
   • Do not over-fertilize, which may cause toxicity.
   • Monitor plant responses and address abnormalities promptly.

III. Effects and Feedback of Foliar Fertilization During Blooming

1. Promotes Flower Bud Formation Foliar fertilization supplies essential nutrients, supporting healthy flower buds. This improves fruit yield, quality, and extends the bearing period.

2. Enhances Stress Resistance Balanced nutrition strengthens drought and disease resistance, reducing pesticide reliance and promoting eco-friendly cultivation.

3. Improves Fruit Quality Nutrients enhance sugar content, flavor, and nutritional value, boosting market competitiveness and economic returns.

4. Optimizes Growth Conditions Improved photosynthesis and environmental adaptability accelerate growth and biomass accumulation, aiding climate resilience.

IV. Recommendations and Precautions

1. Rational Application Follow the "small amounts, frequent applications" principle to avoid over-fertilization. Adjust dosage and frequency based on specific needs.

2. Safety First Wear masks, gloves, and protective clothing to prevent skin or respiratory irritation. Avoid direct contact with chemicals.

3. Scientific Formulations Tailor fertilizer formulas to your citrus trees’ needs, consulting literature or experts for optimal results.

4. Continuous Monitoring Regularly assess growth, leaf color, fruit size, and taste to evaluate effectiveness and refine practices.

5. Integrated Management Combine foliar fertilization with proper watering, pruning, and pest control to maximize growth quality and yield.

Foliar fertilization is beneficial during citrus blooming if performed with suitable formulations, dilution, and techniques. It supports flower bud development, stress resistance, and fruit quality. Prioritize safety, monitoring, and integrated management to optimize results.