1、COMPARISON OF DIFFERENT FOLIAR

For citrus, the standard time for applying foliar fertilizers is when leaves are 1/3 to 2/3 expanded (March-April) to take advantage of the thin cuticle, yet large surface area.

2、Foliar Fertilization for Sustainable Crop Production

Foliar supply of urea to citrus trees for N fertilization has been particularly useful in reducing groundwater pollution with nitrates. The seasonal absorption characteristics of three urea compounds, viz., triazone-urea, liquid urea, and spray grade urea by citrus leaves were examined (Bondada et al. 2001).

3、Foliar Nutrition: Current State of Knowledge and Opportunities

Foliar application treatments, when properly planned and conducted, may stimulate the flowering, increase yield, and improve nutritional and postharvest quality of citrus fruits. “Feed the plants, not the soil.” This statement represents one of the current views on plant mineral nutrition both by soil fertilization and foliar application.

4、Effects of foliar applications of boron on citrus fruit and on foliage and soil boron concentration

The foliar fertilization increased the leaf B concentraction, initially low, to within the adequate range. However, there was no corresponding effect on the fruit yield and juice chemical characteristics.

Tree size and flowering intensity as affected by nitrogen fertilization in non

Optimising N fertilizer application to citrus trees is thus im- portant to regulate vegetative growth, promote flower induc- tion and bud differentiation, and to increase fruit set.

Uptake and Distribution of Soil Applied Zinc by Citrus Trees—Addressing Fertilizer Use Efficiency with 68Zn Labeling

We conclude that the efficiency of Zn fertilizers depends on the fertilizer source and the soil texture, which must be taken into account by guidelines for fruit crop fertilization via soil, in substitution or complementation of traditional foliar sprays.

Fertilizing Fruit Trees

Fruit trees can be fertilized with nitrogen fertilizer based on their annual growth rate or a soil analysis. Most fruit trees require a yearly foliar spray of zinc. A soil analysis can determine other nutrients needed by fruit trees. Applying nutrients that are not needed can cause a nutrient imbalance. ©Colorado State University Extension. 7/09.

Journal of Plant Nutrition BORON UPTAKE AND DISTRIBUTION IN FIELD GROWN CITRUS TREES

The residual effect of 10B on citrus trees during the following growing season was also evaluated based on isotopic analysis of additional samples collected: (i) six months after the first 10B fertilization (March 2004): ma-ture leaves from fruiting terminals according to leaf sampling guidelines for diagnostic of the nutritional status of ...

EFFICACY OF FOLIAR UREA AS AN N SOURCE IN SUBSTAINABLE CITRUS PRODUCTION SYSTEMS

In this study we report on: 1) the effect of pH of a 1% urea solution applied prebloom and the effect of a multiple foliar-urea spray at the rate of 1% to supply 46 g N/tree to mature ‘Cadoux’ clementine mandarin trees (Citrus reticulate Blanco) on leaf N and its changes during 30 days following application; 2) the resulting effect on yield and ...

Foliar Nutrition of Fruit Crops

Summary This chapter contains sections titled: Introduction Uptake of Foliar-Applied Nutrients Factors Affecting Absorption of Foliar-Applied Nutrients Metabolism of Foliar-Absorbed Nitrogen Transl...

Citrus trees, also known as orange trees, are one of the most important fruit-bearing plants, cherished for their sweet fruits. Fertilization is a critical practice to ensure healthy growth and enhance fruit quality. Below is a detailed guide on the timing, methods, and precautions for applying foliar fertilizer.

I. Timing for Foliar Fertilization

1. Spring: Spring marks a period of vigorous growth. Applying foliar fertilizer during this time promotes rapid recovery and strengthens disease resistance. Conduct the first application around bud sprouting, using nitrogen-rich fertilizer to energize growth.

2. Summer: In the hot and humid summer, foliar fertilization supplements nutrients and improves drought resistance. Increase phosphorus and potassium ratios to support fruit maturation and flower bud differentiation.

3. Autumn: As temperatures drop and trees prepare for dormancy, foliar fertilization enhances cold resistance and nutrient storage. Use fertilizers containing microelements like boron and zinc.

4. Winter: During dormancy, minimize foliar applications to avoid disrupting natural rest. if soil dries excessively, light applications can help maintain moisture.

II. Methods for Applying Foliar Fertilizer

1. Dilution Ratio: Follow package instructions to dilute fertilizers with water. Water-soluble formulas can be sprayed directly, while solid fertilizers must dissolve fully before use.

2. Uniform Application: Use a sprayer or soft brush to evenly coat leaves. Avoid direct contact with fruits to prevent quality issues.

3. Optimal Timing: Apply in early morning or evening to avoid scorching leaves. Adjust schedules based on weather and plant needs.

4. Consistency: For prolonged effects, repeat applications every few days as needed.

III. Precautions

1. Fertilizer Selection: Choose formulations suited to the tree’s growth stage (e.g., nitrogen-rich in spring, microelements in autumn).

2. Environmental Factors: Monitor weather and plant health. Avoid applications during extreme conditions (e.g., heavy rain, drought).

3. Safety Measures: Wear gloves and goggles when handling chemicals. Wash skin and tools thoroughly after use.

4. Dosage Control: Stick to recommended amounts. Over-fertilization may lead to excessive growth or damage.

5. Soil Conditions: Adjust based on soil tests. Fertile soils require less frequent applications.

6. Pest Management: Balanced fertilization boosts pest resistance, but regular inspections remain essential.

foliar fertilization is vital for citrus tree health and fruit quality. By scheduling applications scientifically and following best practices, growth and yields can be optimized. avoid excessive use—tailor fertilization to actual needs and soil conditions for optimal results.