Irrigation and Nutrition

Overview

• HLB-affected trees have a small and weak root system, resulting in limited water and nutrient uptake; therefore, making nutrients continuously available maximizes the uptake. 
• Each grove is unique due to several factors such as soil type, soil pH, location, irrigation water quality, soil organic matter, method of fertilization, irrigation scheduling, tree nutrient status, tree age, variety, vigor and HLB-severity.
• Irrigation and nutrition programs should be customized to address these unique situations.

Irrigation

• Increasing the frequency of irrigation enables water availability throughout the day and the tree experiences less water deficit.
• Reducing the duration and increasing frequency reduces excess water drainage, thus keeping adequate water level in the top 6 inches of the soil.
• Enhanced irrigation is highly recommended during dry times of the year, especially during March through June when fruit set and early stages of fruit development occur.

Nutrition

• The goal of a nutrition program is a continuous availability of all nutrients throughout the growing season.
• The focus of the nutrition program should be on leaf nutrient concentrations and not on the rate of nutrient applied.
• Leaf nutrient analysis is an effective tool for assessing trees nutritional needs. It is recommended to do the analysis as
  many times as bulk fertilizer is applied to address trees nutritional needs.
• Soil testing should be done annually, but careful consideration should be given to leaf tissue results. While a soil test may
  show high nutrient content, the nutrient may not be readily available to the plant.
• A nutrition program should be a combination of soil- and foliar- applied nutrients.
• Do not rely solely on foliar application for any nutrient.
• Fertilizer programs should have all nutrients in the right balance and ratios.
• Fertilizer should be placed in the wetted zone.
• Schedule irrigation at the time of soil-applied fertilizer applications.
• Split fertilizer applications are encouraged.
  » Fertigation: apply a minimum of 12 to 30 splits a year.
  » Dry soluble fertilizer: 4 split applications a year.
• When using controlled release fertilizer, apply 2 to 3 times a year.

Resources

• Nutrition of Florida Citrus Trees, 3^rd Edition
• Florida Citrus Production Guide: Nutrition Management for Citrus Trees
• Florida Citrus Production Guide: Fertilizer Application Methods
• Plant Nutrients for Citrus Trees
• A Guide to Citrus Nutritional Deficiency and Toxicity Identification
• Irrigation, Nutrition, and Citrus Fruit Quality
• Soil and Leaf Tissue Testing for Commercial Citrus Production
• Nitrogen (N) for Citrus Trees
• Phosphorus (P) for Citrus Trees
• Potassium (K) for Citrus Trees
• Magnesium (Mg) for Citrus Trees
• Calcium (Ca) and Sulfur (S) for Citrus Trees
• Manganese (Mn) and Zinc (Zn) for Citrus Trees
• Iron (Fe) and Copper (Cu) for Citrus Trees
• Boron (B) and Chlorine (Cl) for Citrus Trees
• Molybdenum (Mo) and Nickel (Ni) for Citrus Trees
• Macronutrient Deficiencies in Citrus: Nitrogen, Phosphorus, and Potassium
• Macronutrient Deficiencies in Citrus: Calcium, Magnesium, and Sulfur
• Micronutrient Deficiencies in Citrus: Iron, Zinc, and Manganese
• Micronutrient Deficiencies in Citrus: Boron, Copper, and Molybdenum
• Diagnostic Nutrient Testing for Commercial Citrus in Florida
• Computer Tools for Diagnosing Citrus Leaf Symptoms (Part 2): Smartphone Apps for Expert Diagnosis of Citrus Leaf Symptoms
• Increasing Efficiency and Reducing Costs of Citrus Nutritional Programs
• Citrus Fertilizer Management on Calcareous Soils
• Citrus BMP Implementation in Florida's Gulf Citrus Production Area: Nutrients
• Florida Citrus Production Guide: Irrigation Management of Citrus Trees
• Citrus Irrigation Management 
• Irrigation Management of HLB-Affected Trees
• Optimizing Irrigation and Young Tree Management
• Common Questions When Using Soil Moisture Sensors for Citrus and Other Fruit Trees