1、A Guide to Citrus Nutritional Deficiency and Toxicity Identification

Symptoms can include thinning tree canopies, retarded growth and foliage with iron deficiency symptoms. Feeder roots may also become darkened, and show restricted growth.

2、Nutrient stress signals: Elucidating morphological, physiological, and

There is a critical knowledge gap in fruit trees regarding the molecular mechanisms of macronutrient function, which impedes our ability to optimize fruit tree growth and productivity, which in turn threatens world food security.

3、Nutritional Disorders of Citrus and Their Management

Deficiency of minerals, viz. macronutrients and micronutrients, results in disorders in plant metabolism, and plants express hunger signs, viz. chlorosis, leaf spot, leaf blotch, leaf blight, dieback, reduced growth of tree, poor fruit quality and decreased number of fruits in citrus tree.

4、Nutrient deficiency

A nutrient deficiency may express itself on the whole tree level causing twig die-back, long thin branches, yellowing, and reduced or abnormal growth. Nutrient deficiencies may alter fruit characteristics such as shape, hardness, peel thickness, and peel texture.

Macronutrient Deficiencies in Citrus : Nitrogen , Phosphorus

Perhaps the most distinctive observation about citrus nutrition is the variety of nutrient deficiencies that can appear under intensive cultivation. Visual deficiency symptoms of N, P, K, Ca, Mg, Fe, Zn, Mn, B, Cu, and Mo have been recognized both in the field and in artificial growing media.

(PDF) Nutrient deficiency symptomology in citrus: An effective

Development of visible symptoms is attributed to metabolic disorders, causing changes in micromorphology before such symptoms are identifiable. The way in which symptoms develop and manifest...

Magnesium and manganese deficiencies in citrus

Citrus trees are demanding feeders and are prone to many disorders related to mineral nutrition. In New South Wales, citrus can become deficient in essential elements usually obtained from the soil. Magnesium and manganese are two of these.

Macronutrient Deficiencies in Citrus: Calcium, Magnesium, and Sulfur

The use of specific symptoms as guides to the nutritional needs of citrus trees has been common for many years. The symptoms of N, Mg, Fe, Zn, Mn, and Cu deficiency are quite definite and easily recognizable.

review: Nutrient deficiencies and physiological disorders of citrus

onutrient deficiencies are frequently encountered in citrus orchards. Citrus cultivation today is threatened due to various nutrient deficiency symptoms, physiological dis. rders, fungal, viral and bacterial diseases, pests and nematodes etc. The intensity of these problems varies.

Diagnosis and management of nutrient constraints in citrus

It is important to consider that HLB-affected trees often display nutrient deficiencies as well; therefore, it is necessary to distinguish deficiencies from HLB symptoms and rectify the deficiencies with right fertilizer formulation.

Symptoms of Secondary Macronutrient Deficiencies in Citrus Trees

Citrus trees are one of the world’s most important fruit crops, producing fruits rich in vitamins and minerals beneficial to human health. due to soil conditions, improper fertilization, or nutritional imbalances, citrus trees may exhibit symptoms of deficiencies in specific secondary macronutrients. Below are common symptoms associated with the lack of these nutrients in citrus:

I. Nitrogen (N) Deficiency

1. Symptoms: Yellowing leaves, slow growth of new foliage, gradual yellowing and shedding of old leaves. Stunted plant growth, thin and weak branches, fewer flowers and fruits, smaller fruit size, poor taste, and reduced yield.
2. Cause Analysis: Nitrogen is essential for synthesizing proteins, chlorophyll, enzymes, and other critical compounds. Its deficiency disrupts photosynthesis, impairs growth, and lowers productivity.
3. Prevention and Control: Increase organic fertilizers (e.g., chicken manure, cow dung) to boost nitrogen supply. Enhance top-dressing frequency, especially during peak growth stages.

II. Phosphorus (P) Deficiency

1. Symptoms: Poor root development, brownish root tips, reduced root density, and weakened absorption capacity. Stunted growth, distorted leaves, severe interveinal chlorosis, malformed fruits, and compromised yield/quality.
2. Cause Analysis: Phosphorus is a key component of cell walls, energy metabolism, and hormone regulation. Its deficiency hinders growth and reduces fruit quality.
3. Prevention and Control: Apply phosphate fertilizers (e.g., calcium superphosphate, diammonium phosphate). Optimize fertilization practices to avoid overapplication.

III. Potassium (K) Deficiency

1. Symptoms: Leaf spots or stripes, necrotic leaf margins, and curling. Slow growth, brittle stems prone to lodging, poor flower/fruit development, sunken fruit surfaces, soft flesh, and inferior taste.
2. Cause Analysis: Potassium regulates photosynthesis and water balance. Its deficiency disrupts physiological functions and impairs fruit quality.
3. Prevention and Control: Use potassium-rich fertilizers (e.g., potassium sulfate, potassium chloride). Maintain balanced fertilization to prevent excesses.

IV. Sulfur (S) Deficiency

1. Symptoms: Stunted growth, general yellowing, and severe interveinal chlorosis. Malformed fruits with thick, rough skin, and poor taste.
2. Cause Analysis: Sulfur acts as a coenzyme in carbohydrate metabolism and protein synthesis. Its deficiency disrupts physiological processes and fruit quality.
3. Prevention and Control: Apply sulfur-containing fertilizers (e.g., ferrous sulfate, zinc sulfate). Ensure balanced nutrient application.

Symptoms of secondary macronutrient deficiencies in citrus vary but can be managed through targeted interventions. In agricultural practice, prioritize soil nutrient management and rational fertilization to meet citrus nutritional needs, ensuring healthy growth and high-quality yields.