Growing Nectarines – Crop Nutrition 101

What soil type, pH and climate do nectarines prefer? 

• Soil: Well-drained sandy loam is preferred to prevent waterlogging and support healthy root development.
• pH: Slightly acidic to neutral (pH 6.0–7.0) ensures optimal nutrient availability.
• Climate: Full sunlight and high elevation sites are ideal to reduce frost damage and promote fruit development.
• Moisture Needs and Irrigation: Regular, moderate watering is essential to maintain consistent soil moisture; avoid waterlogging while ensuring the tree receives enough water, especially during dry periods. Irrigation water quality is an important element to nutrient efficiency and orchard health.

Long-term orchard health – nutrient management strategy for nectarines:

A key goal of nutrient management is to achieve and maintain optimal soil fertility levels over time. Once soil fertility reaches this ideal level, nutrient applications should be adjusted to replace only what is removed by the harvested crop, matching application rates with crop removal rates. When leaves and pruning materials are recycled, nutrient extraction from the fruit generally aligns with tree needs. 

• Fertigation: Efficient for delivering macronutrients like NPK and calcium directly to the root zone, allowing precise application and reducing the risk of leaching and groundwater pollution. Agrolution pHLow High K plus Ca, and Agrolution pHLow 6-31-31 have been shown to increase fruit size. 
• Foliar Sprays: Effective for supplying specific micronutrients and smaller quantities of macronutrients during critical growth stages or when soil uptake is limited. Best applied early in the morning and well-suited for micronutrients with the small quantities needed. Nova PULSE has been shown to improve quality and farm economics.
• Granular/Broadcast Applications: . Distribution of nutrients evenly over the soil surface and incorporated through irrigation or cultivation facilitates setting the initial soil fertility levels and providing sustained nutrient availability, especially with controlled release fertilizers. The importance of post-harvest application (Polysulphate) should not be overlooked! 
• Soil and Leaf Testing: Regular soil and leaf testing is essential for accurate nutrient management, helping to fine-tune applications based on current nutrient levels and tree needs. Nutrients are essential for various tree parts, including fruit, leaves, shoots, roots, and permanent wood, so this approach supports long-term soil fertility and optimal fruit production.

What nutrients affect yield and quality most in nectarines? 

• Nectarine trees primarily need the macronutrients NPK for normal growth but micronutrients are essential to maintain quality.
• In soils that are not deficient in other nutrients, fruit trees generally respond most to N  applications. 
• Besides NPK, sufficient levels of calcium (Ca), boron, copper, and zinc are also crucial for maintaining tree health and producing high-quality fruit. 
• Macronutrients are typically best applied through soil methods like fertigation and supplemented with granular applications, especially for NPK and occasionally calcium. Foliar applications are most effective for delivering micronutrients.
• Post-harvest nutrition (K and other nutrients) is also important for maintaining orchard health and setting trees up for the yield the following year. Soil-applied, gradual release Polysulphate, alongside MAP and SOP, for example, can improved economic returns, enhanced soil quality and nutrient use efficiency (NUE).

Key nutrients for nectarines – nutrient overview:

1. Nitrogen (N)

• Role: Essential for vigorous vegetative growth and leaf development.
• Application Timing: Early spring before new growth starts.
• Application Types: Granular, broadcast, or fertigation. Regular applications are necessary due to high demand and potential leaching from sandy soils.
• Deficiency Symptoms: Yellowing of older leaves and stunted growth.
• Excess: Can cause excessive vegetative growth and poor fruit quality.

2. Phosphorus (P)

• Role: Crucial for root development, flower formation, and fruit set.
• Application Timing: Incorporate before planting and during early growth.
• Application Types: Soil-applied, broadcast, or fertigation. Manage carefully or use acidifying fertigation solutions like Agrolution pHLow or Nova PeKacid to avoid precipitation issues with Mg and Ca.
• Deficiency Symptoms: Reduced growth and dark green leaves.

3. Potassium (K)

• Role: Enhances fruit size, firmness, quality, and stress tolerance.
• Application Timing: Early spring and during fruit development phases.
• Application Types: Soil-applied (Polysulphate), broadcast, or fertigation (Agrolution pHLow High K). Match application rates with nutrient removal rates from harvested fruit.
• Deficiency Symptoms: Yellowing or necrosis of leaf margins, starting in older leaves.

4. Calcium (Ca)

• Role: Strengthens cell walls, improves fruit firmness, and helps prevent disorders like cork spot or bitter pit.
• Application Timing: Spring and summer; frequent applications may be necessary in sandy or acidic soils.
• Application Types: Soil-applied (Polysulphate), foliar sprays, or fertigation. Foliar applications can quickly address deficiencies.
• Deficiency Symptoms: Disorders like bitter pit or cork spot

5. Magnesium (Mg)

• Role: Vital for chlorophyll production and overall plant health.
• Application Timing: Early spring and mid-summer.
• Application Types: Soil-applied (Polysulphate) and foliar sprays.
• Deficiency Symptoms: Interveinal chlorosis in older leaves.

6. Sulfur (S)

• Role: Important for protein synthesis and overall plant health.
• Application Timing: As needed based on soil and leaf testing. 
• Application Types: S-based fertilizers – Polysulphate provides gradual release of nutrients to match crop uptake demands
• Deficiency Symptoms: Similar to nitrogen deficiency.

7. Boron (B)

• Role: Essential for pollen tube growth and fruit set.
• Application Timing: During bloom for best results; regular monitoring is important.
• Application Types: Foliar sprays and soil applications. Avoid over-application to prevent toxicity.
• Deficiency Symptoms: Leaf distortion, poor fruit set, and deformed fruit.

8. Zinc (Zn)

• Role: Supports enzyme functions and prevents growth disorders.
• Application Timing: Late dormant, post-harvest or early spring setting the stage for growth. Foliar applications can be made during the season if necessary, but be cautious of spray deposits on the fruit and potential phytoto
• Application Types: Foliar sprays and soil applications. Use caution with timing and temperature to prevent damage.
• Deficiency Symptoms: Blind wood, little-leaf, and rosettes.

9. Copper (Cu)

• Role: Supports photosynthesis and disease resistance.
• Application Timing: Dormant season or as indicated by tests.
• Application Types: Soil and foliar applications. Be cautious of overuse and contamination from pesticide residues.
• Deficiency Symptoms: Rare; excess can lead to metal interactions.

10. Manganese (Mn)

• Role: Supports enzyme functions; deficiencies are uncommon.
• Application Timing: As needed based on tissue testing.
• Application Types: Foliar sprays or soil applications.
• Deficiency Symptoms: May be masked by iron deficiency symptoms.

11. Iron (Fe)

• Role: Essential for chlorophyll production; commonly deficient especially in higher pH soils.
• Application Timing: Based on soil and leaf tests.
• Application Types: Soil and foliar applications.
• Deficiency Symptoms: Chlorosis in young leaves, severe cases turn leaves nearly white.

12. Sodium (Na)

• Role: Managing high sodium levels is important to prevent salinity and soil structure issues.
• Application Timing: Monitor and manage as needed based on soil and water analyses.
• Application Types: Soil and water management strategies.
• Deficiency Symptoms: Necrotic leaf margins.

Key fertility challenges: 

• Nutrient Imbalance: Balancing macronutrients and micronutrients to avoid deficiencies or excesses. Accurate nutrient management is crucial, as tree nutrient needs vary across fruits, leaves, shoots, roots, and permanent wood.
• Soil pH Management: Adjusting pH to ensure nutrient availability and prevent deficiencies.
• Fertility Maintenance: Long-term monitoring and adjustments needed due to the perennial nature of fruit trees.
• Nutrient Losses: Managing leaching and depletion, particularly in sandy soils or high-rainfall conditions. Consider using gradual release fertilizers like Polysulphate or Controlled Release Fertilizers.

Long-term orchard health is the ultimate goal. Regular soil testing and proper nutrient management are crucial to ensure that nutrients are supplied in the right amounts for healthy nectarine trees and optimal fruit production. 

Sources: 

• B.C. Tree Fruit Production Guide. (n.d.). Fruit tree nutrition. Retrieved August 15, 2024, from https://www.bctfpg.ca/horticulture/fruit-tree-nutrition/
• Penn State Extension. (n.d.). Peach production. Retrieved August 15, 2024, from https://extension.psu.edu/peach-production
• Washington State University Tree Fruit Research & Extension Center. (n.d.). Fruit tree nutrition. Retrieved August 15, 2024, from https://treefruit.wsu.edu/orchard-management/soils-nutrition/fruit-tree-nutrition/
• California Department of Food and Agriculture. (n.d.). Fertilization guidelines for peach and nectarine. Retrieved August 15, 2024, from https://www.cdfa.ca.gov/is/ffldrs/frep/FertilizationGuidelines/Peach_Nectarine.html