Growing apples in the US

Commercial apple production in the US requires careful attention to soil variability, tree nutrient demands, fruit quality, sustainability, water management, and the integration of precision agriculture technologies. Adapting nutrient management practices to address these factors is essential for sustainable orchard management and profitable apple production.

• Proper nutrient management directly influences fruit quality, yield, and marketability.
• Balancing macronutrients like nitrogen, phosphorus, and potassium, along with micronutrients , ensures optimal fruit size, color, flavor, and storability, which are essential for commercial success. Trials with Nova HiPeak™, a PK water-soluble fertilizer, show an increased fruit size of 30%.
• Orchard Establishment: Optimizing fertility management from the outset maximizes tree growth, development, and long-term fruiting success.
• Importance of Irrigation Water Quality: Even in regions with higher rainfall, irrigation water quality influences nutrient availability and the operation of irrigation systems, impacting nutrient uptake by apple trees.
• Calcium Management: Maintaining adequate calcium levels in apple trees is crucial for fruit development and storage quality, often requiring foliar or soil applications to prevent disorders like bitter pit.
• Innovative Nutrient Solutions: Emerging solutions like Polysulphate offer prolonged release of essential nutrients such as calcium, sulfur, and magnesium, along with low chloride potassium, aiding in optimal tree nutrition.
• Intensive Spray Schedules: Effective pest and disease management through intensive spray schedules, combined with foliar applications of macro- and micronutrients, like Nova HiPeak™ and Nova Pulse, ensures optimal tissue nutrient levels during fruit development.
• Improving Fruit Quality and Storage: Strategies like foliar potassium applications contribute to improved fruit quality and storage capabilities, enhancing overall marketability for apple growers.
• Research Insights and Trials: Ongoing research, such as ICL’s North American apple trials, provides valuable insights into fertility management practices, helping growers make informed decisions for their orchards.

What soil type, pH and climate do apple orchards prefer?

Apples are adaptable and can be grown in a range of climates and soils, but certain conditions are considered ideal for their cultivation.

• Deep, well-drained soils, with moderate organic matter content and adequate aeration (like sandy and loamy soils), allow for proper root development and nutrient availability
• The ideal pH for apples falls between 6.0 and 7.0. This slightly acidic to neutral range is conducive to nutrient uptake
• Windbreaks and air circulation can protect trees from damage and help reduce the risk of diseaeses such as scab
• Water needs are approximately 9.5 to 12.5 acre-inches between bud break and leaf fall.
• While adequate and consistent moisture (often provided through drip irrigation) is crucial, it is important to avoid waterlogging, as exsessive moisture can lead to root diseases
• Apple trees are very sensitive to soil salts (maximum salinity of 2-3 mS / cm) and exchangeable sodium.

Key aspects of an apple crop

• The apple tree is more resistant to cold than other species of pome such as the pear tree. Also, it does not need as much heat and light to ripen and the apple tree prefers humid climates to dry ones. Although the flowers are sensitive to late spring frosts, the apple tree supports temperatures below -10ºC, without affecting its bark, although below -15ºC some flower buds may be lost. 
• The main limitation for the cultivation of apple trees in the southern regions is the requirement of cold hours, since although there are varieties with low requirements (around 500 cold hours) most of the most productive varieties need more than 1500 cold hours). 
• In southern and southeast exposures, high light intensity can produce vitreous fruits and high heats favor internal darkening, surface scalds, or sunburn. 
• It is an undemanding crop in the soil, with a shallow root system, although it prefers deep and light clay soils, it does well in heavy or shallow soils. 

Nutrient requirements

• Apples, like any fruit crop, require a range of nutrients for healthy growth, development, and fruit production.
• While nitrogen (N), phosphorus (P) and potassium (K) are key to optimal growth, secondary macronutrients such as magnesium (Mg), calcium (Ca), and sulfur (S) can be crucial for fruit quality.
• Micronutrients, specifically, iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), are important for various enzymatic processes. Deficiencies can be identified through soil and foliar testing.
• Phosphorus and micronutrient deficiencies may appear in soil with high pH.
• Calcium management is very important for the quality of the fruit and a combination of soil and foliar application of calcium is often needed

Estimated nutrient uptake (kg/t):

Dynamic of nutrient uptake over a crop season in apples

Nutrient deficiencies