Onion and Leek Fertiliser and Crop Nutrition

Nitrogen

The role of nitrogen in onion and leek crops:

Nitrogen, whilst not needed in large quantities in onion and leek crops:, is an essential nutrient for crop yield, quality and health. The crops require a steady supply of nitrogen for their development, without surges of supply. Nitrogen supports the development of healthy foliage and as it is a key component of amino acids, nitrogen is essential for various physiological processes in plants, including enzyme activity, nutrient transport, and cell structure. Adequate nitrogen ensures overall plant health and resilience to diseases and environmental stresses.

Identifying Nitrogen Deficiency in onion and leek crops:

One of the earliest signs of nitrogen deficiency is the yellowing of older leaves, starting from the tips and progressing towards the base of the plant.

Utilising Nitrogen in onion and leek crops:

Nitrogen can be applied to onion and leek crops within the base fertiliser requirement either within the Multiflo liquid NPKS fertiliser or within the Nitroflo liquid nitrogen plus sulphur fertiliser. Liquid nitrogen is an excellent choice for onion and leek crop growth as it’s instantly and steadily available to the crops, providing consistent responsive nutrition evenly across the field.

Phosphorus

The role of phosphorus in onion and leek crops:

Phosphorus is essential for root development in onions and leeks and sufficient phosphorus promotes the growth of a healthy root system, which is crucial for nutrient uptake and overall plant vigour. The crops are generally shallow-rooted and a well-developed root system helps them access water and nutrients efficiently. A phosphate-rich liquid starter fertiliser is commonly used on the crops, to help rapid establishment and yield potential.

Identifying phosphorus deficiency in onion and leek crops:

Phosphate deficiency often leads to stunted growth in onions and leeks. The plants may appear smaller than expected, with slower overall development compared to healthy plants and while nitrogen deficiency causes yellowing of leaves, phosphate deficiency may result in unusually dark green leaves. This dark green colour is often accompanied by a purplish tint, particularly on the undersides of leaves.

Utilising phosphorus in onion and leek crops:

Phosphorus can be applied to onion and leek crops in a 100% water soluble form utilising the Multiflo grades of NPKS fertilisers. The liquid, soluble formulation aids instant uptake by the crop.

Polymex

Polymex is an additive that can be included with your Multiflo P application to aid the utilisation of phosphorus, it keeps it mobile within the soil for longer.

Vitomex

Vitomex is a unique nitrate free foliar nutrient which supplies plant stimulating phosphite along with potassium and trace elements chelated in a unique way to improve plant health and tolerance of abiotic stress

Potassium

The role of potassium in onion and leek crops:

Potassium helps regulate water uptake and transport within plants. It enhances the efficiency of water use, allowing onion and leek crops to better withstand periods of drought or water stress. Adequate potassium levels help maintain turgor pressure in plant cells, which is essential for structural support and overall plant health.

Potassium contributes to the development of strong cell walls, which can improve the plant’s resistance to various diseases, helping to maintain crop health and yield potential. Potassium influences the quality and storability of onion and leek crops and contributes to the development of firm and well-coloured bulbs in onions and sturdy, upright stems in leeks.

Additionally, potassium helps regulate the synthesis of organic compounds that affect flavor, texture and shelf life, ensuring that harvested onions and leeks maintain their quality during storage and post-harvest handling.

Identifying potassium deficiency in onion and leek crops:

Classically manifested as yellowing or browning of leaf margins and tips; potassium deficiency often causes death of leaf margins and tips, starting from the older leaves and progressing towards the younger ones.

Utilising potassium in onion and leek crops:

Potassium can be applied within the Multiflo NPKS range of liquid fertilisers, providing the crop with a healthy dose of liquid nutrition alongside other crucial elements for crop establishment and growth.

DP98

DP98 is potassium phosphite formulated to maximise the benefit of phosphite application on root growth in young plants

Vitomex

Vitomex is a unique nitrate free foliar phosphite containing potassium. It’s used to improve plant health, rooting action, yield and post harvest quality.

Sulphur

The role of sulphur in onion and leek crops:

Sulphur is a vital macronutrient for onion and leek plants, playing critical roles in protein synthesis, chlorophyll formation, vitamin synthesis, disease resistance and nutrient uptake. Ensuring sufficient sulphur availability through soil or foliar fertilisation is essential for promoting healthy growth and maximising yield potential in onion and leek crops.

Identifying sulphur deficiency in onion and leek crops:

Sulphur deficiency typically causes overall yellowing of the leaves, starting from the younger leaves and progressing towards the older ones. Unlike nitrogen deficiency, which usually affects older leaves first, sulphur deficiency eventually affects the entire plant uniformly.

Utilising sulphur in onion and leek crops:

Sulphur can be applied within both the Nitroflo and Multiflo base liquid fertilisers. This is to help improve nitrogen use efficiency whilst potentially remedying sulphur deficiency.

Boron

The role of boron (B) in onion and leek crops

Boron is a micronutrient that plays critical roles in cell wall formation, reproductive development, sugar transport, enzyme activation and nutrient uptake in onion and leek crops.

Identifying boron deficiency in onion and leek crops:

Boron-deficient leaves may become brittle and easily breakable due to impaired cell wall development. In onions, boron deficiency may result in misshapen bulbs with irregular growth patterns or internal cracking and in leeks, stems may exhibit abnormal growth or splitting.

Utilising boron in onion and leek crops:

Folex B

Folex B can improve crop performance by reducing or preventing boron deficiency.

Copper

The role of copper (cu) in onion and leek crops:

per plays critical roles in enzyme activation, chlorophyll formation, cell wall formation, reproductive development and disease resistance in onions and leeks.

Identifying copper (cu) deficiency in onion and leek crops:

Copper deficiency can lead to decreased chlorophyll synthesis, resulting in pale or yellowish-green leaves, potentially affecting the plant’s ability to photosynthesise effectively. Leaves may exhibit curling or twisting, particularly at the leaf margins. This distortion can be a result of impaired cell wall development due to copper deficiency.

Utilising copper (cu) in onion and leek crops:

Folex Cu 6

Folex Cu 6 is an inorganic liquid formulation containing copper and sulphate S used to correct copper deficiency. It can be applied to onion and leek crops once established, a second application may be required in dry seasons.

Folex Cu 10

Folex Cu 6 is a copper EDTA formulation used to correct copper deficiency. It can be applied to onion and leek crops once established, a second application may be required in dry seasons.

Zinc

The role of zinc (Zn) in onion and leek crops:

Zinc is a cofactor for many enzymes involved in various metabolic processes within onions and leeks. It helps activate enzymes responsible for DNA synthesis, protein synthesis, and carbohydrate metabolism. Zinc plays a role in enhancing plant defences against diseases and pathogens.

It contributes to the activation of defence mechanisms and the synthesis of phytochemicals that can help plants resist infections and pests. In onions and leeks, adequate zinc levels can contribute to overall plant health and resilience to stress.

Identifying zinc (Zn) deficiency in onion and leek crops:

Zinc-deficient plants may exhibit yellowing or interveinal chlorosis, where the areas between leaf veins turn yellow while the veins remain green. This chlorosis is typically more pronounced in younger leaves.

Utilising zinc (Zn) in onion and leek crops:

Folex Zn

Folex Zn is an inorganic liquid formulation containing zinc and sulphur. It can be applied to onion and leek crops at 3-4 leaves to aid rapid growth.

Zynergy

Zynergy is a combination of copper, zinc and sulphur formulated to optimise nutrient uptake by the plant.