1. Pre-Flowering
What’s happening inside the tree?
As temperatures rise and environmental conditions become favourable, macadamia trees transition from vegetative growth to reproductive development. During the pre-flowering stage, dormant floral buds differentiate and develop into flower racemes, while the tree mobilises stored carbohydrate and nutrient reserves to support this energy-intensive process. At the same time, new vegetative flushes may occur, increasing the demand for nutrients and photosynthetic activity. Successful floral development during this stage establishes the foundation for flowering, pollination and subsequent nut production.
Natural hormonal activity
Gibberellins, cytokinins and auxins all contribute to the transition from vegetative to reproductive growth. Gibberellins promote shoot elongation and the development of flower racemes, while cytokinins stimulate cell division within developing floral tissues. Auxins coordinate the growth of emerging shoots and reproductive structures, supporting balanced canopy development as the tree prepares for flowering.
Why are amino acids important?
Amino acids provide the building blocks required for protein synthesis, enzyme production and the metabolic processes associated with floral development. They also contribute to chlorophyll formation and nitrogen metabolism, supporting the production of the energy required for rapid vegetative and reproductive growth during this stage.
Which key nutrients are important during this stage?
Several nutrients play important roles in supporting floral development and the transition from vegetative to reproductive growth.
Nitrogen contributes to chlorophyll production, protein synthesis and vegetative growth, helping to maintain a healthy canopy capable of supporting the increased energy demand associated with flowering. Phosphorus is important for energy transfer within the plant and supports root activity and the development of reproductive tissues. Boron plays a critical role in floral development, pollen formation and reproductive processes, making it an important nutrient during the lead-up to flowering.
Why does the GrowGreen program complement this stage?
Pre-flowering is a period of increasing metabolic activity as the tree prepares for reproductive development. Fish Emulsion contains biologically derived amino acids and organic nutrients from microbially digested fish that support active metabolism and protein synthesis, while Microbe Plus Kelp provides phytohormones and bioactive compounds derived from microbially digested kelp that complement floral development, vegetative flushing and canopy function. Applied together with Xtend®, the GrowGreen program complements the physiological processes associated with preparing the tree for successful flowering.
2. Flowering
What’s happening inside the tree?
Flowering is one of the most physiologically demanding stages in the macadamia production cycle. Flower racemes continue to develop and open, allowing pollination and fertilisation to occur. During this period, the tree allocates considerable energy and nutrients to support pollen viability, flower longevity and successful fertilisation, while maintaining active photosynthesis to meet the increased metabolic demand. The success of flowering has a direct influence on subsequent nut set and overall yield potential.
Natural hormonal activity
Auxins, gibberellins and cytokinins all contribute to successful flowering and fertilisation. Auxins regulate floral development and the early stages of reproductive growth, while gibberellins promote flower development and pollen function. Cytokinins support cell division and help maintain the metabolic activity required for developing reproductive tissues, contributing to successful fertilisation and the transition to nut development.
Why are amino acids important?
Amino acids provide the building blocks required for protein synthesis, enzyme production and the metabolic processes associated with flowering and fertilisation. They also contribute to nitrogen metabolism and chlorophyll formation, supporting the continued production of photosynthates required to sustain reproductive growth during this critical stage.
Which key nutrients are important during this stage?
Successful flowering and pollination depend on an adequate supply of several essential nutrients. Boron supports pollen germination and pollen tube growth, contributing to successful fertilisation. Calcium is important for maintaining the integrity of developing floral tissues and cell membranes during this highly active reproductive stage. Zinc contributes to enzyme activity and the production of growth regulators involved in flower development and reproductive processes.
Why does the GrowGreen program complement this stage?
Flowering places a substantial demand on the tree’s metabolic and nutritional resources as it progresses from pollination to fertilisation. Fish Emulsion contains biologically derived amino acids and organic nutrients from microbially digested fish that support active metabolism and protein synthesis, while Microbe Plus Kelp provides phytohormones and bioactive compounds derived from microbially digested kelp that complement flowering, pollination and the physiological processes associated with successful fertilisation. Applied together with Xtend®, the GrowGreen program complements the tree’s increased nutritional demand during this critical reproductive stage.
3. Early Nut Set
What’s happening inside the tree?
Following successful pollination and fertilisation, the tree enters the early nut set stage, during which developing nuts begin rapid cell division and initial growth. This is a critical period, as the tree naturally sheds a proportion of young nuts while retaining those it can support to maturity. At the same time, leaves continue producing carbohydrates through photosynthesis, supplying the energy and nutrients required for developing nuts. Successful nut retention during this stage has a major influence on final yield.
Natural hormonal activity
Auxins, cytokinins and gibberellins play important roles during early nut development. Auxins regulate the growth of developing nuts and contribute to fruit retention, while cytokinins stimulate the rapid cell division required during the initial stages of nut growth. Gibberellins support continued development of young fruit and help coordinate the transition from flowering to active nut growth.
Why are amino acids important?
Amino acids provide the building blocks required for protein synthesis, enzyme production and the metabolic processes associated with rapid cell division and early nut development. They also contribute to nitrogen metabolism and support continued photosynthesis, providing the energy required to sustain developing nuts during this critical stage.
Which key nutrients are important during this stage?
During early nut set, the developing crop places increasing demands on the tree’s nutrient reserves. Calcium supports the formation and stability of newly developing cells as young nuts undergo rapid cell division. Potassium plays an important role in carbohydrate transport and the movement of sugars from the leaves to developing nuts, while Boron contributes to the successful transition from fertilisation to early fruit development and assists in the movement of carbohydrates within the plant.
Why does the GrowGreen program complement this stage?
Early nut set is characterised by rapid cell division and increased metabolic activity as the tree establishes its developing crop. Fish Emulsion contains biologically derived amino acids and organic nutrients from microbially digested fish that support active metabolism and protein synthesis, while Microbe Plus Kelp provides phytohormones that complement early nut development, cell division and crop establishment. Applied together with Xtend®, the GrowGreen program complements the physiological processes associated with successful nut retention and early fruit development.
4. Early Kernel Fill
What’s happening inside the tree?
Following nut set, macadamia trees enter the early kernel fill stage, during which the developing kernel begins to accumulate dry matter. As kernel growth progresses, the demand for carbohydrates and nutrients increases, making efficient photosynthesis and the transport of assimilates from the leaves to the developing nuts essential. During this stage, the tree shifts its physiological priority towards supporting kernel development while maintaining a healthy canopy capable of sustaining continued carbohydrate production.
Natural hormonal activity
Auxins, cytokinins and abscisic acid all contribute to kernel development. Auxins help regulate the growth of developing nuts, while cytokinins support continued cellular activity within the kernel. As development progresses, abscisic acid plays an increasingly important role in coordinating assimilate movement, kernel maturation and the tree’s physiological response to environmental conditions.
Why are amino acids important?
Amino acids continue supporting protein synthesis, enzyme production and the metabolic processes associated with kernel development. They also contribute to nitrogen metabolism and help maintain active photosynthesis, supporting the production and transport of carbohydrates required for kernel filling.
Which key nutrients are important during this stage?
As the kernel begins to accumulate dry matter, nutrient demand shifts towards supporting efficient photosynthesis and the transport of assimilates. Potassium is essential for carbohydrate movement and helps sustain kernel filling by facilitating the transport of sugars to developing nuts. Magnesium is the central component of the chlorophyll molecule and supports continued photosynthetic activity, while Nitrogen remains important for maintaining leaf function, protein synthesis and the metabolic activity required to sustain kernel development.
Why does the GrowGreen program complement this stage?
During early kernel fill, maintaining active photosynthesis and efficient carbohydrate allocation is essential for kernel development. Fish Emulsion support continued metabolic activity and protein synthesis, while Microbe Plus Kelp complement kernel development and the physiological processes associated with carbohydrate accumulation. Applied together with Xtend®, the GrowGreen program complements the tree’s nutritional demand during this important stage of nut development.
5. Conclusion
Successful macadamia production depends on matching nutrition with the tree’s changing physiological requirements throughout the growing season. Understanding the role of plant hormones, amino acids and balanced mineral nutrition enables growers to make informed management decisions during the periods that have the greatest influence on flowering, nut set and kernel development.
The GrowGreen macadamia program has been developed around these key physiological stages, providing biological and mineral nutrition during the tree’s periods of greatest nutritional demand. By aligning applications with the crop’s growth cycle, growers can integrate sound agronomic principles into a practical nutrition program that supports productive, high-quality macadamia orchards.