The flowering stage is one of the most important stages for macadamia trees, directly determining the yield and quality of the nuts. To have a bumper crop, proper care of macadamia trees during this period is indispensable. And in today's article, Anh Duong will provide detailed instructions on how to care for macadamia trees when they bloom, helping growers achieve the highest efficiency and increase the economic value of the crop. Let's follow along!

The importance of the flowering stage for macadamia trees

Macadamia flowers grow in long, narrow clusters. The length of macadamia flowers is from 12-15cm. When they first bloom, they are buds like camellia buds. After blooming, the pistil stalk extends 3-4cm. The shape of macadamia flowers is like a squirrel's tail, usually white or pink. One flower can produce more than 14,000 pollen grains. After 10-15 days, the flowers will bloom and fall. Each cluster has 100-800 flowers.

The flowering stage is one of the most important stages in the life cycle of the macadamia tree, directly determining the yield and quality of the fruit. Understanding the importance of this stage and applying appropriate technical care measures will help increase the yield and quality of the fruit, bringing economic efficiency to users.

Understanding the flowering stage of the macadamia tree

The flowering stage is one of the most important stages in the life cycle of the macadamia tree. This is the time when the tree begins to form flowers, moving towards the process of pollination and fruit development.

Flowering time of the macadamia tree

Macadamia trees usually begin to flower after 4-7 years from planting, depending on the variety and growing conditions. In addition, the specific flowering time of the tree also depends on the local climate, but usually in tropical and subtropical regions like Vietnam, the macadamia tree begins to flower in late winter and lasts until early spring.

Pollination mechanism of macadamia trees

The pollination mechanism of macadamia trees takes place through cross-pollination. Pollen from the flowers of one tree will be transferred to the flowers of another tree thanks to the intermediary of insects. This is a complex but important mechanism that helps the tree grow and bear fruit

Insects, especially bees, play an intermediary role in the pollination process. When bees or other insects come to suck nectar from flowers, pollen from the male stamens will stick to their bodies. When they move to other flowers, this pollen will be transferred from their bodies to the pistil of the new flowers, helping the pollination process to take place

Pollination process of macadamia trees

When pollen from a macadamia tree is brought to the stigma of another flower, the pollen will come into contact with the surface of the pistil. After contact, if conditions are favorable, the pollen will germinate and develop into a pollen tube. This pollen tube will grow to the ovule - where the egg cell is located. When the tube reaches the ovule, the reproductive cell of the pollen will combine with the egg cell in the ovule to create an embryo and develop into a seed.

Factors affecting the pollination process

Pollination is the process of transferring pollen grains from the anther to the pistil, which is the first and extremely important step in the reproductive process of flowering plants. This process can occur thanks to different agents such as wind, water, insects or even humans.

Presence of insects

The presence of insects, especially bees, is a prerequisite for the pollination process to take place smoothly. If the number of bees in the macadamia growing area decreases, pollination will be significantly affected, thereby reducing the number of fruits.

Distance between macadamia trees

The distance between trees also affects the cross-pollination process. Plants that are too far apart can reduce the pollination efficiency because insects have more difficulty moving.

Weather conditions

Dry weather, no rain will create favorable conditions for insects to be active and help pollen spread easily. On the contrary, heavy rain or strong winds can hinder pollination.

Maintenance measures for macadamia trees when flowering

When macadamia trees enter the flowering stage, proper care will directly affect the yield and quality of the fruit. Here are some measures you can apply!

Watering

Proper watering is one of the most important factors to ensure that macadamia trees flower and bear fruit well. However, watering too much or too little can be harmful to the tree.

Amount of water for the tree

In Vietnam, when the macadamia tree enters the flowering stage (usually January to March), you should provide enough water for the tree to help the tree develop flowers and increase the ability to bear fruit. The appropriate amount of water is 60-80 liters of water/tree/time, watering 2-3 times/week depending on the size of the tree and weather conditions.

In the Central Highlands, the dry season lasts from November to April, so during this time you need to water regularly to keep the tree moist. You should water 3 times/week during the dry season with the amount of water from 60-80 liters/tree/time.

Time of watering

Early morning is the best time to water macadamia trees, around 5am to 8am. This is when the temperature is still cool, the water will have time to penetrate the soil before evaporating. Watering at this time helps the macadamia tree absorb water optimally, thereby providing enough moisture for the roots throughout the day.

The cool afternoon is the second most suitable time to water the tree, from 4pm to 6pm. At this time, the temperature has decreased and the water will not evaporate too quickly, giving the tree time to absorb. However, you should avoid watering too late in the evening because the humidity is high at night because this can create conditions for fungi to develop.

Note when watering the tree

Do not water the macadamia tree at noon (from 10am to 3pm) especially when the weather is very sunny. High temperatures will cause the water vapor to evaporate quickly, which is not effective for the tree and can cause the tree to go into thermal shock due to the sudden change between water temperature and air temperature.

If there is light rain but not enough to moisten the soil, you can water after the rain to ensure the tree has enough water. However, if it rains heavily and the soil is moist enough, you can postpone watering to avoid waterlogging.

Fertilizing

Proper fertilization is one of the important factors for macadamia trees to flower and bear fruit well. When nutrients are fully provided, the tree will be healthy enough to increase the ability to bear fruit.

Organic fertilizer

You can apply about 10-15 kg of composted manure per tree/year to improve soil structure, provide long-term nutrients, and help the roots absorb nutrients better.

Note that uncomposted manure or green manure can contain pathogens, heat the roots, and cause root rot. Therefore, you should compost thoroughly before fertilizing to help the fertilizer maximize its effectiveness without harming the tree. Organic fertilizer should be applied at the beginning of the rainy season so that the fertilizer decomposes slowly, providing nutrients for the tree throughout the growing season. You should not apply too much organic fertilizer at one time, because it can be toxic to the plant. Organic fertilizer should be applied periodically, 1-2 times a year.

NPK fertilizer (16-16-8 or 20-20-15)

NPK fertilizer (16-16-8 or 20-20-15) you should apply about 0.5 - 1 kg of NPK fertilizer/plant/time. The time to apply fertilizer is usually before and during the flowering stage, divided into 2 applications to provide a balanced supply of nitrogen (N), phosphorus (P), potassium (K) to help the plant develop flowers, and increase the ability to set fruit. When applying NPK fertilizer, you should note the following points:

• Do not apply too much organic fertilizer at one time because it can be toxic to the plant. Organic fertilizer should be applied periodically 1-2 times a year.

• Do not apply directly to the base of the tree to avoid burning the roots.

Potassium fertilizer

Dosage of Potassium fertilizer for a macadamia tree About 200-300g per fertilization and you should fertilize before and during flowering to help the tree become stronger, increase its resistance and promote flowering and fruiting. When fertilizing with Potassium, you should:

• Fertilize Potassium before and during flowering to promote flower formation and development. Potassium helps the tree become stronger, increases the ability to flower and fruit.

• Potassium is a soluble substance, if applied too much it can cause leaf burn or root damage. It is necessary to fertilize in moderation according to the instructions (about 200-300g per tree).

• Potassium can be fertilized with NPK fertilizer or micronutrient fertilizer to provide adequate nutrition for the tree.

Micronutrient fertilizer

Micronutrient fertilizer is a type of fertilizer containing chemical elements with very small content but extremely important for the growth and development of crops. Although only a very small amount is needed, if there is a lack of these trace elements, the tree will be weakened, its productivity will decrease and even die. For macadamia trees, you can use foliar fertilizers containing trace elements such as Mg, Zn, Bo, Cu... and fertilize about 2-3 times during the flowering season to help supplement the necessary trace elements to increase resistance and ensure the quality of flowers and fruits. However, when fertilizing macadamia trees with trace elements, you should pay attention to the following 3 issues!

• Micronutrient fertilizers are only necessary when the tree lacks these elements, and only need to be fertilized in small amounts. Applying too much trace elements can cause poisoning or reduce the ability to absorb other substances.

• Micronutrient fertilizers are usually applied through the leaves for quick absorption by the tree. Fertilizers should be sprayed in the early morning or cool afternoon, avoid spraying when the sun is strong.

• Micronutrient fertilizers can be combined with NPK fertilizers to provide adequate nutrition for the tree during the flower development stage.

Pruning

Pruning helps the tree have an even, airy canopy, ensuring light shines on the branches and flowers as well as increasing the ability to photosynthesize to help the tree grow healthily.

Pruning time

Pruning macadamia trees should be done about 1-2 months before the flowering season or during the flowering stage to ensure that the tree has enough strength to concentrate nutrients to nourish flowers and fruits. Note that do not prune when the flowers are in full bloom to avoid losing flowers and affecting the fruit set rate.

Pruning techniques

When pruning macadamia trees, cut off small branches, branches that grow close to the base and are not capable of flowering or fruiting. Removing ineffective branches, dry branches, and branches with pests and diseases will reduce competition for nutrients and limit the spread of disease to the tree.

In addition, you should also cut off excess branches, branches that grow too high or branches that grow horizontally and are not effective to help the tree be airy and focus on developing the main branches. Branches that grow crosswise, branches that penetrate the middle of the canopy should also be removed to allow better light and air circulation.

When pruning macadamia trees, you should keep healthy branches that are capable of flowering and fruiting well. Note that you should choose branches that are evenly spaced around the canopy, not too close together. These branches are often healthy and receive adequate light to help the photosynthesis process take place effectively, increasing crop yield.

After pruning

After pruning, you should supplement adequate nutrition to recover and grow well. You can add more organic fertilizer or NPK fertilizer, water enough to support the tree's recovery process. At the same time, check and spray pesticides on the tree to prevent bacteria or pests from entering through the cuts.

Spraying pesticides

When macadamia trees enter the flowering stage, spraying pesticides is very important to prevent pests and protect flowers and young fruits. However, it is necessary to choose the right pesticides and spraying time to ensure safety for the tree and the user.

Common pests during flowering

When macadamia trees enter the flowering stage, they become attractive targets for many types of pests. Timely recognition and prevention of these insects is very important to protect the flowers, increase the ability to set fruit and ensure productivity for the tree. Below are some common pests on macadamia trees during flowering:

• Stem borers: Often appear in humid and high temperature conditions. The worms bore into the tree trunk, creating small holes and tunnels inside, reducing the vitality and growth ability of the tree.

• Mealybugs: Thrive in humid and wooded environments. Mealybugs suck sap from leaves and young branches, causing the tree to weaken, turn yellow and reduce productivity.

• Stink bugs: Usually appear in the dry and hot season. Stink bugs suck sap from flowers and young fruits, causing flowers and fruits to fall, affecting productivity.

• Caterpillars: Thrive in humid conditions and with many leaves. Caterpillars eat leaves and flowers, reducing the photosynthetic capacity and productivity of the tree.

• Brown planthoppers: Usually appear in humid conditions and high temperatures. Brown planthoppers suck sap from leaves and branches, causing leaves to turn yellow and fall early, weakening the tree.

Measures to prevent pests for macadamia trees when flowering

When macadamia trees enter the flowering stage, pest control is extremely important to protect the flowers, increase the ability to set fruit and ensure productivity. Here are some effective measures:

Controlling stem borers

For stem borers, you should choose specialized pesticides such as Chlorpyrifos or Cypermethrin to spray into the borer holes. When spraying, you should spray in the early morning or late afternoon for the best results. At the same time, you should cut off and destroy infected branches to prevent the spread of stem borers. At the same time, you must ensure that the garden is cleaned more often.

Preventing mealybugs

You can use biological pesticides such as mineral oil or neem oil to kill mealybugs. Note that you should spray regularly when the mealybugs are growing strongly. At the same time, you should wash the aphids off the tree with a strong water jet. And this should be done early in the morning to avoid damaging the tree. Besides, you can also nurture and protect natural enemies such as ladybugs and parasitic wasps to control mealybugs naturally.

Preventing stink bugs

Placing light traps in the garden to attract and kill stink bugs is a very effective solution for macadamia garden owners. Light traps work most effectively at night when stink bugs are active. You can also use insecticides such as Imidacloprid or Thiamethoxam to spray in the early morning or late afternoon when stink bugs are most active.

Caterpillar control

The most effective way to deal with caterpillars is to collect them by hand and destroy them. Doing this regularly will reduce the number of caterpillars in the garden. If collecting takes a long time, you can use insecticides derived from the bacteria Bacillus thuringiensis (Bt) to kill caterpillars without harming the environment.

Brown planthopper control

Usually, Anh Duong uses insecticides such as Abamectin or Buprofezin to kill brown planthoppers. In addition, Anh Duong also nurtures and protects natural enemies such as parasitic wasps and ladybugs to control brown planthoppers naturally.

Pollination

Pollination is the process of transferring pollen grains from the stamen to the pistil, which is a decisive factor in the fruit set process of macadamia trees. Supporting pollination for macadamia trees when flowering will help increase fruit set rate and improve productivity.

Enhance cross-pollination

You should raise bees in the macadamia garden. Each hectare of macadamia garden should have 2-3 bee colonies to ensure good pollination. Bees are considered the most effective natural pollinators for macadamia trees.

In addition, you also need to ensure a favorable pollination environment by maintaining moderate humidity, pruning trees to create ventilation, thereby helping wind and bees easily access the flowers. Because dry weather conditions and good light also support more effective pollination.

Planting many different varieties

Cross-pollination between different macadamia varieties helps improve fruit yield and quality. Because genetic diversity helps plants have better resistance to harsh environmental conditions and pests. Different macadamia varieties can use resources such as water, light and nutrients more efficiently. Therefore, planting many macadamia varieties will help minimize economic risks due to market fluctuations or weather conditions.

Environmental factors affecting the flowering process of macadamia trees

The flowering process of macadamia trees is greatly influenced by environmental factors. In order for macadamia trees to flower evenly and achieve high productivity, we need to understand these factors and have appropriate adjustment measures. Let's continue reading Anh Duong's article to see what those factors are!

Light

Macadamia trees need strong light for effective photosynthesis. Light helps the tree synthesize nutrients and grow strongly. Lack of light can reduce the tree's ability to absorb nutrients, leading to weak trees and difficulty in flowering.

In addition, the lighting time during the day also affects the tree's ability to flower. Macadamia trees need at least 6-8 hours of light per day to grow well. If there is a lack of light for a long time, the tree may not flower or flower less.

Temperature

Macadamia trees need a period of low temperature to stimulate flower bud differentiation. Temperatures below 17°C lasting about 4-5 weeks are ideal for flowering. Low temperatures help the tree accumulate energy and prepare for the flowering process.

If the temperature exceeds 25°C, the flowering process will be negatively affected. Because high temperatures can cause the tree to lose water quickly, affecting the photosynthesis and flowering process. The ideal temperature for macadamia trees during the flowering stage is from 15-25°C.

Humidity

High humidity during the flowering stage can cause flowers to fall a lot. This often happens in areas with rainfall lasting from February to April. The ideal humidity for macadamia trees is about 60-70%. Too high or too low humidity can affect the growth and flowering of the tree.

In addition, high humidity during the flowering stage can cause flowers to fall a lot. This often happens in areas with rainfall lasting from February to April. The ideal humidity for macadamia trees is about 60-70%. Too high or too low humidity can affect the growth and flowering of the tree.

Notes when caring for flowering macadamia trees

When the macadamia tree enters the flowering stage, special attention must be paid to ensure that the tree flowers evenly, bears good fruit and has high quality fruit. Here are some important notes:

Monitor the weather

During the flowering stage of the macadamia tree, you need to adjust the care measures to suit the weather conditions. For example, in the dry season, you need to increase watering, and in the rainy season, you need to pay attention to drainage to avoid waterlogging.

Observe the tree

You should regularly check the condition of the macadamia tree when it is flowering to detect early signs of abnormalities such as pests, yellow leaves or uneven growth. This helps to handle it promptly and limit damage.

Consult an expert

If you have difficulty caring for the macadamia tree when it is flowering or are facing a complicated problem, ask for advice from people with experience in growing macadamia trees or experts in the industry to find an effective solution!

FAQ - Some questions related to “how to care for macadamia trees when flowering”

• How to properly care for macadamia trees when entering the flowering stage?

The flowering stage is one of the most important stages in the growth and development of macadamia trees. For the tree to flower evenly, bear many and quality fruits, you need to: Avoid watering too much during this stage because it will reduce the pollination ability of the flowers. Supplement the necessary nutrients for the tree, especially trace elements such as Boron, Zinc, to help increase the ability to pollinate and set fruit. Prune diseased branches, dry branches, and branches that grow too thick to create an airy canopy, helping the tree receive more light. Check the tree regularly to detect pests and diseases early. In case of unfavorable weather or low pollinating bee density, additional pollination can be done by hand.

• What types of fertilizers do flowering macadamia trees need to grow best?

The necessary fertilizers for macadamia trees during the flowering stage are organic fertilizer, NPK fertilizer, and micronutrient fertilizer.

• Should you prune macadamia trees during the flowering stage?

Pruning macadamia trees during the flowering stage is a rather sensitive issue and needs to be carefully considered.

• What should you do when macadamia trees are attacked by pests during flowering?

When macadamia trees are attacked by pests during the flowering stage, you should carefully check the parts of the tree such as leaves, flowers, and young fruits to detect early signs of pests and diseases.

• How often and how much water should you water your macadamia tree when it flowers?

You should water it more often, about 2-3 times a week, especially on hot days.

• What weather conditions affect the flowering process of macadamia trees?

The ideal temperature for macadamia trees to flower is usually between 18-23°C.

• How to increase the fruit set rate for macadamia trees during the flowering period?

To increase the fruit set rate for macadamia trees during the flowering period, you need to combine many factors from nutritional care to technical measures.

• What should you do to make macadamia trees flower evenly and healthily?

To make macadamia trees flower evenly and healthily, you need to combine many factors, from proper care to choosing the right variety.

• Is it necessary to supplement micronutrients or special nutrients for macadamia trees when they flower?

It is absolutely necessary to supplement micronutrients and special nutrients for macadamia trees when they bloom.

• When is the ideal time to fertilize macadamia trees during the flowering stage?

The most ideal time to fertilize macadamia trees during the flowering stage is about 1-2 weeks before the tree blooms.

Through the above sharing, we hope you have mastered how to care for macadamia trees when they bloom. By applying these measures correctly, you will have a lush macadamia garden that produces sweet fruit all year round.