Mango Growing Guide

Mangoes flood the markets every summer with their bright red and yellow colors, full of sweetness and tangy flavors. Mangoes are a huge industry for many countries especially India where many more mango varieties reside. Australian markets are dominated by a select few varieties such as the well renowned R2E2 which is characterized by its large fruit that provides a bountiful amount of yellow sweet flesh, another variety called the Kensington Pride is smaller than the R2E2 but provides greater sweetness and tangy flavors.

Mango is a great plant to grow whether it is for a large scale orchid or from a backyard. you can achieve massive yields from mango trees while at the same time achieving high quality produce which can be incredibly satisfying. Managing a mango tree can be a breeze especially in Western Australia where there is a low pressure from insects and diseases. The nutrition for mango trees is fairly straight forward too, unlike most crops you may come across, fertilizer applications can be made just twice a year with slow release fertilizer/compost. There is more emphasis on keeping track of the hormone balance in the mango trees compared with other crops but this can provide an excellent tool to growers looking to change the ripening of your fruit at particular times of the year.  

Seed, propagating, saplings and grafted trees

You have decided to get into growing a mango tree but selecting how you want to get started comes down to what time, money and priorities you have.

Seed is the cheapest way to get started, but it can also be the slowest, have the highest mortality and can provide a tree with unwanted characteristics since the seed will have the genetics of the mother tree and the pollen from another mango tree. Hybrid mango trees can also provide sterile seed or trees that don't produce fruit very efficiently which can be very disappointing if you have been looking after a plant for over four years. A way you can get around those issues is by sourcing seeds from a certified supplier with a good reputation. However, the sale of mango seeds are very hard to come by because there are more preferred techniques...

Propagating is the preferred technique because taking multiple cuttings from a tree can provide clones of that tree containing the desirable characteristics. This can be the most effective way of reproducing hybrid varieties as well. If you know someone with a mango tree or already own one then you can take cuttings and begin propagating your own mango trees. Propagation can have low success rates so starting with more cuttings than you require is a good idea. The benefits of propagating is getting the desired characteristics of your favorite tree, it is faster than starting from seed and is incredibly cheap.

Saplings/grafted saplings are a small tree that may have been propagated or grown from seed already and has grown to usually a foot tall. These are generally already a couple of years old, have a healthy root and foliage system and may only be a couple of years away from fruiting at most! the price can range depending on the quality and type of mango tree you're demanding, an ordinary sapling that is a Kensington pride should be relatively cheap at $30 AUD per tree while a grafted mango sapling or a newly released hybrid can cost between $60-$120AUD depending on where you are and the supply and demand of the variety. Buying saplings are the fastest ways to getting mangoes when starting out, if buying from a reputable seller that is certified you have a good chance of getting an incredibly healthy plant that is disease free and has highly desirable traits.

Transplanting

like all plants, when removed from a pot and into the ground the plant will go through what is called transplant shock. Depending on what your climate is like, the plant will need varying amount of attention. If you're planting your mango tree and you're expecting some hot weather it may be worthwhile to provide some temporary shade, always ensure a good watering once the tree is first planted.

An important part of transplanting, especially if you're developing your orchard or extending, is to know what the planting density of your orchard will be. The closer you have your trees the more often you will be required to prune them to allow adequate light and airflow through, this means smaller trees. greater density orchards can provide greater yields and are sometimes trellised, this is proof that you can have mango trees in small settings such as a suburban backyard or even on an apartment balcony. Mango trees do perform their best in full sunlight but they have been trialed under shade structures showing that they do perform just as well under lower light conditions but just require less nitrogen fertilizer.

If you're developing an orchard make a map and indicate where problem areas may be, if there is some land that is low, has heavier soil and often gets water pooling through winter then you want to create a mound for your tree to grow from so it doesn't have all of its roots submerged. For incredibly wet areas you may consider a drainage system, storm drains are a great way to seep water out of saturated soils. If you expect high winds from a particular direction then you may consider having your rows go perpendicular to that direction to reduce the loss that may be experienced. on the other hand sun damage may be what youre trying to reduce. Carnarvon often experiences a 3pm burn on their mangoes that are not shaded by foliage, having your rows point in the direction of the 3pm sun is believed to reduce the loss, unfortunately I have not seen data emerge proving this.

Phenological cycle

Mango trees determine their yields mostly from the phenological cycle and their hormone balance as it is so far interpreted. A typical cycle for a mango tree is to go into dormancy through the winter and then begin flowering once temperatures are conducive for flushing. After fruit set their will be an initial fruit drop where the tree will determine the carrying capacity, usually only one or two mangoes per stem end which is why it is important to have as many stem ends as possible, this is also where stress can really damage the yield of the crop. There will be a vegetative flush coinciding with fruit development, it can be beneficial to provide some potassium and nitrogen during this time to assist in the fruit development. Once harvest is completed it is important to prune the orchard as soon as possible to stimulate new growth and to control the size of the trees, this can be done every second or third year in this planting density. The orchard goes back into dormancy once temperatures reduce, this sometimes need to be done with a paclobutrazol treatment to induce dormancy in warmer climates.

This Diagram is designed for Mango growers and will require changes depending where your mango trees along the latitude, the further away from the equator you are the later your flowering and harvest will be. It is important to know that the phenological stages of the mango orchard determine when fertilizing and pruning are to occur and when and for how long the tree goes into dormancy.

Nutrition

Mango trees are not hungry feeders, they can be pushed to make extra yields but the health of the tree, the balance of the soil and the life cycle of the plant take priority and dictate when fertilizer is required. From a 100T crop of mangoes you are only removing roughly 85kg of nitrogen, 130kg of potassium, and 130kg of calcium, so as long as you're applying more than you're removing from the soil there is not a lot that can go wrong. I will go through the timings of the fertilizer application and the quantities on a per tree basis assuming that the tree is relatively large and is spaced from the closest tree in the row by 5 meters and the tree across the interrow is 7 meters, this is a planting density of roughly 285 trees per hectare (10,000 square meters).

In the diagram labelled "Paclobutrazol treatment guide" there are two timing for fertilizing and that is to trigger the onset of flowering and after the completion of harvest. It is important that nitrogen fertilizers are not applied during the winter dormancy period, especially in the warm climates, as this can trigger the shoots to flush new leaves which can prevent flowering from occurring in the coming spring.

The first Fertilizer application is in spring with a balanced NPK + trace fertilizer can assist in triggering a synchronized flowering event in the orchard minimizes the variability in fruit development, this can help reduce the amount of times pickers will be required to go through the orchard to selectively harvest the ready to eat mangoes. When I create fertilizer programs I will usually recommend a slow release granular fertilizer with a microbial coating that can be used by hand on smaller scale farms or by a spreader. The idea behind using slow release fertilizers is to provide the nutrition required for the next four to five months without increasing the salinity of the soil through fertilizers coming through fertigation. The grower also spends less time mixing fertilizer in tanks, no dosing systems required for fertigation, no mistakes can be made as it is a compound, no toxic environments can be created. Put simply, the grower can focus on more pressing jobs such as labor management, moisture monitoring, machinery maintenance etc.

The first application will contain most of the nitrogen and potassium in the fertilizer plan, 80g of N, 20g of P, 100g of K + trace elements per tree, this kind of compound can be easily found or custom made for slow release granular fertilizers, if you're fertigating then you can create your mix in your required nitrogen, potassium and phosphorous into your fertilizer tank and dose from the beginning of flowering to mid fruit development. Extra nitrogen can be required if there are vegetative flushes during fruit development. It is perceived that excess nitrogen causes jelly seed in mangoes, this can be the case, however, a study has found that it is caused by a mixture of environmental stresses and the lack of trace elements, trials found that orchards supplied with supplementary trace element nutrition were found to have less occasions of jelly seed.

The second fertilizer application is immediately after the harvest or just prior to pruning, the reason for this is to induce as much vegetative growth as possible because this will be the stems that will flower and support fruit for the coming harvest. It is important especially since pruning has removed a portion of the stems and this is the only time between pruning and flowering to increase the stem ends available since we do not want any growth occurring during dormancy. At this stage we will want to be aiming for 40g of N, 20g of P, 60g of K + trace elements per tree to encourage the vegetative growth but as you can see there is much less nitrogen as to reduce nitrogen availability going into dormancy.

Mango Tree Hormones

A study by Davenport outlines that the stem ends containing the primary buds are determined to be flowers or leaves depending on the concentration of each of the hormones in the particular stem end. There are two main hormones in the plant that we will focus on and they are gibberellic acid (vegetative promoter) and Auxins (reproductive promoter) and they influence if plants grow leaves or flowers. This is important for mango trees and growers because gibberellic acid will cause shoots to become vegetative and not flower come spring and this can mean a smaller harvest.

How does it work? The above diagram will come useful in explaining how growers can manipulate the hormones in the mango tree as is so far believed to be the case. But first we must know the difference between shoot initiation and induction. Shoot initiation causes the action of growth, when a tree grows either leaves, stems or flowers this is caused by shoot initiation. Induction assigns the shoot initiation whether it should grow as a shoot of leaves, flowers or a mix. Shoot initiation is influenced by factors shown on the diagram such as pruning, defoliation, nitrogen sprays, ethylene (used as a ripening hormone), root growth (cytokinins), soil moisture, and the hormones themselves. From your own experience, you may notice that trees will often send out shoots aggressively if severely pruned because this practice initiates shoots, which is a good thing since without leaves the tree would die. Factors influencing induction can be influenced by the frequency of vegetative growth and cool temperatures but are mainly controlled by the concentration of gibberellic acid and auxin hormones in the stems.

How to influence hormone concentration
To optimize mango production there needs to be low concentrations of gibberellic acid in the stem ends come spring where flowering needs to be maximized to reach potential yields. Gibberellic acid is produced every time there is an event that cause the tree to flush, which we can see in figure 2 the arrows pointing towards shoot initiation. Gibberellic is said to breakdown over time as well so ensuring the no shoot initiation happens for a period prior to when we intend to flower is ideal, the time period is generally 5-6months. By doing this we can ensure that the tree has the best opportunity to flower on each of the stem ends. Other factors that assist in the 5-6 month dormancy is cool weather, mild water stress, lack of nitrogen sources, no pruning including protection from defoliation during storm events. Some growers will still experience issues with this dormancy and may want to adjust the flowering event even further and this can be done with a soil drench with the active constituent called Paclobutrazol, this chemical inhibits the production of the gibberellic acid in the plant and therefore greatly reduce the ability of the tree to have shoot initiation and increase the chances of flowering at more stem ends come flowering. The timing for this application is in autumn or 5-6 months prior to when you want to flower.

Paclobutrazol can be an incredibly useful tool, especially for orchards that are in the tropical areas where the winters are warm and promotes vegetative growth. However, paclobutrazol is known to lose efficacy over time and this is believed to be caused by microbial breakdown in the soil. Every year that paclobutrazol is applied to the soil the microbial population responsible for breaking the chemical down grow until the chemical can no longer effectively enter the plant in large enough quantities to assist in the inhibition of gibberellic acid. Growers have used the product on foliage to varying success but this is not recommended and is not registered on the label.

Pests

Fruit Fly
There is a yellow/black fly with speckled wings that pierces fruit and lays eggs under the surface of nearly ripened fruit. Sometimes called the Mediterranean fruit fly or another species call the Queensland fruit fly, can cause large scale damage to your fruit by feeding, piercing and laying larvae into the fruit. There are numerous baits that you can make yourself, there are sticky traps, pheromones', sprays that are chemical or organic. Fruit fly can be a nuisance and like weeds requires constant attention. Organic crop protection (OCP) have some useful traps and products that I find very effective when it comes to controlling fruit fly.

Grubs
Caterpillars in high numbers can cause a lot of damage to the foliage but I have not seen this cause any yield penalties, however, this was during post-harvest and did not directly affect the fruit. Grubs during flowering, fruit set, development and ripening would be a good indicator to take action whether that be a chemical option which there are plenty of in the market or an organic option such as BT (Dipel) or spray oil.

Scale
A common pest found in most orchards as either pink wax scale or mango scale. In small numbers they do not cause a lot of damage but if left unchecked will cause damage to the fruit by leaving marks etc. Managing scale can be done through the use of chemical sprays or organic spray oils but more often than not it can be a good sign that you need to prune your trees and let me light and air through which can manage the populations effectively.

Mealybug
management very similar to scale where signs of mealybug is an indicator to think about pruning your tree to allow light through. Chemical and organic spray oils are available also and left unchecked will cause damage to the skin of the fruit. However, mealybugs can produce honeydew, a sticky sweet substance, and will attract sooty mold into the tree where it will cover foliage and fruit. Together the disease and pest can cause yield penalties.

Locusts
Large swarms are what cause damage to yields, in post harvest settings they are not too much of a worry but from flowering to harvest can cause the tree to stress and drop a lot of fruit. Locusts during dormancy may cause shoot initiation as well and change the balance of hormones in the tree. There are chemical options available and organic spray oils which can be used to kill the locusts or act as an anti feed.

Diseases

Anthracnose
This disease mostly affects the fruit quality during fruit development and post-harvest. Anthracnose is a fungal disease called colletotrichum gloeosporioides and spreads itself with spores through wind and rain, usually only within an orchard or neighboring orchards. Anthracnose on fruit and leaves are dark brown/black spots which results in rotting in the fruit and in severe cases causes die off of stems and branches. The disease is most commonly controlled using copper sprays from the end of flowering to harvest to prevent infection of the fruit. Pruning of infected plant parts and removal from the orchard is also a management strategy to reduce the inoculum available to produce spores.

That is my knowledge and experience of mango production, I now live in the southwest of Australia but I know they grow well in Perth so I think I will try and grow a tree or two and see how they perform since they're normally tropical thriving! The trees love moisture and can perform extremely well in sandy soils as well as heavy clays. Fertilizers are not extremely key to a good mango crop but it can go a far way if you're chasing big fruit and plenty on the tree.

There are plenty of varieties out there to choose from, going to grocery store to find which ones you prefer can be a great starting point otherwise you can go to your local nursery and select a few different varieties to get a lengthy harvest period. Like all plant, mango trees will require care at the start but once the roots have established then are very hardy plants and can survive in areas with only 300mm a year! But any added moisture will go a long way.

I hope with this growing guide you can fulfill your ambitions to grow your very own mango tree in your backyard or solve a few problems occurring in your orchard. Mango trees are relatively straight forward and with regular biannual maintenance can produce bountiful fruit that you can share amongst your family and friends.

Happy Growing!