CHOOSING SEEDS AND GROWING SEEDLINGS
The grower can buy at research centres
either selected seeds of good quality
He sows the seeds in a nursery bed or in baskets. Later, he plants out the seedlings in the plantation.
or young seedlings of good quality
He plants them straight away in the plantation.
But some growers have no research centre nearby.
They can nevertheless have good cocoa plantations by:
choosing their own seeds,
sowing their seeds in a nursery bed,
planting out their seedlings in the plantation.
Nursery bed is the name for the place where the seeds are sown to make them germinate.
If you want to have fine cocoa trees which produce a lot of big pods, you must choose carefully the seeds you are going to sow.
If you choose your own seeds:
choose the biggest pods from the trees which bear a lot of fruit.
The good quality of the tree and of the seed enters into the new plant, which will also yield many big pods.
The best seeds for sowing are those from the middle of the pod.
Sow the seeds as you remove them from the pod.
Never keep the pods more than one week, otherwise the germ may die.
If the germ is dead, the plant will not grow.
In some countries cocoa seeds are often sown directly in the plantation, that is, where the trees are to grow.
But this is a bad way of sowing, for many of the plants will not grow, and you cannot choose the best seedlings.
Take the best beans from the middle of the pod
SOWING SEEDS IN NURSERY BEDS OR IN BASKETS
A good grower should sow cocoa seeds in nursery beds:
Choose a small plot, quite flat, with light and rich soil.
If the site is near a little stream, watering will be easier.
Till the soil fairly deeply, and break up all the lumps of earth so that you get a fine tilth.
Make beds of soil 120 centimetres wide:
Leave a little path of 60 centimetres between one bed and the next, so that you can walk between the beds.
Take a piece of string and mark out little furrows in each bed.
Leave 25 centimetres between one furrow and the next.
In each furrow, leave 25 centimetres between seeds.
Do not push the seed in too deeply, otherwise it will not have enough air and will not grow well.
Nursery bed for cocoa tree seedlings
Cocoa seeds can also be sown En baskets or bags.
When the seedlings are lifted from the nursery bed, the roots may break and little earth remains around the roots.
To avoid this, water the beds before lifting the seedlings.
Sometimes the young seedlings do not grow well and do not gain much height.
Some of them die.
To make the cocoa trees grow better, sow your seeds in small baskets or polyethylene bags.
These baskets or bags can be about 30 centimetres high and 20 centimetres wide.
Fill them with fine soil mixed with manure.
Put the baskets or bags in rows and leave a little path between the rows.
Young cocoa tree in a basket
You should take good care of the seedlings In seed beds or baskets.
Young cocoa tree seedlings are very delicate;
you must protect them from the sun.
Put them in the shade.
In order to protect the seed beds or the baskets from the sun put up a screen 180 centimetres high above each bed.
You can cover this screen with palm fronds.
Young seedlings need a lot of water.
Water them every day.
Remove the weeds which take nourishment away from the seedlings.
Look for insects and kill them, pull out diseased plants and burn them.
Cocoa seed bed under a screen
LIFTING SEEDLINGS FROM NURSERY BEDS
Six months after sowing, when the seedlings have two leaves, take the young cocoa tree seedlings out of the nursery beds.
If you wait too long, the seedlings will be too old and will not grow so easily.
Remove the seedlings from the nursery beds with a spade.
Be very careful not to break the roots.
Sort out the young cocoa seedlings.
Throw away diseased seedlings and badly grown seedlings.
Use only the healthiest seedlings.
If you have sown your seeds in baskets, place the baskets in holes dug in the plantation.
There is no need to remove the basket, as it will rot in the earth.
If you have sown your seeds in polyethylene bags, remove the bag.
Place the ball of earth with the seedling into the hole.
The Cocoa tree bears fruit on its trunk and branches. They are called pods.The pods contain seeds which are called cocoa beans. The beans are made up of a seed coat, a kernel and a germ. Cocoa needs a high temperature, plenty of water and air that is always moist. Therefore, cocoa is grown in the hot and humid regions of Africa (mainly in forest regions), Central and South America, Asia and Oceania.
The secret of the world’s largest seed revealed
(Image: John Brown)
The coco de mer palm of the Seychelles is the stuff of legend. Its seeds – the largest and heaviest in the world – were once believed to grow on trees beneath the waves of the Indian Ocean, and to hold great healing powers. Even when it later turned out that the palm grows on dry land, new folklore emerged: To produce this seed, the male and female plants embrace each other on a stormy night, or so a local story goes.
The legends may be just that, but the palm still has unique appeal. “The coco de mer is the only charismatic plant that can rival the giant panda or the tiger,” says Stephen Blackmore at the Royal Botanic Garden Edinburgh, UK. Now the science behind the charismatic palm’s seeds is proving to be just as fascinating.
So how does a plant that grows in poor quality soil on just two islands produce record-breaking seeds that reach half a metre in diameter and can weigh in at around 25 kilograms?
To find out, Christopher Kaiser-Bunbury at the Technical University of Darmstadt in Germany and his colleagues analysed leaf, trunk, flower and nut samples taken from coco de mer palms (Lodoicea maldivica) living on the island of Praslin.
They found that the leaves have only about one-third of the nitrogen and phosphorus concentrations seen in the leaves of other trees and shrubs growing on the Seychelles. Also, before old leaves are shed, the palm efficiently withdraws most of the nutrients from them and recycles them. Investing so little into the foliage means the palm has more to invest in its fruit.
But that’s not the only way the foliage helps fuel fruit growth. The huge, pleated leaves are remarkably effective at funnelling water down the trunk during rain showers. Kaiser-Bunbury and his colleagues showed that this stream of water also picks up any nutrient-rich detritus on the leaves – dead flowers, pollen, bird faeces and more – and washes it down into the soil immediately around the base of the palm. Consequently, the nitrogen and phosphorus concentrations in the soil 20 centimetres from the trunk were at least 50 per cent higher than in the soil just 2 metres away.
Blackmore has seen first-hand how efficiently the leaves channel water – better than some gutters on local buildings, he says. “But to think about it in terms not just of water flow but of nutrients was a very significant leap of thinking and adds much to the understanding of this amazing tree,” Blackmore adds.
Hans Lambers at the University of Western Australia in Crawley, who studies the way plant species have adapted to incredibly low phosphorus levels in soil in south-western Australia, says the nutrient-channelling leaves of the coco de mer are an “entirely different strategy”.
The discovery is linked to another remarkable thing about the palm: it seems to be unique in the plant kingdom in caring for the seedlings after they germinate.
Many trees have evolved seeds that travel – on the wind or in the gut of an animal – so that seedlings don’t compete with their parent for the same resources. Stranded on two islands and unable to float, coco de mer seeds usually don’t travel very far.
But the researchers found that the seedlings benefit from growing in the shadow of the parent, because they have access to the more nutritious soil there.
“This is exactly what fascinated my colleagues and me most about Lodoicea,” says Kaiser-Bunbury. “We do not know of another [plant] species that does this.”
This still doesn’t explain why the seeds are so large. According to one theory, we have to go back to the dying days of the dinosaurs for an explanation. About 66 million years ago, the ancestral form of the palm probably relied on animals to disperse its relatively large seeds – but it perhaps lost this mechanism when the sliver of continental crust that includes the Seychelles broke away from what is now India, isolating the palm.
This meant the seedlings had to adapt to growing in the gloomy shadows of their parents. Because the large seeds contained a good supply of nutrients, the seedlings were already well equipped to do so, and eventually outcompeted most of the other tree species in the ecosystem: to this day, coco de mer palms are the dominant species in their forests.
Under the unusual conditions of forests dominated by a single species, sibling competition – rather than competition between species – drove evolution, says Kaiser-Bunbury. This meant the palm gradually grew larger and larger seeds to provide seedlings with an even bigger reserve of nutrients to boost chances of surviving against its cousins.
Kevin Burns at the Victoria University of Wellington, New Zealand, studies the way that plants evolve on isolated islands, like the Seychelles, and says that the coco de mer seems to follow a general evolutionary pattern. “Plants tend to evolve large seeds after they colonise isolated islands, and island plant species often have much larger seeds than their mainland relatives,” he says. “Big seeds generally house more competitive seedlings.”
The coco de mer palm hasn’t yielded all of its secrets yet, though. Exactly how the female flowers – the largest of any palm – are pollinated remains a mystery. Blackmore suspects bees are involved, but other researchers think lizards might transfer pollen from the male trees’ 1.5-metre-long, phallic-looking catkins. Local legend, meanwhile, suggests that male trees actually tear themselves from the ground on stormy evenings and lock in a passionate carnal embrace with females. It’s the kind of story that adds to the allure of the palm.
Charismatic coco de mer palm trees of Seychelles seem to be unique among plants in caring for their seedlings with a novel use of leaves