The Coconut palm (Cocos nucifera) is a tree that lies in the palm variation also known as Arecaceae. This crop is viewed as one of the most important in the tropical regions. The tree has a slender trunk that is usually ringed and grows to about 80 feet (25 meters). It has a swollen base and huger leaves that seem to be like giant feathers. The fruits once mature takes up an oval or ellipsoid form and are between 300-450 meters in length and a diameter of 150-200 millimeters. The single seed nut is surrounded by a fibrous husk with a challenging shelling around the embryo, together with the endosperm which has each flesh and liquid.
The coconut fruits are known to have floating characteristics and this makes them follow ocean currents hence spreading throughout the tropics. It is believed that they probably trace their origin to Indo-Malaya islands. They were first described by Marco Polo among other Europeans.
The coconut palm trees do well in areas close to the sea or any other low-lying regions that are just close enough to high waters as long as there is sufficient ground water in circulation and adequate rainfall to aid their survival. The main productions of coconut are traceable to small scale native farms. Only husked ripe nuts are required for propagation. They are normally covered by soil on most part and laid next to the nursery beds and at a reasonably side. The seedlings stay on their nursery bed for about 4 to 10 months before being transferred to the plantation. There are normally planted with a distance of about 8 to 10 meters from each other. This are fruits that require patience because the take about five to six years to mature and begin bearing fruits. However, they are normally fully grown to complete maturity after fifteen years of care. The fruits get ripe within one year while the fruits grow to between 50 and 100 feet in length. The tree continues to be productive for up to about when they are 50 years old.
Once the coconuts are harvested, they yield copra which is the dried and extracted kernel normally used to produce coconut oil. This is the bi product of the mostly used coconut cooking oil. Looking at the world, Indonesia and Philippines are the world leaders of copra and in the regions of Southern Pacific this is their most important product. The coconut meat has more uses such as making of coconut milk once grated and mixed with water. This product may be used to substitute dairy milk.
Coconuts are most commonly used in the western countries which are more industrialized, but at the same time are very much significant to their native people who grow them. For instance, the people of in Indonesia believe that it has very many uses. Apart from the flesh eaten and the drink, the husks are also used to make ropes and other products including baskets, brushes, mats and brooms among others.
The roots of palm trees are very adventurous and are normally found extending about 40 centimeters from the trunk. The swollen part from which they originate is called the bole in most of the tall types and a few dwarf hybrids as well. Coconut trees have a taproot, root hairs as well as many primary roots with many rootlets. The main root normally grows horizontally out of the bole not too far from the ground but the main branches from this root may extent for up to about ten meters. The roots do not have cambium and therefore are clearly alike. The diameter of the main roots normally ranges about one centimeter which the tip actively growing and having the absorption area that absorbs water and other important components of growth. The epidemis is composed on one layer thin walled cells which over time become thick and impervious. When they age, the epidermis normally disintegrates leaving the hard hypodermis and red in color.
The surrounding of the root center is composed of a single cell pericycle sheath which delivers the rootlets and aerenchymatous protuberances or pneumatophores. The respiration exchange normally happens closer to the ground surface so as to facilitate easier diffusion of oxygen in then carbon dioxide out of the root.
The stem of coconut tree develops from the single terminal but often known as the cabbage. It is the only vegetative growing point of the tree. The full development of the base of the trunk takes about 3 to 4 years to mature, given than the conditions are favorable. The base can grow up to about 0.8 meters in diameter in the tall types and tappers quickly to about 0.4 meters (Child 1974). The trunk rarely changes in width once it has been fully formed and in most cases any changes that occur from the base to the crown may be attributed to non-biological factors such as the prevailing climatic conditions.
The stem grows faster in its initial stages and this means that it is impossible to rebuild up if some tissues are damaged. A mature palm however can have up to 18,000 vascular bundles responsible for helping the tree to withstand physical damage to the trunk significantly as long as there is not pest entry through the open area damaged. The initial leaves of a palm tree seedling exhibit leaves that are pinnae fused together appearing as full leaves. Once between 8 and 10 leaves are formed, the follow up ones split into leaflets. At about 3 to 4 years the stem begins growing with a single terminal growing point and this is where the new leaves now develop from. Every year, the palm tree develops about 12 to 16 new leaves and each one of them bears a flower cluster also known as inflorescence with the total leave count totaling to about 30 or 40 per tree. The same number reflects on the leaf primordial and each takes up to 30n months before emerging into a sword leaf. The length of a mature palm leaf is 3 to 4 with about 200 to 250 leaflets each. A leaf stays attached to the palm for three years after which it is shed and the tree is left with a permanent scar.
The method used to determine the age of a coconut tree is by counting the number of fallen leaf scars. The formula is that the number of the scars divided by 13 gives the approximate age of the coconut tree in years. (Mahindapala, 1991). The importance of using this applies in estimating the adult tree for the purposes of breeding. The palm tree is monoecious because it carries both the male and the female flowers hence do not rely on pollination from another plant to bear fruits. The two are arranged in a way that the male flowers ate ion the top while the female ones are on the bottom for an easy pollination.
The detection of the inflorescence premordium occurs roughly four months following the first leaf primordium differentiation, that is, both the male and female flowers, 22 months afterwards. After one year is when the opening of the first fully grown spathe occurs.
The flowers open first a process that starts from the top of each spikelet then goes on towards the base and once each flower has opened, pollen grains shed from the male flower and abscise within just one day. The male phase takes approximately twenty days in most of the palms although carination occurs based on season and variety.
The female flower on the other hand may still continue to receive pollen grains for up to three days and this varies on the environmental conditions. Once the spathe has opened, the female phase may begin just a few after and usually last for about three to five in tall palms but more days in dwarfs. Dwarfs may have it for about 8-15 days. Normal inflorescences may have between ten and fifteen female flowers. Assuming that the pollination is naturally occurring, about 50 to 70 percent of the flowers end up falling off and this normally is motivated by dry season and during severe weather. The surviving flowers would take up to a year to develop and mature.
Climatic environment is a major factor responsible for the length of the male as well as the female phases. They however rarely overlap and this reduces the chances of self-pollination. The Malayan Dwarf for instance experiences something different, in the sense that the overlapping of both the male and female phases promotes selfing and this makes them reasonably homozygous.
After the pollination which leads to fertilization, the fruits grow and mature within one year or less for some particular dwarf cultivars. Estimating the yield may be done by counting the bunch and fruit set.
The fruits are normally a fibrous drupe but he skin is normally smooth on the outside. The color varies from green to brown or reddish brown and even ivory in some cases. The skin is also called the exocarp and the coat the mesocarp and the latter in a young coconuts and is normally white in color and firm in texture. The mature and ripe coconut exhibits a fibrous mass, the husk which gives the coir. The mass holds the nut with a hard shell which encloses the kernel. There is a thin brown seed coat called testa between the shell and the kernel which sticks to the kernel firmly. The kernel once again is the white flesh about 12 millimeters thick and lining the central cavity which contains the nut water inside it. When maturity is approaching, the water in the nut decreases as a result of absorption into the endospermic tissue and in other cases as a result of evaporation. This leads to a sloshing water sound when shaken for matured nuts. The estimation of yield is done but the number of nuts produced per each perm or unit area and weight equivalent copra. The coconut may be attacked by insects whose presence may be seen in terms of their damage, but it is also prone to diseases which may not be visible until they steadily manifest in the plant. This leads to the limitation of harbors any helpful countermeasures to avert the situation.
The lethal yellowing disease is the generally known most common coconut disease and takes up different names in other parts of the world including Africa for instance. It does not affect the plan until its first flowering but it is normally listen in this chapter due to convenience purposes. The symptoms of this disease include premature fruit drop from the tree, blackening of the newly emerged presence. Yellowing occurs first and the eventual death occurs next. The cycle may take up to one year from six months.
This disease called Lethal yellowing was recognized in Jamaica in the twentieth century. Later, after scientific procedures, it was found to be caused by a pathogen characterized as mycoplasma. It sis more complex than a virus but ;lacks the cell development of a bacterium meaning that it is literally between the two in both size and complexity, leaf hoppers are the most responsible for transmission. There leaf hoppers are also somehow related to this transmitting foliar decay though there may be a possibility of other vectors. In the past fifty years, the spread of the disease is alarmingly complex; it reached the Central America and the Caribbean up to to the ornamental coconut palms in southern Florida as well as date palms in Texas. This does not end here is it goes all the way to Jamaica, although they have resulted to planting some dwarfs thought to be partially resistant. Some other exceptions are the hybrids between dwarfs and some promising Tall such as the Panama Tall. In West Africa and some part of east Africa, there have been reports of a disease similar to the Lethal yellowing. It is also dominant in southern India and most recently in Indonesia. An observation suggests that there is a connection between the expression of Lethal yellowing symptoms and the stress of extreme weather. The symptoms are mostly seen during the dry season and sometimes after severe flooding such as the ones with hurricanes.
There is uncertainty concerning the resistance of some coconut varieties that appears tolerant against the Lethal yellowing disease and also the ability of the pathogens to spread from a high infection area to areas with no initial history of the disease. There is need for a long term research on the matter to come up with proper recommendation about this and especially in locations such as West Africa, Florida, Jamaica and Mexico. Conducting molecular insights on the forms of the mycoplasma around the world is in the process and this is carried out parallel with the tolerance research in some palm coconut varieties.
The mature fruit weighs about 0.6 to 3 kilograms and varies between different palm breeds. It is larger on Talls and smaller in dwarfs and also varies ion the load on the bunch. Each tree bears fruits that are identical in color and shape and may only vary in size if a bunch has more than one fruit.
The fruits weight is big enough to cause serious injury to a human if it falls on one or any other creature. The more mature the fruit the more likely is will be released if the tree is shaken although they also do fall on their own especially when the wind has been low for a while. This is due to the fact that they slowly continue to lose the grip till the weight cannot be supported anymore. When a rat feeds on an immature fruit it will definitely fall off. If the hust is high in moisture, it makes the fruit heavy and dangerous as well because it may fall anytime. However, natives rarely suffer from injury by a falling coconut because they know very well to be careful when under the trees. In tourist resorts, this risk is even higher because the tourists will most probably have not prior experience to this and therefore may bot take the caution to avoid injury from a falling palm coconut fruit.