Cycas revoluta it is a gymnosperm species belonging to the Cycadaceae family. Contrary to what many people think, this plant does not belong to the group of palm trees. It is commonly known as cica, cycas, sago palm, Japan sago. In turn, in Japan it is often referred to as king sago palm or sotetsu.
It is a slow-growing, perennial, palm-like plant with a longevity of more than 200 years. It has a medium-thick cylindrical stem, leaves arranged in a rosette, pinnately compound and odd-pinnate, about 50 to 150 cm long, leathery and sharp..
Being a dioecious plant, it presents its sexual structures in separate plants. The male structures produce cones or strobili in their center and look like a pineapple, while the female structure forms a set of ovaries that, after fertilization, produce large yellow-orange seeds..
This plant produces a substance called cicasin that is toxic to both animals and humans. The ingestion of cyca produces vomiting, weakness, diarrhea, failure or liver toxicity that triggers jaundice, ascites and cirrhosis.
Its main use is as an ornamental, it has great commercial value, and the seeds are generally exported from Japan. Despite its toxicity, in some parts of the world they consume parts of this plant, and use its extracts to prepare alcoholic beverages and gums.
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Cycas revoluta It is an arborescent, perennial plant, whose appearance is very similar to that of a palm or small palm tree. This species corresponds to a dioecious plant with underground stems that are covered with the basal part of old leaves..
The stem is cylindrical, measuring about 20 cm in diameter and up to about 6-7 m in height. The plant requires at least 50 years of growth to reach that height.
The leaves are pinnately compound and odd-pinnate. This characteristic is what differentiates the Cycas from other gymnosperms. The leaves are 50 to 150 cm long, stiff, sharp and leathery in texture..
The set of leaves is grouped forming a rosette at the apex of the stem, they are arranged in an opposite way, they present pubescence in juvenile age, and when they mature they lose their trichomes.
In addition, the leaves are dark green with a glossy appearance, forming a crown about 50 cm to 2 m long. The leaf margins have an abaxial curvature, which is distinguished as a vernacion revoluta.
Plant Cycas revoluta is a dioecious species, this indicates that the male and female reproductive structures are separated into different individuals.
Likewise, the reproductive structures are located in the apical area of the stem and are known as strobili. The male strobilus is called the microstrobile, while the female strobile is called the megastrobilus..
The structures produced in these cones or strobili are hairy. The male plant has a pineapple-like structure in its center, and the female plant forms a set of ovaries that, after fertilization, produce large yellow-orange seeds..
-Kingdom: Plantae
-Phylum: Tracheophyta
-Class: Cycadopsida
-Order: Cycadales
-Family: Cycadaceae
-Gender: Cycas
-Species: Cycas revoluta Thunb.
Some synonyms for this plant are: Cycas miquelii, Cycas revoluta var. brevifrons, Cycas revoluta var. planifolia, Cycas revoluta var. proliferates, Cycas revoluta var. revoluta, Cycas revoluta var. robust, Epicycas miquelii.
This plant grows well in loamy soils, with slight acidity, but very rich in organic content and mineral elements. It grows in semi-shady conditions. It resists the cold seasons, but without strong frosts, and it develops well in temperate climates.
It is a species distributed mainly in China and Japan. It is also found in countries such as Bolivia, Colombia, Costa Rica, El Salvador, Guatemala, Honduras, Panama, Venezuela, among others..
An interesting fact is that in the roots of these plants a symbiosis is formed between them and cyanobacteria Anabaena cycadae Y Nostoc sp. This symbiosis allows the fixation of molecular nitrogen through the nitrogenase enzyme present in these prokaryotes..
This plant produces a substance called cicasin that is toxic (lethal) to both animals and humans. Ingestion of cyca, particularly by domestic animals, produces vomiting, weakness, diarrhea, liver failure or toxicity that triggers jaundice, ascites and cirrhosis..
The seeds of cycas contain the highest presence of cycasin. These seeds are the basis of a drink called doku sake (poisonous shake), which produces certain violent effects in people who drink it, and can even cause death.
On the other hand, the use of leaves, especially young shoots can cause toxic effects such as rheumatism. Other toxic substances are beta-methylamino L-alanine, an amino acid that behaves as neurotoxic, in addition to another unidentified toxin that causes paralysis in cows.
Mainly, this species is used as an ornamental for both gardens and public areas, and also as bonsai. It is considered the most commercialized cyca species worldwide. Especially in Japan they are used for ceremonies or funerals.
In addition to its commercial exploitation, in Panama for example, the internal part of the stem is used as food. In India it is used industrially to extract "sago", a substance that contains a lot of starch and serves to thicken sauces..
The seeds or nuts of Cycas revoluta they are also used as food in Sri Lanka, India and Indonesia. These seeds contain about 13% crude protein and about 70% starch..
In other parts of the world, the stem of this plant is part of the restaurant menu. Sago extract is used to prepare alcoholic beverages and to make gums. These products are prepared from the exudates of the female reproductive structures.
Cycas are propagated through seeds. To do this, they must be submerged in water and discarded those that float, since this indicates that the embryo is not developed. Viable seeds are then treated with nematicides to protect them during germination..
For germination, a wet bed composed of sawdust must be prepared and the seeds distributed on them. Afterwards, it must be watered and foliar fertilized for optimal development during the seedling phase (6 months to 1 year)..
In the same way, this species can also reproduce by means of suckers, which are carefully removed as they emerge on the sides of the mother plant. This form is used less frequently, since it is difficult to standardize the size of the suckers to be sown in the field and that the plants do not show differences in growth..
Another way is from bulbs, which allow it to be propagated at any age and kept in a pot. For its part, the form of propagation in vitro has not given good results yet.
It is recommended to water abundantly in the seedbed stage, since cycas have a high water requirement at this stage. This is because the seed requires high humidity to induce the germination process..
Likewise, when sowing from the bulb, it should be done in a fairly humid medium so that the sprout begins to develop..
In the field transplant stage, irrigation can be reduced only to that provided by rainwater.
Fertilizing is often done for cycas as for palms. For this, it is recommended to use controlled release or slow release fertilizers, which are normally used in long-cycle crops..
Subscribing can be done with NPK formula 18-6-8, during the early growth phases.
At the time of the growth of the crowns of the leaves, a fertilization with the formula 24-7-8 NPK can be applied quarterly, as well as some microelements.
The fertilization must take into account that a high application of nitrogen is not necessary since the symbiosis that it carries out with cyanobacteria, allows the plant to obtain this macroelement from said association; but the application of magnesium in a foliar or edaphic form is recommended.
It is a scale, a hemiptera that attacks cycas in all parts of the world. It is known as the Cycad Aulacaspis Scale (CAS). Produces chlorotic spots on the leaves.
This scale is surrounded by a waxy covering that covers the plant and its roots. The leaves dry out, turn brown and later the plant dies.
Systemic insecticides containing imidaclopyr and thiamethoxam are used to control this scale. Another form of control is using the agricultural oil in a foliar way to prevent the scale from adhering to the leaves..
It can also be controlled biologically by insects Cocobius fulvus, Y Cybocephalus binotatus.
It corresponds to a virus that only affects gymnosperms. It belongs to the Nepovirus, subgroup b, family Comoviridae.
Produces necrosis and malformation in new leaves. This virus is transmitted by seeds, through nematodes and asexual spread..
There is a series of pathogenic microorganisms associated with the lesions of the disease known as chasparria in cycas. These pathogens are Colletotrichum proteae, Fusarium sp., Pestalotiopsis foedans, Nigrospora sphaerica, as well as some species of Sclerotium.
This disease produces necrosis in the leaves, and loss of color in the leaflets. It is a very contagious disease at any stage of development. Chemical, physical and cultural control is recommended to treat this disease.
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