Silvicultural aspects and management

The propagation of E. edulis is done by seeds. The degree of fruit ripeness in the bunch is heterogeneous and can be distinguished by its colour. The best fruits can be harvested from the palms of middle age.

Collection and seed storage

Fruit collection should be realized when the fruits pass from green to violet colour until they reach the point of high maturity when the pericarp is black or purple (LIN 1988). The extraction of seeds is done by washing and maceration of the fruit on a sieve to remove the pulp involving the seeds. The seeds of E. edulis have, in their stage of physiological maturity, a high content of moisture (50 to 55%), complicating its storage for different reasons. To eliminate the moisture excess, seeds should be deposited into sieves and dried in a ventilated ambiance for two or three days. In room environments seeds keep their partial viability for six months, in cold storage in tightly closed plastic bags for eleven months (T = 5 to 10 C and RH = high) (AMBIENTE BRASIL, s/d).

Ripe (right) and unripe (left) fruits of E. edulis

Breaking of the dormancy

E. edulis has a hypogeous germination (seed remains in the soil), being slow because the fruits of this palm have a certain period of dormancy (LIN 1988). Recently collected seeds germinate 3 to 8 weeks after planting with rates of 60 to 94% and lose quickly their capacity of germination if dehydrated. Since satisfying storage is difficult the planting of seeds as soon as possible after collection is recommended. Even if the need of pre-germ treatments is questionable, the following are recommended to accelerate germination:

  • Immersion in cold water for 48 hours
  • Storage in moist sand for 30 days
  • Mechanical scarification (detaching the integument) (DAVIDE et al. 1995).  

Seedling production

For the production of seedlings, it is recommended to sow two to three previously skinned seeds in a container or the direct sowing in the field, sown in holes of 5 cm in depth. For the sowing a substrate of river sand should be used which always should be kept wet. Germination starts up between 30 and 170 days.
Transplantation should be done one to three weeks after germination, or after the appearance of leaves. The total time of nursery is at least 9 months.
Since E. edulis is a species whose basic requirements are the shaded ambiances and high moisture of soil and air, planting in full sun is not viable. Seedlings with up to 3 years do not tolerate excessive shade or direct sun (AMBIENTE BRASIL, s/d).
The control of competitive herbs after planting is important and must be done through periodic clearings around the plant, taking care not to damage their surface roots (AMBIENTE BRASIL, s/d). In natural conditions, until the exhaustion of seed reserves (about 6 months), the appearance of a clearing is essential for their survival and the appearance of new individuals.

Mixed plantation with E. edulis and banana

The growth of E. edulis is limited by the low amount of Photosynthetically Available Radiation (PAR) that reaches the ground of the forest. However the species presents capacity of acclimation to the increase as to the decline of PAR and may well establish itself in environments with up to 70% of the amount of PAR in open canopy or at least 20% of direct sunlight (PAULILO 2000). Plants in plantations that receive large amounts of light reach the reproductive age between the seventh and tenth year (MANTOVANI & MORELLATO 2000). Under natural regeneration conditions mortality lies above 80%, higher until 10 cm in height and almost zero when the plants reach heights of 50 to 130 cm (CONTE et al. 2000).

Pests and diseases

E. edulis is susceptible to the attack of the fungi Diplodia sp. and Triclariopsis sp.. Both cause small lesions in the plant and are easily controlled with fungicides (AMBIENTE BRASIL, s/d).
The most damaging insect is the beetle Rhyncochorus sp. The adult deposits eggs at the base of the sheet of E. edulis and the larva develops feeding on the internal leaves, until it reaches the apical meristem, killing the plant (AMBIENTE BRASIL, s/d). E. edulis can also be infested by the beetle family Scolytidae, with light damage.

Monoculture of E. edulis in which palmheart was harvested

Monoculture of E. edulis with relative old plants

Fruits which can be used for propagation

Seeds for planting

Hypogeous germination of E. edulis

Some months old seedling

Seedling production of E. edulis

Plant seedlings ready for planting