(continuation of article: Aeroponic System on Vegetables)

Lukas Setyo Agung

Cultivation process on aeroponic vegetables is more or less the same as conventional method, i.e. seedling - planting - controlling and maintaining - harvesting. The only difference is only in fertilizers irrigation systems and the impact of it.

Let’s start from the beginning, i.e. seedling process. The seedling process is started with preparation of seedling media, i.e. rockwool. Why rockwool?
 

The following are some reasons why we use rockwool as the media:

1. Rockwool has very good absorbability character to absorb water, therefore it does not require watering during transit in the dark room.
2. Rockwool is soft and easy to arrange in the tray. It’s also easy to deploy the plants in styrofoam if the media is rockwoll because we can insert it tightly in the perforated styrofoam.
3. Rockwool will be included when the vegetables are marketed because rockwool is safe and does not contain a harmful substance. In this case, we don’t need to remove rockwool after the vegetables harvested.
   
   The following is the seedling sequence:
    

Figure-1 Rockwool cutting for planting media

Rockwool cut according to tray size, marked with a guide line to ease seeds arrangement in the tray.
A piece of rockwool contains about 30 seeds or 300 seeds per tray.

Figutre-2a Seedling process

When a worker does seedling, the seeds are arranged one by one by using a tweezers (because seeds are very small in size). The seeds are put in the rockwool but cannot be too deeply bedded because it can impact to the germination process. Don’t also just lay the seeds on the rockwool without insertion because it can easily disappear.

Figutre-2b Seedling using tweezers

Figure-3 Dipping the seeds after seedling process into the clean water

After the seedling process completed, the tray dipped in the clean water to absorb water, then drained for awhile till no dripping water.

Figure-4 Dark room to let germination process run perfectly
 

Put the tray in the dark room for incubation process for 2 – 3 days. After the seeds sprouted, take the tray out of the dark room then put it in the room with normal temperature for several hours prior to placing in nursery room.
 

In principle, placing the plants in nursery room has to be in right time where temperature is not too hot (preferable in afternoon).

The following tasks are done in nursery area:

1. Arrange the rockwools with a proper distance with other rockwools.
2. Setup nutrition/fertilizers according to seeds characteristic and age.
3. Monitor the seeds performance and growth every day.
4. Keep the seeds in nursery area till 10 – 12 days when the baby plants are ready to be deployed in production area.

Figure-5 Seeds are placed in the nursery area

The baby plants that considered in good performance and healthy are the ones that ready for moving to production area. The following tasks are done in production area:

1. Prepare planting boxes
2. Plant the baby plants taken from nursery area
3. Setup and maintain fertilizers
4. Control pest and diseases as well as its micro climate.

The planting box is a box made from fiberglass with size: Length=400cm, Wide=100cm, and Height=50cm. Since the fiberglass material is quite expensive, we can use a plastic with certain thickness to substitute fiberglass box, as long as it is setup till we get the same function as fiberglass box.

On top of the planting box, lay the Styrofoam in proper way to maintain position firmness. The styrofoam normally prepared in certain size: Length=100cm, Wide=100cm, and Thickness=2cm, with a high or medium density. The styrofoam is perforated with 1cm diameter hole where each styrofoam consist of 36 holes (6x6) or 49 holes (7x7).

Figure-6 A fiberglass box

The planting box and styrofoam has to be clean before used. The ideal time to prepare the planting box and styrofoam is in the morning.

In afternoon, baby plants deployment to production area is ideal. It’s because of less of sun shine intensity to prevent stressful towards the baby plants. When a worker brings the baby plants and moves from nursery area to production area, it’s not allowed to stack the baby plants in order to avoid broken and damaged plants because of crush injury among the plants.

The baby plants that deserve for moving to production area are the healthy and free pest and diseases plants, not etiolated, size between 10-12cm with normal colors according to the rightful characteristic of the plants.

The baby plants are inserted in the holes of rockwool, one hole for one plant. The plants have to be able to stand uprightly against the rockwool and styrofoam.

Figure-7 The perforated styrofoam for the plants growing during the production

The most important thing during maintenance of the plants is ensuring nutrition/fertilizers that needed by the plants are works well. The common fertilizers is AB Mix Solution where the ingredients composition can be learned from many references. The fertilizers setting and formula is applied according to the related plants. In dry season, the fertilizers concentration is less than it’s applied in rainy season.

In aeroponic systems, the plants are fed through the mist spraying periodically, for instance 10 minutes on, 3 minutes off. The mist is derived from spraying process through a nozzle which has been installed in each fiberglass box. In aeroponic, a clogged nozzle can be harmful to the plants because it prevents feeding and makes the plants withered very soon. The roots also have to be hung down properly to guarantee normal growth.

In the systems, electricity is very crucial because the irrigation systems relies-on working pumps to flow the fertilizers to entire plants.

Figure-8 Mist spraying process to feed the plants through its roots

The mixed and formulated fertilizers in the tank is not allowed for direct contact with sun shine, particularly the Fe (iron) substance because of its sensitiveness.

Although cultivation in green house theoretically will guarantee the quality of production from pest and diseases attacks, however, since the Indonesian climate is very conducive for pest and diseases/pathogen reproduction, the threat of production failure caused by the diseases is still possible, moreover if the workers are loose in control the plants including in-disciplinary behavior while opening/closing the green house’s door.

Several threat that possible to attack the plants in green house are:

1. Pest: larve, maggot, locust, trips, bugs, rat
2. Pathogen: fungus/mildew, bacteria, virus

The threat can be eliminated with:

1. Reduce the earlier population of pest and pathogen
2. Mitigate the speediness of pest/diseases reproduction

Below are several jobs to eliminate the threat:

1. Sanitation
2. Regular and tight monitoring in green house
3. Throw the infected plants out of green house

To get the maximum result, understanding the micro-climate of each plant is very essential. This is including regular checking of temperature, humidity, sun shine intensity and air circulation within the green houses.

--17 March 2009--