# Killies Import > Planted Tanks >  Questions on how nurseries grow aquatic plants

## timebomb

Someone who lurks in this forum sent me a set of questions which, for the life of me, I don't know how to answer. Maybe one of you can answer her questions or some of them. She must be thinking that I own Oriental or something  :Laughing: . Anyway, here they are:

_* Which substrate is used? I have heard about rockwool and cultiwool but I do not know if there are more kinds.
* Which is the normal plant density?. I guess it will be different depending on the plant but how is it approximately? Is it better to plant very dense to avoid algae problems?
* Are emerged and submerged plants grown in a different way? I have read that normally all are grown emerged. If that is the case, are there any problems of acclimatisation after selling them?
* Do they need artificial light? And extra heating? If for example the greenhouse is settled in Israel, would they need artificial light and/or heating?
* How is the CO2 management done? Is the CO2 supplied in the air or with the water of irrigation?. If the plants are submerged, is there enough O2 for their respiration in the water counting only on the O2 that they produce?
* How are the plants transported to the shops? Do they need to be wet? How is it achieved?
* Do the plants need a hardening period before selling them in order to help them in adaptation outside the greenhouse?
* Can they be grown all year around or just some periods of the year? Do they have a long life? In the case they are only grown in some periods of the year, is the greenhouse empty in those periods or can you plant other plants?
* Are the running costs and the investment very high? Is it a profitable business or are the cost higher than the benefits?. Is there a market for the plants or is it very difficult to make clients?
* Are there any techniques used to move the plants along the greenhouse to facilitate the labour work?
* How is the culture management done? Do the plants need pruning or guiding form time to time like other crops? Do they need special care in some periods?
* How are the plants fertilised? Is it mixed with the irrigation water? Or is solid fertiliser used? If fertirrigation is used, are there, in consequence, problems with algae?
* How is the irrigation done (sprinklers, drippers)? And if the plants are submerged, how is the waterr management done? How often is it changed? How is the fertiliser used in that case?
* Are the plants propagated at your nursery using mother plants or do you buy the starting material? If that is the case, do you buy material from tissue culture, seeds or seedlings from other nurseries?
* How is the management of the algae and weeds done? Do you use herbicides? And the pest and diseases management? Are chemicals used or is it possible to use natural enemies? Which are the main pest and diseases in the crops? Are there also important physiological disorders?
* Which are the main difficulties in the cultivation of aquatic plants? Which is the most sensitive period for the crop?_

Tough, aren't they? Elisa, I will try and answer those I know when I have more time.

Loh K L

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## budak

I will try to answer some questions quickly before sleep overcomes me.... (it's way past my bedtime!)

I think the potted plants are enclosed in rockwool, while those planted in the ground enjoy a mix clayish and gravelly substrate (the kind found everywhere in the tropics). 

Plant density appears to be high for non-potted plants, but it's no surprise given the optimum growth conditions. I am not sure how they tackle algae, but since most plants are emmersed, it isn't an issue. The submersed plants appear to be relatively algae-free. No signs of BBA. 

Some plant species do not have emerged forms, so must be grown underwater. I don't think farms try to acclimitise emerged growth forms into underwater forms before selling them.... the hobbyist can easily do that. 

Sunlight is sufficient and free.... the temperature is 25-33C throughout the year. I think in Israel, heating and lighting may need to be supplemented in the winter months. 

No CO2 system is visible. I think the outdoor tanks/vats for submerged plants are large enough such that natural CO2 diffusion is sufficient for the plants. They are essentially similar to natural ponds. I think the water used for irrigation is fairly nutrient rich. 

Plants are shipped dry (actually damp) in plastic bags (with no standing water). This keeps them light (for shipping) and prevents rot. I don't think the plants are "hardened". They are flown directly to the destination country and sent to shops. 

I don't know about the financial aspects of farms. My guess is that the owners prefer to keep this private. 

zzzzzzz

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## timebomb

Elisa,

Wool is used for holding plants whilst they are in transit. They are not used for growing them. In fact, hobbyists usually remove all the wool before putting the plants into our substrate. In the plant farms, their substrate consists mainly of clay. I think they mix into the clay some sort of fertiliser, probably chicken poo or cow dung. Certain cement ponds in the farms can stink to high heaven  :Laughing:  when they are processing the substrate. 

As Budak has pointed out, algae appears only when the plants are grown submersed. In the farms, few plants are grown submersed as its much cheaper and easier to grow them emersed. Algae scares the plant farmers as much as they scare us hobbyists so for those cement tanks that have plants growing submersed and sparsely, more shade is provided. Here's a picture showing how the tank growing Java Moss is shaded. 



As you can see from the picture, a black netting is used to cover the tank to cut down on the sunlight to prevent algae from growing. In tanks where stem plants are grown submersed, the density is so high there's no room for algae to appear. Here's a pic of _Hygrophila polysperma_ being grown submersed in high densities. If you have to know the exact density, you have to count it yourself  :Laughing: .



Some plants like Crypts are known to melt if they are transferred in emersed forms into fish tanks but generally, there's little problem with acclimatisation from emersed to submersed conditions. As far as farms are concerned, it isn't their problem anyway  :Laughing: .

When we were in Oriental, we saw many overhead sprinklers which are used to water the plants. The sprinklers are rigged to timers which are adjusted according to weather conditions. On rainy days, the sprinklers are switched off. Irrigation is through pipes and drain holes. 

Oriental told me they have to deal with pests which sometimes infect their Echinodorus. But I guess that only happens when the plants are grown emersed. The pest, in particular is a Nematode, some sort of parastic roundworm. 

Plants are transported in plastic bags, sealed and put into either card or styrofoam boxes, depending on where they are shipped to. If they are shipped to cold countries, styrofoam boxes are used. To hot countries, they use card boxes which keeps the plants cool. There's very little water in the plastic bags as plants travel better in dry conditions. Water is the element that causes plants to rot during transit. 

As for your final question on the difficulties plant farmers face in the cultivation of aquatic plants, I would imagine cultivating them isn't a problem; selling them is.  :Laughing: 

Loh K L

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## timebomb

> Are the running costs and the investment very high? Is it a profitable business or are the cost higher than the benefits?. Is there a market for the plants or is it very difficult to make clients?


I missed this question just now.

Elisa, we're not sure of the costs but I would imagine the capital outllay would be enormous. Building the cement tanks and rigging everything up to run smoothly would cost a lot of money, probably in the region of millions of dollars. Running costs must be high too as Oriental has shifted most of their labour and land intensive work to countries like China.

However, I'm quite sure it's a profitable business as Oriental has been around for something like more than 30 years. We didn't see any Rolls Royce or fancy cars parked in the farm though  :Laughing:  so maybe the profits aren't that high. 

As for market potential, I would say its huge. But that's just from my point of view as a hobbyist. I gathered this from the responses to my Oriental post in this forum. The number of hobbyists who would give their right arms in exchange for rare aquatic plants are many  :Laughing: . 

Generally, finding clients isn't a problem for the farms. The problem is finding the right ones. Non-payment after goods have been shipped is quite a common occurence, if you know what I mean :smile:.

Loh K L

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## FC

Elisa,

* Are emerged and submerged plants grown in a different way? I have read that normally all are grown emerged. If that is the case, are there any problems of acclimatisation after selling them?
- Emerged aquatic plants are much stronger than submerged ones and the success rate to grow them in the aquarium is often higher too.

* Do they need artificial light? And extra heating? If for example the greenhouse is settled in Israel, would they need artificial light and/or heating?
- Artificial light or heating depends alot on the plant and if the country of propagation has 4 seasons or not. That's if you have short days in winter, you may need artificial light and heating to compensate the short days and cold.

* Are the running costs and the investment very high? Is it a profitable business or are the cost higher than the benefits?. Is there a market for the plants or is it very difficult to make clients?
- Let me put it this way, it is a very high yield products if you compare them to vegetables. Tropica finds customers all over the world, so, it's about product quality, packaging and marketing.

* Are there any techniques used to move the plants along the greenhouse to facilitate the labour work? 
- Not here in Singapore I guess. Simple motorised light conveyor belt would come neat, I think.

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