Wednesday, February 17, 2016

The Backyard as Laboratory and Workshop Series 2: Of allelopathy, dynamic balance, albinism

Do plants fight and kill each other? To what extent can fish grow big in a small pond? Is albinism necessary or just fancy? 
 Dr Abe V Rotor
Living with Nature School on Blog [ ]
Paaralang Bayan sa Himpapawid with Ms Melly C Tenorio
738 DZRB AM Band, 8 to 9 evening class, Monday to Friday

"Please come to my science laboratory at home," I invited my couple friends,"and bring along your daughter who is going to take up biology."

When they arrived that Sunday morning, they expected a four-wall laboratory, complete with test tubes and chemicals, and paraphernalia that only school laboratories have. I have very few of these.

I have a compound microscope, a working table, and space for a small workshop. It's he vacant part of our lot where I observe Nature everyday.

Here are some observations I made.

1. Allelopathic effect of oregano (Origanum vulgare).
Local cultivar of thyme (Thymus sp), a culinary herb, is grown in pots side by side with oregano (right). The middle plant is acutely affected, showing at first stunting, and ultimately growth failure, whereas the thyme at far left is virtually unaffected.

What are the implications of this observation?

 1. Oregano planted close to garden crops will cause stunting and even death of the later, as shown in this setup.

2. Never plant oregano at the base of tree trunks, especially saplings.  A guyabano tree at home simply succumbed to the allelopathic effect of oregano grown at its base.

3. Never use organo as a practical pest control by crushing its leaves and mixing it with sprinkling water. Another plant that should be avoided is eucalyptus.

4. Oregano belongs to the family of mayana.  Even mayana cultivars have strong allelopathic effects among themselves,so that a plot of mixed mayana cultivars planted for their beautiful variations, cannot last long.

One beneficial effect, other than its medicinal property and culinary value, is that the presence of oregano in the garden helps in repelling insects and other vermin. Just don't get it too close to plants.

Here are two cultivars of organo.  Left, Cuban oregano (sometimes referred to as Italian) is used in pizza and other recipes.  Right, the common oregano (O. vulgare) which is used as home remedy for cough, sore throat and fever.  It is also used in cooking dinuguan. Try using oregano leaves in kitchen cabinet to ward off insects, especially cockroach.

NOTE:  Allelopathy is expressed in different ways.  An acacia tree will not allow its own offspring to grow and compete with the mother tree.  The seeds - plenty of them - may germinate, but only those that are at safe distance from direct competition may succeed. Nature has provided ways by which the acacia seeds are disseminated: goats eat the ripe pods, so with other animals, and water carries the dry pods during flood. The same principle applies to date palms in the desert, otherwise direct competition where resources are limited is detrimental to the species.

2. Raising fish in a limited pond - a  lesson in dynamic balance.
These pako fish are now five years old. Out of 12 fingerlings, eight survived, each weighing today around two kilos. How they obtain adequate nourishment is simply by providing them daily ration of dog food pellets which float. Now this is important because you know when feeding stops.  Food that is not immediately consumed will decompose and cause buildup of CO2, and other gases like H2S and NH3. My guests commented, "It's amazing to see such big fish in a small pond, what is your secret?"

I too, am surprised on how these fish have survived to this size and for this long.  There is no assurance how much more they grow. It is an experiment, I must say. But there are rules I have followed which I wish to share. 

1. A small aerator circulates the water and sends it to a sponge filter that is cleaned daily.
Another aerator sends water simulating a spring which spills over an old grindstone, in the process the water is cooled and oxygenated by the algae growing on the stone.The top of the stone is depressed so that detritus is trapped and later collected for disposal.

2. Large stones - ordinary and limestone - placed at the bottom of the pond where sunlight is available serve as pasture of algae. Pako fish are omnivorus: they eat meat (dog food), vegetables (kangkong ), fruits (banana) - and algal crust.

3. Janitor fish that grew up with the fish became their faithful companion, cleaning the bottom and sides of the pond, and on food droppings. They are nature's janitors, hence their name.

4. Dripping water from a faucet disguised as natural spring replaces water lost through evaporation. At times the dripping is increased to freshen up the pond.  Be sure the drainage is well maintained to prevent flooding.  The pond may need once a year thorough cleaning, but this is done when the water gets foul.  

5. Potted plants help keep the environment cool, and seepage which is inevitable when watering. send soil nutrients to the pond which helps fertilize the algae and some aquatic plants. These soil nutrients are NPK, other major and trace elements.  

6. Lastly keep the pond away fro direct rain.  Acid rain may ruin your entire effort
and hobby. Build a fiberglass roof, but allow free air circulation.

7. Avoid causing stress to the fish. Talk to them nicely. Feeding time may be chaotic, spread the pellets evenly.

8. Brownout is a real problem. This is what you can do.  There's a battery-operated aerator but you need a lot of them for the size of this pond. If there's none and the brownout continues. Get a pail and do the aerating yourself. Do it gently. Notice the color of the fish going back to normal, from pale to dark gray with red fintips restored.   

  Paint a mural around your fish pond and make the area a place for recreation and meditation. The sound of spring, and waterfall, occasional splashing - and even guttural sound the fish make, plus pipe-in music of the great masters,especially Mozart, you will feel you have brought Nature into your home.~
3. Albinism - The books tell us of nature committing error.  She forgets to  send the pigments to the next generation.  Result: pigmentless offspring, we call albino. Hence, there are white elephants, rhinos, boas, carabaos, and many living organisms, plants and protists included.  And of course man.  
Here are albino Oscar fish. I was looking for fingerlings of the beautiful Oscar with black and gold and red patterns.

"Sorry, sir.  Nabili na po lahat.  Only these are left." 

It was getting dark and the pet shop was about to close.  What will I do with albino Oscars?  
"Ten pesos each na lang."  That's a bargain. Real Oscar are expensive.

I handed 100 pesos. She gave me ten, then said. "Sir, kunin na ho ninyo ang lahat."  

She gave me the remaining three in the aquarium. Free!  

Here are my albino Oscars today, four years after.  Guess what? 

If the white elephant is beautiful, the white rhino rare, my Oscars are also beautiful and rare. Children in the neighborhood come and I have just a few explanation to make, pointing out that it is a beautiful error.  Being pigmentless is Nature's way of culling members of the population so that the error will not spread out so as to endanger the species. Organisms without pigments die under the sun. And yet my albino Oscar need the sun to brighten their gold and orange patterns. Maybe it's time to look deeper into albinism. 

My guests spent the whole day with us at home. We had pinakbet, cooked the Ilocano way, ar-arusip (seaweeds),buko (young coconut for drinks) -  and inihaw na isda (broiled fish).

"No the fish did not come from the garden pond."  I assured them. ~

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