Kangkong grown by hydroponics technology inside a greenhouse
You may grow your vegetable kangkong in a snap solution
You can ensure that you are growing pesticide-free kangkong if you grew it by the hydroponics technology. You may enclose your hydroponics garden with screen. Hydroponics gardening is also an encouragement to do exercise; to refresh your eyes; and to pull you away for a respite from your computer.
Several experts have seen the importance of vegetables in the diet. Nutritionists advocate vegetable consumption in daily meals. Food service entrepreneurs include vegetables in different menu offerings. Agriculturists develop technologies to improve crop production for higher yields and provide food for the growing population.
Vegetables can be grown in different production systems. They can be grown in soil amended with organic or inorganic fertilizers. In places where land space and soil are inadequate, the hydroponics system is an appropriate alternative.
Hydroponics is a means to grow plants in the absence of soil. This is based on the idea that plants do not require any secret ingredients from the soil; all they need to flourish are inorganic nutrients, water, and aeration. In this system, roots are watered with a well-aerated water solution in a constant manner. The solution contains optimal amounts of the required mineral nutrients (Nebel, B.J, Wright R.T. 2000: Environmental Science. United States of America. 2000).
The nutrient solution gives the vegetables a near-optimal supply of mineral nutrients. The preferable pH level of 5.5 – 6.0 is maintained by adding sulfuric acid especially if the pH level of the solution rises above 7.8. (pH is a measure of acidity.)
The initial level of the solution is set at about 2 cm above the base of the perforated cups. To ensure successful germination or transplanting, the medium is kept moist. As capillary rises and evaporation occurs, the solution level drops slowly at first. As roots develop and take up solution to satisfy the transpiration demand of the plants, the solution level drops faster. Many roots remain in the air space between the support structure and the surface of the solution. The solution does not need to be aerated because the aerial roots and the roots floating on the solution surface provide oxygen for normal root function.
Replenishment of the solution is not needed. The initial depth of greater than 20 cm of solution is sufficient to satisfy transpiration demand over the growth period. Replenishment of the solution is done periodically but without covering the aerial roots. Some 5 cm of solution is added when the level of solution drops to about 20 cm below the base of the media receptacle. Very little solution is discarded even if it is almost entirely taken. Checking the solution level can be done with the use of a dip stick or a simple depth-measuring device. At least 10 cm of solution should remain at the base of the container. Shoot growth will not suffer even if the mean solution does not rise above 28 cm.
Formulated snap solution
This snap solution was formulated by the Institute of Plant Breeding of the College of Agriculture of the University of the Philippines Los Baños, located in Los Baños, Laguna, Philippines. I am a graduate of this university. Snap solution is as follows:
Snap solution A: pH at 6.4; nitrogen at 0.02%; P2O5 gives phosphorus at 0.13%; K2O gives potassium at 0.04%; calcium at 0.06%; magnesium at 0.01%. Mix these ingredients in one solution of one liter tap water.
Snap solution B: SO4 gives sulfur at 0.28 ppm; iron at 63 ppm; zinc at 19 ppm; copper (trace); and manganese at 19 ppm. Ppm means parts per million. Like in solution A, mix these ingredients in one solution of one liter tap water.
The growing medium consists of 10 liters tap water added with 75 milliliter (mL) of solution A and 75 mL of solution B. Pour this medium into one hole or container where one kangkong seedling is grown. You may pour all 10 liters at once or stagger pouring according to the capacity of the container.
You might find it difficult to formulate the snap solution. In its place, you may use Murashige and Skoog solution which is readily available in gardening stores.
The kangkong plant
Kangkong (Ipomoea aquatica Forssk., also Ipomoea reptans Poir) is the upland variety of swamp cabbage (Ipomoeia aquatica) also known as water glorybind, water spinach, water convolvulus, and swamp cabbage, morning glory (as it is listed in some restaurant menus). It is an important green leafy vegetable in Southeast Asia, Taiwan, and Malaysia. It is grown and consumed even in Hong Kong, Southern China, and Papua New Guinea. The other names for Ipomoeia aquatica are kankon (Japanese), ung choi (Cantonese Chinese), toongsin tsai (Mandarin Chinese), ong choy, ungtsai, tung choy (China), kang kong (Filipino, Malaysian), kang kung, rau muong (Vietnamese), pak bung (Thai).
Kangkong is cultivated as a green vegetable in some Asian countries and by Asian Americans in the United States.
Kangkong has two forms: upland (dry) and swamp (wet). The plant has slick surfaced leaves which are arrowhead-shaped, 5-6 inches long, narrow, and pointed. It is a trailing hollow vine with alternate leaves and vertical branches arising at the leaf axils. The succulent foliage is light green in color. It produces a white flower, followed by a four-seeded pod. There are also narrow and broadleaf types (Stephens, J.M. 2003. Kangkong -- Ipomoea aquatica Forsk., also Ipomoea reptans Poir. Professor, Horticultural Sciences Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611. http://edis.ifas.ufl.edu/MV085)
Nutrients and medicinal values
Kangkong is a vegetable that is rich in iron (as shown in its blackish liquid once cooked), beta carotene (precursor of vitamin A), vitamins C and B (folic acid). Beta-carotene neutralizes singlet oxygen, a free radical; vitamins C is an antioxidant; folic acid is involved in the production of new DNA of new cells. Derived from the nutrients in the snap solution, your hydroponics kangkong has traces of: magnesium (impulse transmitter; maintains the calcium/magnesium pump, an action potential that makes the cell live); potassium (also part of the sodium/potassium pump that makes the cell live); calcium (part of the calcium/magnesium pump; an impulse transmitter; part of bones and teeth); phosphorus (a component of adenosine triphosphate, ATP, the energy unit for the cells and all body parts); sulfur (component of the enzyme antioxidant glutathione peroxidase and reductase that dismantle the reactive oxygen species hydrogen peroxide into safe water); iron (part of hemoglobin that carries oxygen in the blood; part of the cytochrome system in the production of energy); zinc (part of the glutathione system and part of the superoxide dismutase, or SOD, particularly CuZn/SOD that protects the mitochondria -- the energy factory, a built-in enzyme antioxidant that dismantles the free radical superoxide; concentrated in the prostate gland and protects against prostate cancer); copper (component of SOD, particularly CuZn/SOD); manganese (also part of SOD, particularly Mn/SOD).
SOD is the enzyme antioxidant largely responsible for the survival of man against the superoxide produced during the production of energy. Enzyme means it can be recycled. Superoxide is derived from the air we breathe which is molecular oxygen, two atoms of oxygen joined together with two unpaired electrons. During the metabolism of glucose, one of the oxygen atoms goes to a molecule of water, the other turns into a superoxide which is a free radical with one unpaired electron. SOD converts superoxide to hydrogen peroxide which glutathione peroxidase dismantles to safe water. Glutathione reductase recycles glutathione peroxidase, ready to neutralize another superoxide. Glutathione synthase manufactures glutathione consisting of glutamate, cystine, cysteine, and co-factors selenium, zinc, lipoic acid, and vitamin B-2. Without SOD and the glutathione enzyme system, woman/man would be sick of progeria who dies of old age when only a teenager based on calendar age (Cranton, E., MD. and A. Brecher. Bypassing Bypass. 1984). In a way, your hydroponics kangkong is a supplement that protects you against free radicals.
Free radicals and reactive oxygen species cause diseases like heart disease, angina, arrhythmia, stroke, diabetes, arthritis, osteoporosis, tumor, cancer, Alzheimer's disease, psoriasis, emphysema, lupus, cataract, glaucoma, diabetic retinopathy, hypertension, multiple sclerosis, rheumatic heart, and many more.
Germination and transplanting
Kangkong seeds are scattered uniformly and thinly in a sowing tray filled with about four inches thick garden soil and watered using ground water. After seven days, prick the seedlings and place them in a seedling tray containing garden soil. Transplant seedlings in styropropylene growing boxes 14 days after pricking (see picture). You may enclose you garden with screen to keep off pests.
Fill the cups (seedling plugs) such that the nutrient solution touches the bottom to at least, ½ inch deep. Replenish solution on the 19th day when the level is more than 1 inch below the cup bottom. Don’t allow the solution to again reach the bottom of the cup. Replenishment is done until the solution level reaches about ½ inch below the cup bottom.
You may start harvesting your hydroponic kangkong in 21 days.
You may harvest again when the side shoots had grown long enough. You may also grow cuttings from your present garden for your next batch of hydroponics kangkong.
Materials in hydroponics gardening
conradofontanilla (author) from Philippines on June 28, 2012:
Rhed e-mailed me but my reply has not reached her yet, asking for a substitute for snap solution. Murashige and Skoog (MS) solution is also fine for hydroponics; it looks like it is made in the US but marketed worldwide so that it may be available in gardening stores.
In my Hub on how to grow hydroponics lettuce I mentioned MS. Enjoy your hydroponics.
conradofontanilla (author) from Philippines on July 08, 2011:
The literature says kangkong can be grown in the United States. So I guess it can be grown in Australia. Are you fond of lettuce?
Lord Sergell of House Stark from Darwin, Australia on July 08, 2011:
Looks nice! Very informative hub. I hope kangkong grows in our country. :) Voted up and useful!
Following you now, follow me too! :D