JOM SOKONG BLOG

KLIK SAYA...

Tuesday, March 29, 2011

Propogation of Selected Herbs

Herbs are one important crops in Malaysia today as the new potential economic source. In my opinion there are four basic methods of propagating plants especially on herbs. They are growing them from seed, making root divisions, making cuttings, and layering. To be successful with any of these methods, it is wise to begin by observing the properties and the growth habit of the plant you want to propagate. The more you know about a plant's habits, the easier it will be to propagate it. Tnis article I would like to share my knowledge in some propogation techniques for selected herbs practiced in Malaysia based on my own experience and refeerence from 3 books and website.






1) GROWING FROM SEED


Plant seeds are prodigious, long-lived, and very energetic. In nature, seeds are propelled out of plants by the force of seedpods bursting. They are carried on the hair of animals or in the bellies of birds or by the wind for long distances, seeking a new home. Some seeds can be planted almost as soon as they are harvested from their parent fruit. Other seeds go through a period of dormancy before they become viable and ready to germinate. Some seeds need to be stratified in order to ripen and become viable. Stratification provides the cold temperatures that the seeds would ordinarily experience in nature over a winter dormant period. Seeds that require stratification must be cleaned, soaked for between 24 and 49 hours, packed in a moist medium such as sawdust or sphagnum, and refrigerated for from one to four months, depending on the species.

Some seeds have even more elaborate dormancy requirements and need not just a period of cold temperature, but alternating periods of warm, cold, and warm temperatures. A third type of dormancy is provided by a very hard seed coat, which is impermeable to moisture until it is scarified, or nicked. Some horticulturists use a small file to scratch the seed coat or drop this type of seed into simmering (not boiling) water to soften it. Even seeds that do not actually need soaking to germinate can benefit from a little soaking in lukewarm water. It livens them and prepares them for germination. Most seeds germinate best in a neutral, porous soil medium. (A few plants, such as rhododendron, like acid soil for germination, but these are definitely the exception.) Materials such as sand, vermiculite (expanded mica), perlite ( a volcanic product), peat moss (from swamps), sphagnum moss (from bogs), crushed granite, and sterilized soil are used in germination mediums. The medium should be light, but substantial enough to allow the seedlings to grow erect, with their roots held firmly. One good starting medium is mixed of equal parts of sphagnum moss and crushed granite. (Sphagnum moss is a favorite material for starting mixes, because it is very resistant to the fungus responsible for damping off in seeds and cuttings. ) Seeds should be sown in rows at least 1 inch apart. Here is a general rule for determining how deep to plant: generally, the depth to which a seed is planted is equal to its vertical dimension.

Water the growing medium well before planting the seeds. Place the flat in a warm place, preferably around 70°F. Seeds need to be misted several times a day until they germinate. When they do, inspect the seedlings carefully for any signs of damping-off fungus. If plants appear damaged, separate them out carefully and destroy them. Biodynamic gardeners spray chamomile tea, which has been steeped a day or more, on germinating plants to prevent damping off. The spray should be applied in a mist like manner to avoid damaging the tender growth. The main perils in germinating seeds, aside from development of the damping-off fungus, are letting the medium dry out and not keeping the temperature warm enough. If you are careful to avoid these conditions, you should be able to help nature produce many healthy seedlings. Biodynamic gardeners give their seeds baths in special herbally based preparations. According to proponents of the system, spraying seeds with weak solutions of the various biodynamic compost preparations speeds germination of healthy plants and inhibits development of fungal diseases. Biodynamic gardeners also advocate use of rainwater in watering seeds and seedlings. This is because rain, as it falls through the air, picks up trace amounts of nitrogen. The biodynamic experts say that seedlings can assimilate this nitrogen readily, and that it strengthens the newly sprouting plants.

The use of rainwater, however, would not be a good idea where there is a lot of pollution nearby or in the direction of prevailing winds. Biodynamic gardeners plant their seeds by the moon. They point out that subterranean moisture rises in the soil during the two weeks of the moon's waxing. At the full moon, the greatest amount of moisture is brought up in the soil by the gravitational pull of the moon. Seeds that take a long time to germinate are planted at the full moon, and for seven days after it. Seeds that germinate quickly, and also those that take a very long time to germinate, are planted two days before the new moon, and up to seven days after it. After plants germinate and have produced several leaves, the seedlings are ready for transplanting into small pots. If you decide to transplant into flats, be sure to space the seedlings at least 1 1/4 inches apart. Take care to handle these tiny plants carefully, without damaging the stem or new roots. A good potting soil can be made with equal parts of compost, sharp sand, and loamy topsoil. Let the seedlings grow in the pots for several more weeks to allow the new plants to extend their root system and produce new leaves. Then they are ready to enter their permanent bed.


2) DIVISION


Herbaceous (nonwoody) perennials are often propagated by crown division, in which a clump of plants is divided into smaller clumps and replanted. Crown division is often done in fall when the plants die back. But some plants are divided in early spring, before the season's new growth really gets underway. Dig up plants to be divided very carefully, and brush away the soil clinging to the roots so you can see what you're doing. Then pull the plants apart if they separate easily, or cut down through the top growth with a sharp spade or knife to divide the clump of plants into several smaller clumps. Hyssop, mugwort, oregano, and tarragon are all best divided by cutting the crowns apart with a knife. Onions, garlic, mints, and German chamomile can be separated with a spading fork after the plants are dug up. When you are dividing plants, be careful to do as little damage to the roots as possible. Separate the divided roots carefully, and make sure each root has a shoot or stem attached. Replant the clumps and water them thoroughly. If you are dividing in fall, mulch the replanted clumps to protect the roots over the winter. For plants that are more tender or that have long taproots, root division is the propagation method of choice. Root divisions are made by cutting the root into pieces, each of which has a bud from which new roots and shoots can grow. Root division can also involve separating offsets from an underground bulb, corm, or tuber.



3) CUTTINGS

There are a number of different types of cuttings: softwood cuttings, hardwood cuttings, stem, root, leaf, and leaf and bud cuttings. In order for cuttings to prosper, they must be taken from healthy plants at the correct time of year, set carefully into a good rooting medium, and kept moist and warm until they root. Hardwood cuttings are the exception. They are usually made from the current year's growth of deciduous trees after the leaves have fallen. Making hardwood cuttings is a good way to create enough plants for hedges and windbreaks. The cuttings should be 6 to 8 inches long with three or four nodes, the topmost one about an inch from the top of the cutting. Bundle the cuttings together, bury them in slightly moist sand, and refrigerate them at about 50°F for a month. Then keep them at a colder temperature, just above freezing, until the spring thaw. After the last spring frost, the cuttings should be planted in a trench with only the top bud showing.



Water them regularly and watch them carefully until they sprout. Don't leave your hardwood cuttings in the refrigerator too long or they might sprout before you get them planted. Softwood cuttings, also known as greenwood cuttings, can be made from most plants, including those with hard wood. This type of cutting is made from the new growth of vigorous deciduous plants. The plant stem used as a cutting should break with a snap when bent. If it crushes between the fingers, it's too young. If it merely bends, it is too old. Softwood cuttings are made in late spring or early summer. The timing varies with the plant, and the best way to tell if the plant is old enough to withstand cutting, but still young enough to yield a good cutting, is to test the stem this way. Cuttings can vary between 2 and 6 inches in length. Make the cut at a 45-degree angle about 1/2 inch from a node to sever the cutting.

Generally, softwood cuttings are taken from ends of branches (they are then called terminal cuttings). As soon as the cutting is made, wrap the bottom of it in a moist paper towel or cloth and place the cutting in a plastic bag. Then, discard most of the leaves after carefully looking at the form of the cutting. Too many leaves will lessen the cutting's chances of rooting. When you are ready to plant, remove the cloth and set the cutting into a bed of sand or fine gravel that is moist. Be sure that it is able to stand erect, and that it is well supported by the rooting medium. Cuttings taken in the late spring or early summer should be well rooted by autumn. If the cuttings are from winter-hardy plants, they can be set out to harden and left to spend their first winter outside after having been transplanted into a medium made of equal amounts of sharp sand and topsoil, enriched with a small amount of compost. But if your rooted cuttings are in pots or containers, watch them carefully during cold spells-the soil in containers freezes sooner than your garden does.


4) LAYERING

Layering is a conservative way of making a new plant from an existing plant. It is most often used to propagate shrubs that are difficult to root. Unlike cuttings, in which the plant part is separated from its parent, in layering, a branch is encouraged to set roots by being bent down into the soil and held in place there, sometimes by means of a weight such as a rock. Layering has the advantage of being a very secure way of propagating a plant without injury to either parent or child. But layering also takes longer than rooting cuttings. Layering should be done in the spring before the buds open on your chosen plant. Choose a good strong branch that is long and flexible enough to bend to the ground easily.

Actually bend it down to the ground and mark the place where the new roots will set. Then, carefully cut the bark from a small section of the branch where it will be buried in the soil. Be certain you do not injure the cambium layer beneath the bark layer during this process. Add some peat moss, sphagnum, and sand to the soil where you will set the branch down to grow roots. Then hold the layered branch in place in the soil, either with a small rock or a forked stick. A thin branch can be held down with hairpins. Some gardeners prefer to effect their layering by building up a small mound of dirt around the branch. Be sure the tip of the branch you are layering protrudes from the soil; it should not be buried. Sometimes gardeners hold up the tip of the branch by bracing it or tying it against a stake. The layered branch will be ready to dig up the following spring. To take up the new plant, carefully unearth it to preserve its new root system and cut the branch just below the new roots. Then plant it as you would any new cutting. This is called simple layering. There is also another type of layering, called tip layering. It is a faster method of propagating in which the tip of a branch is buried in the spring. The new plant can be taken up and separated in the fall.

I hope this article able to add our knowledge about plant propogation selected crops. Seed industry for food crop in Malaysia amounted about RM 30 million exclusive for paddy seed production. Most vegetable seeds are imported from China, Indonesia, Taiwan, Thailand and few other countries. Seedling for tropical fruit about 85% produced locally. The melon and watermelon seeds are 100% imported from outside as hybrid seeds amountung for RM 4.5 million annually. Malaysia has to increase their seeds production program in future to ensure the food security and fod quaility mantained at any time.


By,

M Anem

Putrajaya

Malaysia


No comments:

Post a Comment