Agriculture for Beginners Part 6
They often leave off some of the qualities of the parent plants and at other times have such qualities more markedly than did their parents. Thus they often produce an interesting new kind of plant.
Sometimes we are able by hybridization to combine in one plant the good qualities of two other plants and thus make a great advance in agriculture. The new forms brought about by hybridization may be fixed, or made permanent, by such selection as is mentioned in Section XVIII.
Hybridization is of great aid in originating new plants.
It often happens that a plant will be more fruitful when pollinated by one variety than by some other variety. This is well ill.u.s.trated in Fig.
41. A fruit-grower or farmer should know much about these subjects before selecting varieties for his orchard, vineyard, etc.
=EXERCISE=
With the help of your teacher try to cross some plants. Such an experiment will take time, but will be most interesting. You must remember that many crosses must be attempted in order to gain success with even a few.
SECTION XVII. PROPAGATION BY BUDS
It is the business of the farmer to make plants grow, or, as it is generally called, to propagate plants. This he does in one of two ways: by buds (that is, by small pieces cut from parent plants), or by seeds.
The chief aim in both methods should be to secure in the most convenient manner the best-paying plants.
Many plants are most easily and quickly propagated by buds; for example, the grape, red raspberry, fig, and many others that we cultivate for the flower only, such as the carnation, geranium, rose, and begonia.
[Ill.u.s.tration: FIG. 41.
Brighton pollinated by 1, Salem; 2, Creveling; 3, Lindley; 4, Brighton; 5, Self-pollinated; 6, Nectar; 7, Jefferson; 8, Niagara]
In growing plants from cuttings, a piece is taken from the kind of plant that one wishes to grow. The greatest care must be exercised in order to get a healthy cutting. If we take a cutting from a poor plant, what can we expect but to grow a poor plant like the one from which our cutting was taken? On the other hand, if a fine, strong, vigorous, fruitful plant be selected, we shall expect to grow just such a fine, healthy, fruitful plant.
We expect the cutting to make exactly the same variety of plant as the parent stock. We must therefore decide on the variety of berry, grape, fig, carnation, or rose that we wish to propagate, and then look for the strongest and most promising plants of this variety within our reach.
The utmost care will not produce a fine plant if we start from poor stock.
[Ill.u.s.tration: FIG. 42. GERANIUM CUTTING Dotted line shows depth to which cutting should be planted]
What qualities are most desirable in a plant from which cuttings are to be taken? First, it should be productive, hardy, and suited to your climate and your needs; second, it should be healthy. Do not take cuttings from a diseased plant, since the cutting may carry the disease.
Cuttings may be taken from various parts of the plant, sometimes even from parts of the leaf, as in the begonia (Fig. 46). More often, however, they are drawn from parts of the stem (Figs. 43-45). As to the age of the twig from which the cutting is to be taken, Professor Bailey says: "For most plants the proper age or maturity of wood for the making of cuttings may be determined by giving the twig a quick bend; if it snaps and hangs by the bark, it is in proper condition. If it bends without breaking, it is too young and soft or too old. If it splinters, it is too old and woody." Some plants, as the geranium (Fig. 42), succeed best if the cuttings from which they are grown are taken from soft, young parts of the plant; others, for example, the grape or rose, do better when the cutting is made from more mature wood.
[Ill.u.s.tration: FIG. 43 GRAPE CUTTING Showing depth to which cutting should be planted]
[Ill.u.s.tration: FIG. 44. CARNATION CUTTING]
Cuttings may vary in size and may include one or more buds. After a hardy, vigorous cutting is made, insert it about one half or one third of its length in soil. A soil free from organic matter is much the best, since in such soil the cuttings are much less liable to disease. A fine, clean sand is commonly used by professional gardeners. When cuttings have rooted well--this may require a month or more--they may be transplanted to larger pots.
Sometimes, instead of cutting off a piece and rooting it, portions of branches are made to root before they are separated from the parent plant. This method is often followed, and is known as _layering_. It is a simple process. Just bend the tip of a bough down and bury it in the earth (see Fig. 47). The black raspberry forms layers naturally, but gardeners often aid it by burying the over-hanging tips in the earth, so that more tips may easily take root. Strawberries develop runners that root themselves in a similar fashion.
Grafts and buds are really cuttings which, instead of being buried in sand to produce roots of their own, are set on the roots of other plants.
[Ill.u.s.tration: FIG. 45. ROSE CUTTING]
Grafting and budding are practiced when these methods are more convenient than cuttings or when the gardener thinks there is danger of failure to get plants to take root as cuttings. Neither grafting nor budding is, however, necessary for the raspberry or the grape, for these propagate most readily from cuttings.
It is often the case that a budded or grafted plant is more fruitful than a plant on its own roots. In cases of this kind, of course, grafts or buds are used.
The white, or Irish, potato is usually propagated from pieces of the potato itself. Each piece used for planting bears one eye or more. The potato itself is really an underground stem and the eyes are buds. This method of propagation is therefore really a peculiar kind of cutting.
Since the eye is a bud and our potato plant for next year is to develop from this bud, it is of much importance, as we have seen, to know exactly what _kind_ of plant our potato comes from. If the potato is taken from a small plant that had but a few poor potatoes in the hill, we may expect the bud to produce a similar plant and a correspondingly poor crop. We must see to it, then, that our seed potatoes are drawn from vines that were good producers, because new potato plants are like the plants from which they were grown. Of course when our potatoes are in the bin we cannot tell from what kind of plants they came. We must therefore _select our seed potatoes in the field_. Seed potatoes should always be selected from those hills that produce most bountifully. Be a.s.sured that the increased yield will richly repay this care in selecting. It matters not so much whether the seed potato be large or small; it must, however, come from a hill bearing a large yield of fine potatoes.
[Ill.u.s.tration: FIG. 46. BEGONIA-LEAF CUTTING]
Sweet-potato plants are produced from shoots, or growing buds, taken from the potato itself, so that in their case too the piece that we use in propagating is a part of the original plant, and will therefore be like it under similar conditions. Just as with the Irish potato, it is important to know how good a yielder you are planting. You should watch during harvest and select for propagation for the next year only such plants as yield best.
We should exercise fully as much care in selecting proper individuals from which to make a cutting or a layer as we do in selecting a proper animal to breed from. Just as we select the finest Jersey in the herd for breeding purposes, so we should choose first the variety of plant we desire and then the finest individual plant of that variety.
If the variety of the potato that we desire to raise be Early Rose, it is not enough to select _any_ Early Rose plants, but the very best Early Rose plants, to furnish our seed.
[Ill.u.s.tration: FIG. 47. LAYERING]
It is not enough to select large, fine potatoes for cuttings. A large potato may not produce a bountifully yielding plant. _It will produce a plant like the one that produced it._ It may be that this one large potato was the only one produced by the original plant. If so, the plant that grows from it will tend to be similarly unproductive. Thus you see the importance of _selecting in the field a plant that has exactly the qualities desired in the new plant_.
One of the main reasons why gardeners raise plants from buds instead of from seeds is that the seed of many plants will not produce plants like the parent. This failure to "come true," as it is called, is sometimes of value, for it occasionally leads to improvement. For example, suppose that a thousand apple or other fruit or flower seeds from plants usually propagated by cuttings be planted; it may be that one out of a thousand or a million will be a very valuable plant. If a valuable plant be so produced, it should be most carefully guarded, multiplied by cuttings or grafts, and introduced far and wide. It is in this way that new varieties of fruits and flowers are produced from time to time.
Sometimes, too, a single bud on a tree will differ from the other buds and will produce a branch different from the other branches. This is known as _bud variation_. When there is thus developed a branch which happens to be of a superior kind, it should be propagated by cuttings just as you would propagate it if it had originated from a seed.
[Ill.u.s.tration: FIG. 48. CURRANT CUTTING]
Mr. Gideon of Minnesota planted many apple seeds, and from them all raised one tree that was very fruitful, finely flavored, and able to withstand the cold Minnesota winter. This tree he multiplied by grafts and named the Wealthy apple. It is said that in giving this one apple to the world he benefited mankind to the value of more than one million dollars. It will be well to watch for any valuable bud or seed variant and never let a promising one be lost. Plants grown in this way from seeds are usually spoken of as seedlings.
[Ill.u.s.tration: A LUSCIOUS AND EASILY GROWN BERRY]
PLANTS TO BE PROPAGATED FROM BUDS
The following list gives the names and methods by which our common garden fruits and flowers are propagated:
_Figs_: use cuttings 8 to 10 inches long or layer.
_Grapes_: use long cuttings, layer, or graft upon old vines.
_Apples_: graft upon seedlings, usually crab seedlings one year old.
_Pears_: bud upon pear seedlings.
_Cherries_: bud upon cherry stock.
_Plums_: bud upon peach stock.
_Peaches_: bud upon peach or plum seedlings.
_Quinces_: use cuttings or layer.
_Blackberries_: propagate by suckers; cut from parent stem.
_Black raspberries_: layer; remove old stem.