This resemblance of offspring to parent is known to scientists as heredity, or as "like producing like."

Some Southern corn-breeders take advantage of this law to improve their corn crop. If a stalk can be made to produce two ears of corn just as large as the single ear that most stalks bear, we shall get twice as much corn from a field in which the "two-eared" variety is planted. In the North and West the best varieties of corn have been selected to make but one ear to the stalk. It is generally believed that this is the best practice for the shorter growing seasons of the colder states.



These facts ought to be very helpful to us next year when our fathers are planting corn. We should get them to plant seed secured only from stalks that produced the most corn, whether the stalk had two or more ears or only one. If we follow this plan year by year, each acre of land will be made to produce more kernels and hence a larger crop of corn, and yet no more work will be required to raise the crop.

In addition to enlarging the yield of corn, you can, by proper selection of the best and most productive plants in the field, grow a new variety of seed corn. To do this you need only take the largest and best kernels from stalks bearing two ears; plant these, and at the next harvest again save the best kernels from stalks bearing the best ears. If you keep up this practice with great care for several years, you will get a vigorous, fruitful variety that will command a high price for seed.

EXPERIMENT



Every school boy and girl can make this experiment at leisure. From your own field get two ears of corn, one from a stalk bearing only one ear and the other from a stalk bearing two well-grown ears. Plant the grains from one ear in one plat, and the grains from the other in a plat of equal size. Use for both the same soil and the same fertilizer. Cultivate both plats in the same way. When the crop is ready to harvest, husk the corn, count the ears, and weigh the corn. Then write a short essay on your work and on the results and get your teacher to correct the story for your home paper.

SECTION XX. WEEDS

Have you ever noticed that some weeds are killed by one particular method, but that this same method may entirely fail to kill other kinds of weeds? If we wish to free our fields of weeds with the greatest ease, we must know the nature of each kind of weed and then attack it in the way in which we can most readily destroy it.



The ordinary pigweed (Fig. 56) differs from many other weeds in that it lives for only one year. When winter comes, it must die. Each plant, however, bears a great number of seeds. If we can prevent the plant from bearing seed in its first year, there will not be many seeds to come up the next season. In fact, only those seeds that were too deeply buried in the soil to come up the previous spring will be left, and of these two-year-old seeds many will not germinate. During the next season some old seeds will produce plants, but the number will be very much diminished. If care be exercised to prevent the pigweed from seeding again, and the same watchfulness be continued for a few seasons, this weed will be almost entirely driven from our fields.

A plant like the pigweed, which lives only one year, is called an annual and is one of the easiest weeds to destroy. Mustard, plantain, chess, dodder, cockle, crab grass, and Jimson weed are a few of our most disagreeable annual weeds.

The best time to kill any weed is when it is very small; therefore the ground in early spring should be constantly stirred in order to kill the young weeds before they grow to be strong and hardy.



The wild carrot differs from an annual in this way: it lives throughout one whole year without producing seeds. During its first year it accumulates a quantity of nourishment in the root, then rests in the winter. Throughout the following summer it uses this nourishment rapidly to produce its flowers and seeds. Then the plant dies. Plants that live through two seasons in this way are called biennials. Weeds of this kind may be destroyed by cutting the roots below the leaves with a grubbing-hoe or spud. A spud may be described as a chisel on a long handle (see Fig. 58). If biennials are not cut low enough they will branch out anew and make many seeds. Among the most common biennials are the thistle, moth mullein, wild carrot, wild parsnip, and burdock.



A third group of weeds consists of those that live for more than two years. These weeds are usually most difficult to kill. They propagate by means of running rootstocks as well as by seeds. Plants that live more than two seasons are known as perennials and include, for example, many grasses, dock, Canada thistle, poison ivy, passion flower, horse nettle, etc. There are many methods of destroying perennial weeds. They may be dug entirely out and removed. Sometimes in small areas they may be killed by crude sulphuric acid or may be starved by covering them with boards or a straw stack or in some other convenient way. A method that is very effective is to smother the weeds by a dense growth of some other plant, for example, cowpeas or buckwheat. Cowpeas are to be preferred, since they also enrich the soil by the nitrogen that the root-tubercles gather.



Weeds do injury in numerous ways; they shade the crop, steal its nourishment, and waste its moisture. Perhaps their only service is to make lazy people till their crops.

EXERCISE

You should learn to know by name the twenty worst weeds of your vicinity and to recognize their seeds. If there are any weeds you are not able to recognize, send a sample of each to your state experiment station. Make a collection, properly labeled, of weeds and weed seeds for your school.

SECTION XXI. SEED PURITY AND VITALITY

Seeds produce plants. The difference between a large and a small yield may depend upon the kind of plants we raise, and the kind of plant in turn is dependent upon the seeds that we sow.

Two things are important in the selection of seeds—purity and vitality. Seeds should be pure; that is, when sown they should produce no other plant than the one that we wish to raise. They should be able to grow. The ability of a seed to grow is termed its vitality. Good seed should be nearly or quite pure and should possess high vitality. The vitality of seeds is expressed as a per cent; for example, if 97 seeds out of 100 germinate, or sprout, the vitality is said to be 97. The older the seed the less is its vitality, except in a few rare instances in which seeds cannot germinate under two or three years.

Cucumber seeds may show 90 per cent vitality when they are one year old, 75 per cent when two years old, and 70 per cent when three years old—the per cent of vitality diminishing with increase of years. The average length of life of the seeds of cultivated plants is short: for example, the tomato lives four years; corn, two years; the onion, two years; the radish, five years. The cucumber seed may retain life after ten years; but the seeds of this plant too lose their vitality with an increase in years.

It is important when buying seeds to test them for purity and vitality. Dealers who are not honest often sell old seeds, although they know that seeds decrease in value with age. Sometimes, however, to cloak dishonesty they mix some new seeds with the old, or bleach old and yellow seeds in order to make them resemble fresh ones.

It is important, therefore, that all seeds bought of dealers should be thoroughly examined and tested; for if they do not grow, we not only pay for that which is useless but we are also in great danger of producing so few plants in our fields that we shall not get full use of the land, and thus we may suffer a more serious loss than merely paying for a few dead seeds. It will therefore be both interesting and profitable to learn how to test the vitality of seeds.

To test vitality plant one hundred seeds in a pot of earth or in damp sand, or place them between moist pieces of flannel, and take care to keep them moist and warm. Count those that germinate and thus determine the percentage of vitality. Germinating between flannel is much quicker than planting in earth. Care should be used to keep mice away from germinating seeds. (See Fig. 61.)



Sometimes the appearance of a package will show whether the seed has been kept in stock a long time. It is, however, much more difficult to find out whether the seeds are pure. You can of course easily distinguish seeds that differ much from those you wish to plant, but often certain weed seeds are so nearly like certain crop seeds as not to be easily recognized by the eye. Thus the dodder or "love vine," which so often ruins the clover crop, has seeds closely resembling clover seeds. The chess, or cheat, has seeds so nearly like oats that only a close observer can tell them apart. However, if you watch the seeds that you buy, and study the appearance of crop seeds, you may become expert in recognizing those that have no place in your planting.

One case is reported in which a seed-dealer intentionally allowed an impurity of 30 per cent to remain in the crop seeds, and this impurity was mainly of weed seeds. There were 450,000 of one kind and 288,000 of another in each pound of seed. Think of planting weeds at that rate! Sometimes three fourths of the seeds you buy are weed seeds.

In purchasing seeds the only safe plan is to buy of dealers whose reputation can be relied upon.

It not seldom happens that seeds, like corn, are stored in open cribs or barns before the moisture is entirely dried out of the seeds. Such seeds are liable to be frozen during a severe winter, and of course if this happens they will not sprout the following spring. The only way to tell whether such seeds have been killed is to test samples of them for vitality. Testing is easy; replanting is costly and often results in a short crop.



EXERCISE

Examine seeds both for vitality and purity. Write for farmers' bulletins on both these subjects. What would be the loss to a farmer who planted a ten-acre clover field with seeds that were 80 per cent bad? Can you recognize the seeds of the principal cultivated plants? Germinate some beet seeds. What per cent comes up? Can you explain? Collect for your school as many kinds of wild and cultivated seeds as you can.



CHAPTER IV

HOW TO RAISE A FRUIT TREE

Let each pupil grow an apple tree this year and attempt to make it the best in his neighborhood. In your attempt suppose you try the following plan. In the fall take the seed of an apple—a crab-apple is good—and keep it in a cool place during the winter. The simplest way to do this is to bury it in damp sand. In the spring plant it in a rich, loose soil.

Great care must be taken of the young shoot as soon as it appears above the ground. You want to make it grow as tall and as straight as possible during this first year of its life, hence you should give it rich soil and protect it from animals. Before the ground freezes in the fall take up the young tree with the soil that was around it and keep it all winter in a cool, damp place.

Now when spring comes it will not do to set out the carefully tended tree, for an apple tree from seed will not be a tree like its parent, but will tend to resemble a more distant ancestor. The distant ancestor that the young apple tree is most likely to take after is the wild apple, which is small, sour, and otherwise far inferior to the fruit we wish to grow. It makes little difference, therefore, what kind of apple seed we plant, since in any event we cannot be sure that the tree grown from it will bear fruit worth having unless we force it to do so.



SECTION XXII. GRAFTING

By a process known as grafting you can force your tree to produce whatever variety of apple you desire. Many people raise fruit trees directly from seed without grafting. Thus they often produce really worthless trees. By grafting they would make sure not only of having good trees rather than poor ones but also of having the particular kind of fruit that they wish. Hence you must now graft your tree.

First you must decide what variety of apple you want to grow on the tree. The Magnum Bonum is a great favorite as a fall apple. The Winesap is a good winter apple, while the Red Astrachan is a profitable early apple, especially in the lowland of the coast region. The Northern Spy, AEsop, and Spitzenburg are also admirable kinds. Possibly some other apple that you know may suit your taste and needs better than any of these varieties.

If you have decided to raise an AEsop or a Magnum Bonum or a Winesap, you must now cut a twig from the tree of your choice and graft it upon the little tree that you have raised. Choose a twig that is about the thickness of the young tree at the point where you wish to graft. Be careful to take the shoot from a vigorous, healthy part of the tree.



There are many ways in which you may join the chosen shoot or twig upon the young tree, but perhaps the best one for you to use is known as tongue grafting. This is illustrated in Fig. 64. The upper part, b, which is the shoot or twig that you cut from the tree, is known as the scion; the lower part, a, which is the original tree, is called the stock.

Cut the scion and stock as shown in Fig. 64. Join the cut end of the scion to the cut end of the stock. When you join them, notice that under the bark of each there is a thin layer of soft, juicy tissue. This is called the cambium. To make a successful graft the cambium in the scion must exactly join the cambium in the stock. Be careful, then, to see that cambium meets cambium. You now see why grafting can be more successfully done if you select a scion and stock of nearly the same size.



After fitting the parts closely together, bind them with cotton yarn (see Fig. 65) that has been coated with grafting wax. This wax is made of equal parts of tallow, beeswax, and linseed oil. Smear the wax thoroughly over the whole joint, and make sure that the joint is completely air-tight.



The best time to make this graft is when scion and stock are dormant, that is, when they are not in leaf. During the winter, say in February, is the best time to graft the tree. Set the grafted tree away again in damp sand until spring, then plant it in loose, rich soil.

Since all parts growing above the graft will be of the same kind as the scion, while all branches below it will be like the stock, it is well to graft low on the stock or even upon the root itself. The slanting double line in Fig. 66 shows the proper place to cut off for such grafting.



If you like you may sometime make the interesting and valuable experiment of grafting scions from various kinds of apple trees on the branches of one stock. In this way you can secure a tree bearing a number of kinds of fruit. You may thus raise the Bonum, Red Astrachan, Winesap, and as many other varieties of apples as you wish, upon one tree. For this experiment, however, you will find it better to resort to cleft grafting, which is illustrated in Fig. 68.



Luther Burbank, the originator of the Burbank potato, in attempting to find a variety of apple suited to the climate of California, grafted more than five hundred kinds of apple scions on one tree, so that he might watch them side by side and find out which kind was best suited to that state.

SECTION XXIII. BUDDING

If, instead of an apple tree, you were raising a plum or a peach tree, a form of propagation known as budding would be better than grafting. Occasionally budding is also employed for apples, pears, cherries, oranges, and lemons. Budding is done in the following manner. A single bud is cut from the scion and is then inserted under the bark of a one-year-old peach seedling, so that the cambium of the bud and stock may grow together.



Cut scions of the kind of fruit tree you desire from a one-year-old twig of the same variety. Wrap them in a clean, moist cloth until you are ready to use them. Just before using cut the bud from the scion, as shown in Fig. 69. This bud is now ready to be inserted on the north side of the stock, just two or three inches above the ground. The north side is selected to avoid the sun. Now, as shown at a in Fig. 70, make a cross and an up-and-down incision, or cut, on the stock; pull the bark back carefully, as shown in B; insert the bud C, as shown in D; then fold the bark back and wrap with yarn or raffia, as shown in E. As soon as the bud and branches have united, remove the wrapping to prevent its cutting the bark and cut the tree back close to the bud, as in Fig. 71, so as to force nourishment into the inserted bud.



Budding is done in the field without disturbing the tree as it stands in the ground. The best time to do budding is during the summer or fall months, when the bark is loose enough to allow the buds to be easily inserted.

Trees may be budded or grafted on one another only when they are nearly related. Thus the apple, crab-apple, hawthorn, and quince are all related closely enough to graft or bud on one another; the pear grows on some hawthorns, but not well on an apple; some chestnuts will unite with some kinds of oaks.



By using any of these methods you can succeed in getting with certainty the kind of tree that you desire.



SECTION XXIV. PLANTING AND PRUNING

The apple tree that you grafted should be set out in the spring. Dig a hole three or four feet in diameter where you wish the tree to grow. Place the tree in the hole and be very careful to preserve all the fine roots. Spread the roots out fully, water them, and pack fine, rich soil firmly about them. Place stakes about the young tree to protect it from injury. If the spot selected is in a windy location, incline the tree slightly toward the prevailing wind.



You must prune the tree as it grows. The object of pruning is to give the tree proper shape and to promote fruit-bearing. If the bud at the end of the main shoot grows, you will have a tall, cone-shaped tree. If, however, the end of the young tree be cut or "headed back" to the lines shown in Fig. 72, the buds below this point will be forced to grow and make a tree like that shown in Fig. 73. The proper height of heading for different fruits varies. For the apple tree a height of two or three feet is best.

Cutting an end bud of a shoot or branch always sends the nourishment and growth into the side buds. Trimming or pinching off the side buds throws the growth into the end bud. You can therefore cause your tree to take almost any shape you desire. The difference between the trees shown in Figs. 73 and 74 is entirely the result of pruning. Fig. 74 illustrates in general a correctly shaped tree. It is evenly balanced, admits light freely, and yet has enough foliage to prevent sun-scald. Figs. 75 and 76 show the effect of wisely thinning the branches.



The best time to prune is either in the winter or before the buds start in the spring. Winter pruning tends to favor wood-production, while summer pruning lessens wood-production and induces fruitage.

Each particular kind of fruit requires special pruning; for example, the peach should be made to assume the shape illustrated in Fig. 77. This is done by successive trimmings, following the plan illustrated in Figs. 71, 78, 79. You will gain several advantages from these trimmings. First, nourishment will be forced into the peach bud that you set on your stock. This will secure a vigorous growth of the scion. By a second trimming take off the "heel" (Fig. 78, h) close to the tree, and thus prevent decay at this point. One year after budding you should reduce the tree to a "whip," as in Fig. 79, by trimming at the dotted line in Fig. 78. This establishes the "head" of the tree, which in the case of the peach should be very low,—about sixteen inches from the ground,—in order that a low foliage may lessen the danger of sun-scald to the main trunk.



In pruning never leave a stump such as is shown in Fig. 78, h. Such a stump, having no source of nourishment, will heal very slowly and with great danger of decay. If this heel is cleanly cut on the line ch (Fig. 78), the wound will heal rapidly and with little danger of decay. Leaving such a stump endangers the soundness of the whole tree. Fig. 80 shows the results of good and poor pruning on a large tree. When large limbs are removed it is best to paint the cut surface. The paint will ward off fungous disease and thus keep the tree from rotting where it was cut.

Pruning that leaves large limbs branching, as in Fig. 74, a, is not to be recommended, since the limbs when loaded with fruit or when beaten by heavy winds are liable to break. Decay is apt to set in at the point of breakage. The entrance of decay-fungi through some such wound or through a tiny crevice at such a crotch is the beginning of the end of many a fruitful tree.



Sometimes a tree will go too much to wood and too little to fruit. This often happens in rich soil and may be remedied by another kind of pruning known as root-pruning. This consists in cutting off a few of the roots in order to limit the food supply of the plant. You ought to learn more about root-pruning, however, before you attempt it.



How is a peach tree made? First, the blossom appears. Then pollination and fertilization occur. The fruit ripens. The pit, or seed, is saved. In the spring of the next year the seed is planted. The young tree, known as the stock, comes up quickly. In August of that year a bud of the variety which is wanted is inserted in the little stock, near the ground. One year later, in the spring, the stock is cut off just above the bud. The bud throws out a shoot, which grows to a height of about six feet, and in the fall this little peach tree is sold as a one-year-old tree. However, as is seen, the root is two years old.



How is an apple tree made? The seeds are saved in the fall of one year and planted the following year. The seedlings of the apple do not grow so rapidly as those of the peach. At the end of the year they are taken up and sorted, and in the following spring they are planted. In July or August they are budded. In the spring of the next year the stock is cut off above the bud, and the bud-shoot grows three or four feet. One year later the shoot branches and the top begins to form; and in the fall of the following year the tree may be sold as a two-year-old, although most persons prefer to buy it a year later as a three-year-old. In some parts of the country, particularly in the West, the little seedling is grafted in the second winter, in a grafting room, and the young grafts are set in the nursery row in the spring to complete their growth.

The planting in the orchard of the young peach and the young apple tree is done in practically the same way. After the hole for the tree has been dug and after proper soil has been provided, the roots should be spread and the soil carefully packed around them.

EXERCISE

Do you know any trees in your neighborhood that bear both wild and budded or grafted fruit? What are the chief varieties of apples grown in your neighborhood? grapes? currants? plums? cherries? figs? What is a good apple tree worth? Is there any land near by that could support a tree and is not now doing so? Examine several orchards and see whether the trees have the proper shape. Do you see any evidence of poor pruning? Do you find any heels? Can you see any place where heels have resulted in rotten or hollow trees? How could you have prevented this? Has the removal of branches ever resulted in serious decay? How is this to be prevented?

If your home is not well stocked with all the principal kinds of fruit, do you not want to propagate and attend to some of each kind? You will be surprised to find how quickly trees will bear and how soon you will be eating fruit from your own planting. Growing your own trees will make you feel proud of your skill.



CHAPTER V

HORTICULTURE

SECTION XXV. MARKET-GARDENING

The word horticulture is one of those broad words under which much is grouped. It includes the cultivation of orchard fruits, such as apples and plums; of small fruits, such as strawberries and raspberries; of garden vegetables for the table; of flowers of all sorts, including shrubbery and ornamental trees and their arrangement into beautiful landscape effects around our homes. Horticulture then is a name for an art that is both far-reaching and important.

The word gardening is generally given to that part of horticulture which has for its chief aim the raising of vegetables for our tables.

Flower-gardening, or the cultivation of plants valued for their bloom in making ornamental beds and borders and furnishing flowers for the decoration of the home, is generally called floriculture. Landscape-gardening is the art of so arranging flower-beds, grass, shrubbery, and trees as to produce pleasing effects in the grounds surrounding our homes and in great public parks and pleasure grounds.

Landscape-gardening, like architecture, has developed intoll as the artist makes them on canvas, but uses natural objects in his pictures instead of paint and canvas.

Market-Gardening. Formerly market-gardening was done on small tracts of land in the immediate vicinity of large cities, where supplies of stable manure could be used from the city stables. But with the great increase in the population of the cities, these small areas could no longer supply the demand, and the introduction of commercial fertilizers and the building of railroads enabled gardeners at great distances from city markets to grow and ship their products. Hence the markets, even in winter, are now supplied with fresh vegetables from regions where there is no frost. Then, as spring opens, fruits and vegetables are shipped from more temperate regions. Later vegetables and fruits come from the sections nearer the great cities. This gradual nearing of the supply fields continues until the gardens near the cities can furnish what is needed.



The market-gardeners around the great Northern cities, finding that winter products were coming from the South and from warmer regions, began to build hothouses and by means of steam and hot-water pipes to make warm climates in these glass houses. Many acres of land in the colder sections of the country are covered with heated glass houses, and in them during the winter are produced fine crops of tomatoes, lettuce, radishes, cauliflowers, eggplants, and other vegetables. The degree of perfection which these attain in spite of having such artificial culture, and their freshness as compared to the products brought from a great distance, have made winter gardening under glass a very profitable business. But it is a business that calls for the highest skill and the closest attention.



No garden, even for home use, is complete without some glass sashes, and the garden will be all the more successful if there is a small heated greenhouse for starting plants that are afterwards to be set in the garden.

Hotbeds. If there is no greenhouse, a hotbed is an important help in the garden. The bed is made by digging a pit two feet deep, seven feet wide, and as long as necessary.

The material for the hotbed is fresh horse manure mixed with leaves. This is thrown into a heap to heat. As soon as steam is seen coming from the heap the manure is turned over and piled again so that the outer part is thrown inside. When the whole is uniformly heated and has been turned two or three times, it is packed firmly into the pit already dug.

A frame six feet wide, twelve inches high on the north side and eight inches on the south side and as long as the bed is to be, is now made of plank. This is set upon the heated manure, thus leaving six inches on each side outside the frame. More manure is then banked all around it, and three or four inches of fine light and rich soil are placed inside the frame.



The frame is then covered with hotbed sashes six feet long and three feet wide. These slide up and down on strips of wood let into the sides of the frame. A thermometer is stuck into the soil and closely watched, for there will be too much heat at first for sowing seed. When the heat in the early morning is about 85 deg., seeds may be sowed. The hotbed is used for starting tomato plants, eggplants, cabbage plants, and other vegetables that cannot stand exposure. It should be made about eight or ten weeks before the tender plants can be set out in the locality. In the South and Southwest it should be started earlier than in the North. For growing the best tomato plants, and for such hardy plants as lettuce and cabbage, it will be better to have cold-frames in addition to the hotbed; these need not be more than two or three sashes.

Cold-Frames. A cold-frame is like the frame used for a hotbed, but it is placed on well-manured soil in a sheltered spot. It is covered with the same kind of sashes and is used for hardening the plants sowed in the hotbed. The frame must be well banked with earth on the outside, and the glass must be covered on cold nights with straw, mats, or old carpets to keep out frost.



Care of Hotbed and Cold-Frame. If the sun be allowed to shine brightly on the glass of a cold-frame or hotbed, it will soon raise the temperature in the hotbed to a point that will destroy the plants. It is necessary, then, to pay close attention to the bed and, when the sun shines, to slip the sashes down or raise them and place a block under the upper end to allow the steam to pass off. The cold-frame also must be aired when the sun shines, and the sashes must be gradually slipped down in mild weather. Finally, they may be removed entirely on sunshiny days, so as to accustom the plants to the open air, but they must be replaced at night. For a while before setting the plants in the open gardens, leave the sashes off night and day.



While the hotbed may be used for starting plants, it is much better and more convenient to have a little greenhouse with fire heat for this purpose. A little house with but four sashes on each side will be enough to start a great many plants, and will also give room for some flowers in pots. With such a house a student can learn to manage a more extensive structure if he gives close attention to airing, watering, and keeping out insects.

Sowing. The time for sowing the different kinds of seeds is an important matter. Seeds vary greatly in their requirements. All need three conditions—a proper degree of heat, moisture, and air. Some seeds, like English peas, parsnips, beets, and radishes, will germinate and grow when the soil is still cool in the early spring, and peas will stand quite a frost after they are up. Therefore we plant English peas as early as the ground can be worked.

But if we should plant seeds like corn, string (or snap) beans, squashes, and other tender plants before the ground is warm enough, they would decay.

Seeds cannot germinate in soil that is perfectly dry, for there must be moisture to swell them and to start growth. The oxygen of the air is also necessary, and if seeds are buried so deeply that the air cannot reach them, they will not grow, even if they are warm and moist.



The depth of planting must vary with the character and size of the seed. English peas may be covered six inches deep and will be all the better for such covering, but if corn be covered so deep, it hardly gets above the ground. In planting small seeds like those of the radish, cabbage, turnip, lettuce, etc., a good rule is to cover them three times the thickness of the seed.

In sowing seeds when the ground is rather dry, it is a good plan, after covering them, to tramp on the row so as to press the soil closely to the seeds and to help it to retain moisture for germination, but do not pack the soil if it is damp.

In spring never dig or plow the garden while it is still wet, but always wait until the soil is dry enough to crumble freely.

What Crops to grow. The crops to be raised will of course depend upon each gardener's climate, surroundings, and markets. Sometimes it may pay a grower, if his soil and climate are particularly suited to one crop, to expend most of his time and energy on this crop; for example, in some sections of New York, on potatoes; in parts of Michigan, on celery; in Georgia, on watermelons; in western North Carolina, on cabbage. If circumstances allow this sort of gardening, it has many advantages, for of course it is much easier to acquire skill in growing one crop than in growing many.



On the other hand, it often happens that a gardener's situation requires him to grow most of the crops known to gardening. Each gardener then must be guided in his selection of crops by his surroundings.

Care of Crops. The gardener who wishes to attain the greatest success in his art must do four things:

First, he must make his land rich and keep it rich. Much of his success depends on getting his crops on the market ahead of other growers. To do this, his crops must grow rapidly, and crops grow rapidly only in rich soil. Then, too, land conveniently situated for market-gardening is nearly always costly. Hence the successful market-gardener must plan to secure the largest possible yield from as small an area as is practicable. The largest yield can of course be secured from the richest land.

Second, the gardener must cultivate his rich land most carefully and economically. He crowds his land with products that must grow apace. Therefore he, least of all growers, can afford to have any of his soil go to feed weeds, to have his land wash, or to have his growing crops suffer for lack of timely and wise cultivation. To cultivate his land economically the gardener must use the best tools and machines and the best methods of soil management.

Third, to get the best results he must grow perfect vegetables. To do this, he must add to good tillage a knowledge of the common plant diseases and of the ways of insects and bacterial pests; he must know how and when to spray, how and when to treat his seed, how and when to poison, how and when to trap his insect foes and to destroy their hiding-places.

Fourth, not only must the gardener grow perfect vegetables, but he must put them on the market in perfect condition and in attractive shape. Who cares to buy wilted, bruised, spoiling vegetables? Gathering, bundling, crating, and shipping are all to be watched carefully. Baskets should be neat and attractive, crates clean and snug, barrels well packed and well headed. Careful attention to all these details brings a rich return.

Among the gardener's important crops are the following:

Asparagus. This is a hardy plant. Its seed may be sowed either early in the spring or late in the fall. The seeds should be planted in rows. If the plants are well cultivated during the spring and summer, they will make vigorous roots for transplanting in the autumn.

In the fall prepare a piece of land by breaking it unusually deep and by manuring it heavily. After the land is thoroughly prepared, make in it furrows for the asparagus roots. These furrows should be six inches deep and three feet apart. Then remove the roots from the rows in which they have been growing during the summer, and set them two feet apart in the prepared furrows. Cover carefully at once.



In the following spring the young shoots must be well cultivated. In order to economize space, beets or lettuce may be grown between the asparagus rows during this first season. With the coming of cold weather the asparagus must again be freely manured and all dead tops cut off. Some plants will be ready for market the second spring. If the bed is kept free from weeds and well manured, it will increase in productiveness from year to year.

Beans. The most generally planted beans are those known as string, or snap, beans. Of the many varieties, all are sensitive to cold and hence must not be planted until frost is over.

Another widely grown kind of bean is the lima, or butter, bean. There are two varieties of the lima bean. One is large and generally grows on poles. This kind does best in the Northern states. The other is a small bean and may be grown without poles. This kind is best suited to the warmer climates of the Southern states.

Cabbage. In comparatively warm climates the first crop of cabbage is generally grown in the following way. The seeds are sowed in beds in September, and the plants grown from this sowing are in November transplanted to ground laid off in sharp ridges. The young plants are set on the south side of the ridges in order that they may be somewhat protected from the cold of winter. As spring comes on, the ridge is partly cut down at each working until the field is leveled, and thereafter the cultivation should be level.



Early cabbages need heavy applications of manure. In the spring, nitrate of soda applied in the rows is very helpful.

Seeds for the crop following this early crop should be sowed in March. Of course these seeds should be of a later variety than the first used. The young plants should be transplanted as soon as they are large enough. Early cabbages are set in rows three feet apart, the plants eighteen inches apart in the row. As the later varieties grow larger than the earlier ones, the plants should be set two feet apart in the row.

In growing late fall and winter cabbage the time of sowing varies with the climate. For the Northern and middle states, seeding should be done during the last of March and in April. South of a line passing west from Virginia it is hard to carry cabbages through the heat of summer and get them to head in the fall. However, if the seeds are sowed about the first of August in rich and moist soil and the plants set in the same sort of soil in September, large heads can be secured for the December market.



Celery. In the extreme northern part of our country, celery seeds are often sowed in a greenhouse or hotbed. This is done in order to secure plants early enough for summer blanching. This plan, however, suits only very cool climates.

In the middle states the seeds are usually sowed in a well-prepared bed about April. The young plants are moved to other beds as soon as they need room. Generally they are transplanted in July to rows prepared for them. These should be four feet apart, and the plants should be set six inches apart in the row. The celery bed should be carefully cultivated during the summer. In the fall, hill the stalks up enough to keep them erect. After the growing season is over dig them and set them in trenches. The trenches should be as deep as the celery is tall, and after the celery is put in them they should be covered with boards and straw.

In the more southern states, celery is usually grown in beds. The beds are generally made six feet wide, and rows a foot apart are run crosswise. The plants are set six inches apart, in September, and the whole bed is earthed up as the season advances. Finally, when winter comes the beds are covered with leaves or straw to prevent the plants from freezing. The celery is dug and bunched for market at any time during the winter.

By means of cold-frames a profitable crop of spring celery may be raised. Have the plants ready to go into the cold-frames late in October or early in November. The soil in the frame should be made very deep. The plants should make only a moderately rapid growth during the winter. In the early spring they will grow rapidly and so crowd one another as to blanch well. As celery grown in this way comes on the market at a time when no other celery can be had, it commands a good price.

In climates as warm as that of Florida, beds of celery can be raised in this way without the protection of cold-frames. A slight freeze does not hurt celery, but a long-continued freezing spell will destroy it.

Some kinds of celery seem to turn white naturally. These are called self-blanching kinds. Other kinds need to be banked with earth in order to make the stalks whiten. This kind usually gives the best and crispest stalks.

Cucumbers and Cantaloupes. Although cucumbers and cantaloupes are very different plants, they are grown in precisely the same way. Some gardeners plant them in hills. However, this is perhaps not the best plan. It is better to lay the land off in furrows six feet apart. After filling these with well-rotted stable manure, throw soil over them. Then make the top flat and plant the seeds. After the plants are up thin them out, leaving them a foot or more apart in the rows. Cultivate regularly and carefully until the vines cover the entire ground.

It is a good plan to sow cowpeas at the last working of cantaloupes, in order to furnish some shade for the melons. As both cucumbers and cantaloupes are easily hurt by cold, they should not be planted until the soil is warm and all danger of frost is past.

Cucumbers are always cut while they are green. They should never be pulled from the vine, but should always be cut with a piece of the stem attached. Cantaloupes should be gathered before they turn yellow and should be ripened in the house.



In some sections of the country the little striped cucumber-beetle attacks the melons and cucumbers as soon as they come up. These beetles are very active, and if their attacks are not prevented they will destroy the tender plants. Bone dust and tobacco dust applied just as the plants appear above the ground will prevent these attacks. This treatment not only keeps off the beetle, but also helps the growth of the plants.

Eggplants. Eggplants are so tender that they cannot be transplanted like tomatoes to cold-frames and gradually hardened to stand the cold spring air. These plants, started in a warm place, must be kept there until the soil to which they are to be transplanted is well warmed by the advance of spring. After the warm weather has fully set in, transplant them to rich soil, setting them three feet apart each way. This plant needs much manure. If large, perfect fruit is expected, the ground can hardly be made too rich.

Eggplants are subject to the same bacterial blight that is so destructive to tomatoes. The only way to prevent this disease is to plant in ground not lately used for tomatoes or potatoes.



Onions. The method of growing onions varies with the use to which it is intended to put them. To make the early sorts, which are eaten green in the spring, little onions called sets are planted. These are grown from seeds sowed late in the spring. The seeds are sowed thickly in rows in rather poor land. The object of selecting poor land is that the growth of the sets may be slow. When the sets have reached the size of small marbles, they are ready for the fall planting.

In the South the sets may be planted in September. Plant them in rows in rich and well-fertilized soil. They will be ready for market in March or April. In the more northerly states the sets are to be planted as early as possible in the spring.

To grow ripe onions the seeds must be sowed as early in the spring as the ground can be worked. The plants are thinned to a stand of three inches in the rows. As they grow, the soil is drawn away from them so that the onions sit on top of the soil with only their roots in the earth.



As soon as the tops ripen pull the onions and let them lie in the sun until the tops are dry. Then put them under shelter. As onions keep best with their tops attached, do not remove these until it is time for marketing.

Peas. The English pea is about the first vegetable of the season to be planted. It may be planted as soon as the ground is in workable condition. Peas are planted in rows, and it is a good plan to stretch wire netting for them to climb on. However, where peas are extensively cultivated they are allowed to fall on the ground.

There are many sorts of peas, differing both in quality and in time of production. The first to be planted are the extra-early varieties. These are not so fine as the later, wrinkled sorts, but the seeds are less apt to rot in cold ground. Following these, some of the fine, wrinkled sorts are to be planted in regular succession. Peas do not need much manure and do best in a light, warm soil.

Tomatoes. There is no vegetable grown that is more widely used than the tomato. Whether fresh or canned it is a staple article of food that can be served in many ways.

By careful selection and breeding, the fruit of the tomato has in recent years been much improved. There are now many varieties that produce perfectly smooth and solid fruit, and the grower can hardly go amiss in his selection of seeds if he bears his climate and his particular needs in mind.

Early tomatoes are started in the greenhouse or in the hotbed about ten weeks before the time for setting the plants in the open ground. They are transplanted to cold-frames as soon as they are large enough to handle. This is done to harden the plants and to give them room to grow strong before the final transplanting.

In kitchen gardens tomatoes are planted in rows four feet apart with the plants two feet apart in the rows. They are generally trained to stakes with but one stalk to a stake. When there is plenty of space, however, the plants are allowed to grow at will and to tumble on the ground. In this way they bear large crops. During the winter the markets are supplied with tomatoes either from tropical sections or from hothouses. As those grown in the hothouses are superior in flavor to those shipped from Florida and from the West Indies, and as they command good prices, great quantities are grown in this way.

In the South the bacterial blight which attacks the plants of this family is a serious drawback to tomato culture. The only way to escape this disease is to avoid planting tomatoes on land in which eggplants, tomatoes, or potatoes have been blighted. Lime spread around the plants seems to prevent the blight for one season on some soils.

At the approach of frost in the fall, green tomatoes can easily be preserved by wrapping them in paper. Gather them carefully and wrap each separately. Pack them in boxes and store in a cellar that is close enough to prevent the freezing of the fruit. A few days before the tomatoes are wanted for the table unpack as many as are needed, remove the paper, and allow them to ripen in a warm room.

Tomatoes require a rich soil. Scattering a small quantity of nitrate of soda around their roots promotes rapid growth.

Watermelons. As watermelons need more room than can usually be spared in a garden, they are commonly grown as a field crop.

A very light, sandy soil suits watermelons best. They can be grown on very poor soil if a good supply of compost be placed in each hill. The land for the melons should be laid off in about ten-foot checks; that is, the furrows should cross one another at right angles about every ten feet. A wide hole should be dug where the furrows cross, and into this composted manure should be put.

The best manure for watermelons is a compost of stable manure and wood-mold from the forest. Pile the manure and wood-mold in alternate layers for some time before the planting season. During the winter cut through the pile several times until the two are thoroughly mixed and finely pulverized. Be sure to keep the compost heap under shelter. Compost will lose in value if it is exposed to rains.

At planting-time, put two or three shovelfuls of this compost into each of the prepared holes, and over the top of the manure scatter a handful of any high-grade complete fertilizer. Then cover fertilizer and manure with soil, and plant the seeds in this soil. In cultivating, plow both ways of the checked rows and throw the earth toward the plants.

Some growers pinch off the vines when they have grown about three feet long. This is done to make them branch more freely, but the pinching is not necessary.

A serious disease, the watermelon wilt, is rapidly spreading through melon-growing sections. This disease is caused by germs in the soil, and the germs are hard to kill. If the wilt should appear in your neighborhood, do not allow any stable manure to be used on your melon land, for the germs are easily scattered by means of stable manure. The germs also cling to the seeds of diseased melons, and these seeds bear the disease to other fields. If you treat melon seeds as you are directed on page 135 to treat oat seeds, the germs on the seeds will be destroyed. By crossing the watermelon on the citron melon, a watermelon that is resistant to wilt has recently been developed and successfully grown in soils in which wilt is present. The new melon, inferior in flavor at first, is being improved from season to season and bids fair to rival other melons in flavor.



SECTION XXVI. FLOWER GARDENING

The comforts and joys of life depend largely upon small things. Of these small things perhaps none holds a position of greater importance in country life than the adornment of the home, indoors and outdoors, with flowers tastefully arranged. Their selection and planting furnish pleasant recreation; their care is a pleasing employment; and each little plant, as it sprouts and grows and develops, may become as much a pet as creatures of the sister animal kingdom. A beautiful, well-kept yard adds greatly to the pleasure and attractiveness of a country home. If a beautiful yard and home give joy to the mere passer-by, how much more must their beauty appeal to the owners. The decorating of the home shows ambition, pride, and energy—important elements in a successful life.



Plant trees and shrubs in your yard and border your masses of shrubbery with flower-beds. Do not disfigure a lawn by placing a bed of flowers in it. Use the flowers rather to decorate the shrubbery, and for borders along walks, and in the corners near steps, or against foundations.

If you wish to raise flowers for the sake of flowers, not as decorations, make the flower-beds in the back yard or at the side of the house.



Plants may be grown from seeds or from bulbs or from cuttings. The rooting of cuttings is an interesting task to all who are fond of flowers. Those who have no greenhouse and who wish to root cuttings of geraniums, roses, and other plants may do so in the following way. Take a shallow pan, an old-fashioned milk pan for instance, fill it nearly full of clean sand, and then wet the sand thoroughly. Stick the cuttings thickly into this wet sand, set the pan in a warm, sunny window, and keep the sand in the same water-soaked condition. Most cuttings will root well in a few weeks and may then be set into small flower-pots. Cuttings of tea roses should have two or three joints and be taken from a stem that has just made a flower. Allow one of the rose leaves to remain at the top of the cutting. Stick this cutting into the sand and it will root in about four weeks. Cuttings of Cape jasmine may be rooted in the same way. Some geraniums, the rose geranium for example, may be grown from cuttings of the roots.



Bulbs are simply the lower ends of the leaves of a plant wrapped tightly around one another and inclosing the bud that makes the future flower-stalk. The hyacinth, the narcissus, and the common garden onion are examples of bulbous plants. The flat part at the bottom of the bulb is the stem of the plant reduced to a flat disk, and between each two adjacent leaves on this flat stem there is a bud, just as above-ground there is a bud at the base of a leaf. These buds on the stem of the bulb rarely grow, however, unless forced to do so artificially. The number of bulbs may be greatly increased by making these buds grow and form other bulbs. In increasing hyacinths the matured bulbs are dug in the spring, and the under part of the flat stem is carefully scraped away to expose the base of the buds. The bulbs are then put in heaps and covered with sand. In a few weeks each bud has formed a little bulb. The gardener plants the whole together to grow one season, after which the little bulbs are separated and grown into full-sized bulbs for sale. Other bulbs, like the narcissus or the daffodil, form new bulbs that separate without being scraped.



There are some other plants which have underground parts that are commonly called bulbs but which are not bulbs at all; for example, the gladiolus and the caladium, or elephant's ear. Their underground parts are bulblike in shape, but are really solid flattened stems with eyes like the underground stem of the Irish potato. These parts are called corms. They may be cut into pieces like the potato and each part will grow.

The dahlia makes a mass of roots that look greatly like sweet potatoes, but there are no eyes on them as there are on the sweet potato. The only eyes are on the base of the stem to which they are joined. They may be sprouted like sweet potatoes and then soft cuttings made of the green shoots, after which they may be rooted in the greenhouse and later planted in pots.

There are many perennial plants that will bloom the first season when grown from the seed, though such seedlings are seldom so good as the plants from which they came. They are generally used to originate new varieties. Seeds of the dahlia, for instance, can be sowed in a box in a warm room in early March, potted as soon as the plants are large enough to handle, and finally planted in the garden when the weather is warm. They will bloom nearly as soon as plants grown by dividing the roots or from cuttings.



In growing annual plants from seed, there is little difficulty if the grower has a greenhouse or a hotbed with a glass sash. Even without these the plants may be grown in shallow boxes in a warm room. The best boxes are about four inches deep with bottoms made of slats nailed a quarter of an inch apart to give proper drainage. Some moss is laid over the bottom to prevent the soil from sifting through. The boxes should then be filled with light, rich soil. Fine black forest mold, thoroughly mixed with one fourth its bulk of well-rotted manure, makes the best soil for filling the seed-boxes. If this soil be placed in an oven and heated very hot, the heat will destroy many weeds that would otherwise give trouble. After the soil is put in the boxes it should be well packed by pressing it with a flat wooden block. Sow the seeds in straight rows, and at the ends of the rows put little wooden labels with the names of the flowers on them.



Seeds sowed in the same box should be of the same general size in order that they may be properly covered, for seeds need to be covered according to their size. After sowing the seed, sift the fine soil over the surface of the box. The best soil for covering small seeds is made by rubbing dry moss and leaf-mold through a sieve together. This makes a light cover that will not bake and will retain moisture. After covering the seeds, press the soil firm and smooth with a wooden block. Now sprinkle the covering soil lightly with a watering-pot until it is fairly moistened. Lay some panes of glass over the box to retain the moisture, and avoid further watering until moisture becomes absolutely necessary. Too much watering makes the soil too compact and rots the seed.

As soon as the seedlings have made a second pair of leaves, take them up with the point of a knife and transplant them into other boxes filled in the same way. They should be set two inches apart so as to give them room to grow strong. They may be transplanted from the boxes to the flower-garden by taking an old knife-blade and cutting the earth into squares, and then lifting the entire square with the plant and setting it where it is wanted.

There are many flower-seeds which are so small that they must not be covered at all. In this class we find begonias, petunias, and Chinese primroses. To sow these prepare boxes as for the other seeds, and press the earth smooth. Then scatter some fine, dry moss thinly over the surface of the soil. Sprinkle this with water until it is well moistened, and at once scatter the seeds thinly over the surface and cover the boxes with panes of glass until the seeds germinate. Transplant as soon as the young plants can be lifted out separately on the blade of a penknife.



Many kinds of flower-seeds may be sowed directly in the open ground where they are to remain. The sweet pea is one of the most popular flowers grown in this way. The seeds should be sowed rather thickly in rows and covered fully four inches deep. The sowing should be varied in time according to the climate. From North Carolina southward, sweet peas may be sowed in the fall or in January, as they are very hardy and should be forced to bloom before the weather becomes hot. Late spring sowing will not give fine flowers in the South. From North Carolina northward the seeds should be sowed just as early in the spring as the ground can be easily worked. When the plants appear, stakes should be set along the rows and a strip of woven-wire fence stretched for the plants to climb on. Morning-glory seeds are also sowed where they are to grow. The seeds of the moonflower are large and hard and will fail to grow unless they are slightly cut. To start their growth make a slight cut just through the hard outer coat of the seed so as to expose the white inside. In this way they will grow very readily. The seeds of the canna, or Indian-shot plant, are treated in a similar way to start them growing.



The canna makes large fleshy roots which in the North are taken up, covered with damp moss, and stored under the benches of the greenhouse or in a cellar. If allowed to get too dry, they will wither. From central North Carolina south it is best to cover them up thickly with dead leaves and let them stay in the ground where they grew. In the early spring take them up and divide for replanting.



Perennial plants, such as our flowering shrubs, are grown from cuttings of the ripe wood after the leaves have fallen in autumn. From North Carolina southward these cuttings should be set in rows in the fall. Cuttings ten inches long are set so that the tops are just even with the ground. A light cover of pine leaves will prevent damage from frost. Farther north the cuttings should be tied in bundles and well buried in the ground with earth heaped over them. In the spring set them in rows for rooting. In the South all the hardy hybrid perpetual roses can be grown in this way, and in any section the cuttings of most of the spring-flowering shrubs will grow in the same manner. The Japanese quince, which makes such a show of its scarlet flowers in early spring, can be best grown from three-inch cuttings made of the roots and planted in rows in the fall.



Many of our ornamental evergreen trees, such as the arbor vitae, can be grown in the spring from seeds sowed in a frame. Cotton cloth should be stretched over the trees while they are young, to prevent the sun from scorching them. When a year old they may be set in nursery rows to develop until they are large enough to plant. Arbor vitae may also be grown from cuttings made by setting young tips in boxes of sand in the fall and keeping them warm and moist through the winter. Most of them will be rooted by spring.

The kinds of flowers that you can grow are almost countless. You can hardly make a mistake in selecting, as all are interesting. Start this year with a few and gradually increase the number under your care year by year, and aim always to make your plants the choicest of their kind.

Of annuals there are over four hundred kinds cultivated. You may select from the following list: phlox, petunias, China asters, California poppies, sweet peas, pinks, double and single sunflowers, hibiscus, candytuft, balsams, morning-glories, stocks, nasturtiums, verbenas, mignonette.



Of perennials select bleeding-hearts, pinks, bluebells, hollyhocks, perennial phlox, perennial hibiscus, wild asters, and goldenrods. From bulbs choose crocus, tulip, daffodil, narcissus, lily of the valley, and lily.

Some climbers are cobaea, honeysuckle, Virginia creeper, English ivy, Boston ivy, cypress vine, hyacinth bean, climbing nasturtiums, and roses.

To make your plants do best, cultivate them carefully. Allow no weeds to grow among them and do not let the surface of the soil dry into a hard crust. Beware, however, of stirring the soil too deep. Loosening the soil about the roots interrupts the feeding of the plant and does harm. Climbing plants may be trained to advantage on low woven-wire fences. These are especially serviceable for sweet peas and climbing nasturtiums. Do not let the plants go to seed, since seeding is a heavy drain on nourishment. Moreover, the plant has served its end when it seeds and is ready then to stop blossoming. You should therefore pick off the old flowers to prevent their developing seeds. This will cause many plants which would otherwise soon stop blossoming to continue bearing flowers for a longer period.



Window-Gardening. Growing plants indoors in the window possesses many of the attractions of outdoor flower-gardening, and is a means of beautifying the room at very small expense. Especially do window-gardens give delight during the barren winter time. They are a source of culture and pleasure to thousands who cannot afford extended and expensive ornamentation.

The window-garden may vary in size from an eggshell holding a minute plant to boxes filling all the available space about the window. The soil may be in pots for individual plants or groups of plants or in boxes for collections of plants. You may raise your flowers inside of the window on shelves or stands, or you may have a set of shelves built outside of the window and inclosed in glazed sashes. The illustration on page 119 gives an idea of such an external window-garden.



The soil must be rich and loose. The best contains some undecayed organic matter such as leaf-mold or partly decayed sods and some sand. Raise your plants from bulbs, cuttings, or seed, just as in outdoor gardens. Some plants do better in cool rooms, others in a warmer temperature.



If the temperature ranges from 35 deg. to 70 deg., averaging about 55 deg., azaleas, daisies, carnations, candytuft, alyssum, dusty miller, chrysanthemums, cinerarias, camellias, daphnes, geraniums, petunias, violets, primroses, and verbenas make especially good growths.



If the temperature is from 50 deg. to 90 deg., averaging 70 deg., try abutilon, begonia, bouvardia, caladium, canna, Cape jasmine, coleus, fuchsia, gloxinia, heliotrope, lantana, lobelia, roses, and smilax.

If your box or window is shaded a good part of the time, raise begonias, camellias, ferns, and Asparagus Sprengeri.



When the soil is dry, water it; then apply no more water until it again becomes dry. Beware of too much water. The plants should be washed occasionally with soapsuds and then rinsed. If red spiders are present, sponge them off with water as hot as can be borne comfortably by the hand. Newspapers afford a good means of keeping off the cold.



CHAPTER VI

THE DISEASES OF PLANTS

SECTION XXVII. THE CAUSE AND NATURE OF PLANT DISEASE

Plants have diseases just as animals do; not the same diseases, to be sure, but just as serious for the plant. Some of them are so dangerous that they kill the plant; others partly or wholly destroy its usefulness or its beauty. Some diseases are found oftenest on very young plants, others prey on the middle-aged tree, while still others attack merely the fruit. Whenever a farmer or fruit-grower has disease on his plants, he is sure to lose much profit.

You have all seen rotten fruit. This is diseased fruit. Fruit rot is a plant disease. It costs farmers millions of dollars annually. A fruit-grower recently lost sixty carloads of peaches in a single year through rot which could have been largely prevented if he had known how.

Many of the yellowish or discolored spots on leaves are the result of disease, as is also the smut of wheat, corn, and oats, the blight of the pear, and the wilt of cotton. Many of these diseases are contagious, or, as we often hear said of measles, "catching." This is true, among others, of the apple and peach rots. A healthy apple can catch this disease from a sick apple. You often see evidence of this in the apple bin. So, too, many of the diseases found in the field or garden are contagious.

Sometimes when the skin of a rotten apple has been broken you will find in the broken place a blue mold. It was this that caused the apple to decay. This mold is a living plant; very small, certainly, but nevertheless a plant. Let us learn a little about molds, in order that we may better understand our apple and potato rots, as well as other plant diseases.

If you cut a lemon and let it stand for a day or two, there will probably appear a blue mold like that you have seen on the surface of canned fruit. Bread also sometimes has this blue mold; at other times bread has a black mold, and yet again a pink or a yellow mold.

These and all other molds are tiny living plants. Instead of seeds they produce many very small bodies that serve the purpose of seeds and reproduce the mold. These are called spores. Fig. 112 shows how they are borne on the parent plant.



It is also of great importance to decide whether by keeping the spores away we may prevent mold. Possibly this experiment will help us. Moisten a piece of bread, then dip a match or a pin into the blue mold on a lemon, and draw the match across the moist bread. You will thus plant the spores in a row, though they are so small that perhaps you may not see any of them. Place the bread in a damp place for a few days and watch it. Does the mold grow where you planted it? Does it grow elsewhere? This experiment should prove to you that molds are living things and can be planted. If you find spots elsewhere, you must bear in mind that these spores are very small and light and that some of them were probably blown about when you made your sowing. When you touch the moldy portion of a dry lemon, you see a cloud of dust rise. This dust is made of millions of spores.



If you plant many other kinds of mold you will find that the molds come true to the kind that is planted; that like produces like even among molds.



You can prove, also, that the mold is caused only by other mold. To do this, put some wet bread in a wide-mouthed bottle and plug the mouth of the bottle with cotton. Kill all the spores that may be in this bottle by steaming it an hour in a cooking-steamer. This bread will not mold until you allow live mold from the outside to enter. If, however, at any time you open the bottle and allow spores to enter, or if you plant spores therein, and if there be moisture enough, mold will immediately set in.



The little plants which make up these molds are called fungi. Some fungi, such as the toadstools, puffballs, and devil's snuff-box, are quite large; others, namely the molds, are very small; and others are even smaller than the molds. Fungi never have the green color of ordinary plants, always reproduce by spores, and feed on living matter or matter that was once alive. Puffballs, for example, are found on rotting wood or dead twigs or roots. Some fungi grow on living plants, and these produce plant disease by taking their nourishment from the plant on which they grow; the latter plant is called the host.

The same blue mold that grows on bread often attacks apples that have been slightly bruised; it cannot pierce healthy apple skin. You can plant the mold in the bruised apple just as you did on bread and watch its rapid spread through the apple. You learn from this the need of preventing bruised or decayed apples from coming in contact with healthy fruit.



Just as the fungus studied above lives in the apple or bread, so other varieties live on leaves, bark, etc. Fig. 113 represents the surface of a mildewed rose leaf greatly magnified. This mildew is a fungus. You can see its creeping stems, its upright stalk, and numerous spores ready to fall off and spread the disease with the first breath of wind. You must remember that this figure is greatly magnified, and that the whole portion shown in the figure is only about one tenth of an inch across. Fig. 114 shows the general appearance of a twig affected by this disease.

Mildew on the rose or on any other plant may be killed by spraying the leaves with a solution of liver of sulphur; to make this solution, use one ounce of the liver of sulphur to two gallons of water.

The fungus that causes the pear-leaf spots has its spores in little pits (Fig. 115). The spores of some fungi also grow on stalks, as shown in Fig. 116. This figure represents an enlarged view of the pear scab, which causes so much destruction.

You see, then, that fungi are living plants that grow at the expense of other plants and cause disease. Now if you can cover the leaf with a poison that will kill the spore when it comes, you can prevent the disease. One such poison is the Bordeaux (bor-do') mixture, which has proved of great value to farmers.

Since the fungus in most cases lives within the leaves, the poison on the outside does no good after the fungus is established. The treatment can be used only to prevent attack, not to cure, except in the case of a few mildews that live on the outside of the leaf, as does the rose mildew.

EXERCISE

Why do things mold more readily in damp places? Do you now understand why fruit is heated before it is canned? Try to grow several kinds of mold. Do you know any fungi which may be eaten?

Transfer disease from a rotten apple to a healthy one and note the rapidity of decay. How many really healthy leaves can you find on a strawberry plant? Do you find any spots with reddish borders and white centers? Do you know that this is a serious disease of the strawberry? What damage does fruit mold do to peaches, plums, or strawberries?

Write to your experiment station for bulletins on plant diseases and methods for making and using spraying mixtures.

SECTION XXVIII. YEAST AND BACTERIA

Can you imagine a plant so small that it would take one hundred plants lying side by side to equal the thickness of a sheet of writing-paper? There are plants that are so small. Moreover, these same plants are of the utmost importance to man. Some of them do him great injury, while others aid him very much.

You will see their importance when you are told that certain of them in their habits of life cause great change in the substances in which they live. For example, when living in a sugary substance they change the sugar into a gas and an alcohol. Do you remember the bright bubbles of gas you have seen rising in sweet cider or in wine as it soured? These bubbles are caused by one of these small plants—the yeast plant. As the yeast plant grows in the sweet fruit juice, alcohol is made and a gas is given off at the same time, and this gas makes the bubbles.



Later, other kinds of plants equally small will grow and change the alcohol into an acid which you will recognize as vinegar by its sour taste and peculiar odor. Thus vinegar is made by the action of two different kinds of little living plants in the cider. That these are living beings you can prove by heating the cider and keeping it tightly sealed so that nothing can enter it. You will find that because the living germs have been killed by the heat, the cider will not ferment or sour as it did before. The germs could of course be killed by poisons, but then the cider would be unfit for use. It is this same little yeast plant that causes bread to rise.

When you see any decaying matter you may know that in it minute plants much like the yeast plant are at work. Since decay is due to them, we take advantage of the fact that they cannot grow in strong brine or smoke; and we prepare meat for keeping by salting it or by smoking it or by both of these methods.

You see that some of the yeast plants and bacteria, as many of these forms are called, are very friendly to us, while others do us great harm.

Some bacteria grow within the bodies of men and other animals or in plants. When they do so they may produce disease. Typhoid fever, diphtheria, consumption, and many other serious diseases are caused by bacteria. Fig. 118, e, shows the bacterium that causes typhoid fever. In the picture, of course, it is very greatly magnified. In reality these bacteria are so small that about twenty-five thousand of them side by side would extend only one inch. These small beings produce their great effects by very rapid multiplication and by giving off powerful poisons.



Bacteria are so small that they are readily borne on the dust particles of the air and are often taken into the body through the breath and also through water or milk. You can therefore see how careful you should be to prevent germs from getting into the air or into water or milk when there is disease about your home. You should heed carefully all instructions of your physician on this point, so that you may not spread disease.

SECTION XXIX. PREVENTION OF PLANT DISEASE

In the last two sections you have learned something of the nature of those fungi and bacteria that cause disease in animals and plants. Now let us see how we can use this knowledge to lessen the diseases of our crops. Farmers lose through plant diseases much that could be saved by proper precaution.

First, you must remember that every diseased fruit, twig, or leaf bears millions of spores. These must be destroyed by burning. They must not be allowed to lie about and spread the disease in the spring. See that decayed fruit in the bin or on the trees is destroyed in the same manner. Never throw decayed fruit into the garden or orchard, as it may cause disease the following year.

Second, you can often kill spores on seeds before they are planted and thus prevent the development of the fungus (see pp. 134-137).

Third, often the foliage of the plant can be sprayed with a poison that will prevent the germination of the spores (see pp. 138-140).

Fourth, some varieties of plants resist disease much more stoutly than others. We may often select the resistant form to great advantage (see Fig. 119).

Fifth, after big limbs are pruned off, decay often sets in at the wound. This decay may be prevented by coating the cut surface with paint, tar, or some other substance that will not allow spores to enter the wound or to germinate there.

Sixth, it frequently happens that the spore or fungus remains in the soil. This is true in the cotton wilt, and the remedy is so to rotate crops that the diseased land is not used again for this crop until the spores or fungi have died.

SECTION XXX. SOME SPECIAL PLANT DISEASES

Fire-Blight of the Pear and Apple. You have perhaps heard your father speak of the "fire-blight" of pear and apple trees. This is one of the most injurious and most widely known of fruit diseases. Do you want to know the cause of this disease and how to prevent it?

First, how will you recognize this disease? If the diseased bough at which you are looking has true fire-blight, you will see a blackened twig with withered, blackened leaves. During winter the leaves do not fall from blighted twigs as they do from healthy ones. The leaves wither because of the diseased twig, not because they are themselves diseased. Only rarely does the blight really enter the leaf. Sometimes a sharp line separates the blighted from the healthy part of the twig.

This disease is caused by bacteria, of which you have read in another section. The fire-blight bacteria grow in the juicy part of the stem, between the wood and the bark. This tender, fresh layer (as explained on page 79) is called the cambium, and is the part that breaks away and allows you to slip the bark off when you make your bark whistle in the spring. The growth of new wood takes place in the cambium, and this part of the twig is therefore full of nourishment. If this nourishment is stolen the plant of course soon suffers.

The bacteria causing fire-blight are readily carried from flower to flower and from twig to twig by insects; therefore to keep these and other bacteria away from your trees you must see to it that all the trees in the neighborhood of your orchard are kept free from mischievous enemies. If harmful bacteria exist in near-by trees, insects will carry them to your orchard. You must therefore watch all the relatives of the pear; namely, the apple, hawthorn, crab, quince, and mountain ash, for any of these trees may harbor the germs.



When any tree shows blight, every diseased twig on it must be cut off and burned in order to kill the germs, and you must cut low enough on the twig to get all the bacteria. It is best to cut a foot below the blackened portion. If by chance your knife should cut into wood containing the living germs, and then you should cut into healthy wood with the same knife, you yourself would spread the disease. It is therefore best after each cutting to dip your knife into a solution of carbolic acid. This will kill all bacteria clinging to the knife-blade. The surest time to do complete trimming is after the leaves fall in the autumn, as diseased twigs are most easily recognized at that time, but the orchard should be carefully watched in the spring also. If a large limb shows the blight, it is perhaps best to cut the tree entirely down. There is little hope for such a tree.

A large pear-grower once said that no man with a sharp knife need fear the fire-blight. Yet our country loses greatly by this disease each year.



It may be added that winter pruning tends to make the tree form much new wood and thus favors the disease. Rich soil and fertilizers make it much easier in a similar way for the tree to become a prey to blight.

EXERCISE

Ask your teacher to show you a case of fire-blight on a pear or apple tree. Can you distinguish between healthy and diseased wood? Cut the twig open lengthwise and see how deep into the wood and how far down the stem the disease extends. Can you tell surely from the outside how far the twig is diseased? Can you find any twig that does not show a distinct line of separation between diseased and healthy wood? If so, the bacteria are still living in the cambium. Cut out a small bit of the diseased portion and insert it under the bark of a healthy, juicy twig within a few inches of its tip and watch it from day to day. Does the tree catch the disease? This experiment may prove to you how easily the disease spreads. If you should see any drops like dew hanging from diseased twigs, touch a little of this moisture to a healthy flower and watch for results.

Cut and burn all diseased twigs that you can find. Estimate the damage done by fire-blight.

Farmers' bulletins on orchard enemies are published by the Department of Agriculture, Washington, D.C., and can be had by writing for them. They will help your father much in treating fire-blight.

Oat Smuts. Let us go out into a near-by oat field and look for all the blackened heads of grain that we can find. How many are there? To count accurately let us select an area one foot square. We must look carefully, for many of these blackened heads are so low that we shall not see them at the first glance. You will be surprised to find as many as thirty or forty heads in every hundred so blackened. These blackened heads are due to a plant disease called smut.



When threshing-time comes you will notice a great quantity of black dust coming from the grain as it passes through the machine. The air is full of it. This black dust consists of the spores of a tiny fungous plant. The fungous smut plant grows upon the oat plant, ripens its spores in the head, and is ready to be thoroughly scattered among the grains of the oats as they come from the threshing-machine.

These spores cling to the grain and at the next planting are ready to attack the sprouting plantlet. A curious thing about the smut is that it can gain a foothold only on very young oat plants; that is, on plants about an inch long or of the age shown in Fig. 121.

When grain covered with smut spores is planted, the spores develop with the sprouting seeds and are ready to attack the young plant as it breaks through the seed-coat. You see, then, how important it is to have seed grain free from smut. A substance has been found that will, without injuring the seeds, kill all the smut spores clinging to the grain. This substance is called formalin. Enough seed to plant a whole acre can be treated with formalin at a cost of only a few cents. Such treatment insures a full crop and clean seed for future planting. Try it if you have any smut.



Fig. 122 illustrates what may be gained by using seeds treated to prevent smut. The annual loss to the farmers of the United States from smut on oats amounts to several millions of dollars. All that is needed to prevent this loss is a little care in the treatment of seed and a proper rotation of crops.

EXERCISE

Count the smutted heads on a patch three feet square and estimate the percentage of smut in all the wheat and oat fields near your home. On which is it most abundant? Do you know of any fields that have been treated for smut? If so, look for smut in these fields. Ask how they were treated. Do you know of any one who uses bluestone for wheat smut? Can oats be treated with bluestone?

At planting time get an ounce of formalin at your drug store or from the state experiment station. Mix this with three gallons of water. This amount will treat three bushels of seeds. Spread the seeds thinly on the barn floor and sprinkle them with the mixture, being careful that all the seeds are thoroughly moistened. Cover closely with blankets for a few hours and plant very soon after treatment. Try this and estimate the per cent of smut at next harvest-time. Write to your experiment station for a bulletin on smut treatment.



Potato Scab. The scab of the white, or Irish, potato is one of the commonest and at the same time most easily prevented of plant diseases. Yet this disease diminishes the profits of the potato-grower very materially. Fig. 123 shows a very scabby potato, while Fig. 124 represents a healthy one. This scab is caused by a fungous growth on the surface of the potato. Of course it lessens the selling-price of the potatoes. If seed potatoes be treated to a bath of formalin just before they are planted, the formalin will kill the fungi on the potatoes and greatly diminish the amount of scab at the next harvest. Therefore before they are planted, seed potatoes should be soaked in a weak solution of formalin for about two hours. One-half pint of formalin to fifteen gallons of water makes a proper solution.



One pint of formalin, or enough for thirty gallons of water, will cost but thirty-five cents. Since this solution can be used repeatedly, it will do for many bushels of seed potatoes.

Late Potato Blight. The blight is another serious disease of the potato. This is quite a different disease from the scab and so requires different treatment. The blight is caused by another fungus, which attacks the foliage of the potato plant. When the blight seriously attacks a crop, it generally destroys the crop completely. In the year 1845 a potato famine extending over all the United States and Europe was caused by this disease.



Spraying is the remedy for potato blight. Fig. 128 shows the effect of spraying upon the yield. In this case the sprayed field yielded three hundred and twenty-four bushels an acre, while the unsprayed yielded only one hundred bushels to an acre. Fig. 127 shows the result of three applications of the spraying mixture on the diseased field. Figs. 129 and 130 show how the spraying is done.



EXERCISE

Watch the potatoes at the next harvest and estimate the number that is damaged by scab. You will remember that formalin is the substance used to prevent grain smuts. Write to your state experiment station for a bulletin telling how to use formalin, as well as for information regarding other potato diseases. Give the treatment a fair trial in a portion of your field this year and watch carefully for results. Make an estimate of the cost of treatment and of the profits. How does the scab injure the value of the potato? The late blight can often be recognized by its odor. Did you ever smell it as you passed an affected field?



Club Root. Club root is a disease of the cabbage, turnip, cauliflower, etc. Its general effect is shown in the illustration (Fig. 131). Sometimes this disease does great damage. It can be prevented by using from eighty to ninety bushels of lime to an acre.

Black Knot. Black knot is a serious disease of the plum and of the cherry tree. It attacks the branches of the tree; it is well illustrated in Fig. 132. Since it is a contagious disease, great care should be exercised to destroy all diseased branches of either wild or cultivated plums or cherries. In many states its destruction is enforced by law. All black knot should be cut out and burned some time before February of each year. This will cost little and save much.



Peach Leaf Curl. Peach leaf curl does damage amounting to about $3,000,000 yearly in the United States. It can be almost entirely prevented by spraying the tree with Bordeaux mixture or lime-sulphur wash before the buds open in the spring. It is not safe to use strong Bordeaux mixture on peach trees when they are in leaf.



Cotton Wilt. Cotton wilt when it once establishes itself in the soil completely destroys the crop. The fungus remains in the soil, and no amount of spraying will kill it. The only known remedy is to cultivate a resistant variety of cotton or to rotate the crop.