The Apple-Tree Part 7

With some experience, the cultivator soon learns to make many deft applications of ingrafting. Sometimes a piece of bark may be used as a patch. In the bracing of crotches in young trees, the two trunks may be joined by uniting a small branch from either one, twisting them together to form a bridge like a bolt; they can be made to grow together, forming a solid union. Bolting the parts with iron rods, or holding them together by means of chains, is the usual and commonly the better method. The iron is not to go around a limb, however, for girdling results; the rods or chains should be secured by bolts bored through the wood and pulling against large heads or washers.

The usual repairs are easily made. When trees are badly injured, and particularly when the tree is low in vitality, it may not be worth while to engage in surgery. It may be better to plant a new tree.

Saving very old trees by the mending processes is not likely to be satisfactory. The grower should transfer his affection to a young tree. If the tree has had good care throughout its life, it probably will not need much surgery in old age. The grower will be willing, when the time comes, to take a photograph for memory's sake and to let the tree come to a timely and artistic end.

XIV

CITIZENS OF THE APPLE-TREE

Many years ago, my old friend, the late Dr. J. A. Lintner, State Entomologist of New York, compiled a list of 356 insects that feed on the apple-tree. Later authorities place the number at nearly five hundred species. It must be a good plant that has such a host of denizens. The number of fungi is also large; and the tree often supports lichens, algae, and other forms of life.

The apple-tree is not single in its denizens. No plant lives alone. It has a.s.sociation with its fellows, perhaps contest for s.p.a.ce and nourishment. It provides habitat for many organisms, many of which live on its bounty. I have never seen a bearing apple-tree that was not a colonizing place for other living things. We accept these things as matters of course, as being in place, living their part in nature.

Therefore, one cannot understand the apple-tree unless one knows something of its citizenry.

Probably the most prominent citizen of the apple-tree is the codlin-moth. Its larva is the apple-worm, the one that makes "wormy apples," the burrows going to the core and out again. The insect is native in Europe, but has been known in North America nearly two hundred years, and is widespread in the apple countries of the world.

If one has screens in the apple cellar, one is likely to find small moths on them in the spring, larger than a clothes moth, about three-fourths inch in spread of the soft gray watered-silk wings. This is the imago or mature form of the insect known as the codlin-moth (it lives on codlins or apples). The larvae or "worms" were brought into the cellar in the apples; some of them crawled out, spun themselves in a coc.o.o.n and pupated; in due season the moth emerged, ready to lay the eggs for other larvae. Ordinarily the fruit-grower does not see the moth, for it is a small object amidst the foliage of apple-trees; the larva or apple-worm he knows well.

There may be two or more broods of apple-worms, depending on the length of the season. In the northern apple regions of North America there is usually only one brood, with a partial second brood. The first brood is hatched from eggs laid by moths that emerge in spring.

The moths come from larvae that have lain in coc.o.o.ns all winter, hidden under bark on the trunks and main branches of the apple-tree, in crevices in nearby posts and fences, and sometimes in the ground. The pupae are the transformed larvae or worms that left the apple of the previous year, usually before it fell, and crawled down the tree to find a place to spin the silken brown coc.o.o.ns in which they wrapped themselves to undergo the wonderful transformation.

So is the cycle complete: egg laid in early spring, mostly on the leaves; larva hatched in about one week, crawling to the young apple to feed, where it lives for perhaps a month; larva departed from the fruit to form a coc.o.o.n and to remain quiescent till it pupates the following spring (if there is no second brood) when it transforms into a moth; the moth alive for one week or ten days, laying perhaps as many as one hundred eggs or even more. If there is a second or third brood, the pupa resurrects in ten days or so into the moth; eggs are laid; larvae are hatched; pupae again are formed; and thus is the process continued. But the winter stage is the larva, although perhaps in store-houses the moths may emerge earlier and survive till spring.

The eggs of the first brood are commonly laid on the leaves and fruit.

The young larva or worm eats very little on the foliage. It usually crawls into the blossom end of the apple. The young apple stands erect, with the calyx open (Fig. 6); later the calyx closes and protects the larva that hatched there, forming a good cover for its operations (Fig. 7). The worm drives for the core, where it eats the young seeds and burrows extensively; then, when nearly grown, it sets out for the surface, eating a straight burrow; an opening is made through the skin of the apple, but this exit is plugged until the animal is ready to leave the place and to crawl down the tree to pupate. The larvae of later broods may enter at the side of the apple, where a leaf affords protection or where two fruits come together; but the life-history is the same, varying in its rapidity.

This account discloses the vulnerable point in the life-history, if one is to destroy the insects and to grow fair fruit; if poison is lodged on the erect open-topped little apple, the young larva will get it before he injures the fruit. If the application of the poison is delayed until the calyx closes (Fig. 7), there will be small chance of reaching the worm. The best way to reach the second brood is to destroy all the first brood. The standard practice, therefore, is to spray the trees soon after the petals fall, with the idea of depositing a.r.s.enic in the blossom end.

But the season of egg-laying is long, often extending over a period of three or four weeks, for the moths do not all emerge from the coc.o.o.ns simultaneously. It is customary, therefore, to spray again about two weeks after the first application, with the hope of catching the young worms on their way to the fruit.

There is no question about the efficacy of spraying. Its value has been demonstrated time and again. The methods and the materials may be learned from the experiment station publications in any State, wherein the advice is kept up-to-date.

In the days before the perfecting of the spraying processes, the codlin-moth was controlled by catching the pupating larvae. Taking advantage of the habit of the worm to find lodgment under the bark on the trunk, it was the practice to sc.r.a.pe the loose bark from bole and large branches to destroy the hiding-places and then to tie a band of cloth around the trunk. Under this band the worms were taken, as they spun themselves up in the coc.o.o.ns. This is a lesson taken from the industrious woodp.e.c.k.e.rs, who, in the winter, search the trees for the pupae and make holes through the flakes of bark to get them. The sc.r.a.ping of apple-trees is not much recommended now for the reason that this special necessity is pa.s.sed, and because the better tillage and care together with the soaking of the branches and trunk in the spraying operation, tend to keep the tree vigorous and the bark properly exfoliated.

So the worm in the apple has a delicate and interesting history. From egg to imago the transformations proceed with regularity, and they are marvelous. Had we not traced the sequence, no man could tell by appearances that the larva, the pupa and the moth are one and the same animal. They seem to have nothing in common. So is the egg stage as different as the other three, but we are measurably prepared for this epoch, since we know seeds so well; the egg and the seed are a.n.a.logous. That a moth in the air should come from a crawling worm in an apple is indeed one of the miracles of nature. The worm leaves the apple ere it falls; how the worm knows the time is again a mystery. By some instinct, it is able to cognize a dying apple. The later worms, either the lastlings from the early brood or the product of subsequent broods, may remain in the apple when it is harvested, particularly in an apple picked before it is quite mature and from which the worm has not escaped.

The apple-worm ruins the crop by killing many of the fruits and by blemis.h.i.+ng the remainder. Seldom are there two worms in an apple. They seem to respect each other's hunting-ground. From the worm's point of view and from man's, one is enough.

If man has dominion and if he needs apples, then is he within his rights if he joins issue with the insects. Yet is the insect as interesting for all that. I think we should miss many of the satisfactions of life, and certainly some of the disciplines, if there were no insects. My apple-tree is a great place for a naturalist. Van Bruyssel wrote a book on "The Population of an Old Pear-Tree." "When certain blue spirits begin to flit about me," he writes, "I depart from my study to go and read, in what I am allowed, even by my clerical uncle, to call my book of devotions. The devotions I mean are not in my book-case. No publisher, if he ever thought of such a thing, could bring them out. They are a page of the book of Nature, opened in the country, under blue sky, displayed at all season." What a marvelous company Van Bruyssel found on his old pear tree; and what inexhaustible worlds did Fabre discover in the lives of the spider, the fly, the caterpillar, the wasps, the mason-bees and others!

Therefore we need not pause with the other four hundred and more insect citizens of the apple-tree. Some of them, as the San Jose scale, are not peculiarly apple-tree insects. My tree has another crew of inhabitants, and to this company we may now have introduction.

The spots on the leaves and fruits are not deposits of dirt nor are they caused by mysterious conditions in the atmosphere, as once supposed, nor is it in the nature of leaves to be spotted and of fruits to be scabby; nor are the one-sided dwarfed fruits merely accidents. The organism responsible for these blemishes is less evident than the codlin-moth; yet what fruit-grower knows the eggs of the codlin-moth? But the organisms are as definite as are the insects; no longer are the fungi things without form and without positive cycles.

On the ground are apple leaves, shed in the autumn. On the leaves are spots or lesions,--injured or "diseased"--infected with the apple-scab fungus. Under a good microscope the investigator finds immature fruiting bodies in these areas. In the early days of Spring, these bodies or winter-spores mature. A rain discharges them in astonis.h.i.+ng numbers. Rising in the air (for they are incredibly light), these spores lodge on the unfolding leaves and flowers of the apple, and there begin to germinate, invading the tissue. The tissue is penetrated and killed so rapidly that the practiced eye soon discovers a "spot." The leaf, if badly infected, may not reach full size; it may curl; it may die and fall; the tree thereby is injured.

From the fungus in the active diseased areas, another kind of spore develops rapidly. It is the summer-spore, which may be produced in prodigious numbers, and being discharged carries the disease elsewhere.

All summer the process of spore-formation and distribution keeps up.

If conditions are favorable, the tree is invaded in foliage and fruit.

The flower-stems in the unfolding buds are attacked by the winter-spores and the flower falls. The apples become spotted from the invasion of the summer-spores, perhaps misshapen. Late infections may not show at picking time, but develop on the fruit in storage. The affected leaves are cast in the autumn, the winter-spores begin to form, the snows come and hide the processes, in spring the spores mature; and so does the round of life go on and on.

There are beautiful forms in these fragile fungus threads that eat their way into the tissues of the host. There are fascinating phenomena in the growth and reproduction. Even so and for all that, man protects his tree by spraying it with poison, and thereby again does he have dominion.

The spraying for apple-scab is with lime-sulfur to which may be added a.r.s.enate of lead. This treatment, properly timed, may suffice also for the codlin-moth. As the fungus may attack the flower-stems and kill them, so is the first application made when the flower-buds open and the stems begin to separate, but before the flowers expand; the operator has a period of one to three days in which to spray. A second spraying is given just after the blossoms fall, as for codlin-moth; if the season is wet, a third application may be made ten to fourteen days later; if the fungus seems to spread, a fourth spraying may be applied in midsummer. These sprayings, variously modified, control not only the codlin-moth and the scab fungus but also scale, blister-mite, plant-lice, leaf-roller, case-bearer, bud-moth, red-bug and others.

In the tropics one sees trees bearing great burdens of orchids and bromeliads and ferns and mosses, and one wonders at the strange and exuberant population. Yet here is my apple-tree supporting epiphytes and parasites and insects, protector and nurse of a goodly company; and birds nest on the branches thereof.

XV

THE APPLE-TREE REGIONS

The northern hemisphere is the home of the apple, particularly Central Europe, Canada, the United States. In certain regions in the southern hemisphere the temperature and humidity are right for the good growing of apples, mostly in elevated areas. In New Zealand and parts of Australia, apple-growing is a.s.suming large proportions. Their export trade to Europe and parts of South America has come to be important and undoubtedly is destined greatly to increase.

In Europe, where land is often limited and high in price, apple-trees may be planted closer than in America, even in field conditions, and more attention is given to pruning, heading-in, and the development of fruit-spurs in the interior of the tree-top. I noticed this practice in New Zealand, also. In these directions, the Europeans have much to teach us in the careful growing of good apples. In Europe, the definite training of the apple-tree begins in the nursery; quant.i.ty-production, with standardization, is not there the aim.

In North America the general practice is to let the tree take its course, reaching its full natural stature. The pruning is mostly corrective, to keep the tree in shape and to prevent the top from becoming too thick, rather than in the development of fruiting wood.

The consequence is that our trees become very large, specially in New York and New England where they are long-lived. In the western country, as we have learned, the apple-tree tends to be shorter-lived and does not usually attain such great size. In the New York apple country, orchards may be in good bearing at forty to sixty years from planting, and individual trees may be productive much longer than this. The trees come into good bearing in ten to fifteen years. In the irrigated regions of the West, the trees may be expected to bear a good crop two to five years earlier; to what age they may attain, in large plantations, it is yet too early to state.

The commercial apple regions of North America are in Canada and the northern United States, comprising about two or three tiers of States, with important extensions southward into the mountains and in special parts. The Southern States are not known as apple-growing country, except in special restricted elevated areas, although there are considerable plantations near the Gulf of Mexico.

The geography of apple-growing on the North American continent cannot be better displayed than by copying the table of contents of the larger part of Chapters III and II in Folger and Thomson's excellent recent book, "The Commercial Apple Industry of North America:"

_Commercial Apple Production in Canada_

Nova Scotia Prince Edward Island and New Brunswick Quebec Ontario British Columbia.

_Leading Apple Regions of the United States_

Western New York Hudson Valley New England Baldwin belt The Champlain district New Jersey Delaware Shenandoah-c.u.mberland district Piedmont district of Virginia Minor regions in Pennsylvania, West Virginia and Virginia Mountain region of North Carolina Mountain region of Georgia Ohio Southern Ohio, Rome Beauty district Minor regions in Ohio Kentucky Michigan Illinois Southern Illinois early apple region Mississippi Valley region of Illinois Ozark region Missouri River region Arkansas Valley of Kansas Southeastern Illinois Colorado New Mexico Utah Montana Was.h.i.+ngton Yakima Valley Wenatchee North Central Was.h.i.+ngton district Spokane district Walla Walla district Oregon Hood River Valley Rogue River Valley Other apple districts in Oregon Idaho Payette district Boise Valley Twin Falls Lewiston section California Watsonville district Sebastopol apple district Yucaipa section Wisconsin Minnesota

The varieties of the South and the North, and largely also of the West and the East, are prevailingly different. Canada has a set of apples quite its own. These differences are marked when one visits exhibitions in the various regions. Let the visitor who is a good judge of apples in Michigan and Ohio attempt to judge them in an exhibition in the Annapolis Valley of Nova Scotia, in the Province of Quebec, in North Carolina, in Minnesota, in Oregon. He will be impressed with the wonderful diversity, as well as the undeveloped resources, of the continent.

Southward, apples do not keep well. There are no true winter apples in the Southern States, outside mountain regions. A winter apple of the North becomes a fall apple in the South. In fact, there are marked differences in keeping quality within a single State. On gravelly lands or warm slopes in the southern part of New York, the Northern Spy may become practically a late autumn apple; in the northern parts of the State it is a firm crisp all-winter keeper. In the winter apple, the ripening process proceeds in storage. When the season is so long that maturity is reached on the tree, the subsequent duration is relatively short.

It is not to be inferred, however, that apples are to be grown only in regions and soils naturally well adapted. Such adaptations should be controlling in commercial plantations; but if man has dominion he should be able to accomplish much in untoward or even in hostile conditions. Even the city lot may be able to yield a harvest, if the occupant of it is minded in fruits rather than in other things. Every observant traveler has noted cases in which good results in the rearing of plants and animals have been attained in places that no one would choose for the purpose: the man has overcome his obstacles. I was impressed with this fact in visiting a greenhouse in the Shetland Islands. Cultivation has been carried far beyond the optimum regions.

The merit of the man's performance is measured in the excellence of his result rather than in the quant.i.ty of it. The application of skill is the highest test of ability in plant-growing, and this is often expressed in the most difficult places.

Whatever may be the adaptability of any general territory to the growing of apples in a large way, the probability is that a man of resources and skill will be able to raise good apples for himself, unless, of course, the region is prohibitive. The amateur may be a law unto himself in many of these matters, delighting in the ingenuity that enables him to overcome.