Chapter III: Pear Culture (2)

Perhaps with no other tree-fruits is it more important to begin with good trees, as even with the best it is often difficult to get a good start toward a pear-orchard. Black-heart, caused by winter-killing, is a sign that must be heeded, and a tree badly blackened in its pith, especially if the surrounding wood is discolored, should be discarded. Crown-gall on tap roots affects the tree deleteriously. Trees marked by hail or insects are often worthless. Other marks that commend or condemn trees are: A short stocky plant is better than a tall spindling one. A tree with many branches is better than one with few branches. The roots should be much branched rather than sparsely branched. A tree with smooth, bright bark is better than one with rough, dull bark. Both trunk and branches should be plump and show no signs of shrivelling. A poor pear-tree in the nursery seldom makes a good tree in the orchard. There is great variation in varieties as the trees come from the nursery, a fact to be considered. In New York, two-year-old trees are best.

A good deal of the success that attends the culture of the pear depends on properly setting the young trees and the right care of the young plants. It is superfluous to discuss these operations in detail, but a statement as to proper setting and care will serve as reminders. In this State, pear-trees should always be set in the spring. A young pear-tree should be set in the soil about as deep as it stood in the nursery; in light soils the roots might well be planted a little deeper, and in heavy soils not quite so deep. The soil must be packed firmly about the roots--best done by tramping. Watering is necessary only when the land is parched with drought. When necessary, water should be used liberally. Puddling the roots by dipping them in thin mud before planting serves very well for watering. The surface soil should always be left loose. Rank manure about the roots of young trees is plant infanticide. During the tender nonage of the young pear, cultivation should be intensive; insects and fungi should be kept off; and plants that refuse to grow well must be marked for discarding.

A catch-crop grown between the rows of pears is a profitable adjunct to the pear-orchard for the first four or five years. Few indeed are the pear-orchards in New York that cannot be made to sustain themselves for the first few years by inter-cropping. The crops should be hoed crops, such as potatoes, cabbage, beans, tomatoes, and nearly all crops in demand at the canneries. Along the Hudson, small-fruits are often planted in young pear-orchards, but in Western New York these are not looked upon with favor. Grass and grain are deadly in a young pear-orchard, and no right-minded man would plant them there. This brings us to cultivation.

Cultivation should be the rule; sod mulch, the exception, in growing pears in New York. After pear-trees come into bearing they may be made to produce crops if kept in sod. The grass in sodded orchards should be kept closely mown to form a mulch about the trees. Commercial fertilizers as well as mulch are needed in sodded orchards, and of the several chemical fertilizers nitrogen is most requisite. The man who grows pears in sod must not expect as much fruit, as the crop is lessened in both number and size of the pears. On the other hand, the pears may be better colored, and the trees may be freer from blight.

Tillage is begun in the spring by plowing the land. This operation is followed by cultivation with smoothing-harrow, weeder, or cultivator. There are several reliable guides to tell when and how often a pear-orchard should be cultivated. When the soil becomes dry it should be tilled. A heavy rain should always be followed by the cultivator to prevent the formation of a crust on the surface. At this time, he tills twice who tills quickly. Cultivate when there are clods to be pulverized. Usually a pear-orchard should be cultivated once in two or three weeks until time to sow the cover-crop in midsummer. The depth to till is governed by the season and the nature of the soil. Heavy soils need deep stirring; light soils, shallow stirring. Till moist soils deeply; dry soils, lightly. The time to stop tillage depends on the soil, the climate, and the season. The fruit should be nearly full sized when tillage is stopped and the cover-crop sown.

The cover-crop seed is covered the last time the cultivator goes over the orchard. Clover, vetch, cow-horn turnip, rape, oats, rye, and buckwheat are all used as cover-crops in this State. Combination crops are not popular because of too great cost of seed. The quantity of seed sown is the same as when the crops are grown as farm crops. The crops must be changed from time to time in whatever rotation seems most suitable for the soil. The weather-map must be watched at sowing time to make sure of a moist seed-bed. Whatever the crop, it should be plowed under in the fall or early spring, and under no circumstances should it stand late in the spring to rob the trees of food and moisture. In moist, hot seasons, the cover-crop should be sown earlier than in seasons of slow growth, when, possibly, it acts as a deterrent to blight, and certainly makes more certain thorough ripening of the new wood.

The double nature of pruning must be kept in mind whenever a pruning tool is taken in the pear-orchard. Fruit-trees are pruned to increase the quantity and quality of the crop--this is pruning proper; and to give the trees such form that they are easily managed in the orchard--this is training. Pruning tools are used first when the trees are set, and they should be used every year thereafter as long as the tree lives. The pruning at setting time is particularly important with the pear, since newly set pears are slow and uncertain in starting, and linger in growth for a year or two after going into the orchard. The pruning is much the same as with other trees, but must be done with a little greater care.

The top of the young plant must be pruned to enable the injured root-system to supply the remaining branches with water. The less the roots are injured, the less the top need be cut. Some cut back all of the branches; some remove whole branches and do not head back those that remain. The latter is the better plan for this reason: The top buds on branches are largest and develop first, and the newly set tree will grow best if it develops a large leaf-surface before hot dry weather sets in. Young trees usually have surplus branches; remove those not needed, leaving three, four, or rarely five to form the framework of the tree. A pear so pruned will start growth and acquire vigor more quickly than if all branches are cut back.

A choice must be made when planting as to whether the tree is to be low- or high-headed. The habit of growth of varieties differs so greatly that there can be no rule to determine how high the head of a tree should be started. One can generalize to this extent: The heads of varieties with spreading tops should be started higher than those having an upright or pyramidal top. Without question, the choice should be for a low-headed pear-tree. The trunks of pear-trees suffer terribly from blight and sun-scald. The less trunk and the more it is shaded by branches, the less the tree suffers from these two troubles. Also, low trees are more easily sprayed and pruned; the crop is more easily thinned and harvested; crop and tree are less subject to injury by frost; the top is more quickly formed; and a low-headed tree bears fruit soonest. By low-headed is meant a distance from the ground to the first limb of two feet.

Two shapes of tops are open to choice--the open-centered and the close-centered. In the open-centered, or vase-form top, the tree consists of a short trunk, surmounted by four or five main branches ascending obliquely. In the close-centered top, the trunk is continued above the lower branches and forms the center of the tree. The close-centered pear-tree produces more fruit and is most easily kept to its shape. No doubt it is best for most varieties. The open-centered tree, with its framework of several main branches, has the advantage when trees are attacked by blight, since if one or two branches are destroyed by the disease a part of the tree may still be saved. The head should never be formed by two central leaders forming a crotch, as the trunk is liable to split and ruin the tree.

For several years after planting, the pear needs to be pruned only to train the tree to the height of head determined upon and to form the top. Exceptions are the sorts which produce few branches and thus form straggling heads. This defect is overcome by cutting back some of the branches in the spring, an operation which increases the number of branches. A few other sorts, as Winter Nelis and White Doyenné, have drooping, twisting, wayward branches which can be trained into manageable shape only by cutting back or tying the branches in place. Pear-growers as a rule prune young trees too much. Over-pruning increases the growth of wood and leaf too greatly, and thus delays the fruiting of the plant. A good deal might be said about the use and abuse of heading-in pears--that is, cutting back the terminal growths from year to year. Dwarf pears must be headed-in severely to keep the trees down, but standard trees should be headed-in only to make the tops thicker and broader--a desirable procedure with some varieties.

Old trees often need to be pruned to increase their vigor. Such pruning is often spoken of as _pruning for wood_. When the tops of pear-trees have dead and dying wood, when the seasonal growth is short and slender, when the crops are small and the pears lack size, or when trees are weakened by disease, a healthy condition may oftentimes be restored by severely cutting back some branches and wholly removing others. In such pruning the following rules ought to be observed:

Weak-growing varieties are pruned heavily; strong-growing kinds, lightly.

Varieties which branch freely need little pruning; those having few and unbranching limbs should be pruned closely.

In cool, damp climates, trees produce much wood and need little pruning; in hot dry climates, growth is scant and trees need much pruning.

Rich, deep soils favor growth; trees in such soils should be pruned lightly. In light or shallow soils, trees produce few and short shoots; the pruning of trees on such soils should be severe.

A good deal is said about _pruning for fruit_. It is doubtful, however, whether unfruitful pear-trees can be made more fruitful by the pruning recommended for this purpose. When barrenness is caused by the production of wood and foliage at the expense of fruit-buds, as possibly sometimes happens, summer-pruning may check the over-production of growth and cause flower-buds to form. There seems to be no definite experiments to prove this theory in America, nor do pear-growers generally practice this kind of pruning which has been preached so long and so often. To follow the rules in this operation, summer-pruning should be done when the growth for the season has nearly ceased. If done earlier, the shoots cut back start again and the pruning has been useless. If done too late, there is too little time for the production of fruit-buds. In the unequable climate of this country it is most difficult to know when to prune in the summer to meet the requirements of the theory urged so strongly by European pomologists. A weighty objection to summer-pruning in America is that the wounds might and probably would become centers of infection for blight.

There is no attempt to give a full discussion of pruning in this text. Such details as making the cut, covering the wounds, pruning paraphernalia, filling cavities and the amount to prune, belong to texts on pruning. Perhaps two minor details important in growing pears should be mentioned. Suckers or water-sprouts form so freely on branches of pears that they often seriously devitalize the tree, and usually are centers of blight. They should therefore be removed promptly whenever and wherever found. The time to prune the pear is important. If the work is done too early in the winter, injury may result to the tissues near the wound from cold or from checking. If done late in the spring when sap is flowing, the wound becomes wet and sticky and is a suitable place for the growth of fungi and the blight bacterium.

The pear is as easily grafted as any other pome, and the operation is more certain and more often desirable than with any of the stone-fruits. Almost any method of grafting used with orchard fruits is successful with the pear. But the pear is not often grafted in this State after the tree has been set in the orchard. The great objection is that the vigorous growth made by grafts is nearly always nipped by blight. Possibly the lack of affinity between different varieties is more pronounced than with other pomes. The common European varieties cannot be inter-worked without experimental knowledge of how one variety will grow on another, and it is almost impossible to intergraft common varieties with the oriental hybrids. The temptation is strong in this State to graft such sorts as Bartlett and Seckel on Kieffer. This combination is seldom successful; nor, as a rule, can other European pears be grafted on Kieffer, although some growers have succeeded fairly well in growing Seckel on Kieffer.

Thinning the fruit is not a common practice in pear-growing in this State. There is no doubt but that much might be done to improve pears in both size and quality by thinning, for be it remembered that large size of fruit and high quality are usually correlated in pears. Thinning often saves the vigor of the tree, and it is often good orchard management to destroy insect- or disease-infected fruit by thinning. The objection is high cost. Most growers, however, find that it pays to thin. Thinning is usually done as soon as possible after the June drop. It is most difficult to tell, when thinning, what will prove superfluity at harvest. A skilled grower adjusts the size of the crop to the variety, the vigor of the tree, fertility and moisture in the ground, the season, and insects and fungi. Thinning should begin in the winter with the removal of what seem to be superfluous branches, for even at this time fruit-prospects for the ensuing season are fore-shadowed.

HARVESTING AND MARKETING

Fruit-growing is made up of several quite distinct phases of activity; as, propagation, culture, pruning, pests, harvesting, and marketing. Treated in detail, each of these several operations constitutes matters quite sufficient for separate treatises. In a manual such as this only outlines of present practices are in place. Perhaps of all deciduous fruits the pear needs as particular attention in the various operations which conduct it from the orchard to the table as any other, if, indeed, it is not the most difficult of hardy fruits to handle after it leaves the orchard. The several operations that should be treated in a discussion of handling the pear crop, no matter how brief, are picking, grading, packing, storing, shipping, and marketing.

The time of picking is most important in handling pears. Pears are picked, especially for the markets, long before they are ready to eat out of hand. So harvested, almost without exception, all pears acquire higher quality than when they ripen on the tree. Moreover, when the necessary percentage of sugars and solids has developed to give full flavor the pears are too easily bruised to be shipped. Just how green pears can be harvested and afterward have the rich shades of red and yellow and the delectable flavor of ripe pears develop seems not yet to have been determined.[22] No doubt the stages of development differ somewhat with the variety. In New York, the generally accepted rule is to pick when the stem parts readily from the branch if the fruit is lifted. Some wait until there is a perceptible yellowing of the maturer fruits; others until full-grown, wormy specimens are ripe; still others until the seeds begin to change color. But on the Pacific slope and for the cannery in this State, pears are picked when much greener than in any of the conditions named and yet seem to ripen well. As a matter of economy, the fruits should be left until they attain nearly or quite full size.

The directions just given apply more particularly to the main-crop pears and early and fall sorts. Winter pears in this State should be left on the trees until in danger from freezing. Even so, the season is too short for some choice winter sorts. No matter what the season, pears should be shipped before they reach edible condition. A few of the winter pears, suitable only for culinary purposes, never soften, and change color little or not at all.

Picking pears is not the delicate business that picking the stone-fruits is, but yet must be done with considerable care as a bruise provides a place for subsequent decay. Few picking appliances are needed, but these should be carefully chosen to insure speed and careful handling of the fruit. A full complement of ladders is necessary, and the picking receptacle, either bag, basket, or bucket, should be chosen to fulfill most conveniently its purpose and yet not be a source of danger to the fruit. From the picking receptacle, the pears go to the crate or barrel for carriage to the packing-house; for, unless the fruit is going to the cannery, pears should be graded and packed in the packing-house.

Grading pears is a more difficult operation than grading apples, as mechanical graders have proved of little use, and the work must be done by hand. Only good fruit is worth grading. It follows, that the higher the price and the more special the market, the more carefully should the pears be picked and graded. Pears are usually graded in New York into firsts, seconds, and culls. The State has no law governing the grading and packing of pears as it has of apples and peaches, so that pear-growers must establish their own grades. By common consent of growers and dealers, Grade I consists of pears of one variety, full sized, well formed, free from dirt, skin-breaks, worms, scale, scab or other damage caused by insect or disease, hail pecks, or mechanical injuries. Grade II differs from Grade I only in that the pears may not be of full size nor perfect in form. A leeway of five to ten per cent is allowed for variation incident to grading and handling. Culls are pears which do not meet the requirements of the foregoing grades.

In putting up grades every effort is made to keep the fruit in a package uniform in size. At the beginning of the season the sizes are gauged by putting the pears through rings of the diameter desired. But packers soon become expert in sizing, and with a little practice perform the work quickly and accurately without rings. Of the larger pears, such as Bartlett, Clapp Favorite, Beurré Bosc, and Beurré d'Anjou, fruits are hardly worth putting in a good package that do not measure two and one-fourth inches through the shorter axis.

Grading and sizing pears are greatly neglected, and most of the crop goes to the market in this State wretchedly packed, for which reason maximum prices are seldom received. The industry can never compete successfully with western pear-growing until higher standards are adopted in putting the New York crop on the market.

In common with grading and sizing, packages are neglected in marketing New York pears. Some growers pack in bushel baskets; a few send the crop to market in half-bushel baskets; a large size of the Climax basket is occasionally seen in the markets filled with summer pears or small Seckels; a keg holding about a bushel or more is less used; a pear barrel holding a peck less than an apple barrel was formerly more used than now; Kieffer is often sent to the market in apple barrels. A very few New York growers ship in boxes, but these are few indeed. In all excepting the boxes, the pears, having been graded, are carefully put in the packages, sometimes in layers and sometimes hit or miss, but the package is always faced. Good grades are usually labeled, though the same attention is not given to labeling pears that is given in putting up apples. Truth is, the packing of pears in New York is a decade or two behind the packing of apples.

The commercial pear-grower now stores his pears in cold storage if he keeps them any length of time after harvesting. A few varieties, of which Beurré Bosc is most notable, do not keep well in cold storage, but most of the mainstays in the pear industry keep fairly well in artificial cold. There is, however, much to be learned about the commercial storage of pears. There seems to be little information that can be relied upon as to how low the temperature should go; how humid the atmosphere should be; how long the pears can be kept in good condition; and how different varieties behave under these several conditions.

Perhaps a word should be said as to how the pear can be ripened best in the home. After harvesting, the pears should be placed in a cool sweet-smelling fruit-room in shallow boxes or spread upon shelves to acquire in time full flavor and color. Most pears part with their moisture readily, and the pear-room must not be open to draughts which usually cause the fruits to become hard and leathery or to shrivel. If the pears are to be kept long, wrapping in paper helps to prevent shriveling. Nearly all pears ripen perfectly in cool or cold storage, but a few late winter sorts ripen better if brought into a temperature of 60° or 70° for two or three weeks before their season.

A large part of New York's pear crop is canned in commercial canneries. Canners usually pay high prices, and the crop, when sold to them, need not be so carefully picked, packed, and otherwise handled. It is a mistake to assume that pears for the cannery can be shaken from the tree or handled roughly otherwise. Neither do the canners want the poor grades, after the good pears have been sent to the market. Large sizes are usually preferred, and the fruits must be well formed, free from serious insect, fungous, or mechanical injuries, and at a particular stage of maturity which the canner specifies. The profits in selling to canners are usually more certain, and are often quite as great as in selling on the markets. The cannery is a splendid safety valve to the pear industry in this State. Pears are not dried commercially in New York as they are in California, although it would seem that here in the center of the apple-drying industry of the world pears might also be dried with profit.

Most of the pear crop of this region is now sold to local buyers or on consignment to city dealers. Co-operative methods are just beginning and promise much. There are several reasons why the pear, even more than the apple, which is more and more going to the markets through co-operative associations, should be handled by organizations of growers. Thus, an association could load a car quickly, which few individual growers can do; pears are not now, but would be, graded and packed under one standard; more favorable transportation rates would be secured; and, most important of all, the pear crop would be distributed to the great markets of the country without the disastrous competition that attends individual marketing. If the pear industry is to grow in the State, pears must be largely marketed through the central packing associations that are now being rapidly organized to sell fruits.

No reliable data can be obtained to show what the costs are in growing pears in this State. It would be hard to obtain such data, for pear-growing is now a game of chance from start to finish. Good pear-lands are not hard to obtain, and the risks to tree and crop attendant on weather are not great, but the trees are everywhere subject to blight; which, despite the recommendations of plant pathologists, cannot be controlled, and which annually destroys thousands of trees, ruins others, and sooner or later upsets calculations of costs and profits in almost every pear-orchard in the State. Other pests, as psylla, the scab-fungus, and codling-moth beset the pear and make profits uncertain. When all goes well, the costs are about the same as in growing apples, while the profits are somewhat greater.[23] But with blight to contend with, most of the economic factors are inconstant, and calculating costs and profits is guessing pure and simple.

DISEASES OF THE PEAR

The pear is attacked by a half dozen or more diseases in New York, of which two, at least, need treatment every year, in every orchard, and on nearly every variety. One, pear-blight, is about the most malignant of the diseases of the orchard, for which there is no antidote and no alleviation or preventive except by the most drastic sanitary measures. The other, pear-scab, is always present but not always destructive, although some varieties are always injured by it. The scab, however, is amenable to treatment and at its worst only destroys fruit and foliage, seldom endangering the life of the tree. The four or five other diseases of the pear in New York are of minor importance and are readily controlled by the treatment necessary to keep in check the scab-fungus. Pear-blight merits attention first.

Pear-blight is a malignant bacterial disease, very contagious, usually virulent and so terrible in its consequences as to warrant the common name _fire-blight_. No part of the tree is exempt from destruction by the malign bacterium that causes blight of the pear. Root, trunk, branch, leaf, flower, and fruit are all attacked, turn black and wither under the disease. Few plant diseases produce more disastrous results. The pear competes with the apple in importance in Europe where blight is unknown. In America it is a poor fourth to the apple, peach, and plum, and takes fourth place instead of second because of the ravages of blight. About the most important discovery to be made in pomology is a race of blight-resistant pears. Failing in this, if the pear-industry is to grow, or even continue in its present magnitude, blight-resistant stocks must be found.

The symptoms of pear-blight are so characteristic that the disease cannot be confounded with any other malady or condition of the tree. It appears earliest in the season on the blossoms causing blossom-blight. Attacked by blight, the blossoms wilt, and after the petals fall, fruit and spur show the characteristic blackening of the disease. Blossom-blight may escape the attention of the pear-grower, but twig-blight, a succeeding form of the disease, can escape no one who has the sense of sight. No other disease of the pear brings on such palpable destruction to the tree as twig-blight. No other disease causes such comfortless despair to the grower. Twig, branch, or tree, as the case may be, in all affected parts, turns black, the leaves droop, seeming to show the effects of fire. A marked symptom is, if there can be doubt of those given, that the blackened foliage clings most tenaciously to the dead branches. Twig-blight is the most common manifestation of the disease. Another form of the blight appears as a canker on the trunk and large branches--canker-blight or body-blight. These cankers are dark, smooth, and sunken, with definite margins marked by a crevasse in the winter; but as spring comes on the advancing margins become raised and more or less indefinite. Occasionally an opaque liquid oozes from lenticels newly attacked. On branches, the cankers usually surround a smaller offshoot, sucker, or spur. The disease spreads with great rapidity, by reason of which it is easily told from winter-killing. Injury from cold is also more general, and the foliage browns rather than blackens.

Pear-blight is an American disease, the history of which was briefly given on page 51. Until recently it was confined to regions east of the Rocky Mountains, but since about 1900 it has been a virulent epidemic on the Pacific slope as well, and is now found from coast to coast wherever pears are grown in North America. It seems not to be found in the pear regions of other continents. It attacks the apple, quince, and other pomes as well as the pear, and plant pathologists declare it to be the most destructive disease attacking the pome-fruits. Trees in the nursery suffer as well as those in the orchard. Every variety of the pear bearing edible fruit is attacked. Fortunately, some sorts are more immune than others. Kieffer, Seckel, Winter Nelis, and Duchesse d'Angoulême are most resistant of standard varieties, while Bartlett, Clapp Favorite, and Flemish Beauty are little resistant.

Pear-blight is caused by a bacterium, _Bacillus amylovorous_, the discovery of which by Burrill in 1877 as a cause of this disease is one of the landmarks in plant pathology. The organisms are dormant during the winter, which they pass in the margins of blight-cankers where moisture is sufficient to keep them alive. With the return of vegetative growth, some sort of fermentation seems to set in and drops of a thick, opaque liquid ooze out of the margins of blight-cankers. These contain countless numbers of the blight bacteria which may swarm into the healthy tissues adjoining, or be carried by any one of the great number of kinds of insects which visit trees at flowering time to the pear-blossoms, to growing tips, or to wounds in tender bark. The pruner with his tools may be an unwilling agent in carrying the bacteria from tree to tree. The organisms now multiply apace, killing tissues wherever they find entrance and causing the several manifestations of the disease described under symptoms. Were it not that the bacteria are killed by sunlight and even brief periods of drying, the life of the plants attacked would be the only limits of the disease unless checked by man.

Theoretically, pear-blight can be controlled. Practically, pear-growers fail to control it. Control consists in orchard sanitation whereby the bacterium causing the disease is kept out of the orchard. This proves all but impossible in the average orchard. Sometimes, without doubt, the virulency of the disease is lessened. Possibly, if all the recommendations of plant pathologists could be put in practice, pear-growers would more often succeed in keeping blight down, but the necessary sanitary measures require such watchful care and so great an expense that few pear-growers can carry out the program for controlling this disease. Of those who have studied methods of control and have given advice on the subject, Hesler and Whetzel[24] are as reliable as any and we quote herewith their recommendations:

"In attempting to control fire-blight, the following important points should be borne in mind: (1) That the disease is caused by bacteria which gain entrance to the host tissues only through wounds, or punctures by insects, into succulent, rapidly growing tissues, or through the nectaries of the blossoms. (2) That insects of several kinds are the usual agents of inoculation. (3) That practically all pome fruit-growing sections in North America are infested, and therefore there is always a source from which the bacteria may be disseminated. (4) That all known varieties of the hosts, on which the blight organism occurs, are more or less susceptible; while some show resistance, none are wholly immune. Therefore control consists chiefly in the elimination of the pathogene from the infected trees. This is accomplished by a strict application of the following operations: (a) Inspect all pear trees in the autumn and again in the early spring before the blossoms open, and cut out and treat all cankers in the body and main limbs. With a sharp knife, or draw-shave, remove all the diseased tissue, wash the wound with corrosive sublimate (one tablet to one pint of water), and, when dry, paint the wound with coal-tar or lead paint, preferably the former. The wound-dressing will need renewal every year or so. (b) Throughout the summer, beginning with the fall of blossoms, make an inspection every few days of the young trees. Break out the blighted spurs and cut out diseased twigs, making the cut at least six inches below the diseased portion. Disinfect the cuts with corrosive sublimate. (c) Remove all watersprouts from the trees two or three times during the season. (d) In the nursery remove the blossom-buds, particularly of the quinces. Here inspection must be frequent, particularly in susceptible stock, in order to keep the disease under control. It is often necessary to inspect certain blocks daily, the diseased twigs being cut out as soon as observed. When budded stock of the first year becomes affected, the trees should be dug out, since cutting below the diseased area causes the trunk of the young tree to be crooked and therefore not marketable. (e) Control the insects. The real point of attack lies in this phase of the problem."

Scab (_Venturia pyrina_ Aderh.), after blight, is the best-known and most prevalent disease of the pear in New York. Like blight, it is found wherever pears are grown in North America, and also wherever pears are grown in foreign countries. It attacks the pear at all ages from the youngest to the oldest plant. Twigs, leaves, flowers, and fruit suffer. A closely related and very similar fungus attacks the apple and causes the apple-scab, but the two fungi are not the same and do not spread from the one fruit to the other.

The name describes the disease at maturity so that all may know it. Black, canker-like lesions spot the fruit, leaf, and twig. These are most characteristic on the pear. The scabs first appear on the fruit as olive-green velvety spots; the young fruits may drop; if they persist, growth may cease, the skin crack, or the fruit be distorted; the fruit-stalk is often shriveled. The scab shows on the leaves much as on the fruit and usually attacks the lower surface. On the twigs the scab is not so conspicuous, but appears as a small round spot which may or may not slough off and be replaced by healthy bark. Young twigs are most often attacked, in which case the scabby spots suggest scale insects.

Pear-scab is caused by a fungus. The chief life events of this fungus must be known to control the disease. The organism passes the winter in leaves on the ground. In the spring, the spores which have matured in the spore-cases are forcibly discharged, and, being very light, are carried hither and thither by the wind so that some of them reach the opening flower and leaf-buds. If moisture and heat are sufficient, the spores germinate, and an infection is started. A foothold secured, the germ-tubes branch and form a dense mycelium--the velvety layer visible to the unaided eye. From these masses of mycelium spore-stalks arise in great numbers bearing countless spores which by one agent and another are carried to other leaves, twigs, or blossoms for new infections. New infections continue throughout the growing season. The black scab spots on fruit and leaf are corky layers of tissue formed to heal the wounds made by the fungus which has ceased to grow vigorously in these scabs. The fungus may pass the winter on the twigs as well as in fallen leaves.

Different varieties resist the scab-fungus differently. Flemish Beauty and Summer Doyenné are most susceptible and in seasons favorable to the fungus seldom present fruits with a clean cheek no matter how careful the treatment. Pruning off badly infected twigs and plowing under scabby leaves are good sanitary measures. In New York, two applications of lime and sulphur at the summer strength, if applied annually, are usually sufficient to control the fungus. The first of these applications should be made when the blossoms show color, a few days before they open. The second should be put on when most of the petals have fallen. In seasons favorable to the scab, a third application two weeks after the second may be the means of saving the crop. The spread of the disease is greatly favored by damp warm weather.

Pear-growers are plagued by two leaf-spots, one of which is also known as leaf-blight. The leaf-spot here to be discussed (_Mycosphærella sentina_ (Fr.) Schroet.) is sometimes called the ashy leaf-spot. The disease is not often seriously troublesome in New York, but is capable of doing great damage in both the nursery and orchard. The spots which give name to the disease are conspicuous enough, but even when present in great numbers are often not seen by the pear-grower until there is a premature dropping of the leaves in August or earlier. The trees often put out new growths, with the result that the wood does not ripen and the tree is left in no condition to stand the cold of winter in this northern climate.

As with nearly all diseases of plants, some varieties suffer more than others. Sheldon, Seckel, and Flemish Beauty are more injured than Kieffer, Lawrence, and Mount Vernon. Nursery stock is more often injured the second than the first year set. Only the leaves suffer. The fungus first shows its work in minute purplish spots on the upper surface of the leaf. The mature spots measure about one-sixth of an inch in diameter, are angular in shape, with well-defined margins, and have an outer zone of brownish-purple, with a grayish center. Late in the season, dots, the spore-cases of the fungus, appear in the gray central area. The fungus passes the winter in diseased leaves which fall to the ground in late summer. From these leaves spores are discharged into the air to be carried to the leaves after growth begins in the spring. The disease is usually controlled by the sprays necessary every year to keep pear-scab in submission. In the nursery, two-year-old trees are sprayed just after the new leaves open and twice thereafter at two-week intervals. One-year-olds seldom need to be sprayed.

Leaf-blight (_Fabræa maculata_ (Lev.) Atk.) is a common and destructive fungus in pear-nurseries in New York and is sometimes troublesome in orchards. The quince suffers even more than the pear from this fungus. In the nursery, leaves and twigs are attacked, and in the orchard the pears themselves sometimes suffer. The disease appears in the spring as minute, reddish-brown circular spots on the upper surface of the leaves, but the fungus penetrates through to the lower surface as the disease progresses. Eventually the color changes to dark brown, and later a coal-black, raised spot appears in the center. The spots sometimes run together. Young leaves shrivel under the attacks of the fungus; while old ones, if badly diseased, turn yellow and drop prematurely. Twigs and leaf-stalks are frequently girdled, and the lesions are more elongated. The spots are similar on the fruits to those on the leaves. The fungus spends the winter in fallen leaves. In the spring the spores are discharged from the fruiting organs of the fungi and are carried to the tender leaf or twig of the pear or quince. The parasite begins growth at once and in about a month a new crop of spores develop. This fungus grows on various other pome-fruits which complicates remedial measures. The treatment recommended for leaf-spot should control leaf-blight.

As are all tree-fruits in New York, the pear is attacked by crown-gall (_Bacterium tumefaciens_ Smith & Townsend). This disease, however, is seldom a serious menace to orchard trees this far north, but the vigor of nursery stock is sapped when the galls girdle the tap-root or the stem at the collar. Moreover, trees affected by crown-gall are barred in most states by inspection laws so that nurserymen can ill afford to produce gall-infected trees. It is a wise precaution not to plant badly diseased trees. The galls are tumor-like structures on the roots of the plant, or often at the juncture of root and stem. They vary from the size of a pea to that of a large egg, forming at maturity rough, knotty, dark-colored masses. Another form of the disease appears as a dense tangle of hair-like roots arising from callous-like galls. This form passes under the name "hairy root." Neither preventive nor cure is known. Orchard or nursery should not be planted on ground known to have been infected as the disease is highly contagious. The brambles, especially raspberries, are common carriers of crown-gall, and none of the brambles should be planted as inter-crops in pear-orchards.

Brown-blotch (_Leptothyrium pomi_ (Mont. & Fr.) Sacc. var.) is another fungus which is sometimes troublesome. The fungus causes reddish blotches on the fruit which coalesce into rusty-brown patches often covering the whole surface of the pear. Here, again, the Kieffer suffers most although fruits of other varieties are often disfigured by the blotch. The disease is most common on heavy soils and in densely shaded trees. Pruning to let in the sun is usually sufficient to keep the fungus in check, but a late application of lime and sulphur is often necessary.

Black mold (_Fumago vagans_ Fr.), a fungus which grows in the honey-dew exuded by the nymphs of the pear-psylla, sometimes causes a sooty covering of the pears which spoils their sale. Twigs and leaves are also covered with thin superficial growth of the fungus somewhat to the detriment of growth. The remedy is obvious--control the psylla.

Pink-rot (_Cephalothecium roseum_ Cda.) sometimes does much damage to pears in common or cold storage. The fungus seems able to enter the skin of pears only through injuries, and when reasonable care is used in handling the fruit the rot does little damage. Not infrequently it is found on fruits unpicked, having entered the skin through ruptures made by pear-scab, black-spot, or other fungi. This, of course, seldom happens in well-sprayed orchards.

INSECTS ATTACKING THE PEAR

Several insect pests are very destructive to pear-trees, as many more are often troublesome, while perhaps in addition to the dozen that must always or occasionally be combatted some thirty or forty more have been listed as pear-pests. Young pear-trees are very susceptible to injuries of any kind and if beset by any of the common insect pests do not prosper. As the trees come to maturity, life and vigor of the tree may not be endangered by any but two or three of the worst pests, but the crop is always cut short by infestations of insects on any part of the plant which interferes with the normal life of the tree. The pests most destructive to the pear in New York, about in order of importance, are San Jose scale, psylla, codling-moth, pear-slug, and pear-leaf blister-mite.

San Jose scale (_Aspidiotus perniciosus_ Comstock) is particularly harmful to tree and fruit of the pear. The pears, possibly, are malformed more and show the scales with their discoloration more plainly than the product of any other fruit-tree. A scale-infested pear-tree is easily recognized. Dead and dying twigs or branches and moribund trees are evidences of the dreaded pest. Examination shows the moribund parts to be covered with myriads of minute scales which give the infected bark a scurfy, ashy look. A reddish discoloration is discovered if the bark be cut or scraped. A foothold gained on trunk or branch, fruit and foliage are soon infected. Reproduction is continuous throughout the summer, and the scales increase by leaps and bounds. Smooth-barked young trees succumb within three or four years if the insects are unchecked; the rougher-barked old trees survive the pest indefinitely, although the vigor is lessened to the point of unproductiveness in many old orchards. Pear-growers find the lime-sulphur solution applied in the dormant season the most effective spray in combating San Jose scale. Several insect enemies of the scale help to keep the pest down. A quarter-century ago, it was feared that the pear industry of the State might be ruined by San Jose scale, but no energetic fruit-grower now fears the pest.

Next to San Jose scale, psylla is the most feared pest of the pear in New York. Indeed, this insect is much more difficult to combat successfully than scale, and were it as wide-spread, the pear industry in New York would be hard hit. The psylla is a minute, sucking insect, wingless in its immature stages, but winged and very active as an adult. They are nearly related to plant-lice, and like them suck the juices of the buds and new leaves. Like plant-lice also they reproduce very rapidly. The immature insects secrete a sticky honey-dew which becomes blackened with a fungus, and the presence of this blackish, sticky substance on foliage and branches is usually the first indication of the pest. The adult is about one-tenth inch long, with four membranous wings, the body dark in color and showing brownish-black markings. Seen through a hand lens, the mature insects look like tiny cicadas. The adults hibernate in crevices of the bark, and at the time buds are swelling in the spring come out to lay their eggs. The eggs hatch in two or three weeks, and there may be four or five broods in a season. The pest is best controlled by spraying with such contact insecticides as tobacco extract both to kill the hibernating insects and later the immature psylla. The winter strength of lime-sulphur solution will kill the eggs.

The apple-worm, the larva of the codling moth (_Carpocapsa pomonella_ Linnaeus), destroys great quantities of pears year in and year out in New York, causing greater monetary loss to pear-growers than any other insect pest. The worm and its work scarcely need description--all know "wormy" apples and pears and the agent of the mischief. A pinkish-white, fleshy worm eats a cavity within the pear, usually through and around the core, and then eats its way out to the surface, after which it finds suitable shelter in a crevice of the bark and spins its cocoon. About the time apples blossom the larvae transform into small brown pupae, from which small moths emerge in two or three weeks. The moths are coppery-brown, small, with a wing expanse of about three-quarters inch, and very inconspicuous as they rest during the day on the bark of the pear-tree which they closely resemble; they fly only at dusk. The moth lays its eggs on leaves or the fruit itself and the young larvae immediately begin work on the nearest pear. Control consists in spraying with arsenate of lead. Two and sometimes three sprayings are necessary. The most important spraying is made just after the blossoms fall, while the calyx-cup is still open, so that the poison will lodge in the blossom-end of the upturned pear. Codling moth was once a most serious pest of the pear, but is now easily kept under control by seasonal applications of arsenate of lead.

The pear-slug (_Caliroa cerasi_ Linnaeus), a generation ago, before spraying was common, did much damage to the pear in New York, but is now a negligible pest except in the orchards of the indifferent or slothful since it is easily controlled by spraying. The slugs are small, dark green shiny creatures which eat the surface of the leaves of pear, cherry, and plum. They devour the upper surface of the leaf leaving the veins and the tissues of the lower surface, which turn brown so that the infested tree has the aspect of having been scorched by fire. The slugs molt and finally lose their shiny coat and dirty green color, the full-grown larvae becoming clear yellow. The adult is one of the numerous saw-flys. Eggs are laid within the tissues of the leaves. There are two or three generations in a season. The slugs are most common in the hottest part of the summer or late in the summer. This pest is easily kept in check by applications of arsenate of lead.

The foliage of the pear, in common with that of the apple, is often seriously injured by a mite (_Eriophyes pyri_ Pgst.) which burrows into the tissues of the leaves. The mites attack the young leaves causing reddish blisters which turn black. The blisters are thickened spots which are found to have a corky texture. The young fruits are sometimes attacked, in which case they are badly malformed. The mites are of microscopic size and can be seen only by the aid of a magnifying glass. They hibernate under the scales of the leaf-buds, and are thus ready to attack the young leaves as soon as they unfold, which they do by eating their way in from the under side and then by their work cause the characteristic swellings. As they mature, the mites come out and move to new places and start more colonies. In the autumn, they find their way to the maturing buds and go into winter quarters. An application of lime-sulphur solution at winter strength usually disposes of the mites; that put on for San Jose scale suffices for this pest also. Summer sprays do not reach the mites as they are then hidden within the leaves. The pest was once a serious menace to the pear, but with the advent of winter spraying has become of small importance.

Of the numerous other insects which occasionally become serious pests of the pear, at least twenty have been troublesome at one time or another in New York. Space does not permit a description of these minor pests--they are named as a matter of record. It is not necessary to give remedies for them, as all are controlled by the treatment of major pests which in most orchards need annual applications of one spray or another.

Several scale insects, other than San Jose scale, are more or less pestiferous in the pear-orchards of this State; commonest of these is the oyster-shell, which not infrequently does serious damage to young and unhealthy trees. The scurfy scale found chiefly on the apple sometimes becomes a pest on the pear. A hemispherical scale, about one-twelfth of an inch in length, known as the terrapin scale, now and then infests the pear, but is seldom if ever harmful. As a rule, the treatment for San Jose scale keeps all other scales in check, but all are more difficult to kill than the San Jose and in cases of troublesome infestations may require drastic treatment with a contact insecticide.

A great number of chewing insects, as distinguished from sucking insects, defoliate the pear when given an opportunity, but are kept in check by the treatment for codling moth. The much-dreaded browntail moth and gypsy moth now have a foothold in the State, but as yet can hardly be called pests although their advent threatens the pear industry as it does all other orchard industries. The bud-moth, seldom seen in well-cared-for orchards, is sometimes a vexatious visitor in pear-orchards. Three species of caterpillars, all most striking in appearance, the larval stages of tussock moths, infest pear-trees. These are the white-marked tussock moth, the rusty tussock moth, and the definite-marked tussock moth.

The pear-tree has its share of borers. A small, dark brown beetle, about one-third of an inch in length, the apple twig-borer, sometimes does considerable damage to young shoots of the pear. The flat-headed apple-tree borer works in the sap wood of the pear as in the apple. The shot-hole borer, a tiny insect, eats a small round hole in the trunk of the pear, as it does also in several fruits, but does little damage except in devitalized trees. The shot-borer, a tiny black beetle, one-tenth of an inch long, bores into twigs or small branches and sooner or later causes their death. None of these borers are very harmful on the pear in New York, but all must be reckoned with occasionally. All are difficult to control.

The pear thrips attack the newly opening flower- and leaf-buds and when the insect, a small winged creature with sucking mouth-parts, is abundant much damage is done. This pest in New York is chiefly confined to the Hudson River Valley. The European grain aphis, closely related to the destructive apple aphis, is sometimes a serious pest on pears. Both of these pests are comparatively easily controlled by timely applications of contact insecticides.

Lastly, there are several chewing insects which feed on the leaves of the pear, which, unless checked, sometimes become major pests for a season or two in an orchard here and there. All of them, fortunately, are controlled by the arsenical poisons which are necessary to keep the codling moth down. The pests are: Cigar case-bearer, green fruit worm, pistol case-bearer, and oblique-banded leaf-roller. With these, as with most of the other pests of the pear, cultivation to keep down all foreign vegetation, and orchard sanitation, consisting chiefly of the destruction of infested fruit, foliage, or wood, are essential preventives.