The pears of New York

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.

CHAPTER IV
LEADING VARIETIES OF PEARS

ANDRÉ DESPORTES

This old French sort is sparingly grown in New York, and is still listed by a few American nurserymen. The pears are handsome and very good in quality, but they quickly soften at the center and neither keep nor ship well. While usually of medium size, or sometimes large, the pears often run small. The variety is well worth planting in a collection, but has no value in a commercial plantation, and there are many better sorts for home orchards.

Bartlett is not without serious faults, however. The trees blight badly, and are not much above the average in resistance to blight, the black plague of the pear. Neither are they as hardy to cold or to heat as those of some other varieties. They are scarcely hardier to cold than those of the peach, and cannot withstand the summer heat of the southern, or of the Mississippi Valley states. Another serious defect of the trees is that, more than those of any other standard variety, their blossoms require cross-fertilization. The fruits are satisfactory in all characters excepting quality. There are many better-flavored pears. The fruits lack the rich, perfumed flavor of Seckel on one hand, and the piquant, vinous taste of Winter Nelis on the other. But the pears are much above the average in quality, and since no other variety is so easily grown, nor so reliable in the markets, Bartlett promises long to continue its supremacy for home and commercial plantations. After Kieffer, it is the most desired of all pears by the canning trade. Bartlett is the parent of several other well-known varieties, and of many sorts of small importance.

This pear was found as a wilding by a Mr. Stair, a schoolmaster at Aldermaston, Berkshire, England. From him it was acquired by a Mr. Williams, a nurseryman at Turnham Green, Middlesex, and as it was propagated and distributed by him it became known by his name, although it is still known as Stair’s pear at Aldermaston. It was brought to this country in 1797 or 1799 by James Carter of Boston for Thomas Brewer who planted the variety in his grounds at Roxbury, Massachusetts, under the name of Williams’ Bon Chrétien, by which name it was then and still is known both in England and France. In 1817 Enoch Bartlett, Dorchester, Massachusetts, became possessed of the Brewer estate, and not knowing its true name allowed the pear to go out under his own. Henceforth it was known in America as Bartlett. The American Pomological Society added this variety to its catalog-list of fruits in 1848.

This good old pear has been a standard autumn sort for nearly a century. The internal characters of both flesh and flavor are nearly perfect, but externally much more might be desired as to shape and size. In flesh and flavor, the fruits are of the Bergamot type—fine-grained, buttery, juicy, and sugary, with a musky taste and perfume. The fruits are not as large as is desirable, and are variable in shape and color, external defects which a rather handsome color offsets in part. The trees are more satisfactory than the fruits. They bear enormously and almost annually on either standard or dwarfing stocks; they are very vigorous, with a somewhat distinct upright-spreading habit of growth; are hardier than the average variety of this fruit; and are rather more resistant to blight than the average variety. The fruits are too small for a good commercial product, but their delectable flavor and luscious flesh make them as desirable as any other pear for home use; besides which the trees grow so well, and are so easily managed that the variety becomes one of the very best for the home planter.

Belle Lucrative is of Flemish origin. In 1831 it was growing in the London Horticultural Society’s gardens at Chiswick, and was then described by Lindley as “another of the new Flemish pears.” It had been taken to England by a Mr. Braddick who received the cions from M. Stoffels of Mechlin. By some writers it is considered probable that it originated with M. Stoffels, but the leading Belgian and French writers say that it was raised by Major Espéren, also of Mechlin, about 1827. In this country it first fruited in the Pomological Garden of Robert Manning, Salem, Massachusetts, in 1835 or 1836. The American Pomological Society added the variety to its fruit catalog-list in 1852 under the name Belle Lucrative.

Beurré d’Anjou is an old French pear the origin of which is obscure, although it is supposed to have originated in the vicinity of Angers. Early in the nineteenth century it was introduced into England by Thomas Rivers, noted author and pomologist. The variety was introduced into this country by Colonel Wilder[25] of Boston about 1842, and first fruited with him in 1845. The American Pomological Society added Beurré d’Anjou to its list of fruits recommended for general cultivation in 1852.

BEURRÉ D’ARENBERG[26]

In favorable locations this pear seems to possess all of the characters which constitute a first-class fruit; but, notwithstanding, although it has been in the country nearly a century, it is now scarcely to be found in the nurseries, and orchard trees are becoming rare. The fruits are distinguished by their refreshing, vinous taste and long-keeping qualities. Very often, however, they do not ripen in eastern America, and when not properly ripened the pears are highly acidulous and so astringent as to be almost intolerable to the taste. The frequency with which these poor fruits are borne, always on heavy, cold clays and in cold climates, coupled with rather small, short-lived trees, condemn the variety for most pear regions in the East. In the far West, the crop ripens better, and the pears are splendid winter fruits. The merits of the variety are so varying in New York that it is not now worth while attempting to bring it into new life.

Beurré d’Arenberg, in the opinion of some European writers, holds first place among the pears produced by French and Belgian pomologists. Unfortunately, Beurré d’Arenberg and Glou Morceau are often mistaken the one for the other. Beurré d’Arenberg was raised by Monseigneur Deschamps, Abbé of the Orphan Hospital, Enghien, Belgium. At about the same time, M. Noisette, a nurseryman of Paris, sent out Glou Morceau, which he had procured from the gardens of the Duc d’Arenberg, under the name Beurré d’Arenberg, so that there were two distinct varieties in cultivation under the same name. The true Beurré d’Arenberg of the Abbé Deschamps came to this country about 1827, having been sent over by Thomas Andrew Knight, President of the London Horticultural Society, to the Hon. John Lowell of Boston. The American Pomological Society recommended this variety for cultivation in 1848, but in 1871 the name disappeared from the Society’s catalog.