Читать книгу The Pears of New York - U. P. Hedrick - Страница 27

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The ideal climate for a cultivated plant is one in which the plant thrives as an escape from cultivation wholly independent of care from man. The apple, cherry, plum, and peach are often found wild in one or another part of America, but the pear almost never. The pear does not naturally become inured to the American climate, and in the orchard is not well acclimated even in the varieties which have originated in the country. In particular, as a young tree and until well advanced toward maturity, the pear shows the bad effects of maladjustment to climate, but as an old tree it seems to be far less susceptible to the extremes of climate to which fruit trees are subjected in most parts of America. Both of the two chief constituents of climate, temperature and rainfall, are determinants of regions and sites in pear-growing.

Extremes in temperature, more particularly of cold, are the only phases of temperature that pear-growers need consider in New York. The pear is not nearly as hardy as the apple, and Bartlett, the foremost variety in the State, is almost as tender to cold as the peach. The limits of commercial pear-culture are set in this State by the winter climate. The pear cannot be grown profitably where the temperature often falls below–15° F., for while winter-killing of the wood does not always occur at this temperature it sometimes does, and even occasional injury to the tree is almost fatal to the profitable growing of fruit. Fruit-buds of the pear are a little more tender to cold than the wood, and a season’s crop is often ruined when the temperature drops to–10° F. Pears in the nursery are more tender to cold than trees in the orchard, and unless the wood is thoroughly mature or protected by a heavy covering of snow, nursery stock is likely to be injured by any temperature below zero. The injury of nursery stock is manifested in the well-known “black heart” of young pear-trees subjected to severe cold.

Happily, there is some flexibility in the constitutions of varieties of pears, as with all fruits, and a degree of cold that will kill a variety under one set of conditions may not under another. While, therefore, it is not safe for commercial fruit-growers to gamble with the weather, those who grow pears for their own use may do so with the expectation of losing trees or crop now and then but of having them in most seasons. A little can be done to prevent winter injury by carefully selecting sites protected from prevailing winter winds, and by planting on warm soils on which the wood matures more thoroughly than on cold soils. Careful cultural methods, especially the use of cover-crops, may be helpful. Not much can be done in the way of coddling pear-trees from cold. They cannot be laid down as is sometimes done with peach-trees, nor can they be grown low enough, even as dwarfs, to count on much protection from deep snow.

Happily, also, there are varieties of pears endowed with constitutions fitted for very different climates. Varieties of pears from central and northern Russia show remarkable capacity in resisting cold, heat, dryness, strong winds, and other peculiarities of the climate of the Great Plains, and some of them can be grown in the coldest agricultural regions of New York. A few hybrids, as Kieffer, Le Conte, Garber, Douglas, and others of their kind can be grown in the Gulf States where the common pear cannot withstand the hot summers. Cincinis, Le Conte, and Garber thrive as far south as central Florida and southern Texas. There is considerable variation in the hardiness of the common pear. Tyson, Flemish Beauty, and Beurré Superfin are much hardier than Bartlett, Seckel, or Clapp Favorite, and may be chosen to extend the culture of this fruit to any part of New York in which the Baldwin apple can be grown. It is most surprising to find occasionally these hardiest of the common pears growing in some of the coldest parts of the State, usually as demonstrations not only of superior inherent hardiness but also of hardiness brought about by conditions which enable the trees to enter the winter with unimpaired constitutions.

The pear is seldom injured by heat in the summers of New York. Occasionally fruit and foliage suffer from long-continued heat in the dry weather of a hot summer. More often the trunks of pear-trees are injured by a blazing sun in late winter or early spring, especially when the sun’s rays are reflected by ice or snow and strike the tree intensified. Indeed, sunscald so produced is one of the common troubles of the pear in New York. With the pear, as with all other fruits, there is a sum total of heat units above a certain temperature, put by most experimenters at about 43° F., the awakening point of growth, necessary to carry the crop from blossoms to proper maturity. Of the number of units necessary to mature a crop little is known. Many varieties do not ripen in New York in a cold season, but come to perfect maturity in warm seasons. A study of phenology would throw much light on the failure of pears to ripen properly.

The average date at which the last killing frost occurs in the spring helps to determine the limits in latitude and altitude at which the pear can be grown in New York. The pear blossoms early, and while both in bud and blossom the reproductive organs seem able to stand more cold than those of the peach and sweet cherry, yet even in the most favored regions for growing this fruit in New York a crop is occasionally lost from killing frosts, and there are few years in which frost does not take toll in some part of the State. Damage from frost must be expected when the commonly recognized precautions in selecting frost-resistant sites are not recognized. Little or nothing can be done in New York to prevent injury from frost once trees have been set. Windbreaks, whitewashing, smudging, and orchard-heaters are all failures in frost-fighting in this State.

The pear-grower should know how the blooming time of the varieties of pears he plants agrees in time with spring frosts. To do this he must have weather data and must know the approximate date of blooming of varieties. He ought also to be able to synchronize three of these phases of climate—spring frosts, fall frosts, and the length of the summer—with the ripening dates of varieties. Data as to the average dates of spring and fall frosts can be obtained from the nearest local weather bureau. The accompanying table gives the blooming and ripening dates of pears grown at the New York Agricultural Experiment Station. Blooming and ripening dates vary in different parts of the State, and to make use of the data from this Station the grower must compare the latitude, altitude, and local environment of his orchard with those of the Station. Data for the Station is as follows:

Blooming Season and Season of Ripening of Pear-Varieties
	Blooming season	Ripening season
	Very early	Early	Mid-season	Late	Very late	Very early	Early	Mid-season	Late	Very late
Abraham		*
Alamo			*				*
André Desportes			*			*
Ansault			*					*
Appert			*					*
Bartlett			*					*
Belle Lucrative			*						*
Beurré d’Anjou		*							*
Beurré d’Arenberg			*
Beurré Bosc		*							*
Beurré Clairgeau			*						*
Beurré Diel		*							*
Beurré Giffard			*				*
Beurré Hardy			*					*
Beurré de Jonghe			*
Beurré Superfin								*
Bihorel			*				*
Bloodgood		*					*
Bordeaux			*						*
Buffum			*					*
Canner		*						*
Chamogea			*
Cincincis		*								*
Clapp Favorite			*					*
Cocklin		*							*
Colonel Wilder					*				*
Columbia			*					*
Craig				*					*
Dana Hovey			*						*
Dearborn			*				*
Diamyo		*								*
Dorset	*									*
Douglas			*						*
Doyenné d’Alençon	*								*
Doyenné Boussock		*						*
Doyenné du Comice				*				*
Duchesse d’Angoulême			*						*
Duchesse d’Orléans			*					*
Duhamel du Monceau				*					*
Early Harvest		*					*
Easter Beurré			*						*
Eastern Belle			*					*
Elizabeth			*				*
Fitzwater			*					*

Blooming Season and Season of Ripening of Pear-Varieties—Continued
	Blooming season	Ripening season
	Very early	Early	Mid-season	Late	Very late	Very early	Early	Mid-season	Late	Very late
Flemish Beauty			*						*
Fontenay					*				*
Fox		*						*
Frederick Clapp			*					*
French			*					*
Gansel-Seckel		*							*
Garber			*
Glou Morceau				*					*
Golden Russet				*						*
Grand Isle		*						*
Guyot								*
Hemminway			*					*
Howell		*							*
Japan		*								*
Jargonelle			*				*
Jones		*							*
Joséphine de Malines		*							*
Kieffer		*							*
Koonce			*				*
Krull			*							*
Lady Clapp		*						*
Lamartine		*							*
Lamy			*						*
Lawrence		*							*
Lawson		*					*
Le Conte	*								*
Léon Leclerc (Van Mons)			*					*
Lemon		*					*
Liegel		*							*
Lincoln			*						*
Lincoln Coreless			*							*
Longworth		*							*
Louise Bonne de Jersey			*						*
Louvenjal			*						*
Lucy Duke				*					*
Madeline			*				*
Magnate			*						*
Margaret			*				*
Marie Louise			*						*
Mongolian	*								*
Mount Vernon			*						*
Nickerson			*						*
Ogereau				*
Olivier de Serres			*							*
Onondaga			*						*
Osband		*
P. Barry				*					*
Peffer			*						*
Pitmaston			*						*

Blooming Season and Season of Ripening of Pear-Varieties—Concluded
	Blooming season	Ripening season
	Very early	Early	Mid-season	Late	Very late	Very early	Early	Mid-season	Late	Very late
Pound		*								*
Président Drouard			*						*
Président Mas			*
Raymond			*					*
Reeder			*						*
Riehl Best			*						*
Ritson			*						*
Romain		*					*
Roosevelt		*						*
Rossney			*
Russet Bartlett			*					*
Rutter			*						*
Seckel			*						*
Seneca			*					*
Sha Lea		*								*
Sheldon			*						*
Siebold			*						*
Souvenir de Congrès			*					*
Souvenir d’Espéren				*					*
Sudduth				*				*
Summer Beauty		*
Summer Doyenne			*				*
Treyve	*							*
Triumph			*						*
Tyson			*				*
Ulm			*					*
Vermont Beauty			*						*
White Doyenné		*							*
Wilder Early				*			*
Winter Bartlett					*				*
Winter Nelis				*					*
Worden Seckel			*					*