PEAR 



PECAN 



2517 



worse than they. To plant fully the area intended for 

 fruit, pears will go on the intrusions of heavy or too 

 moist soils, while the freer soil will be given to other 

 fruits. Still the chief product of pears is from the best 

 loams California affords, and the profits from the tree 

 warrant the use of such land. Pear trees are regularly 

 pruned to a low vase form, but seldom opened in the 

 center, the interior being used for bearing wood, and 

 foliage enough retained partially to shade the fruit. 

 The fruit is thinned to favor size and to relieve the tree 

 from overbearing. Irrigation is employed in some parts 

 of the state. The varieties chiefly grown are the fol- 

 lowing: Bartlett, Winter Nelis, Easter, Cornice, Glout 

 Morceau, Hardy, P. Barry (a California seedling), 

 Seckel, Lawson (Comet), Winter Bartlett, Wilder. 



E. J. W T ICKSON. 



PEAR. Alligator P., Persea ffraiissima. Avocado P., Persea 

 gratissima. Balsam P., Momordica Charantia. Garlic P., Cratseta 

 gynandra. Prickly P., Opuntia. 



PEARL BUSH. Exocfiordagrandiflora. P. Fruit: Margyricarpus 

 . P. Weed or Wort: Sagina. 



PEAT is a kind of soil formed by the partial decay of 

 plants in the swamps of the temperate zone. It is a 

 standard potting material in greenhouse work for cer- 

 tain classes of plants, as ferns, orchids, heaths, rhodo- 

 dendrons, and other ericaceous plants, woody plants 

 from Australia and the Cape of Good Hope, and many 

 other choice and difficult subjects. American gardeners 

 complain that they are handicapped in grow- 

 ing such plants because American peat is 

 poorer than European, the lack of fiber 

 being chiefly deplored, but it is probable 

 that just as good peat is to be found in this 

 count ry. 



The peat-bogs of England are often 5 or 

 6 feet deep, and some of the Irish ones are 

 said to be as deep as 40 feet. They have 

 been forming ever since the glacial period, 

 but are now on the decline, owing largely 

 to natural causes. Peat-bogs consist of the 

 remains of many kinds of aquatic and marsh 

 plants, but chiefly sphagnum (which see). 

 This moss grows upward and decays parti- 

 ally below, complete decay being prevented 

 by the antiseptic organic acids formed in the 

 process. Near the top the peat is brown, fibrous, light 

 and porous: lower down it tends to be black, heavy, 

 dense and without visible indication of its vegetable 

 origin. The ash varies from 1 or 2 per cent in newly 

 formed peat to 10, 20, or even 30 per cent in the older 

 peat. Peat is commoruV used for fuel by the Irish peas- 

 antry, but almost never in America, where other and 

 better fuel is plentiful. In greenhouse work peat is 

 valued more for its porous moisture-holding properties 

 than for its plant-food. If dried, it may be used as an 

 absorbent for liquid manure, "not so much for its inher- 

 ent value," says Roberts (in his "Fertility of the Land"), 

 "as for conserving the nitrogen in the manure, and for 

 improving the condition of the stables." For this rea- 

 son the half-decayed peat is extensively used in Europe, 

 under the name of moss litter, as a bedding in stables, 

 and later of course applied to the land. 



The transformation of peat-bogs into arable land is 

 rarely a pressing problem in America. It is usually too 

 ccstly for a new country. The notion, however, is very 

 common that peat lands are extraordinarily rich in 

 plant-food. Nevertheless, according to Roberts, swamp 

 muck and peat are not richer in plant-food than the 

 good soils, with the exception of the nitrogen in the 

 peat, which, however, is far less available than it is in 

 good soils. (American peat contains about .67 per 

 cent nitrogen, .21 per cent phosphoric acid, and .13 per 

 cent potash.) Peat lands differ from good arable soil 

 in being cold, sour, and too wet. To reclaim them, one 

 must drain off the superfluous water and apply lime 



freely to destroy the harmful organic acids. Sometimes 

 sand or clay may be added to improve the texture of 

 such soils. It takes time to reclaim peat lands. Thor- 

 oughly decayed peat intermingled with wet soils is 

 muck. See the article on Muddand-Gardening, Vol. 

 IV, page 2072, WILHELM MILLER. 



PECAN, Carya Pecan, Engler and Graeb. (Con/a 

 olivseformis, Nutt. Hicoria Pecan, Brit.). Plate LXXV, 

 Vol. IV. Of the nut-trees native to North America, the 

 pecan unquestionably ranks first in economic impor- 

 tance. This is true both because of the quantity and 

 value of the wild crop and because of its cultural 

 promise. The acceptability of the quality of the kernel 

 and the relative thinness of shell and ease of cracking 

 in contrast with the other hickories and the native 

 walnuts, have since an early day continued to win 

 favor among consumers, so that the wild crop of 

 Louisiana and Texas long ago assumed commercial 

 importance and for at least thirty years has, in the 



2822. Foliage and flowers of pecan. The hanging parts are the 

 staminate catkins. A pistillate catkin is below P. Details are at 

 a (staminate flowers) and at b (a pistillate flower). 



latter state, been systematically harvested and distrib- 

 uted in carload shipments to northern markets. 



The relatively wide climatic range of the species and 

 the extent of variation in form, size, and quality of nut 

 have stimulated effort to develop methods of nursery 

 propagation in widely separated localities. This has 

 resulted in a larger and more widely scattered develop- 

 ment of commercial nursery propagation of the pecan 

 than of any other nut-tree. 



Under favorable conditions of growth, the pecan tree 

 attains very large size, trunk diameters of 4 to 6 feet 

 being not infrequent, with heights ranging from 100 

 to 175 feet and tops spreading 60 to 70 feet. Some of the 

 largest trees reported were in the Wabash Valley, near 

 the northern limit of natural distribution. A tree having 

 a girth of 18 feet 3 inches breast high from the ground, 

 with an estimated height of 130 feet and a spread of 

 125 feet, is recorded by Reed in Ascension Parish, 

 Louisiana. One having a girth of 19 feet 6 inches with 

 an estimated height of 150 feet and spread of 100 feet, 

 is recorded in Nachitoches Parish, Louisiana. A still 

 larger tree near Webbers Falls, Oklahoma, has the 

 following dimensions: Girth 23 feet 9 inches at 3 feet 

 from ground; estimated height 180 feet. 



