PLANT BREEDING. The variation in plants may be due to natural causes, as environment, etc., or it may be the result of design on the part of man, in which case it is secured by artificially crossing two or more races or varieties. The natural ten dency to be unlike shows itself in 'sports' of vari ous kinds. Artificial variation is secured by fer tilizing the ovules of one plant with pollen from another, the progeny of such a union often ex hibiting Nvidely differing characteristics. Plant breeding is the fixing, by selection, of the desir able traits found in the variations, whether nat urally or artificially produced. The farmer or gardener who seeks to improve his crop by plant ing seed from the most favored individuals is practicing plant breeding,. This kind of plant breeding has been going on in all countries ever since the cultivation of plants was begun. The improvement of plants by selection from arti• tidally produced variations is of more recent ori gin. The production of varieties by crossing has its basis in the sexuality of plants, a discovery of Camerarins in the last decade of the Seventeenth Century. Crossing is the fertilizing of a dower of one variety with the pollen of a dower of an other variety of the same species. Hybridizing is the same operation, but between two species of the same genus. The first artificial hybrid is said to have been produced by an English gardener, Thomas Fairchild, in 1719, when he crossed the Carnation with the Sweet William. The practi cal application of hybridization to plant breeding did not take place until the early part of the Nineteenth Century, when the investigations of Knight, an Englishman, and Van Mons, a Bel gian, were made. In the United States, the earli est investigators along this line were Joseph Cooper and dames Thatcher. Since these pio neers, many persons have devoted their ener gies to the improvement of races of cultivated plants. Conspicuous among these have been Mal let, of England; Rimpau, of Germany: Vilmorin, of France; and Hays, of the United States, all of whom have developed new and improved varieties of cereals; Louis de Vihnorin and his son, Henri de ViImorin, of France; Rabbethge and Giesecke, of Germany, who have developed the sugar-beet; Richter, Girard. and Burbank, who have worked
with potatoes; Livingston with tomatoes; Clark and Hinson with Sea Island cotton; Hovey and Dana with pears; Bull, who originated the Con cord grape in 1540; Allen, Munson, Millardet, and many others, with grapes; Burbank with plums and berries. Many others have worked with all sorts of fruits and ornamentals.
In any system of plant breeding, selection plays a most important part. Sonic natural variants or sports are propagated by cuttings or grafts, which is the most simple method of plant breed ing. Others are grown from seed, like artificial crosses, and plants from these tend to wide varia tion. This tendency can be overcome only by con tinual rejection of all plants that depart from the desired type, seed being saved only from those which most nearly conform to the ideal type. By continuing this process through a number of years or crops, a race will be found that will closely resemble the type in all its individuals. The amount of care and labor involved may he seen from the statement that a breeder of sugar beets examined, in one season, inure than 3,000, 000 roots of an improved variety, only about 30(10 of which were accepted for further trial.
When selection is practiced for producing new races or varieties of cultivated plants, there are a few axiomatic principles to be observed: Al ways cc ntimie selection upon the same lines, once, it is begun. Great size and numerous parts can not usually he secured in the same variety, nor are extraordinary earliness and great productiv ity found associated together.
The following are important contributions to the subject of Plant Breeding: United States Department of Agriculture Year-books for 1897, 1898 and 1899; Experiment Station Record. Vol. VII. (Washington, 1S96) and Vol. XI. (Wash ington, 1899) Carriere, Production ct fixation des rariete's dans les e(:getaux (Paris, 1S65).