104 STATE HORTICULTURAL SOCIETY. 



HOW TO ]\IAKE NEAV VARIETIES OF PLANTS. 



BY DOUGLAS E. PHILLIPS_, CLEVELAND^ OHIO. 



There are two distinct ])liases of plant breeding. The first is hybridiz- 

 ation or cross breeding. This is the process of crossing- different species 

 or varieties sio as to produce new plants Avith some of the characters of 

 both parents. The second pliase is selection, the choosing from new 

 plants those which ai)proach nearest to the ideal we are seeking. Most 

 of the im]iroved forms of plants have been produced by selection alone, 

 fi'om a variation of forms. 



At the very start the important thing is to hav^e some definite ideal of 

 what yon wish to obtain and then work toward that ideal. Choose your 

 parents from the same botanical family and if possible, the same g-enus. 

 Do not a1 tempt to cross the wheat with the milkweed to obtain bread 

 and milk. 



Before attacking the problem of hybridization one must know the es- 

 sential parts of typical flowers and their habits. The vital elements in 

 cross-breeding are the stamens and pistils. The stamens or male bod- 

 ies consist of the filaments and anthers. The pollen or male cells are 

 borne in the anthers. The pistil or female body consists of the ovary 

 where the seed is borne, the style and the stigma. 



The technique of hybridization consists briefly of placing the pollen 

 of one flower on the pistil of another, this process being termed pollen- 

 ization. As most flowers possess both reproductive organs and are cap- 

 able of self-fertilization, the female parent must be emasculated, which 

 consists in removing the stamens from the flower you wish to bear seed. 

 Of course this must be done before any pollen has been shed. 



The necessary tools for this operation of emasculation may be a pair 

 of tweezers and small scissors. If the flowers of the plant chosen have 

 both stamens and'pistils developed, the stamens must be removed from the 

 one that is to bear seed. To do this take the flowers in Avliich no pollen 

 has been sihed. The half-opened ones will usually be in the right condi- 

 tion, but in some flowers, like those of the legumes, the pollen is shed be 

 fore the flower begins to open, and in such cases very young flowers 

 must be chosen. In case some of the pollen may have deposited on the 

 stigma, the emasculated flower may be depollinated by a snuiU stream of 

 water. Now proceed to cut away the sepals, petals and stamens, being 

 sure to remove all of the anthers. If the flowers are in clus'ters you 

 should pick oft' all but the ones you wish to pollenate. Since the iX)llen 

 from other flowers can easily be transferred to yours, protect your 

 flower from foreign pollen immediately after emasculation by covering 

 it with an ordinary paper sack. Tie this on carefully and firmly. Then 

 a ])eriod of several days should elapse before you pollenate, in order to 

 allow the stigma to Income ripe or receptive. By observation only can 

 one tell when the stigina is receptive, the best indication being the appear- 

 ance of a moist, sticky substance on the stigma. This excretion causes 

 the pollen to adhere and aids in the process of fertilization. Both the 



