BUREAU OF PLANT INDUSTRY. 165 



but production is restricted in many ways. The total crop is esti- 

 mated at 4,000,000 bales, though only about 2,000,000 bales pass 

 into commerce or reach the industrial centers. In some of the 

 northern districts the crop is of the Upland type, not unlike some 

 of the small-boll short-staple ^•arieties of our Southeastern States, 

 but most of the Yangtze Valley cotton is of the native Chinese or 

 Asiatic type — very small plants with narrow, deeply lobed leaves, 

 very small bolls, and uneven fiber, much of it so short and kinky 

 that the mills can use it only for coarse thread. Nevertheless, the 

 Chinese cotton appears to be better adapted to the local conditions 

 and farming systems of the coast districts than Upland varieties 

 that are being planted experimentally. Improvement of the crop 

 by selection is shown to be possible by the frequent occurrence of 

 individual plants with fiber an inch or more in length and of good 

 quality, and work of this kind is being undertaken at several agri- 

 cultural stations in the different Provinces. 



CORN. 



An Indian variety of corn that tolerates self-pollination. — In com- 

 mercial seed corn there is alwa3^s a portion of the seed that has re- 

 sulted from the silks rec eiving pollen from the same plant. In all of 

 the varieties previously studied this self-pollinated seed is decidedly 

 inferior, producing only w^eak, unproductive plants. Unless the 

 detasseling of plants in alternate rows to insure cross-pollination 

 becomes a general practice, the presence of self-pollinated seed will 

 continue to result in reduced yields. If without the loss of other 

 desirable qualities varieties could be developed that are tolerant to 

 self-pollination, yields would be materially increased. A beginning 

 in the direction of securing strains tolerating self-pollination has 

 been made through the discovery among t.he varieties of maize grown 

 by the American Indians of one from the Pawnee tribe that does 

 not show the usual loss of vigor when self-pollinated. After being 

 self-pollinated for four successive generations this strain shows no 

 appreciable reduction in yield or vigor. The variety is early and 

 very productive, and in addition to its value as a breeding stock it 

 promises to be very desirable for ensilage, especially in semiarid 

 regions. 



Chlorophyll disorders of corn. — Further study of the minor ab- 

 normalities of corn has shown that the number of these detrimental 

 variations is much greater than had been supposed. It now appears 

 that the complete suppression of these abnormalities in the genera- 

 tion immediately following a cross of the unrelated strains is the 

 explanation of the vigor and high performance that characterize 

 first-generation hybrids. 



A dn^arf variety of corn. — In one of our corn hybrids a brachytic 

 variation has appeared in which the mature plants are only about 2 

 feet in height, though otherwise full sized and normal. There is no 

 reduction in leaf area, and the short-jointed plants are as productive 

 as the tall plants of the same stock. This variation is similar in 

 nature to that which has resulted in the production of bush varieties 

 of ])cans, squashes, and other vegetables. One result of such dwarf- 

 ing of corn is that the root system is greatly enlarged by increasing 

 the number of root-bearing nodes below the surface of the ground. 



