38 EXPERIMENT STATION RECORD. 



of additional diversity. It is cxplaiiu'd tliat cotton fiowers at Yuma are visited 

 by insects tliat are api>arently more active than at ottier points wliere cotton 

 experiments iiave been carried on, and it is considered tliat these insects will 

 render it practically impossible to maintain pure stocks of Egyptian seed if 

 Upland cotton is grown in the same localities. 



It was observed that hybrid plants at least in the first generation are more 

 fertile than the pure Egyptian and produce longer and stronger lint. The pro- 

 duction of very high grades of lint from lirst generation hybrids and their ex- 

 treme vigor and productiveness seem to warrant their cultivation and for 

 this purpose to obtain hybrid seed in commercial quantities. As certain char- 

 acters of the Egyptian cotton are strongly prepotent, especially in the first 

 generation, the production of fields of hybrid i)lants is considered advisable. 

 It is pointed out that if Egyptian were crossed on the small Kekchi-Upland 

 type the young hybrids could readily be distinguished from the Kekchi plants 

 and these removed in thinning. To recognize the young hybrids among Egyp- 

 tian seedlings is regarded as much more difficult if not actually impossible. 



Attention is called to the fact that while the utilization of hybrids is a possi- 

 bility, hybrids in fields of Egyptian cotton are a distinct disadvantage. The 

 elimination of hybrids is quite difficult because many of them show no percep- 

 tible differences in their growth to distinguish them from the pure Egyptian 

 plants before the involucres and floral buds have developed. The removal of the 

 hybrid plants, however, must take place as soon as they begin to flower in 

 order to prevent their pollen from infecting the next generation. To reject the 

 seed of these plants does not completely purify an Egyptian stock that has once 

 been hybridized. 



The results of these observations are taken as making it evident that Upland 

 cotton must either be excluded from regions when Egyptian cotton is to be 

 grown or local sources of supply of pure acclimatized Egyptian seed must be 

 established and very carefully guarded from contact with Upland cotton. If 

 Egyptian cotton growing is to be placed on a commercial basis, the results here 

 discussed also indicate that it is not sufficient to complete the process of 

 acclimatization of Egyptian cotton in any one locality if this seed is to be 

 planted afterwards in any other localities. The need of adjustment to local 

 conditions must be taken into account whenever the crop is to be extended to 

 a different district. 



Cotton growing in Arizona, R. W. Clothier { Arizona Sta. Bui. 60, pp. 426- 

 431). — Experiments seem to indicate that the Egyptian cotton is the best 

 adapted to Arizona conditions. Samples of Mit-afifi fiber grown at the station 

 and submitted to the Lowell Textile School for tests of quality were found to 

 be 14 per cent stronger than Egyptian-grown fiber and there was 15 per cent 

 less waste. The maximum yield at the station farm, 2,200 lbs. of Mit-afifi seed 

 cotton per acre, was obtained upon a heavily irrigated plat. 



The article also contains a digest of data previously noted from Bulletin 128 

 of the Bureau of Plant Industry of this Deiiartment (E. S. R., 20, p. 136) and 

 from Circular 29 of the same Bureau (E. S. R., 21, p. 330). 



Cotton production, 1908, D. C. Roper (Bur. of the Census [U. K.], Bui. 100, 

 pp. 52, dgms. 4, maps 12). — This publication presents a summary of cotton 

 crops of the United States from 1899 to 1908, and treats especially and in de- 

 tail of the crop of 1908. In addition, statistics on the world's production of 

 cotton are given and the relation of the Oovernmeut to the cotton industry 

 and the commercial and industrial importance of American cotton are dis- 

 cussed. 



The figures finally compiled for the crop of 1908, including linters an half 

 bales, show a total production of 13,432,131 bales. Expressed in 500-lb. bales 



