1919] FIELD CROPS. 237 



In 1915 the greatest total amount of water applied to Individual plants was 

 293 liters the fourth week in August, and in 1916, 157.5 liters the second week 

 in August. Observations made during 1916 showed a considerable demand by 

 the cotton plant for water well into the fall (October 7). 



The highest total number of flowers appearing weekly on plants grown in 

 the potomoters in 1915 was 76 during the second week in August. On 18 field 

 plants the maximum was reached the last week in July and amounted to 129. 

 In 1916 the maximum number of flowers appearing weekly on individual plants 

 grown in potometers was 105, and on 10 plants grown in the field 146, this being 

 during the third week in August in both cases. 



These results are held to indicate that later cultivation than is usually given 

 would be beneficial to the cotton plant in conserving soil moisture during the 

 hot summer months. 



A plant industry based upon mutation, T. H. Kearney {Jour. Heredity, 9 

 (1918), No. 2, pp. 51-61, figs. 9). — The author briefly discusses mutation in 

 Egyptian cotton, with special reference to the development of the Yuma, 

 Somerton, Gila, and Pima varieties in southwestern United States. It is stated 

 that the maintenance of the Egyptian type of cotton has until recently depended 

 upon the successive appearance of desirable mutants which have given rise to 

 new varieties. 



While mutation was observed only in heterozygous stocks, the recombination 

 hypothesis is deemed inadequate to explain the origin of such extreme mutants 

 as Yuma and Pima, as a comparison of the parent stock with any other with 

 which it might have had recent opportunity to hybridize, failed to reveal the 

 source of the distinguishing characters of the mutant. Intermediate forms 

 were also either entirely absent or extremely rare. The presumption that 

 American upland cotton varieties may be of mutational origin is regarded as 

 entirely tenable. 



Cotton variety tests, A. O. Lewis and C. A. McLendon (Ga. Bd. Ent. Bui. 

 50 (1918), pp. SO, pis. If). — This reports a continuation of cooperative tests with 

 cotton varieties in an effort to obtain strains suited to growing under boll weevil 

 and wilt conditions in Georgia, with recommendations similar to those previously 

 noted (E. S. R., 38, p. 233). 



Meade cotton, O. F. Cook (Science, n, ser., 47 (1918), No. 1227, pp. 11, 12).— 

 Meade cotton, said to be a new upland long-staple variety approaching Sea 

 Island in length and fineness of fiber, is briefly described. The variety was 

 obtained by the discovery and selection of a superior type of cotton by R. M. 

 Meade in 1912 at Clarksville, Tex., in a field of a variety locally known as 

 Blackseed or Black Rattler, but said to be distinct from the varieties bearing 

 these names in other parts of the cotton belt. The new variety is described 

 as producing a fiber of about 1.5 in. in length ; as flowering earlier and more 

 abundantly than Sea Island, with bolls nearly twice as large; as having a lint 

 index (grams of lint per 100 seeds) of 5.45, as compared with 4.93 for Sea 

 Island ; and as being accepted by buyers as practically equivalent to Sea Island. 



A simple method of selecting heavy seeds in cotton, G. L. Kottur (Poona 

 Agr. Col. Mag., 8 (1917), No. 4. pp. 203-210). — The author presents tabulated 

 data to demonstrate the correlation between seed weight and variety or strain 

 of cotton and to show that factors materially affecting seed weight include sea- 

 son, soil, and early and late picking. 



Dividing cotton seed into four grades, namely, big, medium, small, and red 

 (shriveled, light-colored seed), which are said to have relative percentages 

 of germination of 93, 79, 60, and 35, respectively, a method is described for 

 readily separating big and medium seed from the small and red seed. The 



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