38 



THE AGRICULTURAL NEWS. 



January 29, 1916. 



WEST INDIAN COTTON. 



Messrs. Wolstenholme and Holland, of Liverpool, 

 write as follows, under date December 28, 1915, with 

 reference to the sales of West Indian Sea Island 

 cotton: — 



Since our last report, the sales of West Indian Sea 

 Island cotton have been confined to odd bags of stained cotton 

 at from lO^cZ. to 111*/, per B). Prices continue firm. 



CANONS OF THE COTTON PLANT 



IN EGYPT. 



The following general conclusions drawn by "Slv. W. 

 Lawrence Ralls, M.A., from his research work on Egyptian 

 cotton, have been extracted from an article in the Monthly 

 Bulletin, of Agricultural Intelligence, Rome, for August 1915. 

 We give explanatory observations in connexion with the 

 niore technical terms employed, at its conclusion. 



The old-established conventional methods of cotton 

 cultivation practised by the Egyptain native are the best 

 possible for the given circumstances. 



Ry simple methods the crop can be 'sampled' at 

 a number of Observation Stations, and Crop Records prepared 

 in the form of Curves of Plant Development \ providing an 

 exact and non-subjective Crop Reporting system, which is 

 also capable of being used for Crop Forecasting on a scientific 

 basis 



The deterioration of the yield of cotton per acre in 

 Egypt from 1898 to 191 1', was almost entirely due to the 

 rise of the water-table, through the action and inaction both 

 of individuals, and of the State. This eftect acts in part 

 directly by decreasing the depth of soil available, but mainly 

 by bringing the water-table into contact with the roots sooner, 

 when it rises as a direct and indirect consequence of the rise 

 of the Nile Flood. 



The deterioration of '(juality' within the same period, 

 especially of the Afiti variety, has btcn caused mainly by 

 increased impurity through admixture and natural cro.ssing. 



si'lNNiNG. The best cotton i.s obtained from pure strains, 

 other things being e(|ual. 



The best samples of fine cottons, in the ultimate and 

 absolute test of actual spinning, are those which contain the 

 smallest percentage of abnormally strong hairs. 



The opinions of experts based on 'handling' of commer- 

 cial lint'-, are no guide to the real spinning value and 

 properties of pure strain lint. 



PLANT I'liYsioLocY. 'I'lic plant is the slave of the 

 Limiting Factor of the environment, above or below ground, 

 at any given moment, and in itself constitutes a perfect 

 recorder of such factors. Rut, in interpreting such plant- 

 records, due regard must be paid to the I're-deterniination of 

 characteristics''. An I'ffcct may not be obvious until many 

 weeks after it has been deterinincd. 



The direct response of growth-processes to the limiting 

 factor is often masked in individual buds and organs by 

 pre-determined Depressant Factors', possibly of an auto-toxic 

 nature. 



PLANT BEEEDiNc;. No System of seed-supply for cotton 

 can be entirely successful, unless it provides against contam- 

 ination of the stocks by natural crossing, presumably through 

 seed-renewal. This provision can be most cheaply and safely 

 effected by building bee-proof cages of brass wire gauze over 

 the initial propagation plots''. 



Similarly, deterioration through natural selection can 

 only be avoided by the use of pure .'.trains. 



The propagation of renewal-seed has been etfected at the 

 rate of 1 metric ton of seed alone from a single seed in 

 three generations. Five tons from one seed in the same 

 period is easily practicable. 



GENETICS. Mendel's Law of gametic segregation applies 

 to most or all the characteristics of cotton plants, qualitative 

 or quantitative, even m ^Egyp to- Upland crosses, but with 

 many extraneous complications, even in simple crosses. 



These complications include gametic Re-Duplication in 

 more than one ratio'', and the deformation of measureable 

 characters by Autogenous Fluctuation". 



iREiiJATiON. Cotton flourishes best on soil which is from 

 2 to .3 metres in depth. Drains should keep the water-table 

 to this level. 



In no soil should the water-table be allowed to rise, oven 

 20cm., for more than a day, once the roots have reached it. 



The crop actually uses as much as .50 metric tons of water 

 per feddan (of 4,200 square metres) per day in the late 

 summer, at a time when the available water is the main 

 limiting factor of growth. 



If the water-table be kept down, the injury resulting from 

 over-watering in late summer and autumn is merely due to the 

 washing away of nutrient soil-salts. A crop 0)i rich soil can 

 stand over-watering. 



Skilful deprivation of water hastens the maturity of the 

 crop by a few days, but only at the expense of lint quality, 

 and }-ield. 



' Curves of plant development consist in the graphical 

 representation of a continuous record of the behaviour of the 

 plant. The curves of most practical value are those of 

 flowering and boiling. The curves are only of practical 

 value under the irrigation conditions of Egypt, where the 

 water-supply is a constant factor undisturbed by rainfall. 



'- The term commercial = mixed-strain lint. 



•■' Pi'e-determination of characteristics is exemplified by 

 the t'ase of the develoimient of the length of lint. After the 

 23rd day of lint development, the maximum is reached, and 

 no environmental change after that point will eftect this 

 characteristic. In other words, the maximum manifestation 

 of a characteristic is decided at a certain point in the plant's 

 life-history. 



' A 1 )epre.s.sant factor is one like excessive sunlight,, 

 which has a retarding influence upon growth. 



■"' The sea constitutes a natural cage in the West Indian 

 islands. 



" Re-duplication is more than (me ratio. Information 

 as to the sense in which Mr. Balls uses this phrase is not 

 available. 



" Autogenous Fluctuation is a term of Mr. Ralls' own 

 invention. In this process the manifestation of a character 

 is aff'ected by the inherited nature of the plant body on 

 which it is borne. See 'The l^cvelopment and Properties of 

 R.aw Cotton', p. 10. 



