16G 



THE AGRICULTURAL NEWS. 



May 20, 1916. 



COTTON CONFERENCE. 



THIRD DAY'S PROCEEDINGS. 



In the last two issues of the Aijricultural Newss have 

 appeared siinimarized accounts of the jjroceedings of the 

 second day of the Conference. On the third day, the I'resi 

 dent suggested that the question of methods to be employed 

 in ascertaining the characters of cotto'i should be discussed, 

 ■with a view to ascertaining what methods are best for general 

 adoption for seed selection and seed supply. He pointed out 

 that there were two sides to be considered: the scientific 

 research side, and the experiment station side. On the one 

 hand, laboratory details had to be considered; and on the 

 other, practical field work. As a means of starting a dis- 

 cussion the President asked Mr. Harland (St. Vincent) to 

 read a paper entitled. Some Lint Characters of Sea Island 

 Cotton. In this the reader stated that the most important 

 lint characters were length, strength and fineness, and, in 

 i-espect of these three characters, uniformity. It was also 

 desirable to have other proi)erties such as a low percentage 

 of weak fibre, a large weight of lint per seed, a good amount 

 of twist, etc., but it was thought that workers in the West 

 Indies for the present should confine their attention in 

 .selection work to the first four characters mentioned. 



As regards length or rather its determination, Jlr. 

 Harland stated that mean ma.ximuin length of the fibre is 

 known to be ahereditary character, which is subject to environ- 

 mental modification, and in a pure strain to fluctuation. As 

 a result of experiments, Mr. Harland had found that for the 

 determination of the mean maximum lint length, it was 

 sufficient to measure the length (.m five seeds to give a result 

 which is fairly accurate for purposes of comparison. Uniform- 

 ity of length was next dealt with. It was considered that 

 the only accurate way of estimating uniformity of length 

 was to pull out all the fibres of, say, over 40 mm. 

 from the combed seed, weigh this as available fibre, and 

 express it as a' percentage of the total fibre. Difter- 

 ent standards would be adopted according to the cottons 

 dealt with. Mr. Harland's results showed that in com- 

 paring the jjercentage of available fibre from ditterent 

 Sea Island cottons, it was ordinarily sufficient to take 

 the mean of ten seeds. In regard to weak fibre, it 

 was pointed out that easily separable lint did not 

 necessarily imply a large projjortion of weak and immature 

 fibre. Considering that the estimation of available fibre 

 would provide more valuable data and could be done, using 

 only ten .seeds, it would probably be wise to do away with 

 weak fibre determinations altogether. It was however just 

 as difficult to estimate available fibre as it was weak fibre 

 in plants with easily separable lint, and this difi^itulty could 

 only be got over by selecting plants with lint that were 

 difficultly separable from the seed. 



!Mr. Harland then jwinted out that his observations did 

 not agree with the statement -Ai Cook in America, that 

 continixous selection for high lint i)ercentago was inadvi.saWe 

 on the ground that a liigh lint percentage usually implied 

 a light .seed, and light .seeds being small seeds would gi\e 

 rise to plants which were lacking in vigour. Mr. Harland 

 gave figures to show that if plants with high lint percentage 

 were selected, their seed weight was, as a rule, (juite normal. 

 The speaker had not found that plants with a low seed 

 weight gave rise to progeny deficient in vigour. He had 

 found that vigour was dependent more upon the specific 

 gravity of the seeds than im their actual weight. Me had 

 found that seeds f)f high specific gravity germinated ijuicker 

 and better than those of \o\\ specific gravity, and gave 



a much better stand. The speaker had also found that 

 a correlation existed between lint index and lint percentage. 

 In selecting cottons <a. high lint index was desirable, but 

 care had to be exercised in doing so, as there was some 

 danger that .selection for lint index alone would introduce 

 the coarse fibre, which was associated with high lint index 

 in some of the American cottons. 



Mr. Harland also read a second paper on the diameter 

 of cotton fibres, with some notes on their breaking points. 

 This paper dealt with the best methods of measuring the 

 diameter of cotton fibres. It was concluded that it is 

 imnece-ssary to determine the diameter of single fibres, and 

 that all work should be done by cross-sections of a bundle 

 of fibres embedded in some material like celloidin. In connex- 

 ion with the breaking points of fibre, Mr. Harland describ°d 

 an appliance which his collaborator (Mr. F. W. L'Amie, 

 M.A., B Sc.,) had devised for the purpo.se. 



At the conclusion of the reading of these papers the 

 President said the general conclusions appeared to be that 

 the most experiment station workers can do at present in the 

 West Indies is to determine mean maximum length, unifor- 

 mity of length, and lint index. 



Mr. A. O. Thurston asked whether it was possible to 

 define the difference between immature cotton and ripe cotton. 



The President in reply, stated that that information could 

 be obtained fromBall.s' book, 'The Development and Properties 

 of Raw Cotton". The great point was, he said, that strength 

 did not appear in cotton until the twenty-first day after the 

 Hower opened, and then it went on increasing from the twenty- 

 first to the forty-second day. Thus, if cotton were picked 

 before the twenty-first day, it would be very weak. The 

 maximum strength was attained in about forty-five days from 

 the opening of the corolla. 



In connexion with the correct time for picking, Mr. 

 Hollings (Nevis) stated that he had received a specification 

 of a patent whereby the bolls could be picked before they 

 opened, and opened afterwards by chemical means. .Such 

 cotton T^as stated to be cleaner, stronger and better in every 

 respect than if it were allowed to ripen and open in the usual 

 way 



Dr. Tempany (Antigua) then read a short note on twist 

 in relation to fineness in .Sea Island cotton. In cottons, he 

 said, the classes of fibres which are encountered may be 

 divided under three heads: regularly twisted fibres, irregularly 

 twisted fibres, and fibres with very little, if any, twist. He 

 had found that in coarse, or relatively coarse, cottons, the 

 proportion of regularly twisted fibre was higher than in those 

 of the finest type. He pointed' out that Balls had shown 

 that fineness was probably a function of the thickness of the 

 cell wall of the fibre, while twist was due to the presence in 

 the cell wall of transversely placed |)its, which as the fibre 

 dried caused the twist in ijuestion. The thinner the cell wall 

 the more .shallow would be the pit, and in consequence, the 

 smaller the twisting force. Irregularly twisted fibres were 

 finest, and the projjortion of irregularly twisted fibre within 

 limits prescribed by the original diameter of the uncoUapsed 

 fibres would serve as a direct measure of the fineness. It 

 was characteristic of .the fine cottons that they contained a 

 high proportion of irregularly twisted fibre, as had been shown. 



Dr. Tempany then reverted to a point raised by 

 Mr Harland, namely, the measurement of lint lengths. In 

 the Leeward Islands it has been the habit to measure cotton 

 by pulling the cotton lint from the seed, laying it out on 

 a baize-covereil base board, and measuring the two longest 

 pulls. Balls in his book had suggested that in prefer- 

 ence to pulling, the fibre should be combed out into the 

 form cif a halo. This method had been tried in Antigua, and 



