166 



THE AGRICULTURAL NEWS. 



May 28, 1910. 



WEST INDIAN COTTON. 



Messrs. Wolstenholme and Holland, of Liverpool, 

 write as follows, under date May 9, with reference 

 to the sales of West Indian Sea Island cotton :— 



Since our last report, about 400 bales of AVest Indian 

 Sea Islands have been sold at firm prices. 



The sales include about 60 Anguilla, -lOid. to 21(1: 20 

 St. Martin, 20Ad. to 2\d.: 60 Nevis, I9hd. to 21d; 50 Mont- 

 serrat, 18(1 to 20d.: 80 8t. Kitts, 20rf. to 22irf.: 20 Antigua, 

 20rf. to 21(7.; 60 Barbuda, 20r/.: 2.5 Virgin Isles, 21rf ; 20 

 Barbados, 20'i. to 21(?.; and about -50 Stains from various 

 Islands at 13d to 16rZ. 



The report of Messrs. Henry W. Frost & Co., on 

 Sea Island cotton in the Southern States, for the week 

 ending April 30, is as follows: — 



The market is very quiet, with apparently no demand. 

 The unsold stock is very small, and consists principally of 

 Planters' crop lots held at .38c., 40c., and .50c. 



BACTERIAL DISEASE OF COTTON. 



During the cotton season of 1909, the attention of the 

 Mycologist was called to the apparent prevalence of the 

 disease of cotton bolls throughout practically all the islands 

 of the Windward and Leeward groups. Notice was first 

 taken of it in Montserrat, and specimens were forwarded to 

 the Head Oftice and examined in October of last year. The 

 disease appears to be fairly common in Barbados and, accord- 

 ing to the observation's of the Imperial Commissioner, is of 

 frequent occurrence in Antigua and the majority of the 

 Leeward Islands. While never assuming the proportions of 

 an epidemic, it would seem to cause a constant loss 

 every year, which may vary according to the season, 

 from 2 per cent, to possibly as much as 20 per cent, of the 

 cotton crop. These figures are, however, very uncertain, as 

 no experiments have yet been conducted to discover definitely 

 the extent of the damage done. 



The disease appears to be the same as that described by 

 W. A. Orton, in Farmers' Bulletin, No. 302, of the United 

 States Department of Agricalture, as ' bacterial blight ', and 

 attributed by him to Uacteriuin inalvaceariint. Tliis organism 

 appears to be capable of infecting the leaves, young stems 

 and bolls of cotton. On the leave.?, it causes angular leaf 

 spot — a disease which is of common occurrence on the older 

 leaves of cotton in the West Indies. On the stem, it takes 



the form of Mack arm; in this, brown, sunken areas of 

 dead tissue are formed, which eventually nearly circle the 

 young stems and cause the latter to break otf. This form of 

 the disease is not common in the West Indies. Finally, it 

 causes dark-brown or nearly black, hard, sunken areas on the 

 the bolls, which are often cracked in the centre and are 

 surrounded by a somewhat indefinite line of tissue of a darker 

 green colour than that of the rest of the boll. 



Examination of the Montserrat specimens disclosed two 

 types of disease, one of which was probably identical with 

 that found on cotton bolls in the States and attributed to 

 Bii'-teiiura malracearuiii; the other showed several points of 

 difference, but it is possibly also to be attributed to the same 

 organism. In the first form, very small, diseased areas appear 

 on the side near the tip of the bolls; these are brown in the 

 centre, and are .s,urrounded by a ring of darker green than the 

 rest of the boll. In this early stage, sections show that the 

 dark centre consists of cells full of gummy substances, form- 

 ing a pocket, filled with bacteria, between themselves and the 

 dying epidermis. The sections further suggested that the 

 bacterium, which is motile in some stages, probably enters 

 through the stomata when the boll is damp. These areas 

 extend rapidly, and eventually become hard, dry and cracked, ■ 

 being bounded by a darker green and somewhat indefinite 

 line. When the tip of the boll is attacked, the disease may 

 extend downwards for a distance of nearly one-third of the 

 length of the boll all round. At this stage, it resembles 

 anthracnose, but there is no red line characteristic of the 

 latter disease. The lint under the spots is often green, and 

 even when not discoloured, is wrinkled, abnormally glossy, and 

 very weak. The characters of this lint, though difficult to 

 describe, are easy to identify, with very little practice. In 

 addition to damaging the lint, the disease is a source of loss 

 in two ways: young bolls .so attacked fall, and on older bolls 

 lesions are formed which prevent them from opening pro- 

 perly. It may afso be mentioned that bolls suffering from 

 this disease show round, discoloured patches resembling those 

 of angular leaf spot on the bracts and calices. 



The .second form of the disease coniraepces at the 

 junction of the boll with the stock and spreads upwards and 

 downwards, stopping the growth at one side of the boll and 

 causing it to b^pd over a little on that side. The disease 

 penetrates to the lint and turns it into a colourless mucilage 

 on the side attacked, while that on the other appears 

 healthy. The seeds become abortive on the side attacked, 

 and, later, show the presence of the the bacteria. The spread 

 of the disea.se up the boll from the b-ase is accompanied by 

 a softness of the outer boll tissue and a .simiewhat purple 

 discolouration. Such bolls generally fall; they also show the 

 discoloured patches on the bracts and calices mentioned in 

 connexion with the first form of the disease. 



