246 



THE AGRICULTURAL NEWS. 



August 12, 1905. 



[ 



RATOONING COTTON. 



In the following memorandum Mr. L. Lewton- 

 Brain, B A., F.L.S., discusses the matter of ratooning 

 cotton from the point of view of its connexion with 

 the sjDread of fungoid diseases : — 



One of the best ways of dealing with fungoid diseases 

 of plants is by a rotation of crops. Where this is practised 

 the fungi attacking any one crop have a chance to disai^pear, 

 or, at any rate, to be greatly reduced, before the same crop 

 occupies the same land again. Ratooning will bring about 

 just the opposite state of affairs; fungoid pests will be at 

 their highest development at the end of the first year and 

 the .spores will be present in their greatest abundance to 

 attack any fresh growth. Not only this, but these old fields 

 will be centres of infection for the new crop on neighbouring 

 fields. On the other hand, if the old cotton were destroyed, 

 each disease would have to make a fresh start in each new 

 field, by means of spores from outside chance sources of 

 infection. Sea Island cotton has been cultivated for many 

 generations as an annual crop. It is therefore not to be 

 expected tliat tlie growth of the second year will be equal in 

 vegetative vigour to that of the first year. 



The two most important leaf diseases of cotton are the 

 'mildew' and the ' rust.' Neither of these attacks 3'oung, 

 vigorou.sly growing cotton to any great extent ; the plants 

 vhen growing well seem largely resistant to both diseases. 

 As soon, however, as the jilants begin to get older and less 

 vigorous, both 'I'ust' and ' mildew ' begin to make headwa}-. 

 Every old leaf, at this stage, is covered with disease ; also, 

 almost every new leaf that ai)pears is more or less affected. 

 If the process is carried further and the cotton ratooned, 

 there will be a constant source of infection present in the 

 older leaves, and in all probability nearly all the new leaves 

 on the ratoon growth will be attacked as they open, by either 

 one or both of the diseases. These diseases will certainly 

 reduce the yield of lint and very probably will affect the 

 quality. 



The destruction of the old crop before replanting is also 

 of great importance in dealing with anthracnose of the bolls. 

 In this case if bolls are contiuuallj' on the ratoon plants, 

 there will be a continuous production of crops of spores of 

 Colletotrichum r/ossypii. This fungus certainly attacks the 

 cotyledons of the young seedlings as well as the bolls. 

 Consequently the ratoon crop presents the fungus a splendid 

 means of carrying over from one season to another. The 

 fungus will be in, as it were, an intrenched position, ready to 

 attack first the seedlings and then the young bolls of any 

 neighbouring first-crop cotton. 



Similarly with ' black boll ' in the islands where it 

 occurs. The source of infection of the new crop is again 

 diseased bolls ; and if there is continuous growth from one 

 season to another, the disease will have a much better chance 



■ 1 rstalilishing itself at an early period on the new crop. 

 It is of the utmost importance in dealing with this disease, 

 to destroy thoroughly all infected material before re-planting. 

 To summarize, not only is the ratoon crop itself liable 

 to suffer more severely from fungoid diseases than a first 

 crop, but it is also sure to prove a dangerous source of 

 infection for any freshly planted cotton in its neighbourhood. 



FEEDING COTTON SEED TO PIGS. 



Professor J. P. d'Albuquerque has informed the 

 Imperial Commissioner of Agriculture that a planter in 

 Barbados has recently lost seven pigs to which he had 

 been feeding cotton seed meal. A careful examination 

 of all the facts has led to the conclusion that the 

 probable cause of death was the injurious effect on pigs 

 of the raw cotton seed, of which mention was made in 

 the West Indian Bulletin (Vol. IV, p. 246), in the 

 follo\\ing words : — 



Haw cotton seed cannot be successfully fed to animals, 

 as the lint and dust render it injurious and it is too rich. It 

 appears to be particularly injurious to pigs. 



As this warning appears to have escaped the 

 notice of some planters, and as there may be others who 

 are not aware of this curious action of an otherwise 

 valuable feeding stuff, the following extracts from 

 The Cotton Plant {imhYished by the U.S. Department; 

 of Agriculture), are reproduced for general informa- 

 tion : — ■ 



The carefully conducted experiments noted below 

 indicate, as a rule, that cotton products are positively 

 injurious to hogs, and cannot be safely used, at least not in 

 any quantity. 



ilie mortality of the pigs receiving cotton seed meal was 

 87 jier cent., roasted seed 7.5 percent., and boiled seed 2.5 per 

 cent. It was also observed that the pigs, e.scaping sickness 

 and. death for thirty days beyond the time when sickness 

 usually sets in, were safe from the attack, but were perma- 

 nently stunted in growth. Small amounts of cotton seed 

 meal in the slops are stated to have caused deaths in the 

 college herd of swine in previous years. Curtis concludes 

 ' That there is no profit whatever in feeding cotton seed, in 

 an}- form, or cotton seed meal to hogs of any age.' 



Henry says in his Feeds and Feeding : — 

 All efforts to determine the poisonous principle in the 

 cotton seed — if there be one — have thus far proved futile, 

 and the matter is still a mystery. . . . 



It may be stated in general terms that when cotton seed 

 or its by-]iroductsare fed in reasonable quantity, with a proper 

 complement of other feeding stuffs, satisfactory results are 

 secured with all farm animals except calves and swine. 



