Vol. XVI. No. 391. 



THE AGRICULTURAL NEWS 



123 



planting and gathering of the crop. This method of control 

 may not turn out to be practicable on a large scale, but 

 it has possibilities. 



The experiments against Gelechia gossypielhi in the 

 mature cotton seed fall under two main divisions: mechanical 

 methods and chemical methods. Under the first we have the 

 application of heat or cold and the treating of the seed in a 

 vacuum; and of these the hot air treatment of the cotton seed 

 has been found to be the most effective. One of the machines 

 consists mainly of a furnace for the generation of the hot air, 

 a hot air chamber through which the seed passes in trays on 

 four endless bands made of iron chains, and a motor. 



In working the machine there are four factors to be 

 considered: (1) the temperature of the seed when entering 

 the machine; (2) the time required to pass through the 

 machine; (3) the temperature the machine is regulated to give; 

 and (4) the temperature of the seed at the exit. Of these 

 four factors the last is the most important, and the other 

 three must be regulated so as to keep the temperature of the 

 seed at the exit between 119" F. and 131° F., the best 

 temperature to maintain being 122' F. This treatment 

 seems to be effective against the larvae without damaging 

 the seed. Another machine designed for drying malt 

 has been adapted for the hot air treatment of cotton seed, 

 and has given excellent results.* 



Under the chemical methods of control we get the 

 fumigation of the cotton seed with carbon bisulphide, or 

 with hydrocyanic acid gas. Both of these chemicals have 

 proved satisfactory, but hydrocyanic acid gas seems 

 to be the favourite, since, although it takes longer to 

 act, the danger of explosions is eliminated, while carbon 

 bisulphide is highly inflammable. The treated seed can still 

 be used in the preparation of seed cake or in the extraction 

 of oil, since the the quantity of hydrocyanic acid found in 

 the cake prepared from treated seed is so small that it would 

 in no way prevent its use as cattle food, while no hydro- 

 cyanic acid could be detected in the partly refined oil. 



It has been remarked in an article in the Agricultural 

 Journal of Egypt that the treatment of the seed as mentioned 

 above 'would be futile unless rigorous measures are adopted 

 to destroy all cotton bolls left on the cotton sticks after the 

 last picking.' With the object, therefore, of destroying the 

 pink boll worms infesting the dried bolls left on the 

 cotton sticks at the end of the season some experiments have 

 been carried out to convert the cotton sticks, as soon as 

 they are removed from the fields, into charcoal. It has been 

 found that the charcoal made from the cotton sticks will 

 fetch a price which will more than cover the expense incurred 

 in converting the cotton wood into charcoal. 



The control measures mentioned above in connexion 

 with the pink boll worm are also to a less extent useful in 

 checking some of the other cotton pests in Egypt. 



A copy of the Annual Trade Review, being a special 

 supplement to the Chamber of Conatnerce Journal, the oflBcial 

 organ of the London Chamber of Commerce, has been received, 

 reviewing the trade of the United Kingdom for 1916. For 

 purposes of comparison the pre-war year 1913 is taken, and 

 it is shown that the trade of the United Kingdom has been 

 maintained at an extraordinarily high level, considering the 

 enormous difficulties in labour and shipping, and various 

 restrictions that have had to be faced. The sections of the 

 review, which should be studied by all West Indian merchants 

 and planters, that are of more especial interest in the tropics, 

 are those devoted to the tr^e of London and Liverpool, which 

 include references to tropical produce. 



* Rev. App. Ent., IV, Ser. A, pp. 472-91. 



COTTON IN UGANDA. 



It is pointed out in the Annual Report of the Depart- 

 ment of Agriculture, Uganda, for 1915-16, that the cotton 

 crop is the most important agricultural and economic product 

 of the Protectorate, and there appe^.rs every likelihood that 

 its position in this respect will be maintained. An estipiated 

 capital value of £4,000,000 has been placed upon the cotton 

 industry, which has been carefully built up and fostered by 

 the Government. 



Buying and ginning are done entirely by traders, 

 however. This accounts to a large extent for ' the serious 

 temporary set-back the industry received the previous year, 

 when cotton was practically unsaleable for over six months. 

 The effect of military operations seriously interfered with 

 transportation to the coast, while shipping difficulties also 

 led to large quantities of lint being held up. 



Provision is made in Uganda for seed distribution, and 

 during the season of 1916 seed sufficient to plant 100,000 

 acres was distributed. 



Uganda cotton is of a high standard when marketed 

 in good clean condition, and an average price of 120 to 

 130 points on middling American can be confidently 

 expected, while some consignments realized 150 points 

 on, with occasionally better prices for odd lots. 



As regards ginning percentages, the percentage of lint 

 to cotton seed is stated to vary from season to season, and in 

 different localities. Three ginneries to the eastern Province 

 gave figures of 280^ per cent., 2918 per cent., and 3036 

 per cent., while another factory which handled over 

 1,000,000 B). of seed-cotton had an average ginning 

 percentage of 31-36 percent. As regards spinning results, 

 the Fine Spinners' and Doublers' Association of Manchester 

 reported that the cotton was very inferior to ordinary 

 Egyptian, but that it compared favourably with extra 

 stapled American. 



Surplus cotton seed has a special use in Uganda. In 

 1915-16 only 5,225 tons of cotton seed were exported, com- 

 pared with 9,017 tons last year. The seed consumed locally 

 is used largely for fuel in generating steam power, and as 

 the residue is rich in potash, planters have at their 

 disposal a valuable manure for all crops. 



It is stated that a certain amount of oil was expressed 

 locally, and exported. In many of the cotton ginneries, the 

 seed is entirely used for generating suction gas, and the 

 production of power is thus very economical. 



Coffee in Uganda. — Whereas cotton cultivation 

 is the principal native cultivation in Uganda, coffee main- 

 tains its position as the principal European crop; but it is 

 to some extent a favourite exportable crop grown hy natives. 

 The rapid progress of the industry is shown in the Annual 

 Report of the Department of Agriculture for 1915-16, where 

 it is stated that the value of the exports wa.s only £383 in 

 1910-11, while last year the value was £87,202. Pests have 

 been much in evidence, however, on coffee plantations, though 

 the disease caused by Hemileia vasiatrir does not appear to 

 have been much in evidence. Coffee, on the whole, seems to 

 be proving to be a risky crop. In the more humid parts 

 of the Protectorate, the more disease-resisting species, Cofea 

 robusta, is being grown, the drier and more elevated pans 

 being allotted to Arabian coffee. 



