Vol. X. No. 2.36. 



THE AGRICULTURAL NEWS. 



157 



STUDENTS' CORNER, 



MAY. 



Secoxd Period. 

 Seasonal Notes. 



Where cotton is grown, it will have been decided 

 already as to what parts of the estate shall be planted with 

 this. E.\-periments and other nianner.s of experience in the 

 West Indies appear to show, that as long as the land is kept 

 in a proper state by the employment of tillage and the use 

 of organic nlanures, there is little or no need for artificial 

 manures in cotton cultivation. In respect to the use 

 of pen manure and green dressings on cotton land, consi- 

 deration should be given to the question as to whether the 

 seed should be planted soon after these have been turned in, 

 or whether time should be allowed to elapse before the cotton 

 is sown. State what you know in regard to the application 

 of green dressings to heavy land, especially where this is 

 likely to be wet. In the cultivation for cotton, as well as 

 for other plants, the nature and texture of the soil must 

 be considered in relation to the kind of tillage that is 

 to be employed. An example of this matter is the fact that 

 a very loose sandy soil may be best treated by giving it only 

 a small amount of cultivation, in order that the particles may 

 be left as closely packed together as possible; on such soil, 

 the cotton plant is likely to become very lank, particularly 

 where there is plenty of rainfall. What kind of growth is 

 often shown hy cotton plants raised in soils containing 

 a plentiful supply of nitrogen? Compare the effect on the 

 soil on a cotton estate where the seed is used for feeding the 

 stock, and the manure is placed on the land, with the condi- 

 tions whore the seed is sold from the estate. How would 

 you demonstrate that little of the mineral content of the soil 

 is removed in the cotton lint. Discuss methods of returning 

 to the soil the material in the stems and leaves of the plant. 



Where cotton has been planted at different times on an 

 estate or on neighbouring estates, good opportunities have 

 been afforded for comparing the results of early and later 

 planting. How are these results related to (1) the distribu- 

 tion of the rainfall throughout the year, ('J) the incidence of 

 insect pests? In the latter connexion, with what pest has the 

 time of planting an intimate relationship? Discuss the 

 advantages or disadvantages of early and late planting of cot- 

 ton in an island, such as St. Kitts, where it is grown as an 

 intervening crop with sugar-cane. 



The great importance of careful seed selection for the 

 next cotton crop should be well understood, by now. In 

 making preparations for this, it is well to have reference to 

 the publications of the Department, in order that no impor- 

 tant part of the matter may be omitted; hints in connexion 

 with cotton seed selection are to be found in the West Indian 

 Bullet in, Vols. IV, p. 208; VII, p. 153. Where such selec- 

 tion is carried out in a thorough manner, it will have started 

 from observations on, and the choice of plants in the field, 

 according to the methods described in the references given in 

 the Agricultural Neivs, Vol. IX, p. 36-0. It is best to limit 



seed selection to the product of such plants, and not to prac- 

 tise it on seed from plants of unknown character. If iiupor- 

 ted seed is planted, careful note should be made of the areas 

 where this, is done, and the plants watched throughout the 

 season, in order to ascertain whether it is advisable or not to 

 use such seed. Such observations will have a particidar 

 importance when they are made on the lint in order to deter- 

 mine its yield and quality. It need hardly be mentioned 

 that, so far, facts appear to indicate that selected local seed 

 is superior, for cotton-gi owing, to that of the same kind which 

 has been imported. 



It has been indicated already, recently, that the student 

 will do well where it is feasible, to compare the different 

 methods for the manufacture of sugar. He will thus be 

 enabled to obtain knowledge of the advantages and dis- 

 advantages of each system; he will also be provided 

 with the means of determining the way in which the 

 various kinds of sugar are produced by the different 

 modes of manufacture. Discuss the matter of the adoption 

 of any one of these modes in relation to the production 

 of marketable molasses, under conditions with which you 

 are familiar. Where central factory methods are employed, 

 discuss the question of the extent to which maceration may 

 be used, particularly in regard to the additional expenditure 

 on fuel that is necessitated by its adoption. 



As has been mentioned before, it is probable, in some 

 districts, that at the present time opportunities will be avail- 

 able for studying the life-history and habits of the moth 

 borer of the sugar-cane {Diatraea. saccharalis). Evidence 

 should be obtained as to the nature of the damage that is 

 suffered by the sugarcane from the attacks of this insect, as 

 well as of the way in which such damage results in interference 

 with the life-processes of the plant. Give an account of 

 methods for reducing the numbers of this pest, as well as of 

 the na!;ure of the estate sanitation that should be effected 

 toward the same end. Information concerning the pest may 

 be obtained from the references given on page 109 of the 

 last volume of the Agricultural News, and attention is drawn 

 to the details that are presented there concerning a means of 

 investigating the way in which the moth borer of the sugar 

 cane is parasitized by other insects. 



Questions for Candidates. 



PEELIJIINAEY QUE.STIONS. 



(1) Why is it impossible to remove all the water in 

 a soil, except by heating it? 



(2) What relationships does the depth of a soil bear to 

 the root-systems of the plants that it sustains? 



(3) AVhat uses have you noticed for the stipules of 

 a plant? 



INTERMEDI.\TE QUESTIONS. 



(1) Describe a good method fijr storing cotton. 



(2) How would you show that living plants alter the 

 composition of the air? 



(3) In what chief ^cays may it be determined if a soil is 

 deficient in lime? 



FINAL QUESTIONS. 



(1) Give plans and details of a storehouse for seed 

 cotton on an estate where about 30 acres of cotton is grown 

 from year to year, and where there are no ginning facilities. 



(2) Supply an outline of the measures for plant sanita- 

 tion on a lime estate. 



(3) State what you know of the ways in which varia- 

 tions in plants are made use of for their improvement. 



