Vol. X. No. 233. 



THE AGRICULTURAL NEWS. 



109 



STUDENTS' CORNER. 



APRIL. 



FiKST Period. 



Seasonal Notes. 



During the first months of the year, the picking of 

 the lime crop comes to an end, so that at this time 

 attention is given to the work of bringing the trees into 

 a good state of health, in order that they may bear freely 

 during the coming season. Prepare an account of the meas- 

 ures that you would take in this connexion, having special 

 reference to tillage, the appliration of manures, pruning and 

 the removal of suckers and epiphytes. What should be done 

 with the material that is taken from the tree, and why is 

 the procedure necessary if the plants are to remain healthy? 



It has been mentioned recently in these notes that 

 useful observations can be made on the insect visitors to the 

 cacao flower, in connexion with the determination of the 

 particular means of cross-pollination in this plant. The same 

 is true of the lime, and after the ovaries have become 

 fertilized it is useful to continue the oljservations, in special 

 relation to the development of the fruit, until this is ripe, in 

 order that the time may be ascertained which elapses from 

 fertilization to the ripening of the fruit. The extension of 

 these observations will enable the time to be found during 

 which the crop will last, and the period when it is likely 

 to be heaviest. 



Reference was made above to tillage in lime cultivations. 

 When this is done with the fork, care must be exercised to 

 prevent damage to the roots near the surface, as the.se are 

 of the greatest importance in relation to the nutrition of the 

 plants from the soil. Where a root has been damaged, 

 ascertain the manner in which it heals, and compare this with 

 the similar proce.ss in the case of stems. Further useful work 

 in connexion with the roots of lime trees may be performed 

 by making an examination of the surface roots in different 

 parts of the orchard, and finding out in what way, if any, the 

 number and prevalence of these is related to the character of 

 the soil. 



Why is drainage necessary in relation to: (1) the soluble 

 salts in the soil; (2) the supply of fresh water to it; (3) the 

 renewal of air in it; and (4) the operations of tillage on estates] 

 What are the conditions under which drainage is most likely 

 be needed? Why is drainage often necessary where fairly flat 

 areas of soil are almost surrounded by higher land, and where 

 such land rises quickly from small neighbouring flatter areas? 

 Describe the kinds of drainage that; would be suitable under 

 the different conditions. What relation do the character and 

 composition of the underlying rocks and soils bear to drain- 

 age? It is found, sometimes, that the roots of plants do not 

 utilize the soil below a certain comparativelj' small depth, 

 although its physical condition is apparently favourable to 

 their growth. What is the reason for this, and when this reason 

 obtains, what is the remedy ( What appearance in the roots 

 just below the surface of the soil would lead to an indication 



of the existence of the condition that has jnst been described ? 

 A greater understanding of tlie way in which drainage takes 

 place, and of its importance to plants, will be obtained by 

 considering the question as to why proper drainage actually 

 Increases the amount of water in the soil that is available 

 to plants. 



It is important to remember that when areas of land are 

 well drained, deeper access is given to the organisms, such as 

 earthworms, which open out the soil and enable the air to 

 enter it easily. What circumstance has the same eft'ect in 

 relation to the changes that take place in deep clay soils after 

 they have been drained? A matter of interest is that if air is 

 enabled to circulate in the depths of the soil, nitrates are 

 formed in greater amounts, and the presence of these salts 

 leads to a flocculation of the clay, so that this admits of more 

 easy tillage, and again the access of air is facilitated. While 

 these matters are being considered, discuss the relation of 

 heavy falls of rain to aeration of the soil. 



Give a general account of the kinds of drainage with 

 which j'ou are acquainted. What is the nature of this in 

 cacao and lime plantations, and in sugar-cane and cotton 

 fields, under ordinary conditions? Describe situations in which 

 the ordinary methods of drainage have to be modified to suit 

 special circumstances. What is meant by contour drains? 

 How are they made, and what care is required in order to 

 keep them in a state of efliciency? 



Questions for Candidates. 



PRELIMINARY QUESTIONS. 



(1) Give an account of the chief diflerences between 

 roots and stems. 



(2) Describe shortly the value of humus in the soil. 



(3) What is the difl'erence between pollination and 

 fertilization? 



INTERMEDIATE QUESTIONS. 



(1) Mention the chief uses of leaves to plants, and state 

 when and why it is expedient that all or any of the leaves 

 should be removed from a plant. 



(2) Mention some different forms of seeds, and account 

 for the special peculiarity of each. 



(3) Write a description of the weevil borer of the sugar- 

 cane and give a short account of its life-history. 



FINAL QUESTIONS. 



(1) Can you indicate if there are any broad general 

 differences between the modes of cultivation for dicotyledons 

 and those for monocotyledons ! 



(2) Give a general account of the efi'ects of the chief 

 artificial manures on the soil. 



(3) Describe the uses to which the available locally- 

 grown woods in your district are put, and indicate any 

 special purpose for which one or more of them may be 

 employed. 



A communication from H. C. Prinsen Geerligs, in the 

 Louisiana Planter for February 4, 1911, shows that the 

 total importation of sugar in the United Kingdom during 

 1910 was 1,728,730 tons, of which somewhat less than half 

 (846,862 tons) was refined sugar. The latter came chiefly 

 from: Germany — 335,791 tons, Austria Hungary — 199,46-5 

 tons, Holland — 118,160 tons. Of the raw sugars, 562,161 

 tons was cane-sugar, against 302,455 tons in the previous 

 year. This sugar was supplied as follows: .Java 118,304, 

 Cuba 96,330, British West Indies 78,737, Brazil 51,469, 

 Peru 46,206 tons. The contribution from the British 

 Colonies was 130,138 tons, against 85,264 tons in 1909; but 

 the great increase in the importation of raw sugar was pro- 

 vided chiefly by foreign countries. 



