Vol. XI. No. 2.58. 



THE AQRICDLTURAL NEWS. 



9S 



STUDENTS' CORNER. 



3IARCH. 



Second Period. 



Seasonal Notes. 



What matter in connexion with the life of the sugar- 

 cane i.s indicated by the circumstance of arrowing ! State 

 what you linow of the way in which the arrows of the sugar- 

 cane are formed, and describe the (lowers which they bear. 

 What is the chief importance of the flowering of the sugar- 

 cane, in regard to experimentation with the plant, and to the 

 sugar industry. Mention any varieties of sugar canes with 

 which you are acquainted that arrow freely; state the reason 

 why arrowing takes place to a greater extent in some years 

 than in others. What precautions should be employed in 

 using sugarcane arrows in the production of seedlings.' Give 

 a general account of the work that i.< done in obtaining 

 a supply of sugar-cane seedlings. 



The completion of the harvesting of limes will allow 

 attention to be given to the cultivation of the fields. \Vhat 

 observations and records do you make in order to obtain 

 information as to which fields require pen manure, and which 

 are needing artificial manures { State if you consider that 

 all fields should be given a dressing of pen manure at definite 

 intervals, providing reasons for your answer. What are the 

 chief effects of applications of pen manure, in relation to the 

 soil 1 What are the reasons why the land is likely to suffer 

 through the continual use of artificial manures without pen 

 manure '. The ordering and employnienl of artificial man- 

 ures reiiuire care, not only in the matter of obtaining the 

 kinds best suited to the plants to be treated, but also with 

 respect to the choice to be made where miire than one kind 

 may be used for the provision of a given element of plant 

 food. In relation to this matter, sulphate of ammonia is 

 dearer than nitrate of soda; what conipen.sating circumstance 

 is, however, possessed by the latter, and how would you 

 compare the two manures in this respect 1 The manuring 

 of lime cultivations does not usually take place during 

 the present part of the year. Give reasons for this. What 

 is the proper time for carrying out the mulching of lime 

 plantations, and what is the purpose of the operation? 



Observations conducted in lime fields during the wet 

 season will have given indications as to the places where 

 draining is required. The present time is suitable for taking 

 advantage of these observations, in the dircLition of increasing 

 the number of diains, or of deepening thu.se that exist already. 

 Give an account of the kinds of drainage that are needed in 

 lime cultivation, under different conditions. Speaking gene- 

 rally, drains should be 3 or -1 feet deep, with the exception 

 of contour drains that have been made only for the purpose 

 of preventing the washing away of the soil. 



Questions for Candidates. 



PkELIMINARV (^UKsrlONs. 



. (1) How can plants be grown without^wil, and what use 

 has been made of the methods that are known? 



(2) State broadly what beneficial kinds of work are done 

 by bacteria in the soil. 



(3) Explain what is meant by grafting, and give an 

 account of its uses. 



Intermediate Questiosh. 



(1) Describe the way in which information is obtained 

 as to the elements that must be provided for green plants, 

 through the roots, in order that thejf maj' grow normally. 



(2) In what ways do bacteria affect the nitrogen of the 

 soil in regard to (a) the forms in which it is found, (b) the 

 quantity that is present I 



(3) Describe the process of grafting, in the case of any! 

 plant of commercial importance with which you are familiar. 



Final Questions. 



(1) How has it been shown that the supply of a certain 

 amount of iron is necessary for the proper development of 

 green plants, and what are the more obvious signs of a lack 

 of this element ? 



(2) State what methods are employed, or suggested to 

 be employed, for increasing the beneficial action of micro- 

 organisms in the soil. 



(3) Describe what occurs in the stems of two plants, or 

 parts of plants, that have been grafted successfully the one 

 on the other. 



CAMPHOR IN GERMAN EAST AFRICA. 



Notes given in the Aqricuhtir'tl News from time to 

 time (Vols. VIII, p. 328, IX, p. 233 and X, p. .56) have 

 summarized the results of experiments that have gone to 

 show that the greatest yield of camphor, in proportion to the 

 raw material, is obtained from the leaves and twigs. In 

 relation to the same subject an article in the Journal 

 d' A'jriculture Tropicale for April 1911 draws attention to 

 information contained in Da- I'jla)i:e) for November 18, 1907, 

 to the effect that 300 lb. of camphor seeds were imported 

 into that colony from .lapan, in 1905; most of these 

 were sown at Wilhelmstal, from which place young plants 

 were sent out to nurseries at different stations, as well as to 

 planters. The article proceeds to give attention to results 

 with plants obtained from this source, which were planted at 

 the station -at Amani; the.se results were presented in the last 

 volume of the Ayi iculhival News, p 56. 



It is further stated that interest has been revived in the 

 matter on account of the similar results that have been obtain- 

 ed in such diverse places as Ceylon, Italy (using old trees), 

 the Federated Malay States (Batu-Tiga), and in .lamaica. 

 Attention is drawn, however, to the suggestion that camphor 

 trees thus exploited may not be able to withstand the annual 

 removal of the leaves. In regard to this matter, the state- 

 ment is made that the most detailed experiments, at Batu- 

 Tiga and Amani (those in Italy are omitted from considera- 

 tion, on account of the age of the trees), on trees three and 

 a half to five years old are explicit on the point that, on 

 condition that the leaves are removed to a reasonable extent, 

 the trees do not suffer any harm. The experiments at Amani 

 are precise on this point, and it has been shown that one- 

 third of the foliage should be cut away; when after the fol- 

 lowing rainy season, the trees are ready for a repeti- 

 tion of the treatment. The practical advice based on this is 

 that planters of camphor trees should treat these in such 

 a way as to cause the greatest production of leaves. 



The article discusses briefly the question as to the bring- 

 ing about of a revolution in the camphor industry, owing to 

 the fact that the drug may be obtained so easily and economi- 

 cally from the leaves, and points out the importance of the 

 suitability of German East Africa to the camphor tree, in 

 relation to the matter. 



