Vol. XI. No. 268. 



THE AGRICULTURAL NEWS. 



2.53 



STUDENTS' CORNER. 



AUGUST. 



FiK.sT Period. 

 Seasonal Notes. 



For the greater part, the lack of rainfall has interfered 

 with cotton-planting, so that there lia; been delay in the 

 establishment of the crop. State what experience you have 

 had where fields have received a second planting because 

 there was not sufficient rain to cause the seeds to sprout that 

 were put in at first. How much seed i.s required for an acre 

 of cotton, under favourable circumstances? What are the 

 additional expenses incurred on a small estate through 

 having to put in cotton seed a second time? 



How may cotton seed be selected for planting, in 

 a simple way? State the chief objects of such selection. 

 What treatment should cotton seed receive before it is sown? 

 It is well known that no more than one plant should be 

 allowed eventually to grow in each hole; why is this; What 

 rules would you observe in giving instructions for the 

 thinning out of plants in a cottort field; 



Why is the early planting of cotton insisted upon, in the 

 West Indies? It should be remembered that the importance 

 of such early planting has its effect in causing an early 

 previous opportunity to be taken of removing and destroying 

 the old cotton plants of the former crop. 



What pest is most likely to be found on young cotton, 

 and how would you deal with outbreaks of this pest.' In 

 what way does the pest cause changes that interfere with the 

 normal life-processes of the plant? 



With proper rainfall, the present time falls within the 

 period for the planting of provision crops such as yams, 

 sweet potatoes and cassava. The reports issued by the 

 various agricultural departments should be consulted in order 

 that information may be obtained as to the best varieties of 

 these plants, and trials should be made of the varieties. In 

 the case of the most valuable kinds, it would be useful to 

 establish, if possible, nurseries for the provision of planting 

 material. 



Discuss the advantages and otherwi.se of growing sweet 

 potatoes in rotation with sugar-cane. i'>y what diseases are 

 the provision crops mentioned above likely to be attacked? 



Give a careful account of the way in which the ground 

 is prepared for the planting of such provision crops as have 

 come within the scope of your experience. Supply details as 

 to the amount of planting material that is required for one 

 acre in each case, and of the expenses of the planting. 



Questions for Candidates. 

 Preliminary Questions. 



(1) Give a list of the insect pest.s uf the sugar-cane, of 

 which you have knowledge. 



(2) What are the reasons for destroying all old cotton 

 plants at the end of the season? 



(3) Write a list of the advantages that may be gained 

 by growing crops in rotation. 



Intermediate Qukstions. 



(1) Describe the life history of the moth borer of the 

 sugar cane, and suggest methods for it.s cjutrol. 



(2) Mention any advantages that are incurred in the 

 complete destruction of the plants at the end of a cotton- 

 growing season? 



(3) How is the rotation of crops connected with the 

 control of disease? 



Final Questions. 



(1) Discuss the question as to whether the moth borer 

 assists in the spread of fungus diseases. 



(2) Write an account of what you know concerning the 

 pests that are kept in check by the seasonal destruction of old 

 cotton. 



(3) Mention any reasons for growing different varieties 

 of sugarcane on the same land, in rotation. 



NAMES AND KINDS OF RUBBER. 



There are many systems of classification which are 

 adopted in a study of caoutchouc-yielding plants. One of 

 the most popular is that according to habit; in this three 

 groups are distinguished, viz., trees, climbers and shrubs. 

 In the tree forms we have Ficu$ elasfica in the Malay Archi- 

 pelago, which grows to an enormous height. We have 

 Castilloa, a handsome tree characterized by very rapid 

 growth in the first four or five years, common in Central 

 America and .Mexico. There is the genus Manihot in Xorth 

 Brazil and Bahia, which provides a well-branched tree. In 

 Africa the genus Funtumia is responsible for many trees, 

 and in Brazil Hevea is predominant. Hevea and Ficus are 

 large forest types, the smallest are probably Funtumia and 

 Manihot, Castilloa coming midway between these groups. 

 Among the climbers we have the Landolphia vines of Africa 

 and Madagascar, the genus Forsteronia in the West Indies, 

 and Parameria in the Middle East. The first-mentioned 

 genus is, of course, the most important among the vines; 

 it is exclusively African, and is responsible for rubber of high 

 quality. Among the shrubs there is really only one example, 

 Parthenium argentatum, the Guayule shrub so well known 

 as a source of useful rubber. 



Another useful system of classification is that according 

 to the part of the plant which yields the rubber. Under 

 this heading there are three groups; (1) stem, (2) root, and 

 (3) the whole plant. Among stem rubber one can include 

 arborescent forms such as Hevea and Manihot, and climbers 

 as Landolphia and Parameria. Among the root rubber we 

 have Clitandra, Carpodinus, and many other African genera, 

 from which rubber is obtained by macerating the bulbous 

 roots and extracting with water. The whole plant may yield 

 rubber, as in the case of the Guayule shrub where the whole 

 structure is uprooted and subjected to maceration. Perhaps 

 one might also include Palaquium, since it gives gutta not 

 only from the stems, but also from its leaves. 



It is singular that there are many instances of trade 

 names being associated with the produce from one species 

 only. For instance, fine hard Para we know always comes 

 from Hevea brasilienus; Rarabong from Ficus elastica; Ceara 

 from Manihot Gla-iovii, etc. etc. On the other hand, there 

 are many instances of trade names being applied to produce 

 derived from quite a number of species, and in the last 

 category we find the same species may provide different- 

 named rubbers in different parts of the world. The best 

 example of the last group is probably to be found in the 

 produce from Landolphia Hettdelotii, this species providing 

 Soudan niggers, Gambia balls, Massai, and many other grades 

 known as niggers, twists, and flats. (The India rtibber JovV' 

 nal, June 8, 1912.) 



