Vol. X. No. 231. 



THE AGRICULTURAL NEWS 



77 



STUDENTS' CORNER. 



MARCH. 



First Period. 

 Seasonal Notes. 



It is often observed that lime trees growing wild among 

 other trees, as well as those in abandoned lime plantations, 

 show comparative freedom from severe insect attack, 

 although the general appearance of the plants may or may 

 not be indicative of vigour. Discuss the difference in the 

 conditions surrounding such trees and those of the cultivated 

 plants, with special reference to the chances of infection from 

 pests and diseases, and of recovery after attacks by such 

 enemies Other observations of much interest that might be 

 made are connected with the root disease of limes, to solve 

 the question for instance, as to whether the absence of the 

 fibrous roots that should be produced in the upper layers of 

 the soil in lime cultivations is indicative of the presence of 

 this disease. What are the signs shown by plants attacked 

 by the root disease of limes, and what can Ije done to assist 

 such plants in their struggle against them? In what ways 

 do the diseases of roots interfere with the proper nutrition of 

 the plants attacked? 



Where pen manure has been applied in lime cultivation, 

 it is interesting to watch the effects that more obviously 

 result from its use. Observe if these include the production 

 of a large amount of soft, sappy tissue, and if the (jresence of 

 this tissue encourages attacks by scale insects. What damage, 

 in lime cultivations, may be e.^pected to follow the injudi- 

 cious use of nitrogenous manures? Help in dealing with 

 this question may be obtained by reference to the editorial 

 in the last number but one of the Agricultural News. 



Bengal beans that have been allowed to grow over 

 lime trees should be removed at this time of the year, 

 and observations should be made of the amount of injury to 

 the trees (if any) that has resulted from their use. It would 

 be well, in another season^ to allow the beans to cover 

 selected trees, that are in much the same state of health and 

 growth, to different degrees, in order to determine the extent 

 to which the covering plants may be most usefully allowed 

 to climb over them. A circumstance that has been observed 

 in connexion with this matter is that large amounts of dead 

 wood are often seen, after the removal of the beans, in the 

 case of trees that have been weakened through the attacks of 

 scale insects. 



At the present time, the grafting of cacao is being con- 

 ducted. There is no need to say much about this subject at 

 present, as it has been referred to recently in other issues, on 

 this page. Attention may be drawn, however, to Pamphlet 

 No. 61 of the Department Series, entitled The Grafting of 

 Cacao, in which a complete account of the process will be 

 found, and it may be well to point out that the attainment 

 of success in grafting cacao, as is the case with regard to 

 similar operations with other plants, deijends upon thorough 

 attention to details, as each part of the process has its definite 

 and indispen.sable value. In practice, notes should be taken 

 of the time required for union to take place, a record should 

 be made of the proportion of grafts successfully obtained, in 

 regard to the total number of attempts, and when it is pos- 

 sible, the causes of failure .should be ascertained, for guidance 

 in future work. 



Time may be spent in an interesting and useful manner 

 by making a close study of the Howers of cacao, and by observ- 

 ing the ways in which they are pollinated in nature. The 



results of such observations should be discussed in relation to 

 the employment of spraying as a measure against cacao pests. 

 There are indications that cross pollination will be employed 

 to an increasing extent in the near future, for the production 

 of improved strains of cacao. What do you consider to be 

 the chief characteristics that should receive attention in 

 attempting to obtain such strains ] 



Give an account of the processes to which cacao is sub- 

 jected in order to prepare the bean for market. Why are 

 these processes carried out? What kinds of organisms are 

 chiefly instrumental in producing the changes that occur 

 during the processes? Describe the kind of examination that 

 you would make, in order to find out whether a sample of 

 cacao has been subjected to fermentation in a proper manner, 

 or merely dried without fermentation. 



Consideration should be given to plants, such as arrow- 

 root and cassava, which are raised more especially on 

 account of the fact that they produce starch in quantity. 

 The life-history of such plants should be studied, par- 

 ticularly in relation to the circumstance that they do store 

 starch in this way, and enquiry should be made into the par- 

 ticular part of the plant in which this storage is effected. 

 This will lead to a consideration of the question as to why 

 plants form starch at all, and the matter will have to be 

 viewed in its special relation to carbon assimilation. 



Questions for Candidates 



PRELIMINARY QUESTIONS. 



(1) Give an account of the way in which ordinary green 

 plants absorb water. 



(2) What is humus, and what is the use of it to living 

 plants? 



(3) Explain: heavy soil, tilth, loam. 



INTERMEDIATE QUESTIONS. 



(1) How would you compare several samples of soils 

 with respect to their power to retain water? 



(2) What is guano, and how should it be stored? 



(3) How would you prepare, and employ green dressings 

 for, a field to be planted with cotton? What plants are used 

 for providing green dressings in your neighbourhood? 



FINAL QUESTIONS. 



(1) Describe the principle on which evaporation is con- 

 ducted in the triple effect and the vacuum pan. 



(2) Give an account of the process of improvement by 

 selection, in the case of any plant with which you are familiar. 

 What other important means exists for the improvement of 

 plants, and how does it differ essentially from selection? 



(3) Discuss the advantages which accrue from the taking 

 of retfular inventories, on estates. 



It is stated in the India- Ruhher Journal for January 28, 

 1911, that a British group of capitalists has obtained con- 

 cession of extensive territory at Lunda, Portuguese West 

 Africa, for the exploitation of rubber and its direct export to 

 Great Britain on a large scale, the capital of the group being 

 £1,000,000. The concession has been granted on condition 

 that the holders pay the State 10 per cent, of the profits, 

 make roads, build a railway from the coast to the interior, 

 make every possible improvement in the region, and buy at 

 a fixed price all rubber presented for sale by the natives. 

 Much mineral wealth is stated to be present in the territory 

 granted. 



