Vol. X. No. 238. 



THE AGRICULTURAL NEWS. 



189 





STUDENTS' CORNER. 



JUNE. 

 Second Pekiod. 



Seasonal Notes. 



Discuss the differences lietween the (•iiltivation of a tem- 

 porary crop like sugar or ci>tton and that of a permanent crop 

 such as cacao, limes or nutmegs. In the former kind of 

 cultivation, how can the growing of ground provisions aid in 

 the cultural operations on the estate as well as in keeping the 

 soil in a good state of tilth? Discu.ss the advisability, or 

 otherwise of forking cacao orchards. Is forking necessary 

 for opening np heavy soils in cacao cultivation? Suggest any 

 means that you know \<y which soil may lie turned over with- 

 out disturbing it mechanically. 



Give an account of the different ways of conserving soil 

 moisture. Under what conditions may plants be actually 

 raised for this purpose ! What kind of tillage po.ssesses an 

 intimate connexion with the work of preventing the soil from 

 losing water, as far as possible? In what ways may the quan- 

 tity of water in a soil be reduced, and under what circum 

 stances may such a reduction be advi.sable '! A soil will lose 

 water either if it is opened up too frequentlj', or if on the 

 Other hand it is made too firm. In connexion with this mat- 

 ter, state how the water-holding capacity of a soil may be 

 diminished. Give a description of the circumstances that are 

 likely to arise in a soil which is kept too wet, and mention 

 any useful plants with which you are acquainted that thrive 

 well in situations where the soil is likely to lemain wet. At 

 what periods of the life of a plant do the moisture conditions 

 of the soil possess their greatest effect in relation to its devel- 

 opment i Describe methods by which you could compare in 

 a simple way the capacity of soils of various kinds to hold 

 water. 



One of the most important problems for the agricul- 

 turist is often that of finding a means of increasing the 

 amount of water in the soil. In what way may this be done '! 

 What would be the etf'ect, in relation to this matter, of increas- 

 ing the water-holding capacity of the soil, and how may such 

 an increase be brought about .' What measures may be taken 

 to enhance the tlow of water in a .soil from the lower to the 

 upper layers '. In what ways does this matter refer to the 

 kinds of cultivation that are practised fin estates? With refer- 

 ence to these subjects, although irrigation has not attained 

 importance as yet in the AVest Indies, the affair is of sufKcient 

 interest from a general point of view to make it worth while 

 to obtain an elementary knowledge of it, and to take notice 

 of any matters having reference to it that may occur from 

 time to time. Discuss the relationship between the organic 

 content of the soil where irrigation is used, and that under 

 conditions with which it is not employed. 



Much of what has been said above will show that the too 

 frequent cultivation of soils is undesirable, especially after the 

 protective mulch has become quite dry. In this matter, there 

 has to be considered not only the effect on the soil, but the 

 economic condition that arises from doing work (of cultivation) 



for which there cannot be any return. Another circumstance 

 which requires consideration in the same connexion is the 

 state of development of the plants on the land which is being 

 cultivated. .Many plants, as they attain maturity, produce 

 large numbers of fine roots close to the surface of the soil, so 

 that it is easily understood that any cultivation which injures 

 these merely has the effect of reducing the ability of the 

 plants to take up water, and therefore of minimizing their 

 effective supply. 



Questions for Candidates. 



PRELIMINARY QDESTIONS. 



(1) State what you know of the different kinds of seeds. 



(2) How does water travel through the soil ? 



(3) How would you show that plants breathe ? What 

 necessary condition would have to be fulfilled in the experi- 

 ment 1 



INTERMEDIATE QUESTIONS. 



(1) What are the chief elements (a) taken in, (b) given 

 off, by plants during life ? 



(2) Describe any way in which the mode of germination 

 of the seed of a plant may influence the treatment of the soil 

 after it is sown. 



(3) Give an account of the ways in which mulching is 

 performed. What is the use of mulching .' 



FINAL QUESTIONS. 



(1) Discuss the requirements of any cultivated plant 

 with which you are familiar, in regard to the supply of water 

 at different periods of its growth. 



(2) Write an account of the liest methods of storing the 

 seed of any crop with which you have v.orked. 



(3) State, as far as you can, the significance of the fact 

 that plants give off carbon dioxide. 



WEED DESTRUCTION IN THE 

 PHILIPPINES. 



From an article in the Philippine Agricultural Review, 

 for February 1911 ,it appears that the plant Lantana Camara, 

 which is one of those known as ' wild sage ' in the West 

 Indies, has been introduced, together with other tropical 

 American weeds and ornamental plants, into the island of 

 Negros, in the Philippines. This plant, by its rapid spread 

 and luxuriant growth, has already caused trouble to agricul- 

 turists in Hawaii, where insect pests have been introduced 

 for the purpose of diminishing its spread. 



The measures that are proposed for the eradication of 

 the weed before it becomes disseminated beyond control con- 

 sists in the process of loosening the root sj'stem, which is very 

 weak, by means of a pick or a strong wooden stake, and then 

 cutting through the roots just below the collar; the plants 

 treated in this way are allowed to become dry in the sun, and 

 are then burned as soon as they are fit for this to be done. 



The article draws attention to the characteristic inffor- 

 e.scence of the plant, which consists of a small bunch of 

 reddish or yellowi.sh ffowers, Ijorne near the tips of the 

 branches; the flowers in the centre of the bunch open first, 

 when their colour is pinkish or yellowish, but reddish or 

 purplish after a few days. The most potent circumstance in 

 the spread of the plant is the tact that the fruits are eagerly 

 eaten by birds, which do not however digest the seeds. 



As is well known, the plant is a perennial and attains in 

 the West Indies a height of 5 to 7 feet. In Hawaii, it has 

 been known to grow as tall as 15 feet, but the specimens in 

 Negros were only 6 to 9 feet high, at the time of publication. 



