Vol. XII. No. 301. 



THE AGRICULTURAL NEWS. 



■W) 



STUDENTS' CORNER. 



xove:mber. 



Second Period. 

 Seasonal Notes. 



PERIODIC PHENOMENA OF TROPICAL VEGETATION, 



Although the climatic conditions of the West Indian 

 Islands are more uniform than those obtaining in most 

 tropical countries, the difference between the wet and dry 

 seasons is sufficiently marked to influence vegetative growth. 

 In temperate regions, periods of vegetative rest occur as 

 a whole, and are largely due to the effect of winter. In the 

 Tropics, seasonal changes render periodic variation less 

 obvious, and induce resting periods only for certain functions 

 rather than periods of rest for vital processes as a whole; 

 though the dry season in a measure has a similar effect to 

 the winter temperatures of a cold country. The less marked 

 the climate the less dependent on its influence is the 

 periodicity of the plant. In a nearly uniform climate, 

 internal causes are mainly or solely responsible for the alter- 

 nation of rest, and of activity. 



Although popular opinion is to the contrary, tropical 

 fore.sts are for the most part composed of periodically leafless 

 trees, though it has been found that leaf- fall does not occur 

 periodically in respect of climate. Under identical external 

 conditions some trees lose their foliage even before the end 

 of the rainy season, whilst others shed their leaves at 

 the commencement of the dry season; others again do this 

 quite regularly in the course of several months, and 

 lastlj-, others remain in full leaf until the opening of the 

 resting buds. In some tree.s leaf-fall may be suspended 

 for many years. 



LEAF-FALL A SIGN OF BLOSSOMING. 



In all tropical districts with very weak climatic period- 

 icity, there are woody plants that shed their leaves 

 at longer or shorter intervals (one to six times a year) 

 without any connexion with the season of the year, so that 

 trees of one and the same species, under the same external 

 conditions, acquire fresh foliage and shed their leaves at times 

 that do not agree. Cases of the loss and restoration of leaves 

 independently of the season of the year can only be due to 

 internal causes. Frequently such a leaf-fall • is a sign that 

 the tree is preparing to blossom. 



With regard to periodic phenomena in relation to 

 growth in general, it would seem that evergreen woody 

 plants in districts with precipitations at all seasons of 

 the year are not endowed with continuous growth, but, 

 like deciduous woody plants, experience periodical alterna- 

 tions of rest and activity. More frequent than the simul- 

 taneous awakening of the whole crown of the tree is 

 the development at different times of the terminal buds 

 of individual twigs or systems of twigs from the resting 

 to the active conditions. The independence of individual 

 systems of shoots, for instance, is very strikingly exhibited by 

 the mango tree. Its reddish young foliage does not appear 

 at once all over the surface of its immense dark-green crown, 

 but only at one or at two points, correspondinj^to the system 

 of branches of a longer bough, the terminal buds of which all 

 sprout together, whilst those of other boughs remain at rest. 



Questions for Candidates. 



PRELIM INAJtV (fUEr^TIOXS. 



(1) Name two tropical trees which remain Isafless for 

 a considerable period, Give details as regards length of 

 period, time of occurrence, influence of environment and 

 similar circumstance.*!. - 



(2) How would you proceed tO find the area of a field 

 having an irregular boundary? 



INTERMEDIATE IJUESTIONS. 



(1) Write a short account of perodicity in connexion 

 with the blossoming of lime and cacao trees. 



(2) Give an account of the cultivation of a field for 

 cotton, which is to be followed by a crop of sugar cane. 



FINAL QUESTIONS. 



(1) On what points is information needed in connexion 

 with the fermentation and curing of cacao? 



(2) Discuss the West Indies as a market for West 

 Indian produce. 



DEPARTMENT NEWS. 



The Imperial Commissioner of Agriculture leffc 

 Barbados by the S.S. 'Oruro' on Xoveiuber 7, 1913, for 

 an official visit to .St. Lucia. It is expected that the 

 Commissioner will return by the S.S. 'Korona' on the 

 loth instant. 



Mr. H. A. Ballou, M.Sc, Entomologist on the Statit' 

 of the Imperial Department of Agrictdtuie, left. 

 Barbados by the S.S. 'Parima' on November 8, 

 1913, for Dominica, with the object of conducting 

 investigations in connexion with citrus pests. Mr. 

 Ballou is expected to return by the S.S. 'Korona' 

 on the 15th instant. 



In the last issue of this journal reference was made to 

 a statement which appeared in the Jcmrnal of the Royal 

 Society of Arts, concerning the alleged superiority of Ceylon 

 papain over the West Indian product. In the same journal 

 for September 26, 1913, the !Montserrat Company, Ltd., 

 write to say that they have to take exception to such an 

 assumption. They state that the West Indian papain is so 

 superior to the Ceylon article that it sells readily at a very 

 much higher price, and the demand for it can be met only 

 with difficulty. 



The prosperous condition of Fiji is referred to in the 

 Financier and Bullionisl (September 29, 1913) where the 

 revenue for 1912 is reported to be the highest collected in 

 the history of the colony, and exceeded the revenue for 1911 

 by no less than £43,5.52 4s. \d. The Fiji Islands cover an 

 area of 7,435 sq. miles, or more than the area of Jamaica, 

 Trinidad and Tobago, the Leeward Islands, the Windward 

 Islands and Barbados put together. Further increase in the 

 population is necessary for full development. The opening 

 of the Panama Canal, it is stated, will prove an important 

 event for these islands. 



