ToL. XII. No. 



THE AOrJCULTURAL NEWS 



THE CULTIVATION OF CONIFERS 

 THE TROPICS. 



IN 



Tlie importation of species of Coniferae into the AVest 

 Indies has resulttd in the establishment, on a small scale, of 

 these useful and attractive trees in several of the islands, 

 notably in Domitjics. The cultivation of conifers under dry 

 conditions in the Tropics is dealt with in a recent issue 

 (if the liuUdin A;/)icolr du Congo Belye and since 

 much of the information given is the result of pioneer work 

 with valuable exotic species, the following article has been 

 pr?])ared embodjini; those facts contained in the paper which 

 jire thought to be of direct value and interest with regard 

 to the growing of Conifers in the West Indies. 



Asa matter of general interest it might be pointed out 

 first of all that flowering plants (Phanerogamia) are divided 

 liotanically into two divisions, Gymnospermae and Angios- 

 jjermae. The divisi' n Angiospermae includes all monocoty- 

 ledonous and dicotyledonous plants, the chief characteristics 

 of which aie well known to the agriculturist. The gymnos- 

 j>ermous plants, which contain the group Coniferae, are not 

 generally so well understood, particularly in the Tropics, so 

 that a brief description of their chief biological characteristics 

 may serve as a useful introduction to later information of an 

 economic nature. 



The gymnospermous flowering plants aie not so highly 

 ditlerenliated as the Angiosperms, and in ni iny respects they 

 resemble the Vascular Cryptogams (ferns), forming as it were 

 an intermediate group. They are large plants, either shrubs 

 or trees, and include the Cycads, which in many of their 

 characters, approach the Vascular Cryptogams, the Conilers 

 and a thiul group, the Gnetaceae, which approach nearer to 

 the Angiosperms. Like those of the Angio.sperms, their 

 reproductive organs are aggregated to form flowers which 

 differ markedly, however, from the flowers "t the Angiosperms 

 ill the fact that when carpels are present the ovules are 

 borne freely exposed on their upper surfaces The carpels 

 are not closed up to form ovary, style and stigma. Hence the 

 name Gymnosperm, which means 'naked seed'. The flowers 

 are always unisexual, and the plants are usually monoecious. 

 In the Coniferae, the seeds are polyembryonic, but only one 

 embryo develops. Each embryo contains a number of 

 cotyledons. The seeds are distributed naturally by the wind; 

 and it is also through the same agency that pollination is 

 etl'ected. After germination, the first year's shoot has no 

 scale leaves or dwarf shoots, characteristic of the mature 

 plant, but the tap root, typical of the Coniferae, begins to 

 develop at once. 



The general arranfjement of tissues in the Coniferous 

 tree closely resembles that of the Dicotyledons; and secondary 

 growth, resulting in the formation of wood, is effected in 

 exactly the same way as in I 'icotyledons. But considerable 

 ditTerences exist as regards the -^trucluye of the different 

 tissues, amongst which might be mentioned the absence of 

 true vessels and companion cells in the vascular bundles, and 

 the presence of the peculiar transfusion ti.'ssue near the centre 

 of the leaf. Large resin passages and glands are also typical 

 of both stem and leaf. 



The life-history of the Coniferae is complex, and space 

 does not permit of its description here. It might be noted 

 that the female cone (which is not a fruit in the ordinary 

 botanical sense of the term) takes about three years to mature. 



Physiologically, most conifers are xerophytic (i.e., 

 adapted for growing under dry conditions) and many have 

 Tnycorhizae, or 'root fungi', which fix nitrogen for the tree in 

 return for the tree's supply of carbohydrates. The narrow, 

 acicular form of the leaves, their thick cuticle, the sunken 



.stomata, the presence of a strong hypodermis, the simple 

 vascular system, are marked xerophytic characters, all 

 tending to reduce transpiration to a minimum. At the same 

 time the importance of transpiration to temperate or sub- 

 tropical evergreens growing in the Tropics must not be lost 

 sight of, in connexion with the maintenance of a suitable 

 leaf temperature for the carrying on of photo.oynthesis. 



To return to the account in the publication mentioned, 

 this states that, in the gardens of the Kisantu Mission, 

 Lower Congo, four exotic species of conifers have been grown 

 successfully under natural conditions without any undue 

 care or attention. When once established, they can resist 

 the dry season, and in spite of the naturally poor soil at 

 Kisantu the trees have grown vigorously, as is shown by the 

 photographs in the article from which this information has 

 been obtained. The plants are raised from seed; vegetative 

 reproduction has been found unsuccessful. 



The species first referred to is Araucaria Bidwillii. It 

 is one of the most useful conifers and is very ornamental. 

 It furnishes an excellent cabinet wood, often very beautiful; 

 it produces large cpiantities of nutritious seeds, very agree- 

 able to the taste, and finally a resin, rich in gum, principally 

 employed in the manufacture of varni.-h. By tapping, it is 

 possible to obtain 16 lb. from a single tree in one year. 

 Araucaria Bidwillii is a native of Australia when it attains 

 a height of 100 to 1.50 feet. Eight year old trees growing at 

 Ivisantu measure 40 to .50 feet in height. Specimens of the 

 tree are to be seen in the Dominica Botanic Gardens. 



The second species described is Araui-aria exi-rha, com- 

 monly known as the Norfolk Island pine. It is a very orna- 

 mental tree and its wood resembles that of Araucaria Bid- 

 villii. The resin of this tree is also said to be of good quality. 

 In its native country, Araucaria crcelsa grows to a height of 

 150 to 200 feet and has a girth of 20 to 30 feet. Three-year- 

 old trees at present growing at Kisantu are about 8 feet in 

 height. 



Another si)ecies, Biot i oricnfalis, is less useful than the 

 Araucarias, but is nevertheless valuable for making fences 

 and wind-breaks The wood is very hard and is used for 

 making the handles of tools and implements. 



Finally, the suitability for the Tropics of another species 

 — JunijKrus ljermudiaita — ha.s also been demonstrated at 

 Kisantu. This tree furnishes hard-wood and resin, like the 

 other species. 



It is considered probable that the following species of 

 Conifers would also grow well in the Lower Congo: Araucaria 

 iDibricata, Dotnheya cliihnsis, Columbeaiiuhricata, Araucaria 

 Domheyi, natives of Chili; Araucaria brasiliensis, indigenous 

 to Paraguay; Araucaria CiiMninghaiuii, of Tasmania and 

 Eastern Australia; Araxtcaria Cookii, a native of New 

 Caledonia; and Daynmara orientalis of the Moluccas. 



The Jamaica Colonial Report, 1911-12, indicates con-- 

 tinued progress in agricultural matters in that island. As 

 was stated in a recent number of the Agricultural Ifeics, the 

 Farm School at Hope has been enlarged, and well-bred dairy 

 stock has been imported. The special insecticide 'Paranaph' 

 continues to be employed for ticks on cattle; outbreaks of 

 anthrax have been kept under control. The 'Panama disease' 

 of bananas has caused some anxiety but is being promptly 

 dealt with. Progress continues in the sugar industry: locally- 

 raised .needling canes J. 71 ar d J. 72 have shown good promise, 

 and new machinery is being introduced on several estates. 

 The central facte ry at Itose Hall is in active operation. The 

 cultivation of cassava, castor oil beans, Castilloa rubber, and 

 Sea Island cotton received the attention of progressive ■ 

 planters during the year under review. 



