38 SPICES 



CHAP- 



advisable to plant vanilla in hollowed ground or trenches 

 6 in. deep, so as to keep more easily the roots out of reach of 

 the burning sun, or the soil must be porous enough to prevent 

 it being water-logged. This is not done in Seychelles, where 

 vanilla is grown on the surface of the ground and weeds or 

 twigs accumulated in heaps to protect the roots. This kind of 

 protection is insufficient, because as a rule planters protect the 

 roots only once a year, when the time comes for pruning the 

 vines and clipping the props (March to June). I wish to 

 emphasise the sad consequences of this exposure of the roots, 

 because it accounts to some extent for the irregularity of 

 growth and flowering in any one plantation. These physical 

 conditions of growth are of great importance for delicate plants 

 like orchids, and even when the soil is not porous I think that 

 an attempt should be made to plant in trenches filled first with 

 a good layer of broken stones and then with 6 in. at least 

 of fibrous soil. It was thought that improvement in the 

 growth of the vine also could be obtained by manuring them. 

 Up to now the results obtained are very promising, although 

 the manuring was started after the rains in November last, or 

 a few months ago. 



After several investigations I came to the conclusion that 

 a careful examination of the roots while the plant was under 

 treatment with manure would establish which kind of manure 

 would be welcomed by the vine and which not. Kegarding 

 phosphates I have employed phosphatic guano from Flat Island, 

 which contains 72 per cent of tribasic phosphate and only 040 

 nitrogen (7 kilos per basin). These rocks were broken in 

 small pieces like macadam and placed at mid-distance between 

 two rows of vines placed 4 ft. apart. The coral was used 

 in just the same way (5 kilos per basin). Kainit was also 

 employed in the solid state (1 kilo per basin), but as this salt 

 is hygroscopic, small quantities were arranged in a layer of 

 coco-nut husks placed also at mid-distance between the vines. 

 The kainit would thus dissolve more slowly and be absorbed by 

 the coco-nut husks. After three months it was found to be still 

 incompletely dissolved under these conditions. 



Mtrogen is employed in the soluble state as nitrate of soda. 

 The vines are watered once a week with weak solutions of 8 to 

 16 grams in 100 litres of water (50 litres per basin). As far 

 as these experiments go, it is interesting to record the root 

 development which immediately followed the applications of 

 these measures. As already stated, the roots were, previous to 

 the application, all found within 18 in. of the walls of the 

 basins, but three weeks after the application numerous roots 



