398 MANUAL OF TROPICAL AND SUBTROPICAL FRUITS 



Propagation. 



The work of George W. Oliver in the greenhouses of the 

 Department of Agriculture at Washington has thrown much 

 light on the requirements of young mangosteen plants, and on 

 the best methods of propagation. The following extracts are 

 taken from his report in Bulletin 202 of the Bureau of Plant 

 Industry, "The Seedling-inarch and Nurse-plant Methods of 

 Propagation." 



" Few plants show the results of inattention on the part of the 

 cultivator more plainly than the mangosteen. When once a plant 

 becomes in the least sickly, there is little likelihood of its recovery 

 on its own roots. The mangosteen does not take kindly to heavy 

 soils ; it prefers a well-drained soil containing a large proportion of 

 decayed vegetable matter. When seedlings are removed from flats 

 and put in pots some will die without apparent cause. An over- 

 supply of water causing the soil to become in the least sour is certain 

 to induce sickness much more quickly in the mangosteen than in 

 other species of the genus. Therefore, great care is necessary in 

 handling the plants, especially in the early stages of the seedlings. 



" Unfortunately the mangosteen is not a strong-rooting plant, 

 especially during the first year or two after germination. This pecul- 

 iarity renders it particularly sensitive to dry weather and may account 

 in part for the many failures to grow it successfully. Nearly all 

 the other species of the genus have strong and abundant roots, even 

 in the seedling stages. It therefore seems likely that the mangosteen 

 will thrive better and under more widely varying soil and atmospheric 

 conditions if the young plant is inarched to some species of the genus 

 which has a good root system. 



" The genus Garcinia is a large one, the Index Kewensis listing 

 228 species. Of these about 20 have been tried in the inarching 

 experiments; and while the mangosteen unites with all of them, 

 only a few can be recommended as promising stock-plants. Two 

 other genera of the same family, Calophyllum and Platonia, have 

 been tried. Two species of Calophyllum, C. calaba and C. inophyllum, 

 are not satisfactory because the union between these and the mango- 

 steen is imperfect. This is partly because the stems of the Calophyllums 

 are softer than those of the seedling mangosteen and partly because 

 the growth made by the former as they become older" is much more 

 rapid. Platonia insignis (see below), on the other hand, so far as 

 the experimental work has progressed, is a very promising stock 

 from one to three years after germination, and if it will grow under 



