Edible Products. 



32 



January, 1909. 



merchandise not including timber. Im- 

 ports contributed 20'73 per cent, and 

 exports 52'47 per cent, to the increase. 

 Elephant stealing in the forests pf Siam 

 hampered the imports of teak timber, 

 and the great murrain among cattle in 

 Western China and the Shan States 

 accounts for a heavy decline under that 

 head, but the total trade for the official 

 year 1907-08 amounted to 534 lakhs, an 

 increase of 9-46 per cent.— Indian Agri- 

 culturist, Vol. XXXIII., No. 9. 



MANIOC OR CASSAVA. 

 By Edwin B. Copeland. 



{Continued from <p. 529.) 



Climate and Soil. 

 Manioc is essentially a tropical crop. 

 Even the hardiest varieties are killed by 

 any frost that kills tomatoes. As a 

 result, growers in the United States 

 must use the earliest varieties and 

 harvest their crops in from seven to nine 

 months after planting. The average 

 yields with decent cultivation are not 

 over five tons of roots per acre. This is 

 as high a yield as c ould be counted on in 

 the Philippines in the same time ; in the 

 variety that is raised here, it is after 

 this age is passed that the most rapid 

 growth oceui's. As the plant is repro- 

 duced by stem cuttings, it is necessary 

 in a country subject to frosts to bury 

 the stems during the winter. This 

 makes seed material somewhat expen- 

 sive and of low vitality, so that a con- 

 siderable percentage of the cuttings set 

 out are likely not to live, and this in 

 turn leaves vacant spots in the field and 

 cuts down the yield. It is only in lands 

 nearer the equator, where the temper- 

 ature is comparatively uniform and 

 moderately high, that manioc can 

 develop with its characteristic luxu- 

 riance. An altitude of 3,000 feet is the 

 upward limit of the common occurrence 

 of manioc in Hawaii ; in the Philippines 

 its culture for food can well be carried 

 higher. 



Aside from the fact that it must be 

 warm, manioc is very modest in its 

 demands upon the climate. To drought, 

 the arch enemy of most cultivated 

 plants, it is fairly immune. For the 

 month or so after the cuttings are 

 planted, they need as much rain as do 

 most other plants at the same stage of 

 growth. After this time, a moist 

 temperature and occasional rain pro- 

 mote a most thrifty growth and the 

 succulence of the roots. Root9 used for 

 food have a better texture in wet seasons 

 than in dry. Dry weather, however 



at least such dry weather as occurs in 

 the Philippines, never kills manioc, and 

 rarely, if ever, comes near stopping its 

 growth. The typical insular climate, 

 with a moderate amount of moisture in 

 the air at all times, is most favourable 

 for manioc. Never is it seriously injured 

 by any drought occurring in these 

 Islands, and it is likewise not hurt by 

 heavy rainfall, unless it grows in heavy 

 and undrained soil. 



As is true of all drought-resisting 

 plants, manioc wants all the light it can 

 get, and plants at all shaded or planted 

 too close together must not be expected 

 to be very productive. The ideal soil 

 for manioc is rich, fairly deep, and open. 

 Since very rich soils are often compact 

 and heavy and undrained, and since its 

 tolerance of drought makes it thrive 

 better than most cultivated plants on 

 sandy soils, these are in many places 

 regarded as especially favourable to it. 

 The roots do not endure standing water 

 in the ground around them ; low, heavy 

 soils should therefore be drained or 

 used for some other crop. When heavy 

 soil is used in Jamaica, manioc is planted 

 in raised ridges, and this is the general 

 practice in the French West Indies. 

 The harvesting of the roots will ob- 

 viously be easier and more complete in 

 light than in heavy soil. 



As to the demands of manioc on the 

 food in the soil, there are two opposite 

 opinions, some writers claiming that it 

 is conspicuous among cultivated plants 

 for the rapidity with which it exhausts 

 the soil ; others, that it is like other 

 starchy crops in taking very little from 

 the ground. The former view is 

 supported by, and is probably due to, 

 the fact that in the Straits Settlements, 

 Africa, and to a great extent in South 

 America, manioc is raised on forest 

 clearings, which are used a few times 

 and abandoned. When starch became a 

 staple product of the Federated Malay 

 States, a large amount of land was cut 

 over in this way and then abandoned, 

 with the result that the destruction 

 of the forest was out of proportion to 

 the permanent agricultural develop- 

 ment. The Government met this diffi- 

 culty by refusing to lease land for 

 manioc cultivation unless some per- 

 manent crop, such as coconuts or rubber, 

 are planted at the same time, and this 

 regulation has been widely construed as 

 evidence that manioc is a robber crop. 

 But it is no peculiarity of manioc that 

 it thrives best on virgin soil. Various 

 Philippine crops, including upland rice, 

 are raised according to exactly the 

 same system, and one of the hardest 

 problems in forest regulation here has 



