310 COCOA 



CHAP. 



The average yield cannot be stated with any 

 certainty, as the number of reliable figures is too small, 

 but in Dr. Zehntner's opinion it is not higher than 1 

 kilogram per tree. On a plantation where the planting 

 distance was 12x12 feet (4x4 metres) the average 

 yield per tree was 1^ kilogram. These figures would 

 certainly point to a high average yield of about 450 

 kilograms per acre ; but it is more than possible that 

 the average is not so high and that these figures are 

 based on the yields of exceptionally productive fields. 

 When further and more reliable statistics become 

 available, it will probably turn out that in Brazil, as 

 in most other countries, the average yield varies between 

 200 and 300 kilograms per acre. 



At present there are no data as to the area under 

 cocoa cultivation. Dr. Zehntner estimated in 1911 

 that in the State of Bahia from twenty to twenty-five 

 million trees were in full bearing, while he put the 

 number of young trees at about ten to twelve millions. 

 At any rate the number of trees is rapidly increasing. 



Diseases and insect-pests do occur, but up to the 

 present none of them has done either great or general 

 damage. 



III. SAN THOME AND PRINCIPE 1 



Geography. San Thome, an island with an area 

 of only 1000 square kilometres (360 square miles), is 

 situated in the Atlantic Ocean just north of the 

 equator, about 160 miles east of the mouth of the 

 Gaboon Eiver. With the much smaller island of 

 Principe, situated a little to the north-east, it forms a 

 province of Portugal. About half the island of San 

 Thome' is cultivated and covered with cocoa trees ; 



1 The principal work on the cultivation of cocoa in this country is the 

 S interesting and circumstantial work by Aug. Chevalier, Le Cacaoyer dans 



V Quest africain (fasc. ii. of Les Veyttaux utiles de VAfrique tropicale fran<;aisc. 

 , Paris, Aug. Chalamel). Special subjects have been treated in the following 

 *'c*.. works : Francis Mantero, Manual Labour in San Thome" and Principe (Lisbon, 



1910) ; J. A. Wyllie, The Boa Entrada Plantations (Edinburgh and London, 



1907) ; Jose de Almeida and A. Cannas Mendes, Les Plus Graves Maladies 



du cacaoyer a San Thome (Lisbon, 1910). 



