CROP-PLANTS 363 



slowly. The subject has received some attention in Tanganyika, 

 Kenya, Uganda, in the Congo, and in French West Africa. Work 

 has been in progress since 1927 at Amani, which now collaborates 

 with the new Coffee experimental station at Lyamungu, near 

 Moshi in Tanganyika. Plants of arabica coffee have been trans- 

 ferred to Lyamungu, but the breeding is still supervised by the 

 Amani geneticist. In addition to selection, vegetative propagation 

 and other experiments are in progress with a view to finding out 

 what factors influence variability (Tanganyika, Agriculture, 1935, 

 D.R.). Intensive studies on the root systems of Cojfea arabica have 

 been carried out by Nutman (1934), and climates of coffee planta- 

 tions have been studied in relation to the insect fauna by Kirk- 

 patrick [see Chapter X, p. 287). Nutman has also thrown new 

 light on the question of the value of shade by showing that the 

 leaf stomata close up in full sunlight thus preventing carbon 

 accumulation (Nutman 1937). 



In Kenya pruning is an important feature of the investigational 

 work both in the Kiambu-Ruiru area and at the Scott Agricultural 

 Laboratories. Spraying, propagation, variety trials and diseases 

 are included in the programme (McDonald 1937). Coffee selec- 

 tion has been progressing in Uganda for fifteen years, but little 

 material has yet been published. There are, however, a number 

 of promising selections under test (Thomas 1935). Mr. T. D. 

 Maitland, who (1926) wrote an interesting history of Coffea 

 robusta, produced in Uganda the type known as robusta No. g, 

 which is still the variety grown on many European estates, though 

 during the last five years attention has been focused on the so- 

 called Nganda types, which show considerable promise. The 

 Government controls the supply of seed in districts where natives 

 are encouraged to grow coffee, so that seed from selected trees 

 only is planted. 



In Western Africa robusta coffee is now grown in many parts 

 of French and Belgian territory, but there does not appear to 

 be much opportunity for the market to expand. Consequently 

 coffee has not been a subject of special research in the British 

 West African colonies; indeed it has been almost purposely post- 

 poned until work on other perennial crops, such as oil-palms 

 and cocoa, is fully established. The view is taken that coffee can- 



