48 PLANTING, CULTIVATING, AND PRUNING 



with those of the cocoa tree, and the latter would be 

 redisturbed when the Cyperus roots were extracted. 



Gyperus bulbosus (rotundus) is a serious pest in Gold 

 Coast cocoa plantations, and the writer has seen it grow- 

 ing profusely in cocoa plantations in San Thome. 



Several other weeds found in cocoa plantations develop 

 long, underground, jointed stems, capable of producing 

 new plants from the buds formed at each joint. If the 

 foliage of the parent plant is cut down, encouragement 

 is given to these buds to form new plants, which rapidly 

 take possession of the ground. When colonies of such 

 weeds occur in the neighbourhood of a cocoa tree there 

 is a struggle between its roots and the roots of the weeds. 

 The tender roots of the cocoa tree are rapidly smothered 

 and its growth is severely checked. Fortunately it is 

 possible to cover the vacant ground between cocoa trees 

 with leguminous plants, the growth of which can be so 

 controlled that they do not interfere with the develop- 

 ment of either the permanent or the catch crops. 



Leguminous Cover-Plants. When the commonest weeds 

 found on cocoa plantations are cut down they only return 

 to the soil the plant-foods which they have extracted 

 from it. Leguminous plants, when cut down, return to 

 the soil not only the plant-foods they have taken up 

 from it but, in addition, the atmospheric nitrogen which 

 they are able to fix. It will therefore be apparent 

 that a green covering of leguminous weeds is likely to 

 prove more beneficial than a covering of ordinary weeds. 

 The arborescent types of Leguminosce are not recom- 

 mended for this purpose. When frequently pruned they 

 develop large root-stocks ; these are difficult to eradicate 

 without damaging the roots of the cocoa trees, when the 

 time arrives to remove them in order to provide addi- 

 tional space for the latter. Various herbaceous Legu- 

 minosce, such as Crotalarias, Cassias, and Cajanus, are 

 much better adapted for ground-covering purposes. All 

 of these are, however, more difficult to eradicate than 

 the prostrate and creeping leguminous types, such as the 

 Vignas, Phaseolus, Arachis, and Mucunas. The latter 

 may be rooted up by hand whenever they show signs 

 of encroaching upon the cocoa trees. 



The treatment of leguminous cover-plants and catch 

 crops will be more fully dealt with in a subsequent chapter 



