104 



Ckotalaria and Green Man vr tes as effecting T. GtestboI. 



Crotalaria is undoubtedly of great advantage as a 

 green manure, but it lias yet to be proved if it is a means of 

 cheapening the cost of weeding. There are two objections 

 to it which can however be overcome. 



Firstly the difficulty which is experienced in eradicat- 

 ing T. Gestroi and Forms semMostus, will be enormously 

 increased by the fact that all timber is hidden by growth 

 rendering it necessary to closely inspect each rubber tree 

 and to search about amongst the crotalaria for timber con- 

 taining T. Gestroi. This can be overcome by, first eradicat- 

 ing the pest and then planting green manure. Secondly 

 when the green manure is eventually killed out by shade, 

 the rubber trees will experience a shock from their custom- 

 ary supply of nitrogen being cut off. This can be obviated 

 by interplanting with leguminous trees, such as AWizzia 

 Moluccana. These trees together with others of the legu- 

 minosae have been grown with great benefit to tea and 

 coffee in Ceylon and elsewhere for at least twenty five 

 years. Such growths as CrotaUaria, Mimosa, etc: being 

 utterly unsuited to this class of cultivation. 



In conclusion there are no grounds for the alarmists 

 view of the T. Gestroi pest, though it is imperative that it 

 should be taken in hand at once and dealt with very 

 thoroughly and although the initial cost may be heavy it 

 will be more than justified by the subsequent saving in ex- 

 penditure, on keeping the pest in check, to say nothing of 

 the saving in loss of trees. 



Walter Towgood. 



FIELD NOTES. 



Root Disease. 



1 have received a number of communications about the 

 "Peonies" or white fungus root-disease of para rubber. 

 The disease apjpears to be more widespread than I thought 

 when I wrote in the last November number. A common 

 mistake is cutting the trenches too broad — this demands 

 extra and unnecessary labour, and the excessive quantity 

 of earth taken out covers the inner area round the diseased 

 tree so much that the turning-over does not go deep enough. 

 Where circumstances do not allow of the outer trenches 

 being made, the adjacent row of trees should be examined 

 from time to time. 



