38 



Frederici's gift, a little higlier up the river, part of the 

 fields are on a very ]ow level. 



On thèse three estâtes thousands of trees were diseased 

 and dying of canker, especially in the low fields, while in 

 the higher parts the disease occurred only sporadically. 



In other places where the trees did not appear to hâve 

 suffered from the water, only rare cases of canker were 

 to be met with. 



One must conclude from thèse facts that the stagnant 

 water rendered the trees susceptible so that they easily 

 fell a victira to the cankerparasite. 



Owing to the extent of the disease on thèse estâtes, 

 and the absence of sufficient labour, there could be no 

 question of fighting it energetically. 



The only thing that could be done was, to remove the 

 dead trees as far as possible. Nevertheless the disease 

 came to a stand in the dry months (October, November) 

 following the rainy season. Diseased trees recovered and 

 no other trees became affected. No damage ofany moment 

 has been done since. 



Symptoms of the Canker. 



Cankered trees are flrst recognized by the occurrence of 

 moist patches on the bark, caused by a liquid oozing out, 

 sometimes in considérable quantities. Where it has dried on 

 the bark, this assumes a rusty colour. Thèse places are nearly 

 always found on the trunk and thicker branches; sometimes 

 the younger branches of a tree also show them. When the 

 bark is eut off superficially, it appears to hâve assumed a 

 claret colour (Fig. 1) ; this claret patch is surrounded by a 

 narrow black border which marks it off sharply from the 

 surrounding healthy tissue which isofayellowishred colour. 

 Thèse patches occur in large numbers on the tree; they 

 may extend over a large area or even encompass the 



