450 poisoning of cattle by z)/ploi>7/4 "infected maize. 



General Account of Dfplodia Poisoning in Nature. 

 Geographical distributioji : 



In Natal the reports of the presence of the disease would 

 appear to be limited to the high veld parts of the country, and 

 in these areas the occurrence of a disease in cattle resembling' this 

 condition have been very common during the last two seasons. 

 In most cases it has been impossible to eliminate entirely all other 

 factors, such as poisoning by poisonous plants, etc., owing to lack 

 of opportunity to investigate each outbreak that is reported, but it 

 may be taken that cases of the disease have occurred in most of 

 the high veld mealie-producing centres of this Province. The 

 losses have been most severe during the last season in the Estcourt 

 Division, and it was from this district solely that the material was 

 obtained for experimental purposes. Reports of a few out- 

 breaks have also come to hand from the Ixopo Division, but 

 material obtained from this district failed to reproduce 

 the disease in animals at the Research Laboratory, Onderste- 

 poort. 



Seasonal occurrence: 



The disease is limited to the late winter months, July to 

 September. This is the period when veld grazing is very scanty, 

 and it is the custom for farmers to turn their cattle at this time 

 into the mealie lands for better feed. 



Animals affected : 



The disease is limited to cattle, animals of all ages and 

 sexes being equally susceptible. Some reports have mentioned 

 the fact that sheep were also susceptible, but up to the present 

 it has not been possible to confirm this. Horses, mules, and 

 donkeys would not appear to be susceptible, as these animals 

 graze over the same area where cattle are dying of the disease 

 without suffering any harmful results. No cases have been 

 recorded of goats or pigs having been affected. 



Cause : 



The disease is only found associated with mealie lands, and 

 it is popularly supposed by the farmers of the affected areas that 

 it is caused by feeding on mealie cobs which have lain for some 

 months on the ground. In the experimental investigations 

 mealies which had been subjected to these conditions were found 

 to be capable of producing a similar train of symptoms, and this 

 supports the opinion cf the farmers. Examination of the cobs 

 fed revealed the fact that a very great percentage were infected 

 with the fungus Diplodia zees. Experimental evidence has shown 

 that cultures of Diplodia zccc in sterile maize, when fed to animals, 

 can set up clinical symptoms which are indistinguishable from 

 those shown in animals contracting the disease naturally, and 

 further experiments indicate that the results are produced by a 



