114 T Em ID AD AND TOBAGO BULLETIN. \XIX. 3.^ 



manager that this field had been known for many years as " Damn 

 Piascal " field owmg to the difficult nature of the soil. 



Many more examples could be given of similar relations observed 

 during the past year and there is little doubt that we have here a clue 

 to possible control methods which cannot be ignored ; at the same time 

 exceptions do occur and this year on Petit Morne Estate there was 

 severe damage on an area of black soils in apparently excellent 

 condition and where injury had oever before been observed. 



Eelation between Damage and Eatooning. 



The greater liability of old ratoons to damage has been previously 

 emphasised and two estates have recently adopted a policy of not 

 growmg second ratoons on the areas which had previously shown 

 themselves liable to froghopper attack. 



One of these estates escaped injury almost entirely in 1920. The other 

 had a very severe attack throughout most of the estate even extending 

 to plant canes. It is difficult to draw any cocclusions from these two 

 cases but they are not necessarily contradictory as it has been already 

 shown that the relative ditt'erences between first and second ratoons is 

 greatest when the infestation is slight {i.e. when other conditions are 

 unfavourable to the froghopper). 



It must also be remembered that one of the most important 

 advantages of stopping old ratoons on lands liable to froghopper 

 infestation is that more frequent replanting means more frequent 

 cultivation of the land which will be gradually (but not suddenly) 

 improved in texture and humus content. 



Some other observations are more convincing. Thus on one estate 

 in the north the worst damaged field was in fifth ratoons and all the 

 damage on the estate was confined to canes older than first ratoons. 

 In the south the flat lands of Harmony Hall had shown themselves in 

 past years to be particularly hable to damage. Owing to an almost 

 complete replanting in 1917 they had escaped damage in 1918 and 1919 

 as plants and first ratoons. This year instead of replanting, almost the 

 whole area was left in second ratoons with the result that the damage 

 was as severe as ever before. One or two fields of plant canes alone 

 escaped, indicating what might have been obtained if the policy of 

 dropping old ratoons had been adopted. 



Empusa Fungus. 



At the end of November and the first week in December, 1920 

 occurred the largest outbreak of Emimsa fungus on froghoppers that I 

 have ever seen. 



This fungus appears to require a higher degree of moisture for its 

 development than does the green-muscardine fungus, and in normal 

 years is not found before October. 



It is possible that the large ovtbreak this year was connected with 

 the large third brood which was unusually late and also with the wet 

 weather which was experienced in November. 



Large numbers of infected froghoppers were fovnd on Golconda, 

 Craignish, and Cupar Grange Estates indicating a wide distribution in 

 the Naparimas. On the latter estate several thousand specimens were 



