350 



THE AGRICULTURAL NEWS. 



OCTOEEE 29, 1910. 



FUNGUS NOTES. 



THE DISINFECTION OF INDIAN 



CORN SEED. 



The prevalence of root disease of Indian corn in Antigua 

 and other islands, and the fact that isolated cases of smut 

 of this plant are known to occur to some extent here and 

 there every year, led to the idea that it might he advisable 

 to recommend the disinfection of Indian corn seed before 

 planting. The method to be employed is identical with that 

 followed in the case of cotton seed. Experiments were 

 therefore conducteil in the laboratory of the Head Office, to 

 ascertain if corrosive sublimate solution, in the proportion 

 of 1 part in 1,000, had any harmful effect on the seeds. 



For the first experiment, 600 seeds were counted out in 

 lots of 100, and treated as follows: — 



Lot I was immersed in corrosive sublimate solution, for 

 forty minutes. 



Lot II was immersed in the solution for twenty five 



minutes. 



Lot III was immersed in the solution for twenty minutes. 

 Each lot of 100 seeds was then put into a separate germinat- 

 ing chamber, consisting of a cylindrical glass dish, with 

 a cover fitting well over its sides, and containing four thick- 

 nesses of damp blotting paper. Three L'ts of 100 untreated 

 seeds were put directly into damp chambers made up as 

 described al ove. At the end of five days, the germination was 

 as follows: — 



Treated seeds, Untreated seeds, 



per cent. per cent. 



Lot I 97 7+ 



Lot II 99 7.3 



Lot III 93 S2 



while at the end of thirteen days, the figures were: — 



Treated seeds. Untreated seeds, 



per cent. per cent. 



Lot I 98 81 



Lot II 99 - 86 



Lot III 98 87 



At this point, the experiment was discontinued, as it 

 showed clearly that not only did the corrosive sublimate 

 solution have no harmful effect, but it appeared to assist 

 germination and make it more regular. It was, further, very 

 noticeable that the treated seeds remained clean, while those 

 not treated were covered with moulds. 



As the control seeds in the former experiment were not 

 immersed in water before germination for a period equal to 

 that for which the treated seeds were immersed in the solu- 

 tion, it is evident that the aliove results are not strictly com- 

 parable. Consequently a second experiment was undertaken, 

 using corrosive sublimate solution of the same strength, the 

 same number of seeds and the same apparatus. The seeds 

 were divided into lots of 100, and treated as follows: 

 Three lots were immersed separately in corrosive sublimate 

 solution for twenty minutes, and three more in distilled water 

 for the .same time. They were then put up in the germina- 

 tors, and as before, kept in the dark. At the end of two days, 

 they had commenced to germinate, the numbers being : — 



Treated seeds, Untreated seeds, 

 j)cr cent. per cent. 



Lot I 82 52 



Lot II 76 27 



Lot III 70 38 



Three days later the figures were as follows : — 



Treated seeds. Untreated seeds, 



per cent. per cent. 



Lot I 99 S3 



Lot II 98 60 



Lot III 99 69 



As might well be exijected from the above figures, the 

 treated seeds showed no further germination after these first 

 five days, but the untreated ones continued to germinate, 

 a few at a time, during the next eighteen days, the total 

 period of germination being twenty-three days. The final 

 figures were : — • 



Untreated seeds, 

 per cent. 

 Lot I 98 



Lot II 96 



Lot III 96 



These figures show that not only does the treatment 

 ensure the germination of a higher percentage of seed, and 

 possibly reduce the chance of infection by certain fungoid 

 diseases, but also, that it acts as a direct stimulus to germin- 

 ation, so that a more even, as well as a more regular, stand 

 would result from using treated seed, since all the seed 

 germinates at the same time. 



Mr. C. .J. Simmons, of St. Vincent, informed this Depart- 

 ment a short time ago of the fact that treatment of Indian 

 corn seed in this way is practised on several estates in that 

 island, with most satisfactory results. This method has 

 supplanted the older one of immersing the seed in salt water. 

 The seed is planted while wet, and the somewhat difficult 

 operation of drying is thus avoided. It is recommended that 

 the practice be adopted in other islands, as it is almost cer- 

 tain to prove a decided benefit to the resulting crop. 



THE FROG-HOPPER FUNGUS IN TRINIDAD. 



In the [iresent number of the Agri'-altur'Al Xewf, some 

 account is given of the frog-hopper insect, under the heading 

 of Insect Notes. As considerable damage is inflicted on the 

 sugar-cane in Trinidad, owing to the attacks of this pest, the 

 attention of the Entomologist, Mr. F. W. Urich and of the 

 ilycologist, Mr. J. B. Rorer, is at present directed to the 

 discovery of the best means of controlling its increase. It 

 is men'.ioned that a fungus is found to occur very fre- 

 quently on dead specimens of both the adult and the nymphal 

 stages of the insect. This fungus has been known in Trinidad 

 for some time, but it is only very recently that systematic 

 investigation of its life-histoiy, and of its actual pi rasitism, 

 has been undertaken. In a recent publication of the Board 

 of Agriculture, entitled 'The Frog-hopper Fungus', a short 

 account is given by liorer of the results so far obtained in 

 these investigations. It is from this paper that the informa- 

 tion reproduced here has been taken. 



There is at present considerable doubt as to the identity 

 of the fungus. Hart and Collens first .stated that it was 

 a member of the genus Entomophthora, which contains many 

 entomogenous species; but at a later date, specimens sent to 

 the United States Department of Agriculture were identified 

 as Oospora destructor, and renicitlium anisotliae. {Agri- 

 cultural Kcwx, Vol. VIII, p. 204.) In 1908, specimens were 

 sent to Kew, and Massee in the Kew Bulletin, 1910, p. 4, 

 described the fungus as a new species — Seplocylindrium. 

 mspectum. Rorer states that the fungus in Trinidad 

 is not a Septocylindrium, and that probably that 

 described by Massee developed as a saprophyte while 

 the specimens were in transit. As far as can be deter- 

 mined at present, the parasite belongs to the Oospora 



