Dec. 1894.] 



INJUKIOUS INSECTS AND FUNGI. 



larger, and darker in colour. These teleutospores are found in 

 the same pustules, or sori, with the uredospores, or occasionally 

 alone, and in this case, Sorauer says, they are always upon the 

 stalks. The teleutospores are practically "resting spores," 

 and pass the winter in this condition upon the dead leaves 

 of beet and mangels, and probably upon the ground. From 

 the teleutospores, sporidia are formed, which in suitable circum- 

 stances germinate and produce the oecidium stage upon seed- 

 beet and seed-mangel plants. 



Seeing that the fungus passes its series of stages upon plants 

 of the beet family, the prevention and cure of its attack are 

 rendered comparatively simple. The main object is to prevent 

 the teleutospores from infecting in the spring the plants of 

 mangel and beet set out for seed. To effect this every particle 

 of leafage and stalks should be removed or deeply buried with 

 the plough. None should be allowed to remain on the outsides 

 of fields. If there is fear of infection, or the oecidiospores are 

 noticed, the seed plants should be sprayed with a weak solution 

 of sulphate of copper, of from 10 to 12 lbs. to 100 gallons of 

 water and 6 lbs of lime. Some seed growers plant bulbs 

 of mangel in the early spring for seed. These might be dan- 

 gerous sources of infection. Beta maritima may be a fertile 

 source of infection: as it is a perennial plant the teleutospores 

 of Uromyces hetce would remain on it during the winter, and be 

 distributed far and wide by the wind. Mr. Plowright produced 

 the " oecidia of the fungus on two plants of mangel from the 

 teleutospores from wild plants of Beta maritima grown pn 

 the banks of the River Ouse at West Lynn." It would be 

 desirable to eradicate \Sef(X maritima as far as possible from the 

 neighbourhood of mangel and beet land. It grows by the side 

 of neglected wet ditches, river sides, creeks of salt or fresh 

 water. But it should be added that, this season, in the case 

 of a field of mangels badly infected, which was situated near 

 a creek, the plants of Beta maritima growing there were qtiite 

 -free from appearance of infection. 



When mangel and beet seed-plants have upon their leaves the 

 pustules shown in Fig. 1, they should be sprayed for the sake of 

 their own crop of seed, and to prevent dissemination of the 

 uredospores to neighbouring mangel and beet-root crops, 



If mangel and beet-root crops exhibit signs of infection it 

 would be desirable to spray them with sulphate of copper arid 

 lime solution — 15 lbs. of sulphate of copper and 7 lbs. of lime 

 to 100 gallons of water — before the fungus has been well 

 established, to prevent its spread in the particular field and to 

 other fields. Spraying was tried this season for this disorder, 

 but not until the end of September, or too late to be of much 

 service. 



Sorauer says, in his Fflanzenhranhheiten, that leaves of 

 mangel and beet infected with this fungus should not be given 

 to farm animals. 



