116 CLOVER CULTURE. 



be drawn to the stack or mow, and also that the egg's 

 may be deposited in the stacks early in August. The only 

 remedy we can suggest for the destruction of this pest, should 

 it appear, is to burn up all the old stacks of hay left over 

 from the preceding year, to remove all old hay from 

 barns, and to thoroughly cleanse all sheds and barns where 

 the pest has become established. 



The clovers, however, suffer seriously from other than 

 insect enemies. They are subject to a peculiar kind of rust, 

 (Uromyces trifolii.) This rust is a fungus or low form of 

 plant life, without chlorophyll, or the coloring matter of 

 plants, and without roots, stems, or leaves, which derives its 

 nourishment from the clover plant. It is, therefore, a para- 

 site and is reproduced by spores which float in the air, and 

 when placed under proper conditions, germinate and develop 

 on the leaves of the plant. This clover rust has appeared 

 but recently in the West. It was first reported on white 

 clover in Iowa by Prof. Arthur in 1884 and seems to be more 

 widely distributed than is generally supposed. Prof. Under- 

 wood reported it in the vicinity of Syracuse, N. Y. , in i888. 

 Dr. Roland Thaxter reported it near New Haven, Conn., 

 in the annual report of the Connecticut Agricultural 

 Experiment Station in 1889, page 175. In Bulletin No. 15, 

 Cornell Agricultural Experiment Station, Prof. Dudley re- 

 ports it as common about Ithaca, N. Y., and in August, 

 1890, it was reported in the Monthly Review of the Iowa 

 Weather and Crop Service as commofL at Ames, Iowa, where 

 Prof. Pammel reports that it has been unusually severe during 

 the past summer. This rust usually appears on the rowen 

 or second crop, and it would be an interesting investigation 

 to ascertain whether it affects clover when under hard con- 

 ditions, such, for example, as an exceedingly wet and hot 

 year, or when plants are weakened by previous drouth or by 

 insect enemies. It is difficult to suggest any remedy short 

 of plowing up the field, but it is not likely that it will do any 

 serious damage where clover is grown in short rotation. 

 Where there is much affected clover in a permanent pasture, 

 burning over the field late in the fall would, no doubt, prove 

 advantageous. 



In this connection attention should also be called to the 

 violet root fungus, {Rhizoctonia medicaginis}, which, in parts 

 of Europe, is a serious pest. The fungus covers the roots 

 with a violet mould. Plants affected with this disease wilt 

 suddenly and then die. The disease spreads in circular 

 areas. It also affects alfalfa, in fact, has been reported on 

 that host by Mr. Webber, in Nebraska. (Flora of 



