GRAMINEOUS CROPS. 131 



mildewed wheat plants {Chemical News. vol. 53, p. 255). 

 These compounds may be produced from the decomposi- 

 tion of glucose which is always present (more or less) in 

 the sap of healthy plants. 



Prevention. — (1) As the "mildew of corn" requires 

 moisture for its growth, corn-growing lands should be 

 well drained. (2) Farmyard manure containing infested 

 straw should not be applied to land required for cereals ; 

 as the straw (which formed the litter) contains the teleu- 

 tospores of Puccinia graminis. In fact, it would be well 

 to-destroy mildewed straw. (3) Mr. W. Carruthers, F.R.S. 

 (Journ. Roy. Agric. Soc. [2nd series], vol. xviii., p. 495), 

 states that " the farmer should not permit the barberry 

 to have a place in his hedges or in plantations on his 

 farm." (4) Seed from mildewed corn crops should not 

 be drilled — as Mr. Smith has shown that the disease is 

 hereditary. "It exists in a finely-attenuated state in 

 seeds taken from diseased plants, and can be transmitted 

 in a long interminable line from generation to generation." 

 (5) Clearing hedges of " rusted and mildewed grasses " 

 is an important preventive against the attacks of this 

 farm pest. 



Cure. — (1) The author has shown {Chemical Neios, vol. 

 53, p. 255 ; and Journ. Chem. Soc, 1886, p. 119) that 

 iron sulphate destroys the wheat mildew and its spores 

 in both stages of their life-history. The author's in- 

 vestigations have been completely and entirely confirmed 

 by Mr. G. W. Edgson {Journ. Chem. Soc, 1886, p. 114), 

 M. Delacharlonny {Biedermann's Centralblatt fiir Agric. 

 Chemie, vol. xviii.), Professor Quantin {Journ. de V Agric, 

 1888), M. Gaillot,! and others. Therefore, it is advisable 



' Directeur de la Station Agronomique de Bethune (Pas-de-Calais). 



