70 On the Rust or Mildew. 



in the bark, it proves the source of destruction* Hence also, when 

 the barberry-bush is small, it does not occasion mildew *. 



The practice of cutting the hedges, when a crop of wheat is sown, 

 ought to be universally adopted, as a likely means of lessening the 

 quantity of fungi, that would otherwise injure the crop. By this at- 

 tention to the improvement of his hedges, and the extirpation of 

 weeds, Mr Clack's glebe, on which, from time immemorial, the wheat 

 was subject to rust, has been rendered nearly as free from that dis- 

 order as the open fields of his neighbours -j*. 



10. A curious and most important circumstance, connected with 

 the rust in wheat, remains to be stated. In the northern counties of 

 England, where it is the practice to sow what they call meslin, 

 (blend corn,) or a mixture of rye and wheat, it has been there re- 

 marked, that wheat thus raised is rarely infected by the rust\. It is 

 singular, that the same circumstance has been observed in Italy. In 

 an account drawn up by the late Professor Symonds, of Cambridge, 

 on the climate of that country, it is recorded as a known, but extra- 

 ordinary fact, " that wheat, mixed with rye or tares, (for it is a fre- 

 quent practice there, to sow tares with wheat,) escapes unhurt " It 

 would appear, from tares being so useful, that the seed of the fungus 

 must be taken up by the root, and that if the root be protected it i 

 sufficient. This seems to be countenanced by other circumstances, 

 as, that by treading the ground, and thick sowing crops of wheat, the 

 crop is less liable to be infected by this disease ; the access of the 

 seeds of the fungi, to the root, being rendered more difficult. The 

 effect of tares as a preventive, may easily be tried. The double crops 

 sown in Flanders, where the rust is hardly known, is another circum- 

 stance strongly favourable to the idea, of the advantage derivable from 

 covering the roots of wheat from infection. Mr Knight is decidedly 

 of opinion, that the disease is taken up by the root, (every experiment 

 to communicate it from infected straw, to others, proving abortive) ; 

 and indeed, if it were introduced at the ear of the plant, how could 

 it descend, and infect solely the stem ? which is the case, unless when 

 the disease is inveterate. Others attribute rust to the influence of the 



* Bedfordshire Report, p. 379. The facts brought forward in the County 

 Reports, Cheshire, p. 135, Cambridge, p. 131, seem to prove the fatal effects 

 of the barberry, in occasioning rust. 



f In a recent communication, dated 16th June 1817, Mr Clack states, that 

 in the year 1811, he sowed a field of wheat after clover, which was notorious 

 for rust ; but the crop produced next year was the best in the neighbourhood, 

 which he attributes to his continued attention, in cutting out such shrubs, as 

 were congenial to the growth of rust, in the adjoining coppice and hedges ; 

 and to the consolidation of the soil, by filling it with sheep after sowing, 

 for which purpose, a number should be collected, and slowly driven in a com- 

 pact body, so as to give a simultaneous effect to the land. 



| East Riding Report, p. 127. Mr Tuke, the intelligent author of the 

 North Riding Report, in a letter to the Author, dated 7th March 1818, states, 

 that until the year 1815, rye grown amongst wheat, was generally allowed to 

 be, in that district, a sure preventive of rust or mildew; but that year, rye it- 

 self was infected, and there was very little either wheat or meslin that escaped 

 in Yorkshire. 



See Annals of Agrieulture, vol. iii. p. 153. 



