MILDEW. 



The age of the seeds, the thickness of sow- 

 in? it, and previous or subsequent cultivation, 

 appear to have no preservative influence ; 

 therefore, it now only remains to consider 

 whence ihe seeds of the fungi come to the 

 crop, which will lead to a consideration of the 

 modes of prevention ; and, lastly, whether 

 there is any practicable cure. There seems to 

 me little doubt that the fungus is communi- 

 cated from the soil to the crop. It is certainly 

 not conveyed thither with the seed-corn, for no 

 washing, no cleansing, nor pickling of this has 

 ever been observed to have any effect. In 

 "mildew years," all fields of any infected dis- 

 tricts are affected; and when it is only partial, 

 one end, or a breadth across the middle of a 

 field, of which the seed has all been treated 

 alike, will be grievously injured, whilst the 

 other parts suffer little more than ordinarily ; 

 for I have previously noticed, every year, and 

 in all fields, the mildew is partially present. 

 There is little difficulty in accounting for this. 

 Every Purrinia sheds some hundreds of seeds, 

 more minute and lighter even than those of 

 the puff-ball; and as every wheat crop an- 

 nually produces some, these are wafted over 

 neighbouring closes by every wind during 

 their seeding-time, which is chiefly in the 

 months between May and October. In the soil 

 upon which those seeds alight, they attach 

 themselves to the stubble or other matters, and 

 vegetate, reproducing seeds, or remaining 

 without germination until the following spring. 

 This fungus has also the characteristic of 

 spreading by stooling, or throwing out offsets. 

 This may be seen if its progress is watched 

 upon any culm which it affects. I once placed 

 in a paper box some pieces of straw that were 

 more completely mildewed than any I had be- 

 fore observed; this was left during the whole 

 winter in a closet, which at this season is un- 

 usually damp. Upon opening the box in the 

 spring following, I found the Puccinia had 

 grown, and spread in various rectilinear forms, 

 upon one of its sides, and upon the bottom, a 

 fact which I remember to have seen confirmed 

 in one of the volumes of the Quarterly Journal 

 of Science. The fungus, then, though its na- 

 tural habitat is the culm of the wheat, will 

 vegetate upon other vegetable bodies; and this 

 satisfactorily explains the mode in which it 

 may, after being preserved through the winter, 

 be conveyed to the succeeding year's crop, 

 to say nothing of those seeds which may be at- 

 tached to the straw of the preceding year, and 

 be conveyed to the next year's crop by various 

 modes. 



These facts demonstrate that prevention is 

 impossible ; for however careful a farmer may 

 be to avoid every source whence the seeds oif 

 the Puccinia may arrive, yet every summer 

 wind may waft them to his crops from other, 

 even far-distant lands. To prevent the com- 

 munication to the wheat from the soil by the 

 stooling, or spreading power of the fungus, it 

 will be well to sprinkle the surface with salt, 

 immediately after sowing, at the rate of 5 or 6 

 bushels to the acre; and in the spring, early in 

 May, to apply, in a similar manner, about the 

 same quantity of caustic fresh-slacked lime, 



MILDEW. 



applications of which are not only destructive 

 of the Pucrinia, but also of slugs, and promote 

 the general -health of the crop. 



For testimonies to the power of common 

 salt to prevent, in some instances, the occur- 

 rence of mildew, I would refer the reader to 

 my brother's Essay on the Uses of Salt, p. 50 

 60, where will be found the concurrent tes- 

 timony of Sir John Sinclair, Mr. Sickler, Rev. 

 R. Hoblyn, Mr. S. Robinson, Mr. Wood, and 

 Dr. Paris. Mr. Prevost, quoted by Sir John 

 Sinclair, states that the sulphate of copper, if 

 dissolved in water at the rate of 3J oz. to the 

 gallon, forms a solution which will prevent the 

 attack of mildew upon the wheat plants arising 

 from seed which has been steeped in it. I am 

 afraid it has no such power. 



Salt, if not a complete preventive, is an ef- 

 fectual cure of the mildew. Mr. Chatterton, a 

 Lincolnshire farmer, says, in the 44th vol. of 

 the Jlnnals of Jlgric., that "on the sea-side the 

 wheat is little damaged by the mildew, yet 

 within 3 miles inland the crops are as much 

 affected as those still further from the sea." 

 This fact can be supported by the experience 

 of most farmers whose fields skirt our native 

 shores; and unquestionably it is owing, not 

 only to the soil containing a greater proportion 

 of common salt than is found in more inland 

 soils, but because the sea-haze, which rises al- 

 most nightly in the summer season, bathes, as 

 it were, the crops in the immediate vicinity of 

 the coast; and this haze holds in solution a 

 portion of salt. 



The following well-attested communication 

 from the late Rev. Edmund Cartwright, of Hol- 

 lenden House, near Tunbridge, is conclusive 

 on this subject, and gives full directions to the 

 farmer how to apply, and at what expense, a 

 practical remedy. 



"It gives me great pleasure to have it in my 

 power to furnish you with some information 

 respecting the application of salt, which, per- 

 haps, you are not aware of. I, and a neigh- 

 bour of mine, have applied it as a remedy for 

 the mildew in wheat, with the most unequivo- 

 cal success. I first made the discovery 2 years 

 ago; my experiments at that time were upon 

 a very limited scale; they have this year ex- 

 tended only over an acre and a half, but under 

 circumstances that leave not a shadow of 

 doubt of salt being an absolute specific for 

 mildew, in the most aggravated stages of the 

 disorder; of this I will state to you a convinc- 

 ing proof. In the year 1818 I found a few ears 

 of wheat, which I conceived to be a new and 

 improved variety ; from these ears I raised as 

 much wheat as last year planted a land 4 feet 

 wide andlOO yards in length : the produce I had 

 promised to Mr. Coke ; and, to augment that 

 produce, I had the ground, previously to plant- 

 ing, highly manured ; and as soon as the wheat 

 came up I gave it a good dressing with soot, 

 and this dressing was repeated once or twice ; 

 in consequence of this superabundant dressing, 

 the wheat, as might indeed have been expect- 

 ed, was as rank as the wheat you may observe 

 growing accidentally upon a dunghill, which 

 never fails to rot upon the ground, without 

 i bringing a single grain to maturity. The mil- 



813 



