38 



Mildew. 



Vol. V. 



For the Farmers' Cabinet. 

 Mildew. 



Mr. Editor, — There have been a great 

 many things said and written respecting mil- 

 dew, rust, blight, &c., as they are promiscu- 

 ously called, on wheat and other grain, many 

 of which are very plausible ; and I am much 

 pleased to find so many persons of late turn- 

 ing their attention to its study ; but there can 

 be only one correct source from whence it 

 emanates. 



Dr. Davy, in his Agricultural Chemistry, 

 was the first to excite my attention to this 

 source, its habits, &c. upwards of twenty 

 years ago ; and I have been a pretty constant 

 observer of its progress ever since; and the 

 more I observe it, the more I am confirmed 

 in my opinion that the Doctor was right. 



That it is produced from the seed of cer- 

 tain mosses, that grow most plenteously on 

 uncultivated ground, (where it is not incom- 

 moded by the leaves of the trees) on rocks, 

 on stones, on trees, on fences, on old build- 

 ings, and almost on every thing — stagnant 

 ponds and milldams not excepted — is to me 

 as clear, as that the various kinds of grain are 

 produced from the seeds we cast into the 

 earth. 



Any person, whose mind is not clouded by 

 tlie prejudice of some other favourite theory, 

 may be convinced to an absolute certainty, by 

 going into a wheat-field that is in any degree 

 touched with mildew, towards the last of 

 June, or beginning of July: for he will find 

 the same substance growing plentifully on 

 the ground. Let him observe it at a few 

 subsequent times, and if there be any mois- 

 ture in the ground, he will find it growing up 

 into beautiful yellow, or dark bottle-groen 

 moss ; the two species of which usually attach 

 tliemselves to the wheat and other grain, 

 while standing on the stalk. 



But whether the seeds of these mosses are 

 carried up into the region of the atmosphere 

 along with the vapours exhaled by the sun 

 during the day, and fiill with the dew in the 

 evening, as Dr. Davy supposes, or whether 

 they are wafted by the wind, or rise by their 

 own light and buoyant nature, as many other 

 seeds more than a hundredfold larger, such 

 as the seeds of the thistle, &c., is a matter of 

 little consequence, as there can be no doubt 

 the atmosphere is, through the heat of sum- 

 mer, constantly full of them. 



Now any person who will take the trouble 

 to examine, will perceive, that where these 

 mosses have been washed away by a flood, or 

 heavy rain, he will, perhaps, before twenty- 

 four hours, see innumerable black specks on 

 the same place, which in a few days, will 

 take the yellow or green tint: the same is 

 observable on ponds, and milldams, where, 



when they have been washed away, they 

 will begin to accumulate in a few hours. 



Were it not that I had determined to state 

 nothing but what has come under my own ob- 

 servation, I might be tempted to suggest the 

 idea, that in low and damp places, where 

 these mosses grow abundantly, and where 

 the atmosphere must be constantly full of 

 these fine seeds, the inhaling of them, or 

 swallowing them w;ith our food, or our 

 drink, may be the cause of many diseases, 

 such as intermittent fevers, &c. But enough 

 of this, as it is altogether out of my province 

 as a farmer. 



I should like very much to see a botanical 

 description of the different kinds of mosses, 

 divested of the intricate technicalities, which 

 involve the subject of botany in so much mys- 

 tery. If some of your learned correspondents 

 in the city or its vicinity, would prepare a 

 few tables of botanic names for the Cabinet, 

 placing the vulgar name after the scientific, 

 it would do much to enlighten many of our 

 farmers on this all-important subject. 



There are but five kinds of mosses that I 

 have been able to discover in our county 

 (Cumberland); first, the yellow, most com- 

 mon on uncultivated grounds, from whence 

 originates the red rust on wheat ; second, the 

 black, which is found on rocks and stones in 

 shaded places, from whence originates the 

 black rust; third, the white, or cream-colour- 

 ed, to be found on the north side of oak trees, 

 particularly the black oak ; fourth, the next 

 grows in detached bunches, also on the north 

 side of trees, of a green colour ; and the fifth 

 grows in the form of a small pine, about an inch 

 i# height, in tufts on damp and shaded ground. 



I have now before me demonstration of the 

 error of Mr. List's theory, of the origin of 

 mildew. Never in my recollection (which 

 extends at least thirty years back) was there 

 a finer appearance of rye in our county; it 

 was healthy and forward, the season favour- 

 able in every respect, yet it is universally in- 

 jured : the leaves were covered with the red 

 rust early in May; this did not much injure 

 it, till the bare stalk shot from the leaves that 

 surrounded it, when they also rusted about 

 the middle of June, injuring it more or less, 

 according to its forwardness; and yet this is 

 a high, dry, limestone soil, no swampy or low 

 grounds within miles. Our rye is never sub- 

 ject to mildew, and wheat but seldom. On 

 this twenty-fourth of June, some of our rye is 

 already cut; the wheat is covered with red 

 rust, and will, in a considerable degree, be 

 injured ; yet never did wheat look better, and 

 this is emphatically a wheat county. The 

 rust falls every where, but the grain that is 

 well filled before it attaches itself, is not in- 

 jured ; nor will it easily attach to a dry, 

 smooth stalk that is ripe, or nearly so. 



