354 



Mildew, Blight mid Rust. 



Vol. V. 



Mildew, Blig^ht and Rnst> 



We extract the followinor from an Essay 

 read before the Philadelpliia Society for pro- 

 moting Agriculture, by James Gowen, Esq., 

 at its stated meeting on the 5th May, and or- 

 dered to be published. It is in answer to 

 Col. Kenderton Smith's article on the same 

 subject, at p. '293 of the Cabinet for April. 



"It will be remembered, that at our last 

 stated meeting, a paper on Mildew, Blight 

 and Rust, was read by Col. Kenderton Smith, 

 and ordered to be published. The subject 

 being of more than ordinary interest to farm- 

 ers, from the destruction they so frequently 

 have to deplore of their promising grain-fields 

 by reason of blight, many will be inclined to 

 adopt a remedy coming from sucii authority ; 

 but holding, as I do, the adverse opinion, and 

 believing that the remedy recommended would 

 not only prove abortive, but highly injurious 

 to the American husbandman, and to the 

 cause of agriculture, I feel it a duty to at- 

 tempt a few remarks upon the subject, with 

 the view of claiming from farmers a thorough 

 examination of the whole ground, before they 

 change their practice of sowing grass-seeds 

 with their wheat. But in doing this, I hope 

 it is needless to say that no discourtesy is in- 

 tended to the author of the cause and remedy, 

 or to this society : we are all members and 

 farmers, embarked on tlie same voyage of 

 discovery, and as all have an equal interest 

 in the concern, so should all contribute in 

 work or skill, to render the enterprise profit- 

 able or beneficial. 



" The cause of blight, as stated in the paper 

 under consideration, is, simply the grass cul- 

 tivated with the wheat; it reads — 'The mat- 

 ted coat of grass, when thoroughly saturated 

 in moist seasons, by impeding the sun's rays, 

 causes an excess of moisture in the soil, and 

 preserves the earth at the root of the grain 

 too cold and wet to maintain a healthy vege- 

 tation of the plant at its then near approach 

 to a state of maturity. This checks and ren- 

 ders languid the circulation of the sap at the 

 very time when nature indicates that not 

 only the slalk but the soil should bo basking 

 in the heat which prevails at that season of 

 the year.' And \.\\e remedy is, simply 'the 

 abstaining from sowing grass-seeds with the 

 grain.' But it will be proper to inquire, whe- 

 ther Col. Smith has proved by experience and 

 facts that the disease is occasioned by an ex- 

 cess of moisture and damp, or shade, by rea- 

 son of sowing grass-seeds with the winter 

 grain; or, in other words, that the super- 

 abundant moisture and shade of grass and 

 weeds prevent the rays of the sun from pene- 

 trating to the roots of the plants, and the cold 

 and damp, thereby engendered, producing the 

 rust and blight? And here let me premise, 



1 do not advocate the growing of grass 

 amongst grain as the best mode of obtaining 

 good crops ; I simply mean to show, that the 

 grass sown with the grain does not nor can- 

 not occasion blight — mildew or fungi being 

 remote from the question. The strongest 

 proof, perhaps, advanced by Col. Smith in 

 support of his theory, is the phenomenon of 

 Mr. Fox's field of wheat in the summer of 

 1838, being perfectly free from blight, while 

 the fields in the neighbourhood, in which 

 grass had been sown with the wheat, were 

 all blighted : and more, although Mr. Fox's 

 wheat was much lodged, yet the berry was 

 perfectly filled, and the straw was in no re- 

 spect touched with the mildew, because there 

 was no grass sown with the grain. Now, if 

 grass and weeds, standing among grain, can 

 so shade the ground from the sun as to pro- 

 duce cold and an unhealthy atmosphere at 

 the roots of the wheat, so as to disease it — 

 how much more eflectually would the sun be 

 excluded by the layers of lodged wheat, lite- 

 rally touching each other in such thickness 

 as to render the earth, the roots, and much 

 of the stalks of grain, impervious to the rays 

 of the sun? — then, if the same cause produce 

 the same effect, why was not this lodged 

 wheat blighted? This single circumstance 

 proves that the damp, moisture and shade, 

 produced by grass and weed.s, cannot be the 

 cause of blight, else the lodged wheat would 

 have been blighted. There is nothing per- 

 haps more uncertain or unsatisfactory, than 

 this comparing one field of wheat with that 

 of others, in regard to the cause of blight; 

 because, there may be so many contingencies 

 in the culture or soil unexplained or unpro- 

 vided for, that an exact comparison can sel- 

 dom be made: early sowing, early seed, or 

 early soil, may cause one field to be out of 

 the danger that late sowing, &c. may be ex- 

 posed to, and vice versa. And to show how 

 insidious the attack of blight is, it is known 

 that of a field of wheat deemed nearly ripe, 

 a sample was cut, which hardened and proved 

 sound seed, but the rest that was left to ripen, 

 when reaped, was injured : had it all been cut 

 when the sample was taken, or had it ripened 

 but a few days earlier, it would not have been 

 blighted. If this mode of proving cause by 

 comparison be safe, why is it that all fields 

 of grain in the same neiglibourhood, sown in 

 a given season alike with grasses, are not all 

 blighted alike, or all alike sound ! All have 

 grass or weeds in them, and why are some 

 injured, while the rest escape disease? Mr. 

 Isaac Newton's information, concerning one 

 land in the middle of an eight-acre field being 

 by accident omitted, when the rest v/as sown 

 with grass-seed, and which escaped mildew, 

 while the rest of the field was rendered 

 worthless by it, is a very remarkable case, to 



