MILDEW. 



MILDEW. 



pruning, the cultivated mignonette may be 

 rendered perennial, and even shrubby. 



MILDEW, or RUST. Of all the many dis- 

 eases which attack our cultivated plants, not 

 one is so destructive as the mildew. It is the 

 " plague" of our wheat crops ; and as that fatal 

 distemper is always lurking in some district 

 of climes warmer than our own, so the mil- 

 dew is always in our fields, waiting for cir- 

 cumstances favourable to its outspread, and 

 ready to destroy the expected harvest of the 

 husbandman. So constantly present is this 

 destructive disorder, that in the fairest fields 

 of wheat grown in the richest corn districts of 

 England, and in the most genial years, I never 

 saw a single acre entirely uninfected. Every 

 year the farmer is more or less injured by this 

 disease, for the produce of each acre of wheat 

 is unquestionably reduced annually several 

 bushels. Yet those who suffer most by the loss, 

 the farmers themselves, are almost universally 

 ignorant of the fact ; and their attention is 

 rarely arrested by it till a year occurs in which 

 their crop of wheat is nearly annihilated. 



Its prevailing injurious nature was well 

 known in an age as distant as that of the He- 

 brews ; and it had not spared the Greeks and 

 Romans. Even the poets, as Horace in his 

 Odes, speak of it as the "sterile Rubigo" (Car- 

 min. lib. 3, ode 23) ; and warning voices have 

 not been since wanting to speak loudly of its 

 ravages. Mr. Marshall says, " a certain pre- 

 ventive of the mildew would be a discovery 

 worth millions to this cou ntry ;" and many others 

 have coincided in this estimate of its injuries. 



This disease is known to be the effect pro- 

 duced by a minute fungus belonging to a genus 

 closely allied to that which causes the smut. 

 The roots of this fungus penetrate the vessels 

 of the plant, and are nourished by the sap in- 

 tended for perfecting its seed; consequently, 

 if the fungi are so numerous in each stem as 

 to make it a marked "mildew year," the grain 

 is either partially or totally shrivelled, owing 

 to the roots of these parasites intercepting the 

 sap in its upward passage. 



The ignorance relative to this disease is not 

 a consequence of its novelty, since it has been 

 known and dreaded in the earliest ages to 

 which our knowledge extends. Thus, when 

 God held out as a warning to the Israelites the 

 afflictions he would bring on them if disobe- 

 dient, he enumerated the pestilence and the 

 sword to destroy their persons, "with blasting 

 and with mildew," to lay waste their fields (Deut. 

 xxviii. 22 ; 1 Kings vi'ii. 37 ; 2 Chron. vi. 29) ; 

 and when the same Almighty Being had pu- 

 nished that rebellious people, he reminded 

 them by his prophet ; "I have smitten you with 

 blasting and mildew ; when your gardens and 

 your vineyards, and your fig trees, and your 

 olive trees increased, the palmer-worm de- 

 stroyed them." (Amos iv. 9.) "I smote you 

 with blasting, and with mildew, and with hail, 

 in all the labours of your hands." (Haggai ii. 

 17.) The Hebrews called it ynrcoon, implying 

 a yellow pallidness arising from moisture. To 

 the Greeks it was known as erusibe, tgj<r,> ; and i 

 Theophrastus, who wrote his History of Plants 

 about 320 years before the Christian era, ob- , 

 serves (lib. viii. c. 10) that it occurs more 

 102 



frequently to corn than to pulse ; that in the 

 climate of Greece barley was more subject to 

 it than wheat, and particularly a variety then 

 known as achillum barley. Experience had 

 taught them, that the crops on high lying lands 

 were seldom attacked by this disease ; but that 

 the hollows surrounded by hills, where winds 

 could not get at the crops they bore, were most 

 frequently infected. It is chiefly generated, 

 concludes Theophrastus, during the full moon. 



By the Romans, the mildew was denominated 

 "ntiigo." Pliny informs us, in his History of 

 Plants (lib. vii. c. 28 and 29), that it was tlie 

 prevailing opinion that this disease arises from 

 certain dews settling upon the corn, and obtain- 

 ing a caustic or burning quality from the in- 

 tense heat of the sun. This naturalist himself 

 thought, on the contrary, that the disease arises 

 from cold, considering that infection first occurs 

 during the sun, and always about the new or 

 full moon. Pliny, and the still later writers 

 of the Geoponica (for this work is composed of 

 fragments of Roman writers living after the 

 removal of the seat of empire to Constantino- 

 ple, though written in the Greek language), 

 considered that the best remedies were' stink- 

 ing pungent smokes; hence they recommended 

 fish, horns, goat's dung, &c., to be burned on 

 such side of the field as would enable the 

 wind to diffuse the smoke over and throughout 

 the crop. They evidently had the same pre- 

 judice as is now entertained by our own farm- 

 ers, that the mists which frequently prevail 

 during midday in the hottest periods of sum- 

 mer are the cause of the mildew; for they 

 direct those fumigations to be performed at 

 such time as it is seen in the atmosphere. 

 They also thought that if branches of the laurel 

 were fixed among their corn, the mildew would 

 pass from the crops to those branches. (Geo- 

 pon. lib. v. c. 33 ; Plinii Hist. Plant, lib. xvii. c. 

 17, &c.) One of their practices recommended 

 is much more rational, namely, to bruise the 

 leaves or roots of the colocynth, to macerate 

 these in water, and, before the sun has risen, 

 to sprinkle the infected crop with the liquor 

 thus obtained. It is possible that the juice of 

 the colocynth, which is a violent purgative to the 

 human system, may be destructive to the fungus 

 constituting the disease. It approaches to that 

 which, in modern times, has been found the 

 only effectual curative treatment; and the di- 

 rection that the application should be perform- 

 ed in the morning evinces that it was a direction 

 suggested and confirmed by experience. Co- 

 lumella (lib. ii. c. 12) says, that hoeing corn 

 during wet weather is apt to induce mildew. 



Some modern writers have considered that 

 the rubigo of the Romans is the disease known 

 to us as the smut; but, independent of the 

 name, which evidently referred to the red or 

 rusty hue of the disease, and which is not a 

 characteristic of the last-named disorder, we 

 have the direct testimony of Virgil (Gem: I. 

 150), that the rubigo was a disease of the straw ; 

 his words are, " Mox et frumentis labor addi- 

 tus ; ut mala culmos esset rubigo, &c." 



Horace (Carminum, lib. iii. ode xxiii.) and 

 Ovid (Fast. iv. 907) speak of the same vege- 

 table epidemic. The Greeks and Romans were 

 as conscious as the Hebrews of the destruction 

 3x2 809 



