Mildew

“ There is no mildew in the houses, as far as I have seen, or any tendency toward mouldiness in nooks hidden from the sun; and neither among the people nor the plants do we find anything flabby or dropsical. ”

“ The corn-mildew, the hop-mildew and the vine-mildew are, for example, parasitic upon living plants, and the mildews of damp linen and of paper are saprophytes (Gr. σαπρός, rotten) , that is, they subsist on matter which is already dead. As regards mildews in general, the conditions of life and growth are mainly suitable nutrition and dampness accompanied by a high temperature. The life history of the same species of mildew frequently covers two or more generations, and these are often passed on hosts of different kinds. ”

“ But the grass will grow, especially in warm and damp weather (such as was that of the period of the murder) , as much as two or three inches in a single day. A parasol lying upon a newly turfed ground, might, in a single week, be entirely concealed from sight by the upspringing grass. And touching that mildew upon which the editor of 'Le Soleil' so pertinaciously insists that he employs the word no less than three times in the brief paragraph just quoted, is he really unaware of the nature of this mildew? ”

“ Where this disease has already infested the plants, a brisk shower of rain, succeeded by a smart wind, is believed to be the most efficacious remedy, to prevent its farther progress. If the mildew be observed before the sun rises to its meridian power, it will be advisable to send two men into the field, furnished with a long cord, of which each should hold one end: by dexterously drawing this rope over the ears of corn, the dew will be removed, before the heat of the sun dries and reduces it to that viscous state, in which it obstructs the perspiration of plants. ”

“ Botrytis, &c. (Mildew) .—Under this head we include a multitude of epiphytes, to which the terms mildew, mealdew, mehlthau (Germ.) are applicable. They appear to the naked eye as patches of white [189] dust or meal on the leaves and stems of the affected plants. With the microscope we see that they are beautifully-organized plants, having a kind of rootlet (mycelium) or spawn entering the tissues of the living plants on which they grow, and delicate pedicels supporting spores at the externally visible portion of the plant. ”

“ The spores germinate on rose leaves and start the disease anew.
There will be no difficulty in finding mildews; they are all very similar to the rose mildew in general but they all differ in detail. The gooseberry [188] mildew for example, has a large number of threads running from its winter spheres and each thread is terminated by a little group of branches. The sacs which fall from the opened sphere in the spring, only contain four spores in this case.
The animal enemies of the farmer, so far as they concern the microscopist are more difficult to study. ”

“ As we have mentioned, they are curious because they dwell outside the plants they attack. Rose mildew is unfortunately all too common in every garden, it may be recognised as a white powder covering leaves and buds. Under the microscope, in the summer we shall find that it consists of a number of thread-like structures, not unlike those of the common white mould and that there are a number of erect chains of spores. Towards autumn, a further examination will show us many round dark-brown structures from which project a number of minute threads. ”

“ Of insects and fungi I have only enumerated those which are of importance through the damage they occasion from time to time. Those which prey on the vines, but which cause no great damage, and which the grower need not prepare himself to fight, have here been left out.
POWDERY MILDEW OR UNCINULA. General Notes. —This disease of the grapevine is caused by the growth of parasitic fungus known in Europe as Oidium Tuckeri, and in this country as Uncinula spiralis or powdery mildew. ”

“ Into this area dead leaves are blown, and worms and slugs and snails inevitably find their way, and are washed by the rain into the stagnant gully, which becomes a place for putrefaction and the cultivation of mildew, the spores of which are necessarily blown into the house to infect the food which is stored there. Not only is the area closed by a fixed grating above, but the window is securely and permanently barred, so that this dry area (?) , with its mildew trap, cannot possibly be cleaned without pulling the house to pieces. ”

“ Everyone knows that mildew and vermin do damage in the home and in the field, but very few understand that, in addition to these visible enemies of man, there are swarms of invisible plants and animals some of which do far more damage, both directly and indirectly, than the seen and familiar enemies. ”

“ Through the winter the shoots are covered thickly with the brown mycelium and in the spring the spores contained in the perithecia germinate and start the infection anew, as in the case of the European mildew. This fungus has recently been the subject of legislation, and when it appears in a district strong repressive measures are called for. In bad cases the attacked bushes should be destroyed, while in milder attacks frequent spraying with potassium sulphide and the pruning off and immediate destruction by fire of all the young shoots showing the mildew should be resorted to. ”

“ A fungous disease that may appear when the rose plants are in a damp, shady or ill-ventilated location. Although some varieties are more susceptible than others to this disease, the rose garden located out in the open, where the air has unobstructed access, will not be troubled much by mildew. When the disease appears late in the autumn it need not be feared. ”

“ There are about sixty different kinds of mildew, a special variety for nearly every special kind of fruit or vegetable; and, if a decaying berry of the rarest sort is exposed to the open air, it will soon be covered with its specific kind of mold. ”

“ As a rule, the appearance of green fly, red spider, scale, or mildew, is an evidence of debility in the plant—it may be through too much or too little food; it may be through too much or too little heat; it may be through downright neglect of the most ordinary rules of cultivation. The best remedial agents are air, water, and light; but in aid of these we are compelled occasionally to employ tobacco, soap, sulphur, lime, charcoal, soot, and patent preparations made of no one knows what. ”

“ Among plants, most of these degenerate creatures belong to the group of Fungi. The rust and smut on wheat, the mildew on fruit, and nearly all the thousand spots, blemishes, and diseases of cultivated and other plants, are the result of the parasitism of some members of the family of fungi. ”

“ I am sorry to say that seedlings of these foreign varieties have the same tendency to mildew shown by their parents. The Late Emerald was originated in the old garden at Newburgh, and is a sad example of this fact. For many years it thrived in its birthplace without a trace of mildew, but on my own place it has behaved so badly that I do not recommend it. ”

“ The reason is obvious: the more succulent a plant is, and the greater the quantity of moisture it has imbibed, the more susceptible must it be of injury from frost; the fuller its vessels are the more liable are they to be ruptured. Farmers, whose fears are always alive, anticipate a mildew from the continuance of a raw and foggy air in the spring or early part of the summer: nor are they often mistaken. In such a continued state of atmosphere, the grasses open their innumerable orifices, and imbibe a prodigious quantity of moisture ”

“ Many greenhouse insects can be kept more or less in check by careful and effective hosing of the plants at proper times. At this season roses, grape vines and other plants are often affected by mildew; an effectual remedy is to paint the hot-water pipes with a mixture of sulphur and lime, put on as thick as ordinary whitewash, once each week until it is checked ”

“ Common wheat is more subject to this destructive disease than that which is bearded, especially if the land be newly dunged. As, however, it is highly probable, that the greater dampness of some soils, together with their being over-shadowed by too thick foliage, affords one permanent cause of mildew, Dr. Darwin recommends the land to be properly drained ”

“ These sap the vitality of the plants and check their progress. If you dig up the soil a few inches and mix in it the fresh clipped grass from the lawn or a bit of very old manure you can offset this evil.
“The minute you find mildew on a plant, fight it, or it will spread so rapidly to other plants that you will find it well nigh impossible to kill it. In a very short time, your most beautiful flowers will be nothing but a memory. Powder your diseased plants with soot and sulphur nor care for their looks as long as you save them in the end. ”

“ They are part of the natural environment and play an important role in the environment by breaking down and digesting organic material, such as dead leaves. Also called fungi or mildew, molds are neither plants nor animals ”

“ The seeds are gathered busily all day and stored in shallow surface caches where they are dried by the dust and heat of the sun. During the night, the animals work busily removing the dried seed to much larger chambers deep underground where it is to be stored for the winter. In some way the highly intelligent animal has learned the secret of preventing mildew. Only a few other animals have mastered the same technique ”

“ The disease is seldom troublesome on plants grown thinly in the open air. If it makes its appearance, water thoroughly, but not too often, and sprinkle dry sand over the seed-bed among the plants. [D]
Black Leg or Mildew.—This is a disease which attacks the stems of young plants which are being wintered over. It is undoubtedly due to one or more species of parasitic fungi, but I do not find that the subject has been studied. Doubtless the rupture of the bark by alternate freezing and thawing gives the fungi an opportunity to attack the plant. ”

“ Three other pests, black-rot, downy mildew and powdery mildew, are destructive to European grapes in America. The climate, too, in eastern North America alternates between hot and cold, wet and dry, and the Old World grapes grow well only in equable temperatures and conditions of humidity. ”

“ The spores of many fungi and of other living organisms are constantly being floated about in the air, until they find a suitable resting place, when they settle and proceed to grow and multiply. The souring of milk, the fermentation of a saccharine solution, the moulding of bread, the presence of mildew, the blighting of corn, and numerous other phenomena are due to the growth of organisms carried by the atmosphere from one part to another. ”

“ We therefore look upon this as an invaluable remedy in these states of mildew, whether occurring on the vine, the hop, the turnip, the cucumber, or on other plants, as we have frequently seen it in hothouses—a circumstance which shows the near affinity of all those forms of epiphytes, which, perhaps, after all, only vary with the variations in the structure and economy of the different plants on which they occur.
13. Oïdium abortifaciens (Ergot) ; Secale cornutum (Ergot of Rye) .—The black horn-looking spur which occurs in rye and other grasses was formerly looked upon as a distinct fungus ”

“ The trees which are stationary are covered with parasites, especially those which have grown slowly. The air is filled with the fine sporules of countless mosses, algæ, lichens, fungi, which settle and plant themselves on all quiet surfaces. Under the nails and between the joints of the fingers of the idle flourish crops of mildew, algæ, fungi, and other vegetable sloths, though they may be invisible, the lichens where life still exists, the fungi where decomposition has begun to take place, and the sluggard is soon covered with sphagnum. ”

“ I want you to look at each of these moulds carefully under the microscope, for few people who hastily scrape a mould away, vexed to find it on food or damp clothing, have any idea what a delicate and [Pg 64] beautiful structure lies under their hand. These moulds live on decaying matter, but many of the mildews, rusts, and other kinds of fungus, prey upon living plants such as the smut of oats (Ustilago carbo) , and the bunt (Tilletia caria) which eats away the inside of the grains of wheat, while another fungus attacks its leaves. ”

“ Taylor will think it right to favour you with a statement of the facts, that future "Note"-makers may not perplex future editors with endless "Queries" on the subject.
R.J.
Mildew in Books.—Can you, or any of your readers, suggest a preventive for mildew in books?
In a valuable public library in this town (Liverpool) , much injury has been occasioned by mildew, the operations of which appear very capricious; in some cases attacking the printed part of an engraving, leaving the margin unaffected; in others attacking the inside of the backs only ”

“ His mind, under the influence of that insidious mildew which eventually forms on all but the few, gave itself up furiously to every indignation of the age. ”

“ If you find that the fresh food quickly becomes moldy, how will you think that the mold germs came to it? (If you keep the jars in a warm place, the germs will grow faster, and you won’t have so long to wait before you can see the mold.) What other kinds of germs do flies carry? How do they carry them? A Board of Health caused a liveryman to be fined because he allowed a manure pile to remain behind his stable. Why was his act a misdemeanor? From what do flies come, and how do they grow? On your way to and from school, what have you noticed that could breed or attract flies? ”