Plant blight

“ These questions should be well considered, particularly the last one, as it is a well-known fact that in a general way the term blight is frequently used for various injuries or diseases of plants causing the whole or parts to wither and die, whether occasioned by insects, fungi, or atmospheric influences. ”

“ These tender and delicate, exquisitely beautiful bulbs flourish amongst the succulent Euphorbias and Mesembryanthemums, between the hedgehog-like thorny plants and the woody little densely-branched mats of the permanent flora. The rain stimulates even these last to put out green leaves and flowers, but their time comes later on, when by the return of the usual drought every leaf and flower and the fruit of every bulb has been shrivelled up, turned into powder, and scattered in dust by the wind. ”

“ It is very plain that the blight occurs, as a general disease, in some seasons more than in others, because it depends upon the peculiar condition of the season, the time and degree of frosts. But it does not seem so clear why, when these conditions are favorable to blight, one tree should suffer, and the next in the row should not; why one orchard should be depopulated, and another in the same town not touched. ”

“ Of course, the more quickly the leaves throw off water, the faster the fresh supply pushes up the stem.
If the leaves do their work more quickly than the roots make good the loss, then the plant wilts.
When a leaf is broken from a plant, it soon fades. Its water supply being cut off, it has no way of making good the loss through the leaf mouths.
Just as the air in a balloon keeps its walls firm, so the water in the leaf cells keeps the cell walls firm. ”

“ A small portion of air to be admitted on fine days, to purify the atmosphere of the house. Keep the surface of the soil in the pots free from weeds, as also from moss and lichen; but when doing so do not loosen the soil so as to injure the roots near the surface. Keep every plant free from dead leaves, and all climbing plants neatly tied up. The Achimenes, Clerodendrons, Erythrinas, Gloxinias, and the various bulbs will now be approaching a state of repose, and therefore will require but little or no water. ”

“ We will, in the early summer, occasionally see on various shrubs or trees numerous little twigs and branches dead and decaying and the general saying then will most assuredly be, the shrub or tree is blighted, where a close and thorough investigation will not reveal the slightest sign of blight, merely injuries by frequent climatic changes in the late winter or early spring months. ”

“ The prevalence of blight has been almost universal in the scattered plantings which we have visited in central New York, usually without the owner knowing why his trees were dying. All our European and Coast varieties, as well as most of the hybrids, take blight readily but there is an occasional hybrid that is clearly resistant. ”

“ Plants of it grow well during the early part of the season, but all at once blight strikes them, and they wither in a day, as if something had attacked the root, and in a short time they are dead. This has discouraged the would-be growers of the large-flowered varieties—for all of them seem to be subject to the same disease. ”

“ Never allow any quantity of water to stand in the flats or saucers. This is too frequently practised with plants in general. Such as Cálla Æthiòpica, or African Lily, will do well, as water is its element, (like Sagittària in this country;) and the Hydrángea horténsis, when in a growing state, will do admirably under such treatment. Many plants may do well for some time, but it being so contrary to their nature, causes premature decay; a fœtid stagnation takes place at the root, the foliage becomes yellow, and the plant stunted; and in the winter season, death will ensue. ”

“ The luminous rays also promote the production of green tissue, the green matter of all vegetables. Gardeners blanch certain plants by raising them in the dark. They thus obtain plants of a pale yellow, spindling, without strength or crispness. They are attacked by a true chlorosis, and waste away, as if sprung from barren sand. The sun also aids the transpiration of plants, and the constant renewal of healthy moisture in their tissues. On failure of the evaporation of moisture, the plant tends to grow dropsical, and its leaves fall, from weakness of the stem. ”

“ If you go along the lanes and in the gardens in the height of summer when it is hot and dry and the sun beats on the plants all day, you may see them beginning to wither for want of water. The roots are not able to find enough moisture in the soil to supply the leaves, which, being in the hot air, continue to transpire away the water resources of the plant, so that in the end each of its cells must suffer and the whole become limp and droop. ”

“ Plants have their troubles as well. Perhaps you have noticed on wild cherry trees growing by the roadside, or on plumb trees, that sometimes almost every tree in a clump, and even every branch on a tree, will have a hard black lump, as large as your fist, growing out of the bark. The tree is sick; sick with a patching disease of trees called the black knot.
The disease itself is something like a mold. It breaks through at the growing tip of the branch where the bark is new and thin. Thence it grows down the branch sucking up the living substance of the plant and killing everything as it goes. ”

“ 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. ”

“ I find that I can control the blight easier than I can control the scale on apple trees. If anyone doesn't believe this I invite him and all to come to my place and see for themselves. I think I have nearly one million seedling and grafted paragon trees. I don't think you will find fifty affected trees on the whole place today. I have men going in every grove at the present time who have inspected thousands of trees and found seven that had blight on the limbs, so I know what I am speaking about. ”

“ Cutting into pieces only multiplies the pest; for each piece (Fig. 98) is already a plantlet, with its roots and with a bud in the axil of its scale-like leaf (either latent or apparent) , and with prepared nourishment enough to develop this bud into a leafy stem; and so a single plant is all the more speedily converted into a multitude. Whereas, when the subterranean parts are only roots, cutting away the stem completely destroys the plant, except in the rather rare cases where the root freely produces adventitious buds. ”

“ I have known trees in our city, 4 or 5 varieties, for more than 30 years, bearing more or less fruit year after year, and have never noticed any blight or anything wrong with them. Should blight appear, I should remove all affected limbs to the sound and healthy wood, as we would do to our pear and quince trees when blight appears among them. I do not believe that properly treated hazel bushes will ever suffer much from blight, at least not in our vicinity. Neither do I believe that any more pruning than I have outlined is required or necessary to our hazel plants. ”

“ Sun-spots.—Yellow spots, which may turn brown or black according to the species of plant affected and the intensity of the action, are often caused by the focussing of the solar rays by lens-like thickenings due to inequalities in the glass of greenhouses, or by drops of water on them or on other leaves, e.g. Palms, Dracaena, etc. The action is that of a burning glass, and extends throughout the leaf-tissues. Young grapes, etc., may also be injured in this way. Water-drops on the glass can only act long enough to produce such injuries if the atmosphere is saturated. ”

“ If any one doubts this, just try to raise the plants without mulch, and note how some disease will make its appearance. The plant will stand considerable sun, however, with heavy enough mulch. And the more sun it can take without harm, the better the root growth will be. Too much shade will show in a spindling top and slender leaves, and invariable smallness of root growth, for, let it be borne in mind always, that the plant must derive more or less food from the top, and it is here that the fungi in numerous forms proceed to attack. ”

“ Into this the sap continually oozes, and it is removed twice, sometimes thrice a day by a peon, who sucks it into his mouth and then ejects it into the jar he carries on his back. As soon as the plant exhausts all this sap, which was originally intended to give strength and life to the flowering stem, it dies, and is replaced by innumerable suckers from the old root. Great care must be exercised in cutting the plant—if the least too soon or too late, it is the death of it. ”

“ For a plant to shower its seeds beside itself is almost fatal; so many offspring impoverish the soil and soon choke each other to death, if, indeed, ants and such crawlers have not devoured the seeds where they lie on the ground. Some plants like the violet, jewelweed, and witch-hazel forcibly eject theirs a few inches, feet or yards. The wind blows millions about with every gust. ”

“ Thus in summer the plants are not confined entirely to the water from the ground, but are also refreshed by the rain from above.
But if you look closely along these little channels, and especially at the base of the leaf where they join the stem, you will find that dust particles washed down by the rain collect and form little streaks and patches. The air is full of all sorts of dust particles which are made up of every conceivable substance. Many of these minute grains of dust will be dissolved in the water, and help to supply the plant with food. ”

“ The transfer to new conditions of soil and atmosphere suddenly transforms this inoffensive plant into a vegetable pest, that climbs over all saner growths and chokes them out of existence with the ineradicable monstrosity of its new functions. ”

“ I have seen well-mulched fields with their plants faltering and wilting, unable to mature the crop because the ground had become so hard that an ordinary shower could make but little impression. Moreover, even if kept moist by the mulch, land long shielded from sun and air tends to become sour, heavy, and devoid of that life which gives vitality and vigor to the plant. ”

“ However, it seems probable that the greater portion of root growth is made before the blight attacks the foliage. This seems borne out by the fact that even blighted seedlings usually show nearly as good growth and bud development as those not blighted. In the case of older plants this is probably much more true as the latter part of the season is devoted largely to growing and maturing the berries. The Alternaria blight is dreaded chiefly because of its destructive effects on the seed crop. ”

“ Of course the insect visitors - bees and flies chiefly - alight on the showy staminate blossoms first, and transfer pollen from them to the dull pistillate ones later, as it was intended they should, to prevent self-fertilization. How endless are the devices of the flowers to guard against this evil and to compel insects to cross-pollinate them! The most minute detail of the mechanism involved, which the microscope reveals, only increases our interest and wonder.
Any plant which elects to grow in shallow water must be amphibious ”

“ Little, if any, watering is needed for late autumn plantings.
Those parts of a plant which are not accustomed to exposure are those which suffer from it. You may garden bare-handed in a cold wind and not be the worse for it, but, if both your arms were bared to the shoulders, the consequences would probably be [128] very different. A bundle of rose-trees or shrubs will bear a good deal on their leaves and branches, but for every moment you leave their roots exposed to drying and chilling blasts they suffer. ”

“ Should the soil of fields or greenhouses be much colder than the air, the plant suffers. When in a warm atmosphere, or in a dry atmosphere, plants need to absorb much water from the soil, and the roots must be warm if the root-hairs are to supply the water as rapidly as it is needed. If the roots are chilled, the plant may wilt or die. ”

“ When a floret opens, a quantity of pollen emerges at the upper end of the anther cylinder, pressed up by the growing style. Owing to their slight stickiness and the sharp processes over their entire surface, the pollen grains, which readily cling to the hairs of insects, are transported to the two-branched, hairy stigma of an older floret. But even should insects not visit the flower (and in fine weather they swarm about it) , it is marvelously adapted to fertilize itself. Farmers may well despair of exterminating a plant so perfectly equipped in every part; to win life's battles. ”

“ Such Diseases are very likely to be seen in a general yellowing and death of the leaf, in the dying of the leaf along the main veins and around the edges, showing that the difficulty is one which affects the entire leaf, and not any particular part of it. In general, there is a tendency for the foliage in plants so attacked to wither up and hang on the tree for a time. The peach-yellows and pear blight are Diseases of this kind. ”