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![. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. HOOT CROPS. 53 22 D); and to reproductive organs (Fig. 22 F) within the host-plant. The protoplasm of the conidia either divides or gives rise to a hypha or " germ tube " (Fig. 23). When it divides it produces a number of zoospores provided with cilia (filaments) (Fig. 23 B). The zoospores float about in the atmosphere and thereby spread the disease. Ulti- mately the cilia disappear, and the zoospores settle down upon the leaves of the potato plant, giving rise to ano Stock Photo](https://c8.alamy.com/comp/PG43T2/the-diseases-of-crops-and-their-remedies-a-handbook-of-economic-biology-for-farmers-and-students-plant-diseases-hoot-crops-53-22-d-and-to-reproductive-organs-fig-22-f-within-the-host-plant-the-protoplasm-of-the-conidia-either-divides-or-gives-rise-to-a-hypha-or-quot-germ-tube-quot-fig-23-when-it-divides-it-produces-a-number-of-zoospores-provided-with-cilia-filaments-fig-23-b-the-zoospores-float-about-in-the-atmosphere-and-thereby-spread-the-disease-ulti-mately-the-cilia-disappear-and-the-zoospores-settle-down-upon-the-leaves-of-the-potato-plant-giving-rise-to-ano-PG43T2.jpg ". The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. HOOT CROPS. 53 22 D); and to reproductive organs (Fig. 22 F) within the host-plant. The protoplasm of the conidia either divides or gives rise to a hypha or " germ tube " (Fig. 23). When it divides it produces a number of zoospores provided with cilia (filaments) (Fig. 23 B). The zoospores float about in the atmosphere and thereby spread the disease. Ulti- mately the cilia disappear, and the zoospores settle down upon the leaves of the potato plant, giving rise to ano Stock Photo")
RMPG43T2–. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. HOOT CROPS. 53 22 D); and to reproductive organs (Fig. 22 F) within the host-plant. The protoplasm of the conidia either divides or gives rise to a hypha or " germ tube " (Fig. 23). When it divides it produces a number of zoospores provided with cilia (filaments) (Fig. 23 B). The zoospores float about in the atmosphere and thereby spread the disease. Ulti- mately the cilia disappear, and the zoospores settle down upon the leaves of the potato plant, giving rise to ano
RMRDE38E–. Minnesota plant diseases. Plant diseases. Fig. 16S.—Potato blight. Early stages of the blight on the leaves. After Clinton. usually much branched, so that a miniature bush-like structure is produced and each branch terminates in a spore. These spores, as is true for most of the downy mildews, are in reality spore cases, for when placed in water they later give rise to a large number of swimming spores. When the latter come to rest they germinate into a tube which causes infection of the host plant. As far as is known at present, no winter spores are produced. The mycelium, however, is capabl
![. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 23 ranunculoides under the influence of Aecidium punctahim. In the simpler cases the floral leaves were narrow, elongated, and greenish, stamens were formed but not carpels; in more pro- nounced cases, the petals were only represented as small, simple,. Fig. 5.—Cherry tree in blossom, with three "witches' brooms" in foliage, (v. Tubeuf phot.) stalked, gr Stock Photo](https://c8.alamy.com/comp/PG430J/diseases-of-plants-induced-by-cryptogamic-parasites-introduction-to-the-study-of-pathogenic-fungi-slime-fungi-bacteria-amp-algae-plant-diseases-parasitic-plants-fungi-effect-of-parasitic-fungi-on-the-form-of-host-plant-23-ranunculoides-under-the-influence-of-aecidium-punctahim-in-the-simpler-cases-the-floral-leaves-were-narrow-elongated-and-greenish-stamens-were-formed-but-not-carpels-in-more-pro-nounced-cases-the-petals-were-only-represented-as-small-simple-fig-5cherry-tree-in-blossom-with-three-quotwitches-broomsquot-in-foliage-v-tubeuf-phot-stalked-gr-PG430J.jpg ". Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 23 ranunculoides under the influence of Aecidium punctahim. In the simpler cases the floral leaves were narrow, elongated, and greenish, stamens were formed but not carpels; in more pro- nounced cases, the petals were only represented as small, simple,. Fig. 5.—Cherry tree in blossom, with three "witches' brooms" in foliage, (v. Tubeuf phot.) stalked, gr Stock Photo")
RMPG430J–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 23 ranunculoides under the influence of Aecidium punctahim. In the simpler cases the floral leaves were narrow, elongated, and greenish, stamens were formed but not carpels; in more pro- nounced cases, the petals were only represented as small, simple,. Fig. 5.—Cherry tree in blossom, with three "witches' brooms" in foliage, (v. Tubeuf phot.) stalked, gr
RMRD7T7B–. The encyclopedia of practical horticulture; a reference system of commercial horticulture, covering the practical and scientific phases of horticulture, with special reference to fruits and vegetables;. Gardening; Fruit-culture; Vegetable gardening. 48 ENCYCLOPEDIA OF PRACTICAL HORTICULTURE them. When full grown the stem-mother is purplish-gray covered with a sparse white bloom and is almost as broad as long. The lice of the third generation are full grown in early June and are all winged pinkish individuals. They migrate in a body to an alternate host- plant, as yet unknown. In the fall a g
RMPG43T3–. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. 52 DISEASES OF CROPS. 22) is examined beneath the microscope,i t^g mycelium of the fungus will be seen ramifying among the cells of the leaf. Wherever the mycelium comes in contact with the cells of the host-plant, they become discoloured. This is. Fig. 22.—Potato FnNous (Peronospora infestans). A to B. Transverse section of potato leaf, showing my celiom (spawn) of fungnp. A. Lower surface Witt two stomata (C) and eonidiophores passing through them. D. Conidium (spore). E. Zoo
RMRDE4RG–. Minnesota plant diseases. Plant diseases. 20 Minnesota Plant Diseases. ularly perennial. The latter include both saprophytes and parasites. The fairy-ring mushrooms are good examples of the former, while of the latter, illustrations are found in those rust funffi which attack balsam fir and other cone-bearing plants and form witches' brooms. The mycelium of the fungus caus- ing smut of grains is of a peculiar kind. It often finds its way into the host plant when the latter is very young and tender, and continues to grow in the delicate growing parts and dies. Fig. 8.—Fairy rings of a mushroo
RMPG4660–. Farm friends and farm foes : a text-book of agricultural science . Agricultural pests; Beneficial insects; Insect pests. CHAPTER XX The Smut Fungi The Smuts form a distinctive group of parasitic plants called by botanists Ustilaginales. The mycelium develops in the tissues of the host plant and causes serious injury to the parts infested. Spores are developed in the form of the blackish powder so characteristic of Corn Smut and Oats Smut. These primary spores germinate under favor- able conditions and often bring about the development of enormous numbers of secondary spores. Nearly every one
RMRE2JY8–. Introduction to botany. Botany. 240 INTRODUCTION TO BOTANY by the grape leaf, until the fungus permeates the entire leaf. If the leaf is not able to make a surplus of food material, the amount taken by the parasite may result in the starvation and death of the grape leaf. Possibly, also, the parasite may excrete substances that poison the host plant.. Fio. 187. Experiments in destroying potato blight Photograph by the New York Agricultural Experiment Station illustrating the results of spraying potatoes to prevent disease. Those that were not sprayed yielded at the rate of 161 bushels per ac
RMPG4EN5–. Minnesota plant diseases. Plant diseases. 34° Minnesota Plant Diseases. host plant, living in one cell of the host. When it forms spores it develops a long tube, which reaches to the surface of the host plant and throws out spores, which are provided with swimming lashes and by means of these swim in raindrops or in the dew. The swimming spores come to rest and invade the same or other plants. A thick-coated, resting winter-spore is produced inside of the host and this may carry the plant over to the fol- lowing year. Diseased plants should therefore be burned and cabbages should not be pla
RMRDDWXY–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 25. the ovules become atrophied, whereas the rest of the flower is hypertrophied. Similarly with flowers of cowberry deformed by Uxobasidium. 2. Hypertrophy.âMany para- sitic fungi cause abnormal enlarge- ment or other malformation of plants which they attack. The simplest case of hypertrophy is seen in the enlargement of a uni- cellular plant as a result of an en
RMPG45CP–. Minnesota plant diseases. Plant diseases. 6o Minnesota Plant Diseases. cases of rusts all of the spore forms are found on the same kind of host plant and it is now a well-known fact that the rusts are extreme specialists in the selection of their hosts. So exact has this selction become that certain rusts will attack one grain plant and are unable to attack other even closely related grasses. In this respect they are among the most proficient of all known parasitic fungi. Still further complications may, however, arise. A rust fungus may increase its distribution by selecting in the spring t
RMRDGWE7–. Plant studies; an elementary botany. Botany. THE NUTKITIoN OF I'LAXTS 161 oaks and tlu'ir allies, etc. (Figs. 140, 1.50). Tlie delicate branching filaments (hypha?) of the fungus spread through the soil, wrap the rootlets with a mesh of hyplux', and pene- trate into the cells. It seems clear that the fungus obtains food from the rootlet as a parasite; but it is also thought that the hyphal threads, spreading widely through the soil, are of great service to the host plant in aiding the rootlets in absorl)ing. If this be true, there is mutual ad- vantage in the association, for the small amoun
RMPG4ENR–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 335 crease in size and number with great rapidity until the whole leaf finally becomes yellow, then dries up and shrivels. The oldest leaves, i. e., those nearest the hill, are usually first affect- ed and then the disease travels toward the tip of the host plant with great speed. The spread of the disease is particularly fa- vored by hot weather and by a damp atmosphere. The yield of cucumbers is quickly affected, because the whole plant is rapidly weakened or may be entirely destroyed. On the older plants. 2.-' Fig. 168.
RMRDHJ21–. Foundations of botany. Botany; Botany. BOOTS 39 it may readily be transferred to moderately damp soil, and that the whole plant presents curious modifications when made to grow in earth instead of water. 51. Parasitic Roots.' — The dodder, the mistletoe, and a good many other parasites, live upon nourishment which they steal from other plants, called hosts. The parasitic. Fig. 15. — Aerial Adyentitlous Roots of the Ivy. roots, or haustoria, form the most intimate connections with the interior portions of the stem or the root, as the case may be, of the host-plant on which the parasite fasten
RMPG4BMC–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 224 ASCOMYCETES. rupture of the epidermis. Numerous leaves may be diseased and each carry many cushions, yet Vuillemin, who described the disease,^ does not believe the host-plant is affected to any serious degree. M. (Gnom.) coryli Batsch. (Britain and U.S. America). The black stromata are found in withered spots on the leaves of hazel {Corylus); as a rule, each stroma carries only one peri- thecium with a long bea
RMRDEH8N–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 53 ual, it is living parasitically on the remainder of the host plant. That the broom itself is not injured, but rather stimulated, in its growth is seen, by the production of such numerous and large-sized branches. But the ultimate effect upon the whole. Fig. 23.—Witches'-broom on balsam fir, caused by a rust fungus (Aecidium elatinuin). The branches of the broom are vertical instead of horizontal, as are the normal, un- diseased branches in the right of the picture. Original. plant is injurious because the normal balance o
RMPG42J9–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 186 ASCOMYCETES. The dark-red masses of thick-coated, warty perithecia appear in autumn and winter on the dead branches only; the asci contain eight bicellular hyaline spores which germinate directly to form a mycelium. Infection of a new host-plant is effected by the mycelium, which enters by open wounds into living branches; it is quite unable to penetrate the living bark and is dependent on wounds. The mycelium s
RMRDDX0N–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. MODE OF LIFE OF THE PARASITIC FUNGI. 9 I can however hardly regard as parasites, fungi like these which live on an accidental outflow from plants or plant-cells, even though they regularly frequent places where an outflow is to be expected. They exert no influence on the host-plant, and they are nourished by substances which can no longer be regarded as belonging to the host. I would rather include them amongst non-
RMPG44NH–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 3o6 GENERAL PLANT PATHOLOGY Africa, the West Indies and Florida. In Florida,^ Cassytha filiformis is abundant on the dunes and in the rosemary scrub, where it spins its yellow, or reddish-orange stems from bush to bush. Fungous Organisms as the Cause of Disease.—The first part of this book dealt with the morphology, physiology, and taxonomy, of. Fig. 123.—Photomicrograph of the section of a dicotyledonous host plant para- sitized by dodder, Cuscuta sp. At D and D' note.haustoria enterin
RMRE3A9N–. Practical botany. Botany. 384 PEACTICAL BOTANY pushed underground. The upper portion of the stem, if it en- counters a tvig or small plant, quickly winds about it and sends sucking roots or haustoria into the tissues of the host. By means of these it draws from the host enough plant food to develop the dodder plant until it flowers and seeds. If it encounters no suitable host plant m the course of four or five weeks, the seed- ling dies. Some extraordinary flowering para- sites develop scarcely any stem, but con- sist mainly of haustoria and an immense flower. Rafflesia, the most remarkable
RMPG45D5–. Minnesota plant diseases. Plant diseases. 54 Minnesota Plant Diseases. individual, formed by the partnership of a fungus and certain branches of the host, and living at least partially as a parasite upon the remainder of the host plant. It behaves as does a par- asitic mistletoe plant and is not unlike it in appearance. Most of the witches'-brooms of Minnesota trees are due to rust fungi. One of the most common is the birds-nest broom upon red. Fig. 24.—Witches'-broom on white spruce, caused by a mistletoe (Razoumofskya pusilla). The spruce is badly affected. Numerous brooms are seen below a
RMRDDWYW–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 22 REACTION OF HOST TO PARASITIC ATTACK. of Other examples, since many of these will be referred to again in other chapters, particularly when hypertrophy is under consi- deration. § 5. EFFECT OF PARASITIC FUNGI ON THE FOEM OF THE HOST-PLANT. 1. Arrest of growth, and Atrophy. While a large number of fungi produce more or less extensive enlargement of parts of their host, others cause arrest of organs, crippling, imp
RMPG45C0–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases.. eral fungi suffocate plants, causing death with or with- out true parasitism. A shelf fungus not uncommon in Min- nesota grows on the ground and often envelopes the bases of shrubs or sap- lings with its dark brown fruiting body. When it meets seedlings this envelopment may prevent the further growth of the host and suffocation re- sults. One of the black fungi attacks several kinds of grass plants and prevents the unfold- ing of the leaves and finally causes the death of its host plant. Stunting of plants and plant parts.
RMRDNEJ0–. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. BROOM-RAPES, BALANOPHOREiE, RAFFLESIACEjE. 201 termed a floral cushion. The cells in this cushion, however, now group them- selves in a definite way; ducts and vessels are produced, and, at the same time, a differentiation into axis and flowers is exhibited. These members continue their development, increase in size, and finally the enlarged bud breaks through the cortex of the host-plant under shelter of which it has been evolved. In the genus Cytinm alone do we find a stem richly furnished with lea
RMPG45CN–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 6i that in the latter case the nutrient material must first pass through the walls of the host plant before it can be taken up b)'^ the fungus thread. The interior-dwelling fungi may get their nourishment in several ways. In many, special sucker- threads are sent into the living substance of the plant. In other cases the fungus threads run between the cells of the tis- sues without ever coming into direct contact with the living substance. On the other hand, fungi may gain entrance to the cells and live entirely within them.
RMRDE323–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 389 The fungus threads, which are found in the swollen parts of the host plant and which cause the stimulation, whereby the increase of growth or swelling of the stem takes place, form their winter rust-spores inside of the cells of the epidermis of. Fig. 206.—Sunflower rust. Winter and summer spore clusters on the leaf of <l sunflower. Original. the host. This epidermis is much altered on account of the action of the fungus. Its cells have thin, instead of thick, outer walls, and are much increased in size. These spores
RMPG404R–. Fungous diseases of plants : with chapters on physiology, culture methods and technique . Fungi in agriculture. 124 FUNGOUS DISEASES OF PLANTS very short period of growth. Nevertheless, under conditions more favorable for the host plant the blight may never extend more than a few inches, resulting merely in a tip pruning. In the case of the apple this twig blight is the rule, the disease apparently being usually unable to maintain itself in the larger branches. Young fruits of the apple, an inch in diameter, are. Fig. 32. Water Sprouts of Apple killed by Blight frequently affected; and the c
RMRE2FD9–. Fundamentals of botany. Botany. SAPROPHYTISM AND SYMBIOSIS 341 semi-parasitism is that of the blue-green alga, Nostoc, species of which grow in little pockets or cavities in the tissues of the water-fern Salvinia, of Gunnera manicata,. Fig. 249.—Photomicrograph of a cross-section of the stem of a (ficoty- ledonous host-plant infested with the parasite, dodder {Cuscuta Sp.). Note the haustoria extending from the dodder (D, D') into the cortex of the host (H). Greatly enlarged. of Anthoceros, and of other plants, without apparent injury to the host (Fig. 160). 312. Artificial Parasites.—By rec
RMPG4FGD–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 133 gus which is closely related to the last two groups of fungi and particularly to the caterpillar fungus. This fun- gus exerts a strangling action on the host plant. It appears as a whitish or light-tan-colored ring around the young leaves at the tip of the plant. The threads soon form a solid mass en- closing the young leaves and pre- venting them from unfolding. The branch on which the fungus is thus formed may. ultimately die ofif. When the fungus has in- creased somewhat in thickness the sac-spore capsules make their
RMRE0N42–. A manual of botany. Botany. THALLOPHYTA—FUNGI 87 out a number of short protrusions, each composed of a nimiber of hyphse. These, which are called stromaia, bear each a rounded head, which is covered by a number of depressions. In each of these is developed a perithecium (figs. 845, 846, and 847), the asci of which develop each eight filiform ascospores (fig. 848). These, when they germinate on the flowers of the host-plant, again produce the sphacelia form. Sub-Class V.—jEcidiomycetes. In this group are included two orders of parasitic plants, which are characterised by a stUl further degrad
RMPG4B81–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 312 USTILAGINEAE. germination produce a thread-like promyeelium bearing apical conidia, which conjugate in pairs before emerging from the host-tissues. The following species form conidia on the host-plant: Entyloma serotinum Schroet. occurs on leaves of Symphytum tuberosum, S. officincdis, and Borago officinalis. E. canescens Schroet. On Myosotis (Britain). E. fuscum Schroet. On Papaver Rhoeas and /'. Argemone. E. b
RMRDTWE7–. Plants; a text-book of botany. Botany. THE FOOD OF PLANTS 89 oaks and their allies, etc. (Figs. 76, 77). The delicate branching filaments (hyphse) of the fungus spread through the soil, wrap the rootlets with a mesh of hyphse, and pene- trate into the cells. It seems clear that the fungus obtains food from the rootlet as a parasite; but it is also thought that the hyphal threads, spreading widely through the soil, are of great service to the host plant in aiding the rootlets in absorbing. If this be true, there is mutual ad- vantage in the association, for the small amount of nourishment tak
RMPG26KB–. Injurious insects : how to recognize and control them . Insect pests; Insect pests. 200 PESTS OF GABLES ASD FIELD CROps or more generation5 on some alternate host plant, and sunives there through the winter. TSTien found on garden crops, the lice may be killed by spraying with tobacco extract or 5 per cent kerosene emuMon. Fumi- gation with carbon bLstil- phide will destroy them, using an inverted rub as a fumigating chamber. The dose should be at the rate of one tablespoonful of car- bon bisulphide to a 20 gallon tub. Aphis punk may be substituted for the carbon bisulphide and a light frame
![. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. SCLEROTINIA. 259 cowberry shoots, the stomata being always avoided. In less than three weeks conidia are produced. The mode in which the germ-tubes attack the host-plant is very remarkable. Woronin says: " The germ-tubes developed from the ascospores grow inwards towards the vascular bundles of the host-plant and enter them; then they continue to develop, but now in the opposite direction from the interior of . Stock Photo](https://c8.alamy.com/comp/RDD8AD/diseases-of-plants-induced-by-cryptogamic-parasites-introduction-to-the-study-of-pathogenic-fungi-slime-fungi-bacteria-amp-algae-plant-diseases-parasitic-plants-fungi-sclerotinia-259-cowberry-shoots-the-stomata-being-always-avoided-in-less-than-three-weeks-conidia-are-produced-the-mode-in-which-the-germ-tubes-attack-the-host-plant-is-very-remarkable-woronin-says-quot-the-germ-tubes-developed-from-the-ascospores-grow-inwards-towards-the-vascular-bundles-of-the-host-plant-and-enter-them-then-they-continue-to-develop-but-now-in-the-opposite-direction-from-the-interior-of-RDD8AD.jpg ". Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. SCLEROTINIA. 259 cowberry shoots, the stomata being always avoided. In less than three weeks conidia are produced. The mode in which the germ-tubes attack the host-plant is very remarkable. Woronin says: " The germ-tubes developed from the ascospores grow inwards towards the vascular bundles of the host-plant and enter them; then they continue to develop, but now in the opposite direction from the interior of . Stock Photo")
RMRDD8AD–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. SCLEROTINIA. 259 cowberry shoots, the stomata being always avoided. In less than three weeks conidia are produced. The mode in which the germ-tubes attack the host-plant is very remarkable. Woronin says: " The germ-tubes developed from the ascospores grow inwards towards the vascular bundles of the host-plant and enter them; then they continue to develop, but now in the opposite direction from the interior of .
RMPG4FNR–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 83 (b) Many rusts have remarkable powers of stimulation, not only in their influence on size but also in the age of parts. Al- though a host plant may bear the load of such a parasite the fungus may still stimulate it sufificiently to enable it to maintain its normal age relationships so that the fungus and host may live together for years. In the darnel grass lives a smut-hke fungus which is parasitic and which infects the embryo in the seed before the latter is ripe, and thus this fungus lives on from year to year in- fect
RMRDD8CA–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. CEYPTOMYCES. 247 especially Salix incana, but also on ^S*. purpurea. When the black apothecial cushions break out through the bark, the twigs of the host-plant are frequently still green and leaf-clad. The apothecia originate in the lower bark and so loosen the epidermal layers as to cause the appearance of yellow spots. Black centres appear in the spots, due to the formation of a. Fig. 132.—Cryptomyces maximum. 1,
RMPG4EMT–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 345 Club-root of cabbage, radish, turnip and other cruciferous plants (Plasmodiophora brassicae Wor.). This disease is not un- common in Minnesota but the exact extent of its distribution is not known. The cause of the disease is not a true fungus but is a slime mold or fungus animal. It forms no fungus threads but produces spores somewhat similar to those of the true fungi. The spores gain entrance to the host plant, usually in the root region though the parasite may also exist in the leaf.. Fig. 179.—Club-root of turnips.
RMRDE4NM–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 59 the rest of the plant. Then arise the carbuncle-like swellings of the leaves. If a kernel of the cob is attacked it increases perhaps tenfold in size. During this increase of size the fungus is also gaining strength and keeping pace with its partner plant-part, and when the proper moment has arrived for the formation of its spores it proceeds rapidly and utilizes all the extra food stored up by the swollen host plant-parts and de- stroys the latter rapidly. Such a parasite stimulates its host to unusual activity for a lon
RMPG4FFP–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 145 cup fungi, and in particular parasitic forms, build storage or- gans, often as large as a small filbert nut, and the cups are produced in clusters upon this storage organ in the follow- ing spring. Wild anemones, cultivated clovers and plant bulbs are often attacked by such storage-organ-forraing cup fungi, as are also plants of the blueberry family. In the latter case the storage organ replaces the fruit of the host plant and cases are known where the same fungus lives on two different hosts in its life- time just as do
RMRDYB8A–. Plant life, considered with special references to form and function. Plant physiology. THE FUNGUS BODY OF HYPHAL ELEMENTS. 43 51. Parasites.—Especially is this true of tliose fungi wliich grow in the interior of living organisms. The higher plants are liable to be fastened upon by parasitic fungi, and com- pelled to act as hosts to their unbidden and unwelcome guests. Such a host plant may be entered when a mere seedling, in which case the fungus grows with its growth, or it may not be attacked until older or even mature. The host may be permeated in all its jjarts by the fungus filaments ;
RMPG455P–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 132 MYCOLOGY Other without paraphyses, so that they form a velvety layer on the surface of the host plant. Eight ascospores are generally found, as in the genus Exoascus, but in Taphrina (Taphria) the number may be increased considerably by budding, so that the whole ascus will be. Fig. 42.—Exoascus and Taphrina. A—F, Exoascus pruni, A. Appearance on diseased twig; B, cross-section of diseased fruit; C. mycelium in tissues of host; D, young asci; E, mature ascus with spores; F, germinat
RMRDDWY7–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 24 REACTION OF HOST TO PARASITIC ATTACK. True atrophy is best seen in those cases where flower-forma- tion is suppressed. This effect of parasitic fungi on their host is by no means uncommon, the fungus alone reproducing itself, while the assimilating host-plant remains sterile. This atrophy is found not only in annual plants, but also in those where the symbiosis might be designated as perennial. The last-mentioned
RMPG4GRW–. The fungi which cause plant disease . Plant diseases; Fungi. 128 THE FUNGI WHICH CAUSE PLANT DISEASE .-â tents crowds toward the tips of these cells and a basal septum cuts off the ascus proper from the stalk cell, Fig. 88. The spores then form within the ascus. The ascospores may bud either before or after extrusion from the ascus, pro- ducing conidia, which may themselves bud indefinitely, producing secondary, tertiary, etc., crops. In this condition the conidia strongly resemble yeast cells. On the host plant ascospores germinate by germ tubes, which are ca- p a b 1 e of infecting prope
RMRDE691–. Farm friends and farm foes : a text-book of agricultural science . Agricultural pests; Beneficial insects; Insect pests. CHAPTER XX The Smut Fungi The Smuts form a distinctive group of parasitic plants called by botanists Ustilaginales. The mycelium develops in the tissues of the host plant and causes serious injury to the parts infested. Spores are developed in the form of the blackish powder so characteristic of Corn Smut and Oats Smut. These primary spores germinate under favor- able conditions and often bring about the development of enormous numbers of secondary spores. Nearly every one
RMPG0R77–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 112 PHYCOMYCETES. on stems, flower-stalks, radical and cauline leaves, and floral envelopes. Leucochytrium. (1) Forming simple vesicles: S. punctatum, Schroet. On Gagea joratensis. S. rubrocinctum, Magnus, forms little red eruptions on Saxi- fraga gramdata, the cell-sap of the host-plant becoming red. S. alpinum, Thomas. On Viula lijlora. S. anomalum, Schroet. (U. S. America). On Adoxa Moscha- tellina, less common o
![. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VII] USTILAGINALES 189 formation of clamp-connections (fig. I53«), or between unrelated cells through a conjugation tube (fig. IS3(^). Where basidiospores are formed they conjugate in a similar manner. In every case the nucleus of one of the paired cells passes over into the other, and the two nuclei lie close together, though without fusion. The mycelium throughout the develop- ment of the host plant consists of binucleate cells and breaks up in spore- formation into binucleate segments (fig. 152 a). Each young spore has thus two nuclei Stock Photo](https://c8.alamy.com/comp/RDX0XE/fungi-ascomycetes-ustilaginales-uredinales-fungi-vii-ustilaginales-189-formation-of-clamp-connections-fig-i53-or-between-unrelated-cells-through-a-conjugation-tube-fig-is3-where-basidiospores-are-formed-they-conjugate-in-a-similar-manner-in-every-case-the-nucleus-of-one-of-the-paired-cells-passes-over-into-the-other-and-the-two-nuclei-lie-close-together-though-without-fusion-the-mycelium-throughout-the-develop-ment-of-the-host-plant-consists-of-binucleate-cells-and-breaks-up-in-spore-formation-into-binucleate-segments-fig-152-a-each-young-spore-has-thus-two-nuclei-RDX0XE.jpg ". Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VII] USTILAGINALES 189 formation of clamp-connections (fig. I53«), or between unrelated cells through a conjugation tube (fig. IS3(^). Where basidiospores are formed they conjugate in a similar manner. In every case the nucleus of one of the paired cells passes over into the other, and the two nuclei lie close together, though without fusion. The mycelium throughout the develop- ment of the host plant consists of binucleate cells and breaks up in spore- formation into binucleate segments (fig. 152 a). Each young spore has thus two nuclei Stock Photo")
RMRDX0XE–. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. VII] USTILAGINALES 189 formation of clamp-connections (fig. I53«), or between unrelated cells through a conjugation tube (fig. IS3(^). Where basidiospores are formed they conjugate in a similar manner. In every case the nucleus of one of the paired cells passes over into the other, and the two nuclei lie close together, though without fusion. The mycelium throughout the develop- ment of the host plant consists of binucleate cells and breaks up in spore- formation into binucleate segments (fig. 152 a). Each young spore has thus two nuclei
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 329 Heteroecism.'^" All of the examples just given are autcecious, i. e., all known spore forms are found on the same species of host plant. In many other rusts, however, heteroecism prevails, i. e., one stage of the fungus is found on one species of host and another stage upon another host; rarely three host plants are involved in the cycle. Aside from the rusts only one other fungus (Sclerotinia ledi) is known to show heteroecism. HetercEcism has been experimentally proved in some one hun- Stock Photo](https://c8.alamy.com/comp/PG4641/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-329-heteroecismquot-all-of-the-examples-just-given-are-autcecious-i-e-all-known-spore-forms-are-found-on-the-same-species-of-host-plant-in-many-other-rusts-however-heteroecism-prevails-i-e-one-stage-of-the-fungus-is-found-on-one-species-of-host-and-another-stage-upon-another-host-rarely-three-host-plants-are-involved-in-the-cycle-aside-from-the-rusts-only-one-other-fungus-sclerotinia-ledi-is-known-to-show-heteroecism-hetercecism-has-been-experimentally-proved-in-some-one-hun-PG4641.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 329 Heteroecism.'^" All of the examples just given are autcecious, i. e., all known spore forms are found on the same species of host plant. In many other rusts, however, heteroecism prevails, i. e., one stage of the fungus is found on one species of host and another stage upon another host; rarely three host plants are involved in the cycle. Aside from the rusts only one other fungus (Sclerotinia ledi) is known to show heteroecism. HetercEcism has been experimentally proved in some one hun- Stock Photo")
RMPG4641–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 329 Heteroecism.'^" All of the examples just given are autcecious, i. e., all known spore forms are found on the same species of host plant. In many other rusts, however, heteroecism prevails, i. e., one stage of the fungus is found on one species of host and another stage upon another host; rarely three host plants are involved in the cycle. Aside from the rusts only one other fungus (Sclerotinia ledi) is known to show heteroecism. HetercEcism has been experimentally proved in some one hun-
![. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. ROOT CHOPS. 53 22 D); and to reproductive organs (Fig. 22 F) within the host-plant. The protoplasm of the conidia either divides or gives rise to a hypha or " germ tube " (Fig. 23). When it divides it produces a number of zoospores provided with cilia (iilaments) (Fig. 23 B). The zoospores float about in the atmosphere and thereby spread the disease. Ulti- mately the cilia disappear, and the zoospores settle down upon the leaves of the potato plant, giving rise to ano Stock Photo](https://c8.alamy.com/comp/RDGX67/the-diseases-of-crops-and-their-remedies-a-handbook-of-economic-biology-for-farmers-and-students-plant-diseases-root-chops-53-22-d-and-to-reproductive-organs-fig-22-f-within-the-host-plant-the-protoplasm-of-the-conidia-either-divides-or-gives-rise-to-a-hypha-or-quot-germ-tube-quot-fig-23-when-it-divides-it-produces-a-number-of-zoospores-provided-with-cilia-iilaments-fig-23-b-the-zoospores-float-about-in-the-atmosphere-and-thereby-spread-the-disease-ulti-mately-the-cilia-disappear-and-the-zoospores-settle-down-upon-the-leaves-of-the-potato-plant-giving-rise-to-ano-RDGX67.jpg ". The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. ROOT CHOPS. 53 22 D); and to reproductive organs (Fig. 22 F) within the host-plant. The protoplasm of the conidia either divides or gives rise to a hypha or " germ tube " (Fig. 23). When it divides it produces a number of zoospores provided with cilia (iilaments) (Fig. 23 B). The zoospores float about in the atmosphere and thereby spread the disease. Ulti- mately the cilia disappear, and the zoospores settle down upon the leaves of the potato plant, giving rise to ano Stock Photo")
RMRDGX67–. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. ROOT CHOPS. 53 22 D); and to reproductive organs (Fig. 22 F) within the host-plant. The protoplasm of the conidia either divides or gives rise to a hypha or " germ tube " (Fig. 23). When it divides it produces a number of zoospores provided with cilia (iilaments) (Fig. 23 B). The zoospores float about in the atmosphere and thereby spread the disease. Ulti- mately the cilia disappear, and the zoospores settle down upon the leaves of the potato plant, giving rise to ano
RMPG45Y7–. The fungi which cause plant disease . Plant diseases; Fungi. 392 THE FUNGI WHICH CAUSE PLANT DISEASE Uredo Persoon (p. 389) Spores produced singly on the terminal ends of mycelial hyphse. Germination by a germ-tube which does not produce basidio- spores, but enters the host-plant through the stomata. These forms are in the main discussed under their telial genera. U. orchidis Wint. and U. satjrrii Mass. are in the leaves of cultivated orchids. U. tropaeoli Desm. is found onTropaeolum; U. arachidis Lag. the peanut;^''^ U. auran- Q KJ tiaca Mont, on Oncidium.^ U. au- N( U tumnalis Diet, on Chr
![. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 23 ranunculoides under the influence of Aecidium punctahim. In the simpler cases the floral leaves were narrow, elongated, and greenish, stamens were formed but not carpels; in more pro- nounced cases, the petals were only represented as small, simple,. Fig. 5.—Cherry tree in blossom, with three "witches' brooms" in foliage, (v. Tubeuf phot.) stalked, gr Stock Photo](https://c8.alamy.com/comp/RDDWYH/diseases-of-plants-induced-by-cryptogamic-parasites-introduction-to-the-study-of-pathogenic-fungi-slime-fungi-bacteria-amp-algae-plant-diseases-parasitic-plants-fungi-effect-of-parasitic-fungi-on-the-form-of-host-plant-23-ranunculoides-under-the-influence-of-aecidium-punctahim-in-the-simpler-cases-the-floral-leaves-were-narrow-elongated-and-greenish-stamens-were-formed-but-not-carpels-in-more-pro-nounced-cases-the-petals-were-only-represented-as-small-simple-fig-5cherry-tree-in-blossom-with-three-quotwitches-broomsquot-in-foliage-v-tubeuf-phot-stalked-gr-RDDWYH.jpg ". Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 23 ranunculoides under the influence of Aecidium punctahim. In the simpler cases the floral leaves were narrow, elongated, and greenish, stamens were formed but not carpels; in more pro- nounced cases, the petals were only represented as small, simple,. Fig. 5.—Cherry tree in blossom, with three "witches' brooms" in foliage, (v. Tubeuf phot.) stalked, gr Stock Photo")
RMRDDWYH–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 23 ranunculoides under the influence of Aecidium punctahim. In the simpler cases the floral leaves were narrow, elongated, and greenish, stamens were formed but not carpels; in more pro- nounced cases, the petals were only represented as small, simple,. Fig. 5.—Cherry tree in blossom, with three "witches' brooms" in foliage, (v. Tubeuf phot.) stalked, gr
RMPG4FK6–. Minnesota plant diseases. Plant diseases. Fig. 47. — An insect mold. (Fly chol- era fungus.) 1. A cluster of threads with spores cling- ing to hairs on the insect's body. 2. Fungus threads from the fat-body of an insect. 3. Spore -bearing threads, highly m a g n i fi e d. 4. Above, a single spore; below, germinating spore, forming a sec- ondary spore. Highly magnified. After Brefeld. are sent into the threads of the host plant where they obtain nourishment for the para- site. They are also found on certain of the blue-mold group of fungi. Insect molds {EntomophthorinecE). Of all the algal fu
RMRE03PF–. Nature study and agriculture. Nature study; Agriculture. PLANT riREASES 187 fungus that bears the red spores earher in the season. The spores produced late in the season Uve through the winter and start life the next spring by infecting some host plant again. The mildews cover the leaves of plants with a white sub- stance either of a powdery or of a woolly form. The leaves of our lilacs nearly always show mildew except in early summer, and the grape, rose, woodbine, and willow are often affected. Of course, the larger part of the fungus is out of sight within the tissues of its host, and the
![. Plant studies; an elementary botany. Botany. Fig. 'SA'.. a hrancti of Peronospora in contact with two cells of a host ])lant, and sending into them its large hanstoria.—After DeBakt.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Coulter, John Merle, 1851-1928. New York, D. Appleton and Company Stock Photo](https://c8.alamy.com/comp/PG3D37/plant-studies-an-elementary-botany-botany-fig-sa-a-hrancti-of-peronospora-in-contact-with-two-cells-of-a-host-lant-and-sending-into-them-its-large-hanstoriaafter-debakt-please-note-that-these-images-are-extracted-from-scanned-page-images-that-may-have-been-digitally-enhanced-for-readability-coloration-and-appearance-of-these-illustrations-may-not-perfectly-resemble-the-original-work-coulter-john-merle-1851-1928-new-york-d-appleton-and-company-PG3D37.jpg ". Plant studies; an elementary botany. Botany. Fig. 'SA'.. a hrancti of Peronospora in contact with two cells of a host ])lant, and sending into them its large hanstoria.—After DeBakt.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Coulter, John Merle, 1851-1928. New York, D. Appleton and Company Stock Photo")
RMPG3D37–. Plant studies; an elementary botany. Botany. Fig. 'SA'.. a hrancti of Peronospora in contact with two cells of a host ])lant, and sending into them its large hanstoria.—After DeBakt.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Coulter, John Merle, 1851-1928. New York, D. Appleton and Company
RMRDE4NF–. Minnesota plant diseases. Plant diseases. 6o Minnesota Plant Diseases. cases of rusts all of the spore forms are found on the same kind of host plant and it is now a well-known fact that the rusts are extreme specialists in the selection of their hosts. So exact has this selction become that certain rusts will attack one grain plant and are unable to attack other even closely related grasses. In this respect they are among the most proficient of all known parasitic fungi. Still further complications may, however, arise. A rust fungus may increase its distribution by selecting in the spring t
RMPG2XTJ–. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. 28o DIVISION II.—COURUE OF DEVELOPMENT OF FUNGI. the outer surface of somewhat cushion-shaped bodies, which are formed by the interweaving of mycelial hyphae immediately beneath the epidermis of the host, more rarely at a greater depth, and burst through it when they form spores. Both are formed acrogenously on crowded sporiferous cells (sterigmata, basidia), which cover the outer surface of the hymenium, either alone or in certain species mixed with or surrounded by
RMRE0KE4–. Elementary plant physiology. Plant physiology. Fig. 68.—Cuscuta attached to stem and leaves of an aster. After Johnson. converted into starch in leaves in which the stomata are closed ? gg. Nutritive relations of a parasite.—Secure some living specimens of Cuscuta, or dodder, to he found as yellow cord-like stems, at- tached to Impatiens and other plants on the margins of swamps and in meadows in late summer. Examine fresh material, and place remainder in formalin or alcohol. Note manner in which the dodder is attached to the host plant. Cut thin sections through the organs of attachment and
RMPG3RM5–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. PLASMODIOPHORA. 525 decay, so that not only is the root itself worthless, but the aerial shoot is badly developed. The destruction is greatly favoured by moist rainy years. The malformations of the root are the result of hypertrophy of the host-cells due to a stimulus exerted by the plasmodium of Plasmodiophora, not only on the contents of cells inhabited by it, but also extending into the cells of the whole neigh-
RMRDE382–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 335 crease in size and number with great rapidity until the whole leaf finally becomes yellow, then dries up and shrivels. The oldest leaves, i. e., those nearest the hill, are usually first affect- ed and then the disease travels toward the tip of the host plant with great speed. The spread of the disease is particularly fa- vored by hot weather and by a damp atmosphere. The yield of cucumbers is quickly affected, because the whole plant is rapidly weakened or may be entirely destroyed. On the older plants. 2.-' Fig. 168.
![. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. SPHACELOTHKCA. 303 this fungus as follows :' " Sphacelotheca forms its compound sporophore in the ovule of its host. When the ovule is normally and fully developed in the young flower, the parasite, which always grows through the flower-stalk into the place of insertion of the ovary, sends its hyphae from the funiculus into the ovule, where they rise higher and higher and surround and penetrate its tissue to su Stock Photo](https://c8.alamy.com/comp/PG4B8N/diseases-of-plants-induced-by-cryptogamic-parasites-introduction-to-the-study-of-pathogenic-fungi-slime-fungi-bacteria-amp-algae-plant-diseases-parasitic-plants-fungi-sphacelothkca-303-this-fungus-as-follows-quot-sphacelotheca-forms-its-compound-sporophore-in-the-ovule-of-its-host-when-the-ovule-is-normally-and-fully-developed-in-the-young-flower-the-parasite-which-always-grows-through-the-flower-stalk-into-the-place-of-insertion-of-the-ovary-sends-its-hyphae-from-the-funiculus-into-the-ovule-where-they-rise-higher-and-higher-and-surround-and-penetrate-its-tissue-to-su-PG4B8N.jpg ". Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. SPHACELOTHKCA. 303 this fungus as follows :' " Sphacelotheca forms its compound sporophore in the ovule of its host. When the ovule is normally and fully developed in the young flower, the parasite, which always grows through the flower-stalk into the place of insertion of the ovary, sends its hyphae from the funiculus into the ovule, where they rise higher and higher and surround and penetrate its tissue to su Stock Photo")
RMPG4B8N–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. SPHACELOTHKCA. 303 this fungus as follows :' " Sphacelotheca forms its compound sporophore in the ovule of its host. When the ovule is normally and fully developed in the young flower, the parasite, which always grows through the flower-stalk into the place of insertion of the ovary, sends its hyphae from the funiculus into the ovule, where they rise higher and higher and surround and penetrate its tissue to su
RMRDDYHN–. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. 52 DISEASES OF CROPS. 22) is examined beneath the microscope,i t^g mycelium of the fungus will be seen ramifying among the cells of the leaf. Wherever the mycelium comes in contact with the cells of the host-plant, they become discoloured. This is. Fig. 22.—Potato FnNous (Peronospora infestans). A to B. Transverse section of potato leaf, showing my celiom (spawn) of fungnp. A. Lower surface Witt two stomata (C) and eonidiophores passing through them. D. Conidium (spore). E. Zoo
RMPG45AE–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. CHARACTERISTICS OF THE TRUE EUNGI 49 have been ascribed by Eriksson to the presence of the protoplasm of the rusl mixed with the protoplasm of the host. To this included fungous protoplasm he gave the name mycoplasm. Some fungi are symbiotic, that is, they are found in intimate re- lation with chlorophyll-containing plants and obtain from them food of a carbonaceous character, but without apparently injuring the green symbiont. When they live with a^gae, they commonly form lichens; or i
![. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. HOOT CROPS. 53 22 D); and to reproductive organs (Fig. 22 F) within the host-plant. The protoplasm of the conidia either divides or gives rise to a hypha or " germ tube " (Fig. 23). When it divides it produces a number of zoospores provided with cilia (filaments) (Fig. 23 B). The zoospores float about in the atmosphere and thereby spread the disease. Ulti- mately the cilia disappear, and the zoospores settle down upon the leaves of the potato plant, giving rise to ano Stock Photo](https://c8.alamy.com/comp/RDDYHH/the-diseases-of-crops-and-their-remedies-a-handbook-of-economic-biology-for-farmers-and-students-plant-diseases-hoot-crops-53-22-d-and-to-reproductive-organs-fig-22-f-within-the-host-plant-the-protoplasm-of-the-conidia-either-divides-or-gives-rise-to-a-hypha-or-quot-germ-tube-quot-fig-23-when-it-divides-it-produces-a-number-of-zoospores-provided-with-cilia-filaments-fig-23-b-the-zoospores-float-about-in-the-atmosphere-and-thereby-spread-the-disease-ulti-mately-the-cilia-disappear-and-the-zoospores-settle-down-upon-the-leaves-of-the-potato-plant-giving-rise-to-ano-RDDYHH.jpg ". The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. HOOT CROPS. 53 22 D); and to reproductive organs (Fig. 22 F) within the host-plant. The protoplasm of the conidia either divides or gives rise to a hypha or " germ tube " (Fig. 23). When it divides it produces a number of zoospores provided with cilia (filaments) (Fig. 23 B). The zoospores float about in the atmosphere and thereby spread the disease. Ulti- mately the cilia disappear, and the zoospores settle down upon the leaves of the potato plant, giving rise to ano Stock Photo")
RMRDDYHH–. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. HOOT CROPS. 53 22 D); and to reproductive organs (Fig. 22 F) within the host-plant. The protoplasm of the conidia either divides or gives rise to a hypha or " germ tube " (Fig. 23). When it divides it produces a number of zoospores provided with cilia (filaments) (Fig. 23 B). The zoospores float about in the atmosphere and thereby spread the disease. Ulti- mately the cilia disappear, and the zoospores settle down upon the leaves of the potato plant, giving rise to ano
RMPG3YE9–. Fungous diseases of plants : with chapters on physiology, culture methods and technique . Fungi in agriculture. FUNGI IMPERFECT! 303 The germ tubes arise from any cell of the spore, and it is stated that they may enter the host either by means of the stomates or by directly penetrating the cuticle. This fungus grows vigorously in pure cultures. Upon prune agar it has been found (Jones) that the spores might be produced as a chain of two, and on account of this character the plant has been placed in the related genus Alternaria. As is, of course, well known, the step from Macrosporium to Alte
RMRDC1T4–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 224 ASCOMYCETES. rupture of the epidermis. Numerous leaves may be diseased and each carry many cushions, yet Vuillemin, who described the disease,^ does not believe the host-plant is affected to any serious degree. M. (Gnom.) coryli Batsch. (Britain and U.S. America). The black stromata are found in withered spots on the leaves of hazel {Corylus); as a rule, each stroma carries only one peri- thecium with a long bea
RMPG4BB2–. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. 168 DIVISION II.—COURSE OF DEVELOPMENT OF FUNGI. is gradually becoming finely granular, it divides into the numerous sporangia which form the sorus {c, d). The swarm-cells [g) discharged from the sporangia become new resting-cells, if they find a host. This is the history, for example, of Synchytrium Mercurialis, S. Anemones, &c. The course of development in the Eusynchytrieae is somewhat different; an unlimited number of generations of sori may be and actually ar
RMRDE4M0–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases.. eral fungi suffocate plants, causing death with or with- out true parasitism. A shelf fungus not uncommon in Min- nesota grows on the ground and often envelopes the bases of shrubs or sap- lings with its dark brown fruiting body. When it meets seedlings this envelopment may prevent the further growth of the host and suffocation re- sults. One of the black fungi attacks several kinds of grass plants and prevents the unfold- ing of the leaves and finally causes the death of its host plant. Stunting of plants and plant parts.
RMPG46DM–. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. CHAPTER VII.—PHENOMENA OF VEGETATION.—PARASITES. 361. spores; they appear in nature rather as epiphytic growths on the walls of cavities in the bodies of animals which are easily accessible from without, such as the passages of the ear and the bronchi. In most cases the spore of the parasite begins the emission of a germ-tube independently of the host, either after simple absorption of water or by appropriation at the same time of food-material produced outside the ho
RMRDWCKB–. Plants and their ways in South Africa. Botany; Botany. Classification of Plants 293 from escaping. The stigmas ripen before the anthers ; b)- the time the latter are ripe the hairs are withered; the insect then escapes carrying some of the pollen with it. The flowers are borne along an under- ground rhizome which sends out haustoria into its host plant. Cytinus has handsome scarlet flowers with a six-parted perianth. The flowers are dicecious. The pollen grains from the numerous anther chambers remain in fours. Found on Eriocephalus (Harvey), Aga/husma (Dr. Bolus), Selago (Dr. Kolbe) and oth
RMPG40KH–. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. 394 THE NON-VASCULAR PLANTS. Fig. igi. — A lichen growing upon the bark of a tree. of plants besides bacteria which are included under fungi but which are very different from ordinary fungi. They are different in that they completely envelop the host from which they draw nourish- ment. They are com- posed of fungi and algae which grow together. The principal part of the structure is formed by the hyphse of the fungi, and enmeshed among them are found the c
RMRDC25B–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 186 ASCOMYCETES. The dark-red masses of thick-coated, warty perithecia appear in autumn and winter on the dead branches only; the asci contain eight bicellular hyaline spores which germinate directly to form a mycelium. Infection of a new host-plant is effected by the mycelium, which enters by open wounds into living branches; it is quite unable to penetrate the living bark and is dependent on wounds. The mycelium s
RMPG1M84–. Injurious insects : how to recognize and control them . Insect pests; Insect pests. CPTAPTER X The Xati kal Exeiiies of Ixssects That insects lune ;i host of natural enoiuies which constantly prey on them is as certain as the fact that insects exist at all. If it were not so, and if our pests reacheci the full limit of their jiowers of inci'ease lui- checked, there would shortly lie no living plant left on the face of the earth, and no trace of aninial life. Insects possess preeminently the ability to multiply rapidly and to spread widely. Thus it has been computed that the progeny of one pl
RMRE1JJT–. Plant studies; an elementary botany. Botany. Fig. 239. A branch of Peronospora in contact with two celle of a host plant, and sending into them its large haustoria.âAfter DeBaey.. JPt 'â Fig. 240. Peronospora, one of the Phycomycetes, ehowing at a an oogonium (o) con- taining an egg, and an antheridium (n) in contact; at o the antheridial tube pene- trating the oogonium and discharging the contents of the antheridium into the egg; at c the oogonium containing the oospore or resting spore.âAfter DeBaet.. Please note that these images are extracted from scanned page images that may have been d
RMPG42X0–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 130 PHYCOMYCETES. wet season is very favourable to it. The mycelium is non- septate and spreads through the intercellular spaces of the host, nourished by button-like haustoria sunk into the host-cells. The antheridium comes into contact with the oogonium by a fertilization tube, which, however, remains closed. The oospores hibernate in leaves and fruit. Frevention} Ammoniacal copper carbonate solution, eau celeste,
RMRDYHJY–. An introduction to vegetable physiology. Plant physiology. OTHEE METHODS OP OBTAINING FOOD 203 which eventually burst the cortex above them, and protrude through the host plant. These, in Bafflesia itself, de- velop a single flower which, in some cases, is of enormous size. The plant produces no outgrowths of any kind except the buds described. Other genera show some modification of this structure, but exhibit exactly similar physio- logical peculiarities. Certain other para- sites which resemble these in many respects differ in attacking only sub-aerial por- tions of their hosts. The most e
RMPG3CCE–. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. CHAPTER V.—COMPARATIVE REVIEW.—VREDINEAE. 279 Section LXXX. In the second and much most common case the gena-tube of the aecidiospores does not become a promycelium, but forces its way by acropetal growth through a stoma into the interior of the host, and there developes directly into a mycelium. The mycelium ultimately forms gonidia on distinct hymenia and always by acrogenous abjunction ; and the gonidia, which can germinate either directly or after a period of rest
RMRDE21D–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 3o6 GENERAL PLANT PATHOLOGY Africa, the West Indies and Florida. In Florida,^ Cassytha filiformis is abundant on the dunes and in the rosemary scrub, where it spins its yellow, or reddish-orange stems from bush to bush. Fungous Organisms as the Cause of Disease.—The first part of this book dealt with the morphology, physiology, and taxonomy, of. Fig. 123.—Photomicrograph of the section of a dicotyledonous host plant para- sitized by dodder, Cuscuta sp. At D and D' note.haustoria enterin
RMPG4EKA–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 359 protuberances, each of which has an opening at its apex. These openings communicate with the pear-shaped cavities of the cap- sules, which contain the numerous spore-sacs, each bearing eight spores. These are the winter spores and are capable of causing infection during the year following their formation. The fungus. Fig. 191.—Black knot of wild cherry, showing various stages in the development of the knots. Original. mycelium may also live over the winter in the tissues of the host and grows from year to year. The ultim
RMRDWAD1–. Textbook of botany. Botany. i8o TEXTBOOK OP BOTANY. Fig. 112. — A, dodder growing upon a hop vine and bearing a cluster of flowers. B, a cross section of the hop vine, showing how the roots of the dodder grow into the host until they reach its bast and wood. After Kerner. suckers, which push into the tissues of the host. The suckers grow until they reach the bast and wood of the host plant. Then they are in a position to rob the host of its manufactured food which is being transported in the bast, as well as of the water and dissolved substances that have come up through the wood from the ro
RMPG42YM–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 38 REACTION OF HOST TO PARASITIC ATTACK. men other substances make their appearance in the lignified walls, chiefly tinctorial phlobaphenes. The walls of the wood-elements are, however, not lignified to the same extent. The primary layer of the wall is, as a rule, lignified most and contains but little cellulose. In con- sequence, on treatment with lignin-solvents, it becomes first dissolved while the secondary and
RMRDE375–. Minnesota plant diseases. Plant diseases. 34° Minnesota Plant Diseases. host plant, living in one cell of the host. When it forms spores it develops a long tube, which reaches to the surface of the host plant and throws out spores, which are provided with swimming lashes and by means of these swim in raindrops or in the dew. The swimming spores come to rest and invade the same or other plants. A thick-coated, resting winter-spore is produced inside of the host and this may carry the plant over to the fol- lowing year. Diseased plants should therefore be burned and cabbages should not be pla
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 333 phologically inseparable as are also their secia when grown upon their common host. An excellent example of such biologic specialization is offered in the common pine Peridermium. iEcia may be produced upon the pine by sowing of Coleosporium teliospores from Senecio, Campanula, Pulsatilla, etc., but the seciospores which develop on the pine are capable of in- fecting only those species of hosts from which the teho- spores were taken. Similarly Eriksson "* has de- termined that though rus Stock Photo](https://c8.alamy.com/comp/PG4633/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-333-phologically-inseparable-as-are-also-their-secia-when-grown-upon-their-common-host-an-excellent-example-of-such-biologic-specialization-is-offered-in-the-common-pine-peridermium-iecia-may-be-produced-upon-the-pine-by-sowing-of-coleosporium-teliospores-from-senecio-campanula-pulsatilla-etc-but-the-seciospores-which-develop-on-the-pine-are-capable-of-in-fecting-only-those-species-of-hosts-from-which-the-teho-spores-were-taken-similarly-eriksson-quot-has-de-termined-that-though-rus-PG4633.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 333 phologically inseparable as are also their secia when grown upon their common host. An excellent example of such biologic specialization is offered in the common pine Peridermium. iEcia may be produced upon the pine by sowing of Coleosporium teliospores from Senecio, Campanula, Pulsatilla, etc., but the seciospores which develop on the pine are capable of in- fecting only those species of hosts from which the teho- spores were taken. Similarly Eriksson "* has de- termined that though rus Stock Photo")
RMPG4633–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 333 phologically inseparable as are also their secia when grown upon their common host. An excellent example of such biologic specialization is offered in the common pine Peridermium. iEcia may be produced upon the pine by sowing of Coleosporium teliospores from Senecio, Campanula, Pulsatilla, etc., but the seciospores which develop on the pine are capable of in- fecting only those species of hosts from which the teho- spores were taken. Similarly Eriksson "* has de- termined that though rus
RMRDE33W–. Minnesota plant diseases. Plant diseases. 362 Minnesota Plant Diseases. palisade fashion on the surface of the pocket. Each sac contains about eight spores, which on germination may directly cause in- fection of a host plant. The fungus of this disease is very closely related to the peach leaf-curl fungus and to others forming witches'-broom on birch, alder and cherry trees. It is a sac- fungus with an arrangement of sacs similar to that in the true cup fungi, but has no true cup, since the sacs occur directly on the tissues of the host.. Fig. 193.—Plum pockets. These plums are devoid of sto
RMPG45PN–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 519 In part=Mycosph£erella, Leptosphcpria. The genus is a very large one similar to Phoma and Phyllosticta except in its spore form and in the ostiole which is frequently very large. Septoria and Phleospora are distinguished only by the lesser development of the walls of the latter and many species which in early stages pass as Phleospora would in older stages be classed as Septoria. Septoria and Rhabdospora are distinguished only by the part of the host affected, stem or leaf, and many forms in
RMRE0RTE–. An introduction to vegetable physiology. Plant physiology. OTHEE METHODS OF OBTAINING FOOD 209 Bafftesiacece. The em- bryo, after emerging from the seed, pene- trates the cortex of its host, usually a root, though not always, and gradually forms a hol- low cylinder surround- ing its woody centre. This sheathing struc- ture is composed of rows of cells, and in appearance resembles the mycelium of a fun- gus. Buds arise upon this investment, which eventually burst the cortex above them, and protrude through the host plant. These, in Rafflesia itself, develop a single flower which, in some case
RMPG4B7K–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 314 USTILAGINEAE. epispore, and the clusters appear black or leaden-grey. Ger- mination as in Entyloma. Melanotaenium endoirenum (Unger) (Britain). This is found on Galium MoUiigo and G. verum. The mycelium permeates the whole intercellular system of the host, and is nourished by large tufted haustoria. The host-plants remain small, with shortened internodes, shrunk leaves, and undeveloped flowers. The spores occur
RMRE0N67–. A manual of botany. Botany. THALLOPHTTA—FUNGI many the former is much the greater in extent and forms the larger part of the mycelium, being buried in the substratum on which the fungus is growing. In such oases the shoot is com- posed of a few hyphse, bearing the reproductive organs. In other cases the shoot is large and bulky. In some parasitic forms the root hyphse take the form of haustoria, or sucking organs, which penetrate into the cells of the host plant {fig. 819), the rest of the mycelium being found only between the latter. Sometimes, instead of forming a feltwork of mycelium, the
RMPG40KE–. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. Fig. igi. — A lichen growing upon the bark of a tree. of plants besides bacteria which are included under fungi but which are very different from ordinary fungi. They are different in that they completely envelop the host from which they draw nourish- ment. They are com- posed of fungi and algae which grow together. The principal part of the structure is formed by the hyphse of the fungi, and enmeshed among them are found the cells of the alga. (See Figure
RMRE3CHH–. A handbook of cryptogamic botany. Cryptogams. BA S IDIOM YCE TES 389 and forms on the surface a hymenium of club-shaped basids each of which produces four basidiospores. The spores divide at maturity trans- versely into four cells, only the two end cells of which germinate, doubt- less at the expense of the contents of the remaining two. The germ- tubes penetrate the epiderm of the leaf of the host, and a new mycele is formed which again bears basids. If, however, germination takes place elsewhere than on the proper host-plant, and conditions for the vegeta- tion of the fungus be otherwise f
RMPG0R68–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. CYSTOPUS. 123 Cystopus (Albugo). The mycelium is branched and grows between the cells of living plants, obtaining its nourishment by means of haustoria. The conidial cushions rupture the epidermis of the host. The conidia or sporangia are smooth-coated, and are produced acropetally in chains on short stalks from which they fall off separately when ripe. The sporangia germinate and discharge. Fig. 33.—Cystopvs candid
RMRDE4P3–. Minnesota plant diseases. Plant diseases. 54 Minnesota Plant Diseases. individual, formed by the partnership of a fungus and certain branches of the host, and living at least partially as a parasite upon the remainder of the host plant. It behaves as does a par- asitic mistletoe plant and is not unlike it in appearance. Most of the witches'-brooms of Minnesota trees are due to rust fungi. One of the most common is the birds-nest broom upon red. Fig. 24.—Witches'-broom on white spruce, caused by a mistletoe (Razoumofskya pusilla). The spruce is badly affected. Numerous brooms are seen below a
RMPG4FB3–. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. CHAPTER Vn.—PHENOMENA OF VEGETATION.—LICHENS. 397 hand the same species of Alga may serve as host to different species of Fungi, and serve accordingly as a component part in very different forms of thallus. The following list contains the genera and groups of Algae which are known to form Lichens; the reader is at the same time referred to Schwendener's and Bornet's special vi^orks and to some others also which will be named below, and to the general works on the Alga
![. Florists' review [microform]. Floriculture. "."*^?•? --^ ?'»: 'v. August 24, 1916. The Florists'Review 21 clined to think it will, for so far as I can make out from the specimen sub- mitted it is the cuscuta, commonly known as the dodder plant, a parasitic twiner belonging to the order of eon- volvulaceee. The seed germinates in the ground and as soon as the shoot gets through the soil it attaches itself to a plant and becomes a parasite, sucking its nourishment from the host plant and eventually strangling it. Th« dodder, in one or another of its many species, is found in most cou Stock Photo](https://c8.alamy.com/comp/RRM9WM/florists-review-microform-floriculture-quotquot-v-august-24-1916-the-floristsreview-21-clined-to-think-it-will-for-so-far-as-i-can-make-out-from-the-specimen-sub-mitted-it-is-the-cuscuta-commonly-known-as-the-dodder-plant-a-parasitic-twiner-belonging-to-the-order-of-eon-volvulaceee-the-seed-germinates-in-the-ground-and-as-soon-as-the-shoot-gets-through-the-soil-it-attaches-itself-to-a-plant-and-becomes-a-parasite-sucking-its-nourishment-from-the-host-plant-and-eventually-strangling-it-th-dodder-in-one-or-another-of-its-many-species-is-found-in-most-cou-RRM9WM.jpg ". Florists' review [microform]. Floriculture. "."*^?•? --^ ?'»: 'v. August 24, 1916. The Florists'Review 21 clined to think it will, for so far as I can make out from the specimen sub- mitted it is the cuscuta, commonly known as the dodder plant, a parasitic twiner belonging to the order of eon- volvulaceee. The seed germinates in the ground and as soon as the shoot gets through the soil it attaches itself to a plant and becomes a parasite, sucking its nourishment from the host plant and eventually strangling it. Th« dodder, in one or another of its many species, is found in most cou Stock Photo")
RMRRM9WM–. Florists' review [microform]. Floriculture. "."*^?•? --^ ?'»: 'v. August 24, 1916. The Florists'Review 21 clined to think it will, for so far as I can make out from the specimen sub- mitted it is the cuscuta, commonly known as the dodder plant, a parasitic twiner belonging to the order of eon- volvulaceee. The seed germinates in the ground and as soon as the shoot gets through the soil it attaches itself to a plant and becomes a parasite, sucking its nourishment from the host plant and eventually strangling it. Th« dodder, in one or another of its many species, is found in most cou
RMPG43W3–. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. LEGUMINOUS CBOPS. 21 The twining stem of dodder is of a yellowisti colour, containing (in the spring and summer) clusters of pLnkish, funnel-shaped flowers, and is provided with suckers (Mg. 5 B) which are used for extracting nourishment from the host upon which it lives. The seeds of dodder have a rough surface, and are smaller than those of the clover plant. The seeds of both clover and dodder are of a brown colour, but the former have a smooth surface.. Cloyee Dodder (Gxiscu
![. Textbook of botany. Botany. 386 TEXTBOOK OF BOTANY. Fig. 219. dark portion of the figure repre- sents masses of escaping spores. the com smut are sometimes as large as a man's fist; tiiey occur on the stem, leaves, or roots, in the ears or in the tassels. A large part of an ear, or even a whole ear, may be replaced by the black masses. The fungus that causes the disease is made up of branching threads which A smutted ear of §'"0^ between the cells of the corn. Notice the immense size host plant and send branches of the diseased kernels. The ^^^^ ^-^^ ^^gij^ ^q obtain food. The fungus do Stock Photo](https://c8.alamy.com/comp/RDW9KA/textbook-of-botany-botany-386-textbook-of-botany-fig-219-dark-portion-of-the-figure-repre-sents-masses-of-escaping-spores-the-com-smut-are-sometimes-as-large-as-a-mans-fist-tiiey-occur-on-the-stem-leaves-or-roots-in-the-ears-or-in-the-tassels-a-large-part-of-an-ear-or-even-a-whole-ear-may-be-replaced-by-the-black-masses-the-fungus-that-causes-the-disease-is-made-up-of-branching-threads-which-a-smutted-ear-of-quot0-between-the-cells-of-the-corn-notice-the-immense-size-host-plant-and-send-branches-of-the-diseased-kernels-the-gij-q-obtain-food-the-fungus-do-RDW9KA.jpg ". Textbook of botany. Botany. 386 TEXTBOOK OF BOTANY. Fig. 219. dark portion of the figure repre- sents masses of escaping spores. the com smut are sometimes as large as a man's fist; tiiey occur on the stem, leaves, or roots, in the ears or in the tassels. A large part of an ear, or even a whole ear, may be replaced by the black masses. The fungus that causes the disease is made up of branching threads which A smutted ear of §'"0^ between the cells of the corn. Notice the immense size host plant and send branches of the diseased kernels. The ^^^^ ^-^^ ^^gij^ ^q obtain food. The fungus do Stock Photo")
RMRDW9KA–. Textbook of botany. Botany. 386 TEXTBOOK OF BOTANY. Fig. 219. dark portion of the figure repre- sents masses of escaping spores. the com smut are sometimes as large as a man's fist; tiiey occur on the stem, leaves, or roots, in the ears or in the tassels. A large part of an ear, or even a whole ear, may be replaced by the black masses. The fungus that causes the disease is made up of branching threads which A smutted ear of §'"0^ between the cells of the corn. Notice the immense size host plant and send branches of the diseased kernels. The ^^^^ ^-^^ ^^gij^ ^q obtain food. The fungus do
RMPG460Y–. The fungi which cause plant disease . Plant diseases; Fungi. zu THE FUXGI WHICH CAUSE PLANT DISEASE The basidiospores are capable of infecting onlj- the appropriate alternate host and that when the parts are still j^oung and tender. An abnormal development of germ tubes instead of the usual promycelium has been reported in some instances. According to Lloj'd & Ridgwaj^ ^°' several crops of basidiospores are pro- duced in one season. The various species usually make good subjects with which to studj^ infection. The teliospore masses placed in water soon become covered with basidiospores.
RMRDAMNM–. Injurious insects : how to recognize and control them . Insect pests; Insect pests. 200 PESTS OF GABLES ASD FIELD CROps or more generation5 on some alternate host plant, and sunives there through the winter. TSTien found on garden crops, the lice may be killed by spraying with tobacco extract or 5 per cent kerosene emuMon. Fumi- gation with carbon bLstil- phide will destroy them, using an inverted rub as a fumigating chamber. The dose should be at the rate of one tablespoonful of car- bon bisulphide to a 20 gallon tub. Aphis punk may be substituted for the carbon bisulphide and a light frame
RMPG4GKX–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 149 earlier known as Gloeosporium ribis (Lib.) Mont. & Desm. Old leaves bearing the latter fimgus were wintered out-doors in filter paper and in the spring were found with this ascigerous stage. The ascospores were isolated, grown in pure culture and typical conidia were produced. The ascospores also infected the host leaves successfully producing there the typical Gloeosporium. The conidial stage is the only one ordinarily seen. The acervuli are subepidermal elevating the epidermis to form a
RMRDEXN1–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 145 cup fungi, and in particular parasitic forms, build storage or- gans, often as large as a small filbert nut, and the cups are produced in clusters upon this storage organ in the follow- ing spring. Wild anemones, cultivated clovers and plant bulbs are often attacked by such storage-organ-forraing cup fungi, as are also plants of the blueberry family. In the latter case the storage organ replaces the fruit of the host plant and cases are known where the same fungus lives on two different hosts in its life- time just as do
![. An outline of the history of phytopathology . Plant diseases; Plant diseases. THE UNGEEIAN PERIOD 35 In his book, Exantheme der Pflanzen,' published in 1833, linger devotes 20 pages to the relation of fungi to the plants on which they live. He calls them entophytes or "disease organisms," not parasites,^ holding firmly to the idea of the previous period that they originate from the diseased host tissues, but at the same time he. Franz Unger. The greatest autogenetist. (After a portrait in Wittrock's "Acta Horti Bergiani.") recognizes them as distinct organisms, worthy of Stock Photo](https://c8.alamy.com/comp/PG4G46/an-outline-of-the-history-of-phytopathology-plant-diseases-plant-diseases-the-ungeeian-period-35-in-his-book-exantheme-der-pflanzen-published-in-1833-linger-devotes-20-pages-to-the-relation-of-fungi-to-the-plants-on-which-they-live-he-calls-them-entophytes-or-quotdisease-organismsquot-not-parasites-holding-firmly-to-the-idea-of-the-previous-period-that-they-originate-from-the-diseased-host-tissues-but-at-the-same-time-he-franz-unger-the-greatest-autogenetist-after-a-portrait-in-wittrocks-quotacta-horti-bergianiquot-recognizes-them-as-distinct-organisms-worthy-of-PG4G46.jpg ". An outline of the history of phytopathology . Plant diseases; Plant diseases. THE UNGEEIAN PERIOD 35 In his book, Exantheme der Pflanzen,' published in 1833, linger devotes 20 pages to the relation of fungi to the plants on which they live. He calls them entophytes or "disease organisms," not parasites,^ holding firmly to the idea of the previous period that they originate from the diseased host tissues, but at the same time he. Franz Unger. The greatest autogenetist. (After a portrait in Wittrock's "Acta Horti Bergiani.") recognizes them as distinct organisms, worthy of Stock Photo")
RMPG4G46–. An outline of the history of phytopathology . Plant diseases; Plant diseases. THE UNGEEIAN PERIOD 35 In his book, Exantheme der Pflanzen,' published in 1833, linger devotes 20 pages to the relation of fungi to the plants on which they live. He calls them entophytes or "disease organisms," not parasites,^ holding firmly to the idea of the previous period that they originate from the diseased host tissues, but at the same time he. Franz Unger. The greatest autogenetist. (After a portrait in Wittrock's "Acta Horti Bergiani.") recognizes them as distinct organisms, worthy of
RMRDE4CR–. Minnesota plant diseases. Plant diseases. Minnesota Plant Diseases. 133 gus which is closely related to the last two groups of fungi and particularly to the caterpillar fungus. This fun- gus exerts a strangling action on the host plant. It appears as a whitish or light-tan-colored ring around the young leaves at the tip of the plant. The threads soon form a solid mass en- closing the young leaves and pre- venting them from unfolding. The branch on which the fungus is thus formed may. ultimately die ofif. When the fungus has in- creased somewhat in thickness the sac-spore capsules make their
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