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Diseases fungi Stock Photos and Images
RF2DM2RGB–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
![. The fungi which cause plant disease . Plant diseases; Fungi. and the mycelium there develops richly under the epidermis. The outer cells remain sterile and constitute the membrane; the inner gelatinize and develop into spores. S. reiliana (Kiihn) Cl.^* "'^ ^^ '*" ^^ Sori very prominent forming irregular masses including more or less of the entire panicle, usually 5-15 cm. in length; often at first pro- tected by the leaf-sheath. A whitish false membrane encloses the black- brown spore-mass and the ray-like re- mains of the j)eduncles or columellas. In time it becomes ruptured and t Stock Photo](https://c8.alamy.com/comp/RDDAM0/the-fungi-which-cause-plant-disease-plant-diseases-fungi-and-the-mycelium-there-develops-richly-under-the-epidermis-the-outer-cells-remain-sterile-and-constitute-the-membrane-the-inner-gelatinize-and-develop-into-spores-s-reiliana-kiihn-cl-quot-quot-sori-very-prominent-forming-irregular-masses-including-more-or-less-of-the-entire-panicle-usually-5-15-cm-in-length-often-at-first-pro-tected-by-the-leaf-sheath-a-whitish-false-membrane-encloses-the-black-brown-spore-mass-and-the-ray-like-re-mains-of-the-jeduncles-or-columellas-in-time-it-becomes-ruptured-and-t-RDDAM0.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. and the mycelium there develops richly under the epidermis. The outer cells remain sterile and constitute the membrane; the inner gelatinize and develop into spores. S. reiliana (Kiihn) Cl.^* "'^ ^^ '*" ^^ Sori very prominent forming irregular masses including more or less of the entire panicle, usually 5-15 cm. in length; often at first pro- tected by the leaf-sheath. A whitish false membrane encloses the black- brown spore-mass and the ray-like re- mains of the j)eduncles or columellas. In time it becomes ruptured and t Stock Photo")
RMRDDAM0–. The fungi which cause plant disease . Plant diseases; Fungi. and the mycelium there develops richly under the epidermis. The outer cells remain sterile and constitute the membrane; the inner gelatinize and develop into spores. S. reiliana (Kiihn) Cl.^* "'^ ^^ '*" ^^ Sori very prominent forming irregular masses including more or less of the entire panicle, usually 5-15 cm. in length; often at first pro- tected by the leaf-sheath. A whitish false membrane encloses the black- brown spore-mass and the ray-like re- mains of the j)eduncles or columellas. In time it becomes ruptured and t
![. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 672 ADDITIONAL EXERCISES "Dflute this stock resin solution with 8 parts of water before adding to the Bordeaux mbcture, that is in preparing a so-gallon barrel of the mixture, the copper sulphate and lime are diluted enough to make 40 gallons after which 2 gallons of stock resin solution are diluted to 10 gallons, then added to the Bordeaux." This solution exceeds ordinary Bordeaux in adhesive properties and has been highly recommended for asparagus rust. Method of Malting Sma Stock Photo](https://c8.alamy.com/comp/PG4DHW/a-text-book-of-mycology-and-plant-pathology-plant-diseases-fungi-in-agriculture-plant-diseases-fungi-672-additional-exercises-quotdflute-this-stock-resin-solution-with-8-parts-of-water-before-adding-to-the-bordeaux-mbcture-that-is-in-preparing-a-so-gallon-barrel-of-the-mixture-the-copper-sulphate-and-lime-are-diluted-enough-to-make-40-gallons-after-which-2-gallons-of-stock-resin-solution-are-diluted-to-10-gallons-then-added-to-the-bordeauxquot-this-solution-exceeds-ordinary-bordeaux-in-adhesive-properties-and-has-been-highly-recommended-for-asparagus-rust-method-of-malting-sma-PG4DHW.jpg ". A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 672 ADDITIONAL EXERCISES "Dflute this stock resin solution with 8 parts of water before adding to the Bordeaux mbcture, that is in preparing a so-gallon barrel of the mixture, the copper sulphate and lime are diluted enough to make 40 gallons after which 2 gallons of stock resin solution are diluted to 10 gallons, then added to the Bordeaux." This solution exceeds ordinary Bordeaux in adhesive properties and has been highly recommended for asparagus rust. Method of Malting Sma Stock Photo")
RMPG4DHW–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 672 ADDITIONAL EXERCISES "Dflute this stock resin solution with 8 parts of water before adding to the Bordeaux mbcture, that is in preparing a so-gallon barrel of the mixture, the copper sulphate and lime are diluted enough to make 40 gallons after which 2 gallons of stock resin solution are diluted to 10 gallons, then added to the Bordeaux." This solution exceeds ordinary Bordeaux in adhesive properties and has been highly recommended for asparagus rust. Method of Malting Sma
RF2DM2MX9–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDE26N–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 232 MYCOLOGY the primary ones. The gills may be free from the stipe, adnexed, or even decurrent. A section of a mature gill shows the following disposition of the hyphal layers. The central part of the gill consists of paraUel, down- ward directed hyphae, that form the trama. Running out obliquely from the trama are shorter ceUs which constitute the subhymenium. The basidia, together with their accompanying paraphyses and cysti- dia, form a paHsade-Uke layer (the hymenium) whose cells s
RMPG4H4G–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 63 similar to that of the parent. The most usual mode is for the mycelium to rise directly from the spore. In other instances the spores produce zoospores which migrate, come to rest, then develop a mycelium. In still other cases a short mycelium, promycelium, is formed and from this small conidia, sporidia, are made. Figs. 217, 240. These conidia give, direct rise to the mycelium. Spores of some species may by genmiation lead a more or less prolonged existence without return to the mycelial stag
RF2DM18RD–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDE73G–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 63 similar to that of the parent. The most usual mode is for the mycelium to rise directly from the spore. In other instances the spores produce zoospores which migrate, come to rest, then develop a mycelium. In still other cases a short mycelium, promycelium, is formed and from this small conidia, sporidia, are made. Figs. 217, 240. These conidia give, direct rise to the mycelium. Spores of some species may by genmiation lead a more or less prolonged existence without return to the mycelial stag
RMPG45FT–. The fungi which cause plant disease . Plant diseases; Fungi. 638 THE FUNGI WHICH CAUSE PLANT DISEASE Tuberctilariacese (p. 565) Hyphse compacted into a globose, discoid, or verruciform body,. FiQ.430.—Stysanus. Fia. 431.—Isariopaia. After Saccardo. After Saccurdo. the sporodochium; sporodochia typically sessile, waxy or subge- latinous, white, bright-colored or dark to black. In part =Nectria, Claviceps and Hymenoscypha, etc. See pp. 146, 201, 211. Key to Sections of Tuberculariaces Hyphse and conidia hyaline or bright-colored I. Mucedineae. Conidia globose to fusoid or falcate Conidia conti
RF2DM1030–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 231 Perithecia were found by Viala»" and by Prillieux»" on old wood, long dead from such attack. These belong to the genus Rosellinia and are believed to present the ascigerous form of Dema- tophora necatrix. Similar claims of relationship of this fungus to several other genera have been made and its actual position cannot be consid- ered as established with certainty. R. massinkii Sacc. Perithecia sparse, globose or depressed, carbonous, 165 fi; asci cyhndric, 54 x 8 At; spores dark-br Stock Photo](https://c8.alamy.com/comp/RDDBDX/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-231-perithecia-were-found-by-vialaquot-and-by-prillieuxquot-on-old-wood-long-dead-from-such-attack-these-belong-to-the-genus-rosellinia-and-are-believed-to-present-the-ascigerous-form-of-dema-tophora-necatrix-similar-claims-of-relationship-of-this-fungus-to-several-other-genera-have-been-made-and-its-actual-position-cannot-be-consid-ered-as-established-with-certainty-r-massinkii-sacc-perithecia-sparse-globose-or-depressed-carbonous-165-fi-asci-cyhndric-54-x-8-at-spores-dark-br-RDDBDX.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 231 Perithecia were found by Viala»" and by Prillieux»" on old wood, long dead from such attack. These belong to the genus Rosellinia and are believed to present the ascigerous form of Dema- tophora necatrix. Similar claims of relationship of this fungus to several other genera have been made and its actual position cannot be consid- ered as established with certainty. R. massinkii Sacc. Perithecia sparse, globose or depressed, carbonous, 165 fi; asci cyhndric, 54 x 8 At; spores dark-br Stock Photo")
RMRDDBDX–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 231 Perithecia were found by Viala»" and by Prillieux»" on old wood, long dead from such attack. These belong to the genus Rosellinia and are believed to present the ascigerous form of Dema- tophora necatrix. Similar claims of relationship of this fungus to several other genera have been made and its actual position cannot be consid- ered as established with certainty. R. massinkii Sacc. Perithecia sparse, globose or depressed, carbonous, 165 fi; asci cyhndric, 54 x 8 At; spores dark-br
RMPG463R–. The fungi which cause plant disease . Plant diseases; Fungi. 330 THE FUNGI WHICH CAUSE PLANT DISEASE aecia are on pines (Peridermium), while the other stages are on dicotyledons. In the Gymnosporangiums the pycnial and secial stages are on Rosacese; the telial on Juniperus and its kin. While a few general rules can be worked out concerning host relations there are many exceptions and to know one stage of a heteroecious rust generally gives little or no clue to what its complementary host may be. The mycelium of the rusts is usually intercellular and local though in a few instances it is exte
RF2DM19TT–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDDAY6–. The fungi which cause plant disease . Plant diseases; Fungi. 266 THE FUNGI WHICH CAUSE PLANT DISEASE structures are regarded by Hasselbring ^^^ as organs of attachment to aid in infection, though they doubtless serve other pxu-poses as well. Perithecia of this species were first obtained by Clinton ^^^ who grew them in abundance on artificial media from sowings of coni- diospores taken from ptire cultures. The typical Gloeosporium stage was also grown from ascospores. Perithecia were also found in pure cultures on apple agar by Spaulding and von Schrenk. They appeared in black knotted masses
RMPG44KD–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. PATHOLOGIC PLANT ANATOMY 367 grandifiora. They are formed on the side of the branches exposed to the sun and the bark cells are elongated in a radial direction, finally breaking through the epidermis as spongy masses of cells. Leaves also produce intumescences. Originating in the mesophyll cells, they. JC Fig. 144.—Cross-section of ^ part of a strongly hypertrophied bark of Ribes aureum. K, Cork; P, periderm; H, abnormally elongated bark cells. {Kuster, Pathologische Pflanzenanatomie, 1
RF2DM1MYX–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDE4RW–. The fungi which cause plant disease . Plant diseases; Fungi. 656 THE FUNGI WHICH CAUSE PLANT DISEASE Conidia in chains Conidiophores lacking 15. Exosporina, p. 656. Conidiophores present Sporodochia globose 16. Sphaeromyces. Sporodochia stellate 17. Actinomma. Epidochium Fries (p. 655) Sporodochium thick, tremelloid, subglobose or wart-form, black or pallid, erumpent; sporophores filiform, equal or apically swollen; conidia ovoid, oblong or pyriform, solitary or catenulate. Some fifteen species. E. oryzse Miy. is foimd '* on rice. Epicoccum Link (p. 655) Sporodochia globose or convex, cellul
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 129 on plum and wild cherry, causing "plum pockets." The ovary is the seat of attack. The mycelium after bud infection pervades the mesocarp which hypertrophies and alone produces a much enlarged fruit, usually with entire sacrifice of the other fruit parts. Asci are formed over the diseased surface much as in the last species. The mycelium is perennial in the bast and grows out into the new shoots and buds each spring. In- fection also reaches other shoots and trees by means of the spo Stock Photo](https://c8.alamy.com/comp/PG4GRP/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-129-on-plum-and-wild-cherry-causing-quotplum-pocketsquot-the-ovary-is-the-seat-of-attack-the-mycelium-after-bud-infection-pervades-the-mesocarp-which-hypertrophies-and-alone-produces-a-much-enlarged-fruit-usually-with-entire-sacrifice-of-the-other-fruit-parts-asci-are-formed-over-the-diseased-surface-much-as-in-the-last-species-the-mycelium-is-perennial-in-the-bast-and-grows-out-into-the-new-shoots-and-buds-each-spring-in-fection-also-reaches-other-shoots-and-trees-by-means-of-the-spo-PG4GRP.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 129 on plum and wild cherry, causing "plum pockets." The ovary is the seat of attack. The mycelium after bud infection pervades the mesocarp which hypertrophies and alone produces a much enlarged fruit, usually with entire sacrifice of the other fruit parts. Asci are formed over the diseased surface much as in the last species. The mycelium is perennial in the bast and grows out into the new shoots and buds each spring. In- fection also reaches other shoots and trees by means of the spo Stock Photo")
RMPG4GRP–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 129 on plum and wild cherry, causing "plum pockets." The ovary is the seat of attack. The mycelium after bud infection pervades the mesocarp which hypertrophies and alone produces a much enlarged fruit, usually with entire sacrifice of the other fruit parts. Asci are formed over the diseased surface much as in the last species. The mycelium is perennial in the bast and grows out into the new shoots and buds each spring. In- fection also reaches other shoots and trees by means of the spo
RF2DM3F5T–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDEFTD–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 124 MYCOLOGY cell may proliferate a new hook with penultimate, tip and stalk cells and this another, and during this process of proliferation, the nuclei derived by descent from the antheridial nuclei remain distinct from those of the ascogonium (carpogo- nium). Even the two nuclei derived from the tip and stalk cells show this dif- erence, and their descendants remain distinct with the pro- liferation of a new hook with stalk cell. The series of ac- companying figures taken from the pa
![. The fungi which cause plant disease . Plant diseases; Fungi. Fig. 47.—^P. citriophora; de- velopment of swarmsporea from sporangia. After Smith and Smith. and the contents of the antheridium are carried over to the egg by a fertilizing tube. Members of the genus are aggressively parasitic only under most favorable environmental conditions of heat an(f moisture. Some sixteen species are known. P. de baryanum Hesse, is most com- mon''"'' as the cause of "Damping Off." Zoosporangia or "conidia" globose to eUiptic, usually papillate, 20-25 n; gemmae similar in form and s Stock Photo](https://c8.alamy.com/comp/PG4H33/the-fungi-which-cause-plant-disease-plant-diseases-fungi-fig-47p-citriophora-de-velopment-of-swarmsporea-from-sporangia-after-smith-and-smith-and-the-contents-of-the-antheridium-are-carried-over-to-the-egg-by-a-fertilizing-tube-members-of-the-genus-are-aggressively-parasitic-only-under-most-favorable-environmental-conditions-of-heat-anf-moisture-some-sixteen-species-are-known-p-de-baryanum-hesse-is-most-com-monquot-as-the-cause-of-quotdamping-offquot-zoosporangia-or-quotconidiaquot-globose-to-euiptic-usually-papillate-20-25-n-gemmae-similar-in-form-and-s-PG4H33.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. Fig. 47.—^P. citriophora; de- velopment of swarmsporea from sporangia. After Smith and Smith. and the contents of the antheridium are carried over to the egg by a fertilizing tube. Members of the genus are aggressively parasitic only under most favorable environmental conditions of heat an(f moisture. Some sixteen species are known. P. de baryanum Hesse, is most com- mon''"'' as the cause of "Damping Off." Zoosporangia or "conidia" globose to eUiptic, usually papillate, 20-25 n; gemmae similar in form and s Stock Photo")
RMPG4H33–. The fungi which cause plant disease . Plant diseases; Fungi. Fig. 47.—^P. citriophora; de- velopment of swarmsporea from sporangia. After Smith and Smith. and the contents of the antheridium are carried over to the egg by a fertilizing tube. Members of the genus are aggressively parasitic only under most favorable environmental conditions of heat an(f moisture. Some sixteen species are known. P. de baryanum Hesse, is most com- mon''"'' as the cause of "Damping Off." Zoosporangia or "conidia" globose to eUiptic, usually papillate, 20-25 n; gemmae similar in form and s
RF2DM3F5H–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
![. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. I68 MYCOLOGY dark brown to paler brown apothecium, i to 4 cm. across and almost stemless. P. wruginosa is a stalked, green form whose mycelium pene- trates the wood of beeches and oaks and imparts to them a copper- green color, which makes it valuable for the manufacture of the famous "Tunbridge ware." The attempt has been made to extract the pig- ment, or to manufacture it synthetically for use as a shingle stain, but without much success. P- WillkommiipToduces on larch trees Stock Photo](https://c8.alamy.com/comp/RDEFHM/a-text-book-of-mycology-and-plant-pathology-plant-diseases-fungi-in-agriculture-plant-diseases-fungi-i68-mycology-dark-brown-to-paler-brown-apothecium-i-to-4-cm-across-and-almost-stemless-p-wruginosa-is-a-stalked-green-form-whose-mycelium-pene-trates-the-wood-of-beeches-and-oaks-and-imparts-to-them-a-copper-green-color-which-makes-it-valuable-for-the-manufacture-of-the-famous-quottunbridge-warequot-the-attempt-has-been-made-to-extract-the-pig-ment-or-to-manufacture-it-synthetically-for-use-as-a-shingle-stain-but-without-much-success-p-willkommiiptoduces-on-larch-trees-RDEFHM.jpg ". A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. I68 MYCOLOGY dark brown to paler brown apothecium, i to 4 cm. across and almost stemless. P. wruginosa is a stalked, green form whose mycelium pene- trates the wood of beeches and oaks and imparts to them a copper- green color, which makes it valuable for the manufacture of the famous "Tunbridge ware." The attempt has been made to extract the pig- ment, or to manufacture it synthetically for use as a shingle stain, but without much success. P- WillkommiipToduces on larch trees Stock Photo")
RMRDEFHM–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. I68 MYCOLOGY dark brown to paler brown apothecium, i to 4 cm. across and almost stemless. P. wruginosa is a stalked, green form whose mycelium pene- trates the wood of beeches and oaks and imparts to them a copper- green color, which makes it valuable for the manufacture of the famous "Tunbridge ware." The attempt has been made to extract the pig- ment, or to manufacture it synthetically for use as a shingle stain, but without much success. P- WillkommiipToduces on larch trees
RMPG45JY–. The fungi which cause plant disease . Plant diseases; Fungi. 586 THE FUNGI WHICH CAUSE PLANT DISEASE Hyphae inflated at both apex and joints 2. Arthrobotiys. Hyphae not inflated Conidia spirally pleurogynous 3. Haplariopsis. Conidia solitary, acrogenous or capitate Conidia capitate at apex. .. 4. Cephalothecium, p. 586. Conidia solitary at apex Fertile hyphae long 5. Trichothecium. Fertile hyphae very short 6. Didymopsis. Fertile hyphae branched Branching irregular 7. Diplosporium. Branching verticillate 8. Diplocladium. Branching dichotomous; sterig- mata subtemate 9. Cylindrocladium. Conid
RF2DM2PD8–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 95 them the pumpkin, squash, cucumber, muskmelon, watermelon, gourd, in fact according to the work of Selby '"^ any cucurbit ap- pears hable to attack. Clinton infected muskmelons with spores produced on cucumber. The fungus is especially prevalent on cucumbers raised under glass. Bremia Regel (p. 84) As in Peronospora except that just below the ends of the conidio- phore branches there are pronounced swellings from which spring radially a number of short branches each bearing an ovate, papi Stock Photo](https://c8.alamy.com/comp/RDE6RT/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-95-them-the-pumpkin-squash-cucumber-muskmelon-watermelon-gourd-in-fact-according-to-the-work-of-selby-quot-any-cucurbit-ap-pears-hable-to-attack-clinton-infected-muskmelons-with-spores-produced-on-cucumber-the-fungus-is-especially-prevalent-on-cucumbers-raised-under-glass-bremia-regel-p-84-as-in-peronospora-except-that-just-below-the-ends-of-the-conidio-phore-branches-there-are-pronounced-swellings-from-which-spring-radially-a-number-of-short-branches-each-bearing-an-ovate-papi-RDE6RT.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 95 them the pumpkin, squash, cucumber, muskmelon, watermelon, gourd, in fact according to the work of Selby '"^ any cucurbit ap- pears hable to attack. Clinton infected muskmelons with spores produced on cucumber. The fungus is especially prevalent on cucumbers raised under glass. Bremia Regel (p. 84) As in Peronospora except that just below the ends of the conidio- phore branches there are pronounced swellings from which spring radially a number of short branches each bearing an ovate, papi Stock Photo")
RMRDE6RT–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 95 them the pumpkin, squash, cucumber, muskmelon, watermelon, gourd, in fact according to the work of Selby '"^ any cucurbit ap- pears hable to attack. Clinton infected muskmelons with spores produced on cucumber. The fungus is especially prevalent on cucumbers raised under glass. Bremia Regel (p. 84) As in Peronospora except that just below the ends of the conidio- phore branches there are pronounced swellings from which spring radially a number of short branches each bearing an ovate, papi
RMPG44TW–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 238 MYCOLOGY SO that the food value of this form is less than had formerly been sup- posed. The fatty substances soluble in ether are present to the amount of 4 to 8 per cent. The carbohydrates (cellulose, glycogen, trehalose, mannite, glucose, etc.) make up the largest part of the dry matter of the mushroom. Starch usually present in higher plants is absent in these fungi. The ash varies greatly, varying from i.o8 to 15 per cent. with potassium as the most , abundant element. Sulphuric
RF2DM1KB2–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDE6PT–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 105 Sporangia globular; columella not constricted 8. Circinella. Sporangia pear-shaped; colu- mella constricted 9. Piiella. Mycelium metallic; suspensors spiny 10. Phycomyces. Sporangia of two kinds, the primary many-spored; the secondary few- spored Subfamily III. Thamnidiese. PUobolus crystallinus (Wigg.) Tode, a form with beautiful crystalline sporangia on yellowish, evanescent sporangiophores has been frequently noted as injuring or smudging chrysanthemum, rose and other leaves 121-122 y^y j^
RMPG44PR–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. GENERAL CONSIDERATION OF PLANT DISEASES 275 matic and meteorologic conditions may be influential, when these dis- turb the normal life of the plant. Light, heat, cold, rain, dew, hail, frost, wind and lightning play an important role. The gaseous emana- tions from gas pipes, smelter works, smokestacks, including soot, dust from cement works, acids, poisons, and dye stuffs, which pollute streams, all are determining causes of disease. Traumatism or mechanic injury may be of various sorts
RF2DM19N1–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDDAP5–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 301 The chlamydospores may be simple or compound, fertile or in part sterile and are variously shaped and marked as described in the genera below. The chlamydospores may germinate at once or after a more or less protracted rest interval. In germination in water or nutrient solution (manure water, etc.) a short tube is protruded, the pro- mycelium, this differing in character in the two families, Figs. 217, 231. From the promycelium of most species there develop conidia, (often called sporidia) 1-
![. The fungi which cause plant disease . Plant diseases; Fungi. BASIDIOMYCETES (p. 64)ivfis." if; So; ss.'U; es; eo' " This class is distinguished from all others by its basidium, which typically is a sporophore bearing on its distal end short stalks, the sterigmata, usually four, on which are borne spores, basidiospores, one on the tip of each sterigma. Fig. 215. In the great ma- jority of genera the basidia are typical and are clearly recognizable as such. In many of the lower basidiomycetes the basidia deviate somewhat from the typical form. Thus in the Hemibasidii, the smut fimgi, Stock Photo](https://c8.alamy.com/comp/PG4689/the-fungi-which-cause-plant-disease-plant-diseases-fungi-basidiomycetes-p-64ivfisquot-if-so-ssu-es-eo-quot-this-class-is-distinguished-from-all-others-by-its-basidium-which-typically-is-a-sporophore-bearing-on-its-distal-end-short-stalks-the-sterigmata-usually-four-on-which-are-borne-spores-basidiospores-one-on-the-tip-of-each-sterigma-fig-215-in-the-great-ma-jority-of-genera-the-basidia-are-typical-and-are-clearly-recognizable-as-such-in-many-of-the-lower-basidiomycetes-the-basidia-deviate-somewhat-from-the-typical-form-thus-in-the-hemibasidii-the-smut-fimgi-PG4689.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. BASIDIOMYCETES (p. 64)ivfis." if; So; ss.'U; es; eo' " This class is distinguished from all others by its basidium, which typically is a sporophore bearing on its distal end short stalks, the sterigmata, usually four, on which are borne spores, basidiospores, one on the tip of each sterigma. Fig. 215. In the great ma- jority of genera the basidia are typical and are clearly recognizable as such. In many of the lower basidiomycetes the basidia deviate somewhat from the typical form. Thus in the Hemibasidii, the smut fimgi, Stock Photo")
RMPG4689–. The fungi which cause plant disease . Plant diseases; Fungi. BASIDIOMYCETES (p. 64)ivfis." if; So; ss.'U; es; eo' " This class is distinguished from all others by its basidium, which typically is a sporophore bearing on its distal end short stalks, the sterigmata, usually four, on which are borne spores, basidiospores, one on the tip of each sterigma. Fig. 215. In the great ma- jority of genera the basidia are typical and are clearly recognizable as such. In many of the lower basidiomycetes the basidia deviate somewhat from the typical form. Thus in the Hemibasidii, the smut fimgi,
RF2DM3FPC–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDE1WD–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. PATHOLOGIC PLANT ANATOMY 373 149). Four nuclei in one cell is the most we have seen, but it is prob- able that larger numbers occur. It would seem from the studies of Erwin F. Smith, which, however, are incomplete, that most of the cell divisions in crown gall are by mitosis. Frequently, however, there have been found nuclei variously lobed and in process of amitotic division, and this is probably the way in which several nuclei are formed in one cell (Fig. 149).. Fig. 149.—Nuclear divi
RMPG4E7R–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 22 MYCOLOGY mondy to demonstrate small particles whose size is only many millior times that of a millimeter. The accompanying figure (Fig. 4) adopted from Fuhrmann' represents the relative size of the spheric bacteria and the rod-shaped organisms, while the breadth of the largest known bacterial cell, that of Beggiatoa mirabilis, which approaches that of a human hair in thickness, is represented in the larger area where the width of the cell is twice its length. I 3' 3 o©. II ^676 >
RF2DM2MAE–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
![. The fungi which cause plant disease . Plant diseases; Fungi. BASIDIOMYCETES (p. 64)ivfis." if; So; ss.'U; es; eo' " This class is distinguished from all others by its basidium, which typically is a sporophore bearing on its distal end short stalks, the sterigmata, usually four, on which are borne spores, basidiospores, one on the tip of each sterigma. Fig. 215. In the great ma- jority of genera the basidia are typical and are clearly recognizable as such. In many of the lower basidiomycetes the basidia deviate somewhat from the typical form. Thus in the Hemibasidii, the smut fimgi, Stock Photo](https://c8.alamy.com/comp/RDDAPP/the-fungi-which-cause-plant-disease-plant-diseases-fungi-basidiomycetes-p-64ivfisquot-if-so-ssu-es-eo-quot-this-class-is-distinguished-from-all-others-by-its-basidium-which-typically-is-a-sporophore-bearing-on-its-distal-end-short-stalks-the-sterigmata-usually-four-on-which-are-borne-spores-basidiospores-one-on-the-tip-of-each-sterigma-fig-215-in-the-great-ma-jority-of-genera-the-basidia-are-typical-and-are-clearly-recognizable-as-such-in-many-of-the-lower-basidiomycetes-the-basidia-deviate-somewhat-from-the-typical-form-thus-in-the-hemibasidii-the-smut-fimgi-RDDAPP.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. BASIDIOMYCETES (p. 64)ivfis." if; So; ss.'U; es; eo' " This class is distinguished from all others by its basidium, which typically is a sporophore bearing on its distal end short stalks, the sterigmata, usually four, on which are borne spores, basidiospores, one on the tip of each sterigma. Fig. 215. In the great ma- jority of genera the basidia are typical and are clearly recognizable as such. In many of the lower basidiomycetes the basidia deviate somewhat from the typical form. Thus in the Hemibasidii, the smut fimgi, Stock Photo")
RMRDDAPP–. The fungi which cause plant disease . Plant diseases; Fungi. BASIDIOMYCETES (p. 64)ivfis." if; So; ss.'U; es; eo' " This class is distinguished from all others by its basidium, which typically is a sporophore bearing on its distal end short stalks, the sterigmata, usually four, on which are borne spores, basidiospores, one on the tip of each sterigma. Fig. 215. In the great ma- jority of genera the basidia are typical and are clearly recognizable as such. In many of the lower basidiomycetes the basidia deviate somewhat from the typical form. Thus in the Hemibasidii, the smut fimgi,
RMPG4587–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 94 MYCOLOGY thallic species are all homogamic, that is, there is no difference in the size of the two gametes which conjugate. This group includes such. Fig. 28.—Zygospore formation in Sporodinia grandis from material growing on toad- stool. (Slide prepared by H. H. York, Cold Spring Harbor, July 29, 1915.). 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
RF2DM1979–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDE1XG–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. PATHOLOGIC PLANT ANATOMY 367 grandifiora. They are formed on the side of the branches exposed to the sun and the bark cells are elongated in a radial direction, finally breaking through the epidermis as spongy masses of cells. Leaves also produce intumescences. Originating in the mesophyll cells, they. JC Fig. 144.—Cross-section of ^ part of a strongly hypertrophied bark of Ribes aureum. K, Cork; P, periderm; H, abnormally elongated bark cells. {Kuster, Pathologische Pflanzenanatomie, 1
RMPG44K7–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. PATHOLOGIC PLANT ANATOMY 369 cutting under water, the other extending into moist air. The bark cells were enlarged greatly, producing ball-like or weakly lobed forms. Only single cells in the bud hypertrophied and they grew out into large colorless vesicles. Miehe has found Tradescantia virginica a suitable object to produce callous hypertrophies experimentally. The destruc- tion of cells, or cell groups, of the epidermis causes the formation of empty places which are filled by the neig
RF2DM29NP–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDDANR–. The fungi which cause plant disease . Plant diseases; Fungi. 304 THE FUNGI WHICH CAUSE PLANT DISEASE and was called U. avense in 1591. The species of Ustilago on oats, wheat and barley were considered identical until Jensen' showed that they are not intercommunicable. Wolff* showed that seedlings can be infected through the first sheath leaf. Brefeld' studying infection more closely found it to be accompKshed by germ tubes from sporidia and that plants are free from infection after the growing leaves have pushed one centimeter through the sheath leaf. The mycelitma, after infec- tion, grows
RMPG45T5–. The fungi which cause plant disease . Plant diseases; Fungi. 420 THE FUNGI WHICH CAUSE PLANT DISEASE in thickness, usually found in imbricated masses projecting from the trunks of living trees. Pileus subcircular and umbilicate when young, soon becoming flabelliform and explanate; surface ochra- ceous to fulvous, covered with broad, appressed, darker scales. Fig. 301.—Polyporus squamosus. After Clements. which are very close together in young specimens; margin in- volute, thin, entire; context fleshy-tough, juicy, milk-white; very thick, odor strong; tubes decurrent, white or pale yellowish,
RF2DM18AX–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDE2DY–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 194 MYCOLOGY. Fig. 68.—Portion of a. teliosorus of cedar apple in February showing mycelia stroma and the binucleate condition of the cells of young teliospores. (After Reed. H S , and Crabill, C. H., Techn. Bull. 9, Va. Agric. Exper. Slat., May, 191S-) basidiospores teleutospore uredospore.. 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 resem
RMPG44W3–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. MUSHROOMS AND TOADSTOOLS 233 the gills. As the pileus expands the membrane becomes detached first at the margin of the cap, and it falls down around the stipe, as a frill, plaited in delicate folds, corresponding to the former lines of contact with the lamellas and is now known as the annulus superus, frill, or armilla. Special milk tubes are found in such forms as species of Lac- tarius for when these toadstools are wounded a milky fluid oozes out in drops. Each basidium usually bears
RF2DM3H84–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDEFYY–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 94 MYCOLOGY thallic species are all homogamic, that is, there is no difference in the size of the two gametes which conjugate. This group includes such. Fig. 28.—Zygospore formation in Sporodinia grandis from material growing on toad- stool. (Slide prepared by H. H. York, Cold Spring Harbor, July 29, 1915.). 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
RMPG457E–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. I02 MYCOLOGY cate sporangial wall, which soon disappears leaving the spores on a hemispheric columella. These spores are ii to 70M broad. The 300/j broad zygospores are produced from similar branches of a dichotomously branched zygosphore. The mycelium of the species of Thamnidium enters the nutritive substratum. The large sporangia are terminal while the smaller secondary sporangia are borne on lateral branches in whorls below the terminal sporangium. This is typically seen in Th.. Fig
RF2DM1MDE–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDE1YN–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. SYMPTOMS OF DISEASE (SYMPTOMATOLOGY) 347 • trees of great age are formed by the action of the climate of high mountains, or by growth in porous sand on exposed sea dunes. Atro- phy, or the non-formation of parts, or organs, is a phase of dwarfing. It is seen in the dwindling of organs in size, as the result of various causes, such as the attack of fungi. The carpels of Anemone are atrophied in plants infested by JScidium and the whole flower is sup- pressed when the cherry is attacked b
RMPG45B7–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 44 MYCOLOGY from a green alga like Vaucheria. With our present knowledge, it is impossible to name any one existing alga as the progenitor of a definite fungous form, but we are safe in assuming in a general way that certain phyla of fungi have been derived from certain phyla of algae, by the loss of chlorophyll and in the loss of an independent existence. Another view, which is open to argument, is that certain of the prototrophic. jJJuIl^ Fig. 13.—Development of Mucor mucedo. a, b, c,
RF2DM2P0K–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
RMRDE1TC–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 386 GENERAL PLANT PATHOLOGY. Fig 153.—Tubercles of velvet bean produced by inoculation. (After Moore, Geo. T., Yearbook, Depl. Agric, 1902, pi. xxxvii.). 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.. Harshberger, John W. (John William), 1869-1929. Philadelphia : P. Blakiston's Son & Co
RMPG4590–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. ECOLOGY or FUNGI 75 are active in rotting the brush, one set entering the limbs and branches above the ground and the other gaining access to the brush actually in contact with the soil. Brush is rotted at the top when piled with one group of fungi and at the bottom by another group, while the middle of the pile, not in contact with the soil and yet protected from the sunlight, apparently will not rot to any extent until the. Pig. 23.—Fairy ring formed by Marasmius oreades, an edible to
RF2DM3E4G–Branches leaves and pear fruits affected by orange rusty spots and horn-shaped growths with spores of the fungus Gymnosporangium sabinae in a human home garden. Pear leaves with pear rust infestation.
![. The fungi which cause plant disease . Plant diseases; Fungi. 324 THE FUNGI WHICH CAUSE PLANT DISEASE verrucosely sculptured, borne singly, or sometimes in chains, (5) teliospores, smooth or variously sculptured but not echinulate, borne singly or in chains. In every species the mycelium even- tually gives rise to teliospores, which produce in germination four basidia, either remaining within the spore-cell or borne in the air on a short promycelium, each basidium supporting a single, stalked or sessile basidiospore. The order of some two thousand species, constituting the "rust" fu Stock Photo](https://c8.alamy.com/comp/RDE669/the-fungi-which-cause-plant-disease-plant-diseases-fungi-324-the-fungi-which-cause-plant-disease-verrucosely-sculptured-borne-singly-or-sometimes-in-chains-5-teliospores-smooth-or-variously-sculptured-but-not-echinulate-borne-singly-or-in-chains-in-every-species-the-mycelium-even-tually-gives-rise-to-teliospores-which-produce-in-germination-four-basidia-either-remaining-within-the-spore-cell-or-borne-in-the-air-on-a-short-promycelium-each-basidium-supporting-a-single-stalked-or-sessile-basidiospore-the-order-of-some-two-thousand-species-constituting-the-quotrustquot-fu-RDE669.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. 324 THE FUNGI WHICH CAUSE PLANT DISEASE verrucosely sculptured, borne singly, or sometimes in chains, (5) teliospores, smooth or variously sculptured but not echinulate, borne singly or in chains. In every species the mycelium even- tually gives rise to teliospores, which produce in germination four basidia, either remaining within the spore-cell or borne in the air on a short promycelium, each basidium supporting a single, stalked or sessile basidiospore. The order of some two thousand species, constituting the "rust" fu Stock Photo")
RMRDE669–. The fungi which cause plant disease . Plant diseases; Fungi. 324 THE FUNGI WHICH CAUSE PLANT DISEASE verrucosely sculptured, borne singly, or sometimes in chains, (5) teliospores, smooth or variously sculptured but not echinulate, borne singly or in chains. In every species the mycelium even- tually gives rise to teliospores, which produce in germination four basidia, either remaining within the spore-cell or borne in the air on a short promycelium, each basidium supporting a single, stalked or sessile basidiospore. The order of some two thousand species, constituting the "rust" fu
RMPG4HBR–. The fungi which cause plant disease . Plant diseases; Fungi. DIVISION II BACTERIA, SCHIZOMYCETES 18. 31-39 (p..3) Bacteria are extremely minute, unicellular organisms, which in outline present three primary forms each of great simplicity, namely the spheres (cocci), ^ the straight rods (bacteria), the curved rods (splrilli). In addition to these forms which comprise the vast majority of known species of bacteria there are also bacteria consisting of fila^ mentous bodies, either sim- ple or branched, attached or free. Fio. 4.—The three type forms of bacteria; a, spheres; b, rods; c, spirals.
![. The fungi which cause plant disease . Plant diseases; Fungi. 16 THE FUNGI WHICH CAUSE PLANT DISEASE to the peculiar and characteristic form knovra as "Nail Head" or "Drum Stick" bacteria. In nearly all species of the Eubacteria the spores are solitary. There are three modes of spore germination. The most com- mon, polar germination, consists in a rupture of one pole of the spore and the development of a normal vegetative cell through the opening. The second mode, equatorial, Fig. 9, consists in a rupture in the side instead of the end of the spore. The third mode,. FiQ. 9 Stock Photo](https://c8.alamy.com/comp/RDE7E8/the-fungi-which-cause-plant-disease-plant-diseases-fungi-16-the-fungi-which-cause-plant-disease-to-the-peculiar-and-characteristic-form-knovra-as-quotnail-headquot-or-quotdrum-stickquot-bacteria-in-nearly-all-species-of-the-eubacteria-the-spores-are-solitary-there-are-three-modes-of-spore-germination-the-most-com-mon-polar-germination-consists-in-a-rupture-of-one-pole-of-the-spore-and-the-development-of-a-normal-vegetative-cell-through-the-opening-the-second-mode-equatorial-fig-9-consists-in-a-rupture-in-the-side-instead-of-the-end-of-the-spore-the-third-mode-fiq-9-RDE7E8.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. 16 THE FUNGI WHICH CAUSE PLANT DISEASE to the peculiar and characteristic form knovra as "Nail Head" or "Drum Stick" bacteria. In nearly all species of the Eubacteria the spores are solitary. There are three modes of spore germination. The most com- mon, polar germination, consists in a rupture of one pole of the spore and the development of a normal vegetative cell through the opening. The second mode, equatorial, Fig. 9, consists in a rupture in the side instead of the end of the spore. The third mode,. FiQ. 9 Stock Photo")
RMRDE7E8–. The fungi which cause plant disease . Plant diseases; Fungi. 16 THE FUNGI WHICH CAUSE PLANT DISEASE to the peculiar and characteristic form knovra as "Nail Head" or "Drum Stick" bacteria. In nearly all species of the Eubacteria the spores are solitary. There are three modes of spore germination. The most com- mon, polar germination, consists in a rupture of one pole of the spore and the development of a normal vegetative cell through the opening. The second mode, equatorial, Fig. 9, consists in a rupture in the side instead of the end of the spore. The third mode,. FiQ. 9
RMPG461J–. The fungi which cause plant disease . Plant diseases; Fungi. FiQ. 259.—Triphragmium ulmaris, germi- nating teliospore. After Tulasne. Fig. 260.—Phragmi- dium bulbosum, teliospore germi- nating. After Tu- lasne. are in pulverulent sori, surrounded by clavate or capitate, hyaline paraphsrses. II. Urediniospores single. III. Teliospores separate, pedicellate, consisting of from three to ten superimposed cells, the uppermost of which has a single apical germ pore, the others about four each, placed laterally. The aecial stage is a Caeoma but with a border of incurved pa-. Please note that these
RMRDE26H–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. MUSHROOMS AND TOADSTOOLS 233 the gills. As the pileus expands the membrane becomes detached first at the margin of the cap, and it falls down around the stipe, as a frill, plaited in delicate folds, corresponding to the former lines of contact with the lamellas and is now known as the annulus superus, frill, or armilla. Special milk tubes are found in such forms as species of Lac- tarius for when these toadstools are wounded a milky fluid oozes out in drops. Each basidium usually bears
RMPG451W–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. RUST FUNGI 193 the teliospore reaches maturity, the nuclei fuse, and the uninucleate condition then continues again until the formation of the aecia. In the micro- and lepto-iorms, which have no aecium or uredinium, we find that the association takes place at points in the ordinary mycelium, but. Fig. 67.—Portion of a section of cedar apple about 5 mm. below a teliosorus. Note (i) Binucleate intercellular inyceliiim; (2) the haustoria in various stages of development; (3) the doubling o
RMRDE5NK–. The fungi which cause plant disease . Plant diseases; Fungi. 420 THE FUNGI WHICH CAUSE PLANT DISEASE in thickness, usually found in imbricated masses projecting from the trunks of living trees. Pileus subcircular and umbilicate when young, soon becoming flabelliform and explanate; surface ochra- ceous to fulvous, covered with broad, appressed, darker scales. Fig. 301.—Polyporus squamosus. After Clements. which are very close together in young specimens; margin in- volute, thin, entire; context fleshy-tough, juicy, milk-white; very thick, odor strong; tubes decurrent, white or pale yellowish,
![. The fungi which cause plant disease . Plant diseases; Fungi. 16 THE FUNGI WHICH CAUSE PLANT DISEASE to the peculiar and characteristic form knovra as "Nail Head" or "Drum Stick" bacteria. In nearly all species of the Eubacteria the spores are solitary. There are three modes of spore germination. The most com- mon, polar germination, consists in a rupture of one pole of the spore and the development of a normal vegetative cell through the opening. The second mode, equatorial, Fig. 9, consists in a rupture in the side instead of the end of the spore. The third mode,. FiQ. 9 Stock Photo](https://c8.alamy.com/comp/PG4HBB/the-fungi-which-cause-plant-disease-plant-diseases-fungi-16-the-fungi-which-cause-plant-disease-to-the-peculiar-and-characteristic-form-knovra-as-quotnail-headquot-or-quotdrum-stickquot-bacteria-in-nearly-all-species-of-the-eubacteria-the-spores-are-solitary-there-are-three-modes-of-spore-germination-the-most-com-mon-polar-germination-consists-in-a-rupture-of-one-pole-of-the-spore-and-the-development-of-a-normal-vegetative-cell-through-the-opening-the-second-mode-equatorial-fig-9-consists-in-a-rupture-in-the-side-instead-of-the-end-of-the-spore-the-third-mode-fiq-9-PG4HBB.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. 16 THE FUNGI WHICH CAUSE PLANT DISEASE to the peculiar and characteristic form knovra as "Nail Head" or "Drum Stick" bacteria. In nearly all species of the Eubacteria the spores are solitary. There are three modes of spore germination. The most com- mon, polar germination, consists in a rupture of one pole of the spore and the development of a normal vegetative cell through the opening. The second mode, equatorial, Fig. 9, consists in a rupture in the side instead of the end of the spore. The third mode,. FiQ. 9 Stock Photo")
RMPG4HBB–. The fungi which cause plant disease . Plant diseases; Fungi. 16 THE FUNGI WHICH CAUSE PLANT DISEASE to the peculiar and characteristic form knovra as "Nail Head" or "Drum Stick" bacteria. In nearly all species of the Eubacteria the spores are solitary. There are three modes of spore germination. The most com- mon, polar germination, consists in a rupture of one pole of the spore and the development of a normal vegetative cell through the opening. The second mode, equatorial, Fig. 9, consists in a rupture in the side instead of the end of the spore. The third mode,. FiQ. 9
RMRDE71Y–. The fungi which cause plant disease . Plant diseases; Fungi. 76 THE FUNGI WHICH CAUSE PLANT DISEASE Pythium Pringsheim '^ (p. 75) The mycelium is found in abundance in and about the infected tissue as fine, branched continuous threads. These, in the terrestial. Fig. 45.—Cucumber seedlings. Pots 5, 6, and 8 inoculated with Pythium. Pot 7, Control. After Atkinson. species, bear conidia on branches which are of the same character as the myceHum itself. The conidia germinate either by a rupture of the wall or by the formation of a beak-like process through which the protoplasm is extruded, after
RMPG44R5–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. FUNGI IMPERFECTI (dEUTEROMYCETES) 265. Fig. 107.—Anthracnose cankers on bean pods (Colletolrichum Lindemuthianum). {After Whetzel, H. H., Ball. 255, Cornell Agric. Exper. Stat.). 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.. Harshberger, John W. (John William), 1869-1929. Philadelphia : P. Blakiston's Son & Co
RMRDE1Y2–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. SYMPTOMS OF DISEASE (SYMPTOMATOLOGY) 351. Fig. 140.—Branch-knot or witches'-broom of the Hackberry {Cellis occidentalis). {After Kellerman, W. A., Mycological Bulletin, Nos. 61-72, July, 1906.. 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.. Harshberger, John W. (John William), 1869-1929. Philadelphia : P. Blakiston'
RMPG453N–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. i66 MYCOLOGY Family 4. Ascobolace^.—The apothecia of the fungi of this family are unstalked. They are superficial and grow up on manure. The peridium is mostly thin, or wanting, and the hypothecium, which is well developed, consists of rounded parenchyma-like cells. In Ascobolus, the ascospores are discharged from the asci by a squirting. Fig. 58.—A, B, Lachnea sculellala. A, Habit; B, ascus with paraphysis; C, D, Lachnea hemisphierica; C, habit; D, ascus with paraphysiS; E, Sarcospktsr
RMRDE7EY–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 15. «ES3iP Fig. 7.—Spores of bacteria showing their position within the cells. After Frost & McCampbeU. or scattered over the whole surface, diffuse or peritrichiate. They are the organs of locomotion. Within the wall is the pro- toplast consisting of a peripheral layer, inner strands, imbedded granules and vacuoles bearing cell sap. The existence of a nucleus comparable to that in higher plants is a much controverted point. Spores: Typically a bacterial spore consists of a highly refractive,
RMPG4DR5–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. Fig. 207.—Screw micrometer eyepiece (Filar micrometer). adjusted at right angles to the first and a fine wire, parallel to the reference wire, which can be moved across the field by the action of the micrometer screw. The trap head is divided into 100 parts, which pass successively a fixed index as the head is turned. A fixed comb with the intervals between its teeth corresponding to one complete revolution of the screw head is found in the field. As in the previous method, the value of
RMRDEXYX–. The fungi which cause plant disease . Plant diseases; Fungi. FiQ. 259.—Triphragmium ulmaris, germi- nating teliospore. After Tulasne. Fig. 260.—Phragmi- dium bulbosum, teliospore germi- nating. After Tu- lasne. are in pulverulent sori, surrounded by clavate or capitate, hyaline paraphsrses. II. Urediniospores single. III. Teliospores separate, pedicellate, consisting of from three to ten superimposed cells, the uppermost of which has a single apical germ pore, the others about four each, placed laterally. The aecial stage is a Caeoma but with a border of incurved pa-. Please note that these
RMPG4HAR–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 23 agree in the following particulars: They are yellow rod-shaped organisms of medium size, straight or slightly crooked with rounded ends. The segments multiply by fission, after elongation. They are generally less than 1 /i in diameter. The segments occur singly, in pairs or in fours joined end to end, or in clumpy masses of variable size (zooglceae), more rarely they are united into long chains or into filaments in which no septa are visible. Endospores have not been observed. The segments are
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 129 on plum and wild cherry, causing "plum pockets." The ovary is the seat of attack. The mycelium after bud infection pervades the mesocarp which hypertrophies and alone produces a much enlarged fruit, usually with entire sacrifice of the other fruit parts. Asci are formed over the diseased surface much as in the last species. The mycelium is perennial in the bast and grows out into the new shoots and buds each spring. In- fection also reaches other shoots and trees by means of the spo Stock Photo](https://c8.alamy.com/comp/RDE6K2/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-129-on-plum-and-wild-cherry-causing-quotplum-pocketsquot-the-ovary-is-the-seat-of-attack-the-mycelium-after-bud-infection-pervades-the-mesocarp-which-hypertrophies-and-alone-produces-a-much-enlarged-fruit-usually-with-entire-sacrifice-of-the-other-fruit-parts-asci-are-formed-over-the-diseased-surface-much-as-in-the-last-species-the-mycelium-is-perennial-in-the-bast-and-grows-out-into-the-new-shoots-and-buds-each-spring-in-fection-also-reaches-other-shoots-and-trees-by-means-of-the-spo-RDE6K2.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 129 on plum and wild cherry, causing "plum pockets." The ovary is the seat of attack. The mycelium after bud infection pervades the mesocarp which hypertrophies and alone produces a much enlarged fruit, usually with entire sacrifice of the other fruit parts. Asci are formed over the diseased surface much as in the last species. The mycelium is perennial in the bast and grows out into the new shoots and buds each spring. In- fection also reaches other shoots and trees by means of the spo Stock Photo")
RMRDE6K2–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 129 on plum and wild cherry, causing "plum pockets." The ovary is the seat of attack. The mycelium after bud infection pervades the mesocarp which hypertrophies and alone produces a much enlarged fruit, usually with entire sacrifice of the other fruit parts. Asci are formed over the diseased surface much as in the last species. The mycelium is perennial in the bast and grows out into the new shoots and buds each spring. In- fection also reaches other shoots and trees by means of the spo
RMPG44NT–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. PLANTS AS DISEASK PRODUCERS 303 Loranthus, Phoradendron and Viscum include the well-known mistletoes. The American mistletoe, Phoradendron flavescens (Fig. 119), extends from southern New Jersey, Maryland, Ohio, Indiana and Missouri to Texas. It is a slow-growing green parasite, which on account of its chlorophyll is not entirely dependent upon its host for its carbohydrates (Figs. 120 and 121). It is essentially a water parasite, and consequently, its parasitic roots or sinkers grow in
RMRDE28W–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. RUST FUNGI 213 spores on germination produce a four-celled basidium (Fig. 78), or promycelium, from which are cut off basidiospores, which infect the. partially developed apple leaves, or apple fruits (Fig. 79). The dis- ease apparently does little damage to the red cedar trees, but the. 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 t
RMPG454N–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. SAC FUNGI CONTINUED 149 for producing oxalic acid. Il has' stiff slender conidiophores several millimeters in height. The terminal part can be studied only after the bleaching or removal of the dark masses of conidiophores.. 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.. Harshberger, John W. (John William), 1869-192
RMRDE21A–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. PLANTS AS DISEASE PRODUCERS 309 two branches together. Squirrels in search of food bite off the twigs of trees. Deer and moose browse upon the tender branches and bark of various trees, the moose especially, upon Acer pennsyhanicum and Sorbus americana. Grizzly bears rub their backs against the bark of trees and sometimes in this way decorticate them. Rodents peel off the outer protective layers of roots as food, or as material with which to line their burrows. The mycelia of Rhizoctoni
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE. Mjrxogastrales (p. 5) This order comprises some forty-seveij genera and four iiun- dred species of great variety and beauty. The plasmodium, which varies from a millimeter or less to several decimeters in diameter, pro- duces either flat encrusted masses of ""^ '''^"^ spores, aethalia, or develops spores in ^^J^ sporangia which show some superficial f^X-^'''' ^â '' resemblance to very small puffballs, Fig. 2. The interior of the sporan- ---iitJ gium is often permeated by a threa Stock Photo](https://c8.alamy.com/comp/PG4HCF/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-mjrxogastrales-p-5-this-order-comprises-some-forty-seveij-genera-and-four-iiun-dred-species-of-great-variety-and-beauty-the-plasmodium-which-varies-from-a-millimeter-or-less-to-several-decimeters-in-diameter-pro-duces-either-flat-encrusted-masses-of-quotquot-quot-spores-aethalia-or-develops-spores-in-j-sporangia-which-show-some-superficial-fx-resemblance-to-very-small-puffballs-fig-2-the-interior-of-the-sporan-iitj-gium-is-often-permeated-by-a-threa-PG4HCF.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE. Mjrxogastrales (p. 5) This order comprises some forty-seveij genera and four iiun- dred species of great variety and beauty. The plasmodium, which varies from a millimeter or less to several decimeters in diameter, pro- duces either flat encrusted masses of ""^ '''^"^ spores, aethalia, or develops spores in ^^J^ sporangia which show some superficial f^X-^'''' ^â '' resemblance to very small puffballs, Fig. 2. The interior of the sporan- ---iitJ gium is often permeated by a threa Stock Photo")
RMPG4HCF–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE. Mjrxogastrales (p. 5) This order comprises some forty-seveij genera and four iiun- dred species of great variety and beauty. The plasmodium, which varies from a millimeter or less to several decimeters in diameter, pro- duces either flat encrusted masses of ""^ '''^"^ spores, aethalia, or develops spores in ^^J^ sporangia which show some superficial f^X-^'''' ^â '' resemblance to very small puffballs, Fig. 2. The interior of the sporan- ---iitJ gium is often permeated by a threa
RMRE1J0A–. A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. Spore-Ctilture. III place the spores in water, and they will germinate at once— for example, U. segetum, longissima, etc.; but some require a longer period of immersion, e.g. T. tritici, which will not germinate till after being several days in water. The germination of the Tilletia spores can also be conducted in a hanging-drop culture in the following manner
RMPG45M9–. The fungi which cause plant disease . Plant diseases; Fungi. 562 THE FUNGI WHICH CAUSE PLANT DISEASE Key to Genera of Melflnconiaceae-Scolecospora Conidia aUantoid 1. Naemospora. Conidia bacillar to filiform Conidia fasciculate at the apex of the conidiophores 2. Tiichodytes. Conidia solitary Masses white or pale, f oliicolous; conidia filiform 3. Cylindrosporium,p. 562. Masses gray or dark, usually rami cole; conidia falcate 4. Cryptosporium, p. 564. Masses bright-colored, saprophytic; conidia falcate 5. Libertella, p. 564. Cylindrosporium Unger Acervuli subepidermal, white or pallid, disci
RMRDE73A–. The fungi which cause plant disease . Plant diseases; Fungi. 68 THE FUNGI WHICH CAUSE PLANT DISEASE Key to Genera op-Olpidiaceae Vegetative body amoeboid Vegetative body of definite form Sporangia free in the cells of the host Sporangial membrane very delicate, evanescent Sporangial membrane firm, swarm spores escaping by a definite open- ing Sporangium globular or ellipsoid Sporangium with only one or two openings Swarm spores uniciliate Vegetative cells globose or sub- globose Vegetative cells stellate Swarm spores biciliate Sporangium with several openings Sporangium elongate Sporangial m
RMPG451M–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 194 MYCOLOGY. Fig. 68.—Portion of a. teliosorus of cedar apple in February showing mycelia stroma and the binucleate condition of the cells of young teliospores. (After Reed. H S , and Crabill, C. H., Techn. Bull. 9, Va. Agric. Exper. Slat., May, 191S-) basidiospores teleutospore uredospore.. 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 resem
RMRDEG9B–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 22 MYCOLOGY mondy to demonstrate small particles whose size is only many millior times that of a millimeter. The accompanying figure (Fig. 4) adopted from Fuhrmann' represents the relative size of the spheric bacteria and the rod-shaped organisms, while the breadth of the largest known bacterial cell, that of Beggiatoa mirabilis, which approaches that of a human hair in thickness, is represented in the larger area where the width of the cell is twice its length. I 3' 3 o©. II ^676 >
RMPG4DKA–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 646 LABOKATURY EX liRCISES Clicslnul Blight {Endolhia (Diaporlhc) parasitica (Murrill) Anderson).âInocula- tion into the chestnut tree should be made into scarifications of the bark made by means of a sterile scalpel. The bark should be washed before inoculation by means of a weak formalin solution followed by distilled water. The summer spores can be rubbed into place by means of a sterile platinum needle. Appel's Potato Rot (Bacillus phyto- phthorus, Appel.).âThis organism read- ily g
![. The fungi which cause plant disease . Plant diseases; Fungi. 312 THE FUNGI WHICH CAUSE PLANT DISEASE. and the mycelium there develops richly under the epidermis. The outer cells remain sterile and constitute the membrane; the inner gelatinize and develop into spores. S. reiliana (Kiihn) Cl.^* "'^ ^^ '*" ^^ Sori very prominent forming irregular masses including more or less of the entire panicle, usually 5-15 cm. in length; often at first pro- tected by the leaf-sheath. A whitish false membrane encloses the black- brown spore-mass and the ray-like re- mains of the j)eduncles or colu Stock Photo](https://c8.alamy.com/comp/RDDAM4/the-fungi-which-cause-plant-disease-plant-diseases-fungi-312-the-fungi-which-cause-plant-disease-and-the-mycelium-there-develops-richly-under-the-epidermis-the-outer-cells-remain-sterile-and-constitute-the-membrane-the-inner-gelatinize-and-develop-into-spores-s-reiliana-kiihn-cl-quot-quot-sori-very-prominent-forming-irregular-masses-including-more-or-less-of-the-entire-panicle-usually-5-15-cm-in-length-often-at-first-pro-tected-by-the-leaf-sheath-a-whitish-false-membrane-encloses-the-black-brown-spore-mass-and-the-ray-like-re-mains-of-the-jeduncles-or-colu-RDDAM4.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. 312 THE FUNGI WHICH CAUSE PLANT DISEASE. and the mycelium there develops richly under the epidermis. The outer cells remain sterile and constitute the membrane; the inner gelatinize and develop into spores. S. reiliana (Kiihn) Cl.^* "'^ ^^ '*" ^^ Sori very prominent forming irregular masses including more or less of the entire panicle, usually 5-15 cm. in length; often at first pro- tected by the leaf-sheath. A whitish false membrane encloses the black- brown spore-mass and the ray-like re- mains of the j)eduncles or colu Stock Photo")
RMRDDAM4–. The fungi which cause plant disease . Plant diseases; Fungi. 312 THE FUNGI WHICH CAUSE PLANT DISEASE. and the mycelium there develops richly under the epidermis. The outer cells remain sterile and constitute the membrane; the inner gelatinize and develop into spores. S. reiliana (Kiihn) Cl.^* "'^ ^^ '*" ^^ Sori very prominent forming irregular masses including more or less of the entire panicle, usually 5-15 cm. in length; often at first pro- tected by the leaf-sheath. A whitish false membrane encloses the black- brown spore-mass and the ray-like re- mains of the j)eduncles or colu
RMPG4GT4–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 125 these prized as table delicacies, and the Laboulbeniales, an order rich in species which are all parasitic upon insects. Protodiscales (p. 123) The 4-8 to many-spored asci form a flat palisade-like hymenium which arises directly from the mycelium; paraphyses none; spores, one-celled, elliptical or round. Key to Families of Protodiscales Parasitic 1. Exoascaceas, p. 125. Saprophytic 2. Ascocorticiaces. Of these families the second contains only one genus and two species found in bark. The firs
RMRDE201–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 344 GENERAL PLANT PATHOLOGY is induced in all probability by the presence of oxidizing enzymes in patches of cells where the chlorophyll pigment is destroyed and not in other adjoining areas. The formation of spots on leaves (Fig. 134), stems, flowers, or fruits is due to a variety of causes. The grayish or whitish spots on the under surface of grape leaves are due to mildews, on the stems of cruciferous plants to white rusts and on the leaves of the parsnip are found white spots due to
RMPG467W–. The fungi which cause plant disease . Plant diseases; Fungi. 300 THE FUNGI WHICH CAUSE PLANT DISEASE disappearing partially or wholly through gelatinization; fertile my- celium compacting into masses and giving rise to numerous chlam- ydospores formed from its contents. Conidia rarely develop on the exterior of the host. Sori prominent, usually forming dusty or agglutinated spore-masses that break out in definite places on the host or more rarely remain permanently embedded in the tissues. Spores (chlamydospores) light to dark colored, single, in pairs, or in spore-balls, the latter often co
![. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 514 SPECIAL PLANT PATHOLOGY to the grape" leaves (Fig. 186), where it produces under ordinary conditions spots of mildew, especiaUy on the lower leaf surface. In bad cases, the whole lower leaf surface may be covered with the downy, or cottony mass of hyphae which gives the fungus its common name. The parasitic hyphae live in the intercellular spaces of the host and send into the host cells smaU knob-like haustoria. The presence of the mycelium seriously interferes with the normal Stock Photo](https://c8.alamy.com/comp/RDE1F2/a-text-book-of-mycology-and-plant-pathology-plant-diseases-fungi-in-agriculture-plant-diseases-fungi-514-special-plant-pathology-to-the-grapequot-leaves-fig-186-where-it-produces-under-ordinary-conditions-spots-of-mildew-especiauy-on-the-lower-leaf-surface-in-bad-cases-the-whole-lower-leaf-surface-may-be-covered-with-the-downy-or-cottony-mass-of-hyphae-which-gives-the-fungus-its-common-name-the-parasitic-hyphae-live-in-the-intercellular-spaces-of-the-host-and-send-into-the-host-cells-smau-knob-like-haustoria-the-presence-of-the-mycelium-seriously-interferes-with-the-normal-RDE1F2.jpg ". A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 514 SPECIAL PLANT PATHOLOGY to the grape" leaves (Fig. 186), where it produces under ordinary conditions spots of mildew, especiaUy on the lower leaf surface. In bad cases, the whole lower leaf surface may be covered with the downy, or cottony mass of hyphae which gives the fungus its common name. The parasitic hyphae live in the intercellular spaces of the host and send into the host cells smaU knob-like haustoria. The presence of the mycelium seriously interferes with the normal Stock Photo")
RMRDE1F2–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 514 SPECIAL PLANT PATHOLOGY to the grape" leaves (Fig. 186), where it produces under ordinary conditions spots of mildew, especiaUy on the lower leaf surface. In bad cases, the whole lower leaf surface may be covered with the downy, or cottony mass of hyphae which gives the fungus its common name. The parasitic hyphae live in the intercellular spaces of the host and send into the host cells smaU knob-like haustoria. The presence of the mycelium seriously interferes with the normal
RMPG45EB–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 661 Soon the sclerotia form as mustard-seed-like bodies. They are produced in great abundance on all media but neither these struc- tures nor the mycelium have yet been seen to bear spores of any kind. The fungus was first studied by Halsted =' and later by many others. It was described and named by Saccardo from speci- mens communicated by Stevens. S. cepivorum Berk. Minute, spherical, gregarious, black. It is found on various species of Allium, causing rot.. Fig. 447.—S. roUsii, sclerotia. Afte
RMRDE1N3–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 486 SPECIAL PLANT PATHOLOGY A stem section shows a browning of the vascular ring and the vessels are found occupied by bacteria (Fig. i68). When the cabbage plant is attacked early in the season, it is killed outright, or else it fails to form the characteristic head. Infections may take place through injury of the surface, but the greater part of them are through the water pores, which exude drops of water, which collect during cool. Fig. i68.—Brown-rot of turnip {Pseudomonas brassica)
RMPG44F8–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. DETAILED ACCOUNT OF SPECIFIC DISEASES OF PLANTS 481 truncate at the base and measure 28 to 30/i by 7 to 9/i. According to Clinton, they do not retain their vitality long. An investigation of perithecial formation indicates that perithecia begin to form in October, or even later, and reach maturity in the following April, when mature ascospores have been found especially on the under sur- faces of the leaves. They are im- bedded in the leaf tissues and are slightly pyriform in shape, inc
RMRDEG6K–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 44 MYCOLOGY from a green alga like Vaucheria. With our present knowledge, it is impossible to name any one existing alga as the progenitor of a definite fungous form, but we are safe in assuming in a general way that certain phyla of fungi have been derived from certain phyla of algae, by the loss of chlorophyll and in the loss of an independent existence. Another view, which is open to argument, is that certain of the prototrophic. jJJuIl^ Fig. 13.—Development of Mucor mucedo. a, b, c,
RMPG44X2–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 224 MYCOLOGY in their being less awl-shaped and pointed. /. obliquus on stumps, /. carneus on tulip poplar, I. fusco-violaceus on pine trunks are American species. Family 7. Polyporace^.—The fruit body of the fungi of this family are of various substance and shape. The hymenium lines the inner surface of pores, or grooves, or is spread over the under surface of the fruit body. The depressions are either united vein-like grooves, tubes, or honeycombed cells, or twisted passages. Concentr
RMRDE19E–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. DETAILED ACCOUNT OF SPECIFIC PLANT DISEASES SSI the broken stub of the main root system. Nature attempts to repair the damage in the tobacco by the formation of a cluster of. new roots, so that affected plants may not be killed, but remain in the stunted form (Figs. 196 and 197). The intercellular mycelium is septate, hyaline at first and consists of narrow hyphae. The fungus produces three kinds of spores, which. Fig. 196.—Tobacco roots affected by rot (Thielavia basicola). i. Inoculat
 that three common forms were examined, viz., Ithyphallus impudicus Didyophora duplicala and the Phallus Ravenellii. ' ' Two families are distinguished: Clathrace^ and Phallace^ which Stock Photo")
RMPG44T4–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 250 MYCOLOGY phora (Figs. 99 and 100), and IlhyphaUiis. From such studies, he confirms the making of two genera out of them. His plates show. Fig. loo.-Diclyophcraphanoidca. Fully developed fruil-bodv with veil 2 ^ natural size. {After Alf Moller in Die natiirlichen pjlanzcfamilicn I. i.-l * p. 29" ) that three common forms were examined, viz., Ithyphallus impudicus Didyophora duplicala and the Phallus Ravenellii. ' ' Two families are distinguished: Clathrace^ and Phallace^ which
![. The fungi which cause plant disease . Plant diseases; Fungi. Fig. 47.—^P. citriophora; de- velopment of swarmsporea from sporangia. After Smith and Smith. and the contents of the antheridium are carried over to the egg by a fertilizing tube. Members of the genus are aggressively parasitic only under most favorable environmental conditions of heat an(f moisture. Some sixteen species are known. P. de baryanum Hesse, is most com- mon''"'' as the cause of "Damping Off." Zoosporangia or "conidia" globose to eUiptic, usually papillate, 20-25 n; gemmae similar in form and s Stock Photo](https://c8.alamy.com/comp/RDE70Y/the-fungi-which-cause-plant-disease-plant-diseases-fungi-fig-47p-citriophora-de-velopment-of-swarmsporea-from-sporangia-after-smith-and-smith-and-the-contents-of-the-antheridium-are-carried-over-to-the-egg-by-a-fertilizing-tube-members-of-the-genus-are-aggressively-parasitic-only-under-most-favorable-environmental-conditions-of-heat-anf-moisture-some-sixteen-species-are-known-p-de-baryanum-hesse-is-most-com-monquot-as-the-cause-of-quotdamping-offquot-zoosporangia-or-quotconidiaquot-globose-to-euiptic-usually-papillate-20-25-n-gemmae-similar-in-form-and-s-RDE70Y.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. Fig. 47.—^P. citriophora; de- velopment of swarmsporea from sporangia. After Smith and Smith. and the contents of the antheridium are carried over to the egg by a fertilizing tube. Members of the genus are aggressively parasitic only under most favorable environmental conditions of heat an(f moisture. Some sixteen species are known. P. de baryanum Hesse, is most com- mon''"'' as the cause of "Damping Off." Zoosporangia or "conidia" globose to eUiptic, usually papillate, 20-25 n; gemmae similar in form and s Stock Photo")
RMRDE70Y–. The fungi which cause plant disease . Plant diseases; Fungi. Fig. 47.—^P. citriophora; de- velopment of swarmsporea from sporangia. After Smith and Smith. and the contents of the antheridium are carried over to the egg by a fertilizing tube. Members of the genus are aggressively parasitic only under most favorable environmental conditions of heat an(f moisture. Some sixteen species are known. P. de baryanum Hesse, is most com- mon''"'' as the cause of "Damping Off." Zoosporangia or "conidia" globose to eUiptic, usually papillate, 20-25 n; gemmae similar in form and s
RMPG4GNW–. The fungi which cause plant disease . Plant diseases; Fungi. 142 THE FUNGI WHICH CAUSE PLANT DISEASE. Fig. 97.—Mycelium showing septation and branching. After Stevens and Hall. the host's tissue the hyphal threads are thicker, richer in proto- plasm, more septate, and much more branched and crooked than outside of the host. Aerial hyphal filaments when they touch a solid repeatedly branch in close compact fashion form- ing the attachment organs. At the exhaustion of the food supply and the consequent term- ination of the vegetative period the mycelium becomes very dense in spots and within t
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