RMMCKC6G–. Fig. 124.—Stereum fruiliiloium. i, group of fungi on a piece of oak wood ; 2, section through fungus, showing stratification ; 3, basidia with spores, and two paraphyses. Fig. I sUghtly reduced ; 2, slightly mag. ; 3, highly mag. remaining portions of wood become darker in colour, and very hard. At a later stage the diseased wood presents the appearance of having been riddled by insects. Tuberculose, woody, crowded, looking like one much cracked specimen, under surface and glabrous margin brown- ish-black, substance distinctly stratified ; hymenium convex, cinnamon, then pale, primrose ; spo
RMRCD91T–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. KEITHIA 287 germinate as freely as the coloured ones, and in less time, probably due to the thinner spore-wall. According to Fuckel ('Symb. Myc.', p. 286) Tromella foliacea (= Ulocolla foiiacea, Brefeld) is a conidial form of Bulgaria. This statement, however, has not been corro- borated, and should be attended to by those having an j^tHttP^-nTTTurf^. Fig. 83.—Bulgaria pclymorpha. i, fungus on trunk ; 2, section of same ; 3, spores ; 4, asci with spores.
RMMCMPY5–. Fig. II. — Dodder (Cuscuta (!ro»ovii), parasitic on a species of As/er in Kcw Gardens. .'at. size. and withers within forty-eight hours, and during clamp weather is completely destroyed in that time. A series of experiments conducted at Kew with two species of dodder proved that neither calcium sulphide nor calcium sulphate (gypsum) had any effect whatever on the dodder, although completely covered with the substance and kept damp for a week. Dodder is introduced to land in the form of seed, mi.xcd
RMRCDR2G–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. ;o6 DISEASES OF CULTIVATED PLANTS LICHENES The majority of lichens are not parasites, and when growing on the bark of trees, are simply saprophytes, deriving no nourishment from the tree. On the other hand, when lichens are present in abundance on the bark of cultivated trees. 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 no
RMMCKCBX–. Fig. 85. — Uromyces coh/iui. i, portion of a diseased Colchicum leaf; 2, teleutospores, one of vvhicli has germinated and produced a promycelium bearing three secondary spores. Fig. i reduced, Fig. 2 mag. dark brown, apex much thickened, with a small, hyaline, wart- like papilla, 26-35 X 20-26 /x. If the disease appears early, spray with Bordeaux mixture ; when the pods are formed, use permanganate of potash. Broad bean rust {Uromyces fabae, De Bary) is a parasite very common on the leaves and stems of broad beans, peas, also on various wild leguminous plants, vetches, etc. The aecidium stag
RMRCDR45–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 48o DISEASES OF CULTIVATED PLANTS Appel and Laubert, Ber. Deutsch. Bot. Ges., 23, p. 218. Clinton, State of Conn. Exp. St. Rep. (1907-8). Frank, Ber. Deutsch. Bot. Ges., 16, p. 280. Harz, Eijiige A'ei/e Hyphoniyceten, p. 129, pi. 31 (1871). Johnson, Ecofiom. Proc. Roy. Soc. Dublin., i, p. 161 (1903). Massee, Kew Bull., Jan. 1909. EXOSPORIUM (Link.) 1 Stroma compact, convex or with the centre depressed; spores elongated, many-septate, coloured. This genus
RMMCKX8H–. Fk;. 35.—Exoascus alni-incanae, causing enlarged scales of alder catkins. to a pink or red colour, and are more or less curled up. The surface is covered with a delicate white bloom when the spores arc produced. Diseased leaves soon diu and decay. The mycelium hibernates in the buds. As the mycelium is perennial in the living plant, pruning all diseased shoots is the only remedy.
RMRCD9HT–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. WOUNDS WOUNDS V'ounds may conveniently be arranged under two distinct headings : (i) natural wounds, effected by the plant itself for economic reasons; (2) wounds resulting from outside in- fluence, as pruning, birds, game, insects, storms, grass-cutting machines, etc. Self pruning.—Many different kinds of trees shed certain of their twigs annually, as the litter of twigs under such trees. Fig. 2.—An example of good pruning. The wound was at once protec
RMMCMTCF–. Fk;. 9.-Tuber of potato pietccii by the underground creep- ing stolons of coucli-grass ( Tri/icum >r/<cus). Nat. .size. is a well-known offender in this respect, but species of Tricholoma and Lycoperdo?i also i^articipate. Wlien a fairy- ring once commences, it increases in diameter year by year, the mycelium constantly growing outwards into new ground, hence each season the crop of toad-stools is just outside the zone of ground occupied by the crop of the previous season. The mycelium obtains food partly from humus, and partly from the living roots of the grass. Soak the ground thorou
RMRCD9CT–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. PLASMOPARA 119 Plasviopara viticola (Berl. and de Toni), was introduced to Europe from the United States, where it is equally injurious to both wild and cultivated vines. Every portion of the plant above ground is attacked, but more especially the foliage, where its presence is first indicated by the appearance of pale,. Fig. 25.—Basidiospora entospora. 2, 3, Sclerospora graminis, conidial stage and oospore ; 4, Bremia lactucae, portion of conidial stage
RMMCKCD0–. Fig. ^-j.—Sclerotinia fuckeliana. i, vine leaf with Botrytis form of fungus ; 2, conidiophores of Botrytis ; 3, a head or cluster of conidia ; 4, sclerotia bearing Botrytis form of fruit ; 5, asclerotium bearing two ascophores ; 6, like fig. 5, on a larger scale ; 7, a shrivelled grape with sclerotia ; 8, ascus with spores. All e-xcept Fig. i mag. Ascophores yellowish-brown, 0-5-4 mm. across, stem slender, 2-3 springing from a small black sclerotium; spores lo-ii X6-7 /x.
RMRCD959–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. DIDYRIELLA 209 DIDYMELLA (Sacc.) Perithecia immersed, membranaceous, asci 4-8-spored, paraphyses present; spores elongated, i-septate, hyaline. Differs from Sphaerella in having paraphyses. Orange-tree canker {Didymella ciiri., Noack) forms long canker-like v/ounds with thickened margins on the branches of orange-trees in Brazil. The first symptom of disease is the. Fig. 59.— VenturiiZ pirina. i, conidial form of fungus on pear leaf; 2, conidial form of
RMMCMTWA–. Fig. 8. — Thelephora laciniata, a non-parasitic fungus growing up the stem and suffocating a young larch. Reduced. and although not a parasite, it often proves highly injurious to young trees when first planted, by growing up the stem for some distance and enveloping the lower part of the seed- ling to such an extent that it is strangled or suffocated. The
RMRCD912–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 298 DISEASES OF CULTIVATED PLANTS Mint rust, caused by Puccinia fnenihae (Pers.), often com- pletely destroys entire beds of mint. All stages of the fungus are produced on the same host. The cluster-cup condition of the fungus appears first somewhat early in the season, and is most abundant on the stems, which become much twisted, distorted, and swollen, and more or less covered with the. I'iG. 87.—Puccinia asparagi. 1, aecidium stage on a young shoot of
RMMCKC6M–. KiG. 119.—Poh'porus sII1/1/re 14s. Block of white spruce wood showing injury c;iusccl by this fungus. (After Schrenk.) Pohporiis si/uamosus (Fries.). This very common fungus occurs abundantly on dead trunks and stumps of many kinds of trees exclusive of conifers, and is also equally common on old decaying trees, which it jirobably has in some measure been instrumental in destroying, but so far there is no reliable evidence to this effect. Usually imbricated or several pilei from one point. Piki on a more or less lateral stem, fan-shaped or nearly circular, fleshy behind, and becoming thin to
RMRCD8XN–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 3l6 DISEASES OF CULTIVATED PLANTS country); i-septate, rarely 2-septate, each cell having two or four germ-pores. Spermogoniaand aecidia on a different host to teleutospores. Uredospores unknown.. F"lG. 95.—Gymttoiporangium clavariacforme. I, teleutospore stage on juniper branch; 2, teleutospores; 3, teleutospores ger- minating and producing secondary spores, (7, a ; 4, aecidium stage on pear leaf ; 5, aecidium stage on branch, leaves, and fruit of
RMMCMRFT–. Kin. 12. I, ectotropic mycorhiza of larch, nat. size; 2, mycorhiza of same, mag. ; 3, section of root-tip of same, showing mycorhiza surrounding it, highly mag. ; 4, portion of mycelium of same bearing amorphous masses of o.alate of lime, highly m:ig. ; 5 and 6, cndotropic mycorhiza in cells of root of an orchid, Aiigraccum, highly mag. ectotropic mycorhiza, whereas these structures are present on roots of the same plant lacking mycorhiza. Ectotropic mycorhiza can be readily found on species of poplars and willows, and on most members of the Cupuli- ferae and Conifcrae. The hyphae forming e
RMRCD92X–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 2;6 DISEASES OF CULTIVATED PLANTS one time male or fertilising bodies. After the dead infected leaves have been lying on the ground throughout the winter, ascospores are formed in cavities in the stroma. These ascospores escape into the air in the spring and infect the young leaves. The spermatia are cylindrical, hyaline, about 6-9 X i /<â . Ascospores needle-shaped, hyaline, often slightly curved, 60-80 X I "5-2-5 ii; paraphyses very slender, ti
RMMCKC4B–. Fig. Tfi.—CoUetotrkhu)Hlimit- muthianuiH. i, diseased pod of scarlet-runner ; 2, section through a pustule of the fungus showing conidiophores bearing conidia at their tips, also two long, sterile spines, which should have been dark in colour, highly mag. Halsted, p. 246. Massee, 1898. Voglino, Fungidannosi alle Fiante Coltivaie, pi. 8. Torny Bot., 20, Gard. C/iro/t., May 7, Witches' brooms of cacao.—In 1900 Ritzema Bos announced the presence of a serious disease of the cacao-tree, which appeared under the guise of witches' brooms, which he attributed to a fungus he named Fxoascus ihcobroma
RMRCD991–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 174 DISEASES OF CULTIVATED PLANTS BOTRYOSPHAERIA (Ces. and De Not.) Stroma innate, subrotund, brownish ; asci clavate, 8-spored; paraphyses present; spores elongated, hyaline, continuous. Briar scab.—This disease, caused by Botryosphaeria dothidea (Ces. and De Not.), now and again appears as an epidemic in a garden, and amongst cultivated roses, it. Fin. 44.—Botryosphaeria diplodia. I, fungus on portion of stem of a wild rose, roduccci ; 2, ascus contain
RMMCKY5E–. Fig. â ^d. â Taphrina h hi lata, i, leaf of pear-tree with blisters caused by the fungus, reduced ; 2, asci on epidermis of a leaf, highly mag. blisters, which are on the under surface of the leaves. Mycelium not perennial in the tissues. The species are not as a rule injurious to any marked extent.
RMRCDR3E–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. CERCOSPORA 487 proved by inoculation experiments that when the spores are placed on a young celery leaf, a disease spot becomes evident about the fourth day, and that mature spores are produced in four weeks. The pale olive sporophores originate from colourless mycelium in the tissue of the leaf, and come to the surface of the leaf in clusters through the stomata of the leaf. Spores. Fig. 147.—Cercospora apii. i, celery leaf attacked by the fungus ; 2, f
RMMCMP1F–. Tig. 15.—Typical forms of basidia, with spores in ilie Hasidio- mycetes. i, Tulostoiiia mamiiiositm ; 2, nacrowyces deliijutscens 3, hasidia with spores, and cystidia of Peniop/iora iticonspicua ; 4, bisporoiis basidia of I.ycopcrdon cc/iina/tim ; 5, two spores of same showing persistent stfrigmata ; 6, Si/inx/ert/n -///^are ; 7, portion of hymfniiim of a typical agaric, liiccyhc mtcjosfera, with basidia, bearing spores, cystidia, or sterile basidia, and elongated cystidia. All highly mag. There is much difference of opinion as lo the exact position, in the sequence of evolution, of the tw
RMRCD8RF–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. ARMILLARIA 357 coloured, cordlike rhizoraorphs have a compact cortex con- sisting of short cells with thick, coloured walls ; these change gradually into thin-walled hyphae towards the centre of the rhizomorph, which in reality is an elongated sclerotium.. Fig. 110. - Agaricus mellcus. Base of stem of young Scots fir killed by the fungus. A portion of the stem is cut away to show the dense white layers of mycelium under the bark. These rhizomorphs radiat
RMMCKBXB–. Deep ploughing and treating with sulphate of potash are recommended when the land has produced a diseased crop. As the eehvorm attacks many different kinds of plants, it is important to avoid growing a crop on land that is infected,
RMRCD8KE–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 430 DISEASES OF CULTIVATED PLANTS Die back of willow shoots {Diplodina salicina, Cke. and Mass.) attacks the tips of willow shoots and causes them to die back for a distance of six inches or more. The shoots become brown and the scales of the buds are indurated. The fungus bursts through the bark at numerous points, form-. FiG. 133.—Ascochytaaspidistrac. i, on portion of a leaf of.ispuiis/ra liirida ; 2, perithecia of the fungus bursting through the e|3i
RMMCKC26–. Fig. ^o.—IIi-tcrosporium cchinulatum. i, portion of a diseased carnation ; 2, cluster of conidiophores bearing coniiiia; 3, conidium germinating, and producing secondary spores. Figs. 2 and 3 highly mag. leaves of a plant are attacked, owing to the spores being washed from one leaf to another. When the fungus is mature the tissue of tlie injured spots becomes brown, and often crumbles away leaving a hole. On cultivated species of Auricula. Excess of moisture favours the parasite. Spray with potassium sulphide and ventilate well.
RMRCD8PY–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 370 DISEASES OF CULTIVATED PLANTS of yellow mycelium, which occur round the root, and appearing between chinks in the bark. It is suspected that the mycelium migrates from one tree to another underground, as in P. schweinitzii. Effused, separable, tough, pores minute, often oblique, whitish, then becoming tinged yellow. Schrenk, E. von, U.S. Dept. Agric, Div. Veg. Phys. and Pathol., Bull. No. 25 (1900). Porta Laestadii (Fr. and Berk.). I once found this
RMMCMM2A–. Fig. 18. — Urophlyctis alfaljae. Nodules on root and collar of lucerne plant, formed by the fungus. (After Salmon.) Salmon, who gives the following account of the epidemic : ' The following inoculation experiments were carried out to demonstrate that the resting-spores, on being set free from the
RMRCD93D–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. DISEASES OF CULTIVATED PLANTS jronia, and Herniite Island, Cape Horn. "^^&^' ^:-^-^ //'J^ % "^^/^---^. Fio. 72.—Cyttaria gunnii. i, fungus on living branch o(/'agus Cunninghatnii, somewhat reduced ; 2, section of a fungus; 3, .iscus and spores, highly mag. All the species arc ediljlc, and closely resemble each other. All are parasitic on the southern evergreen species oi Fagus. PEZIZA(DiLi.) Ascophore sessile, fleshy and brittle, externa
RMMCX0YA–. Fig. 2,^.—Phyllactinia siiffulta. i, hazel leaf with patches of mildew; 2, perithecia, a, appendages ; b, mycelium ; c, ascus escapingfrom a perithecium « ; 3, asci containing spores. Fig. i somewhat reduced ; remainder highly mag. potassium in solution should also answer, commenced sufficiently early in the season. if sprayinc PHYLLACTINIA (Lkv.) Perithecia depressed, appendages straight, sharp pointed, with a bulbous base; asci many, rarely 3-4 spored.
RMRCE2E9–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. EELWORMS 559 to the fact that the eelworms in the tissues of a fern frond cannot extend beyond the portion of parenchyma circum- scribed by a vein. According to Ritzema Bos, when the air is moist the eelworms migrate from old diseased parts of the leaf and enter the adjoining healthy portions, emerging and entering through the stomata, and that when attacked plants. Fig. i-jo.—Apheleiichus olesistus. i, surface view of fragment of frond, showing eelworms
RMMCKC1K–.
RMRCE2F7–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 542 DISEASES OF CULTIVATED PLANTS that is surrounded by several other birches, many of which remain perfectly free from disease, while others show a few scattered tufts only of infected buds. Eriophyes nerviseqinis (Can.) forms minutely velvety patches, consisting of crowded, more or less irregularly club-shaped hairs, on the under surface of living beech leaves. These patches are sometimes of a beautiful crimson colour, more frequently reddish brown, an
RMMCMDG2–. Fit., jo. K.'..,j/us !.c..:/is. I. scLlion of a dibcisuil lily bulb, tin (lark ponion of the base of the bulb is thi- part attacked by the fundus 2, fruitiiig condition of llic fungus growing on the root of a bulb 3, cluster of sporangia of the fungus ; 4, cluster of sporangia mori highly mag. ; 5, optical view of a sporangium ; a, columella, the portion b, l>ctween the columella and outer wall is filled with spores ; 6, spores, some of which are germinating ; 7, spores more highly mag., showing the markings on the cpispore ; 8, zygospore; 9, mycelium of the fungus running lx.'tween cells
RMRCD9GJ–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 62 DISEASES OF CULTI'ATEI) PLANTS fungus may frequently be seen growing up heather stems, it also spreads for a considerable distance on the ground. The general colour is brown, texture soft and fibrous, almost shaggy on the upper surface, wrinkled or papillose below, margin shaggy or torn. Fairy-rings.—Several different kinds of fungi form the well-known fairy-rings, which often greatly disfigure and injure lawns, bowling-greens, etc. Maras/nius oreade
RMMCTR53–.
RMRCD95H–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. >^. ^^ Fig. 58.— Venturia inaequalis. i, conidial stage (Fusicladium dendriti- f«;«) on apple leaf; 2, 3 and 4, conidial stage; 6, section of perithecium ( Venturia stage) ; 7 and 8, asci and spores of Venturia ; 9, apple twig with Fusicladium stage, as appearing during winter and spring. Figs, i and 9 reduced ; remainder highly mag. practicable. I am not convinced. I believe that it is as practicable to remove the dead shoots from a tree as it is to
RMMCWYTH–. KiG. ^o.—Microsphaera ^rossuluriac. i, gooseberry leaf with patches of mildew ; 2, a perithccium with its appi-nd- ages; 3, tip of an appendage ; 4 and 5, asci containing sjiorcs. Fig. I nat. size ; the remainder highly mag. season, and is readily recognised under the microscope by the elaborate tips of the appendages. Mycelium delicate, greyish-white on both surfaces of the leaf; perithecia usually in small, scattered groups, dark brown, appendages once or twice as long as diameter of j)eridium, 4-6 times forked at the tip; asci 3-10, ovate, containing 3-6 spores of variable size, 20-30 x 1
RMRCD99K–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. [6o DISEASES OF CULTIVATED PLANTS Black root rot {Thielavia basicola, Zopf) was first met with in England on the roots of peas, and called Torula basicola by Berkeley and Broome. Four kinds of fruit have been described, the highest of which is an ascigerous form discovered in Germany by Zopf, on the root of a Senecio. Some doubt was at one time entertained as to whether the. l-"i(j. .— Thielavia basicola. i, diseased pea root; 2, portion of first
RMMCKC05–.
RMRCD8Y2–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. GYMNOSPORANGIUM 315 chains. Closely allied to Phragmidhtm, differing mainly in the relatively greater number of cells forming the teleuto- spore. Both stages grow on the same host-plant. Burnet leaf spot {Xenodochus carbonarius, Schlecht.) is parasitic on this plant. The aecidium stage forms large, orange-red, roundish patches on the leaves, and elongated patches on the stems. This is followed by the black, wart- like pustules of the teleutospore stage o
RMMCKC86–. Fig. 107.—Ithyphallus caniinis. Hymenium of fungus partly covered with olive mucus, in which the very minute spores are embedded. Several flies are present feeding on the mucus. Nat. size. smell. The fungus will be readily recognised by the aid of the accompanying illustration. Mixing the soil with quicklime kills the mycelium. Istvanffi, G., Ann. de rinst. Atnpelog. Roy. Hongrois, 3 (1904). AGARICACEAE The members of this group come under the category of mushrooms and toadstools, in common parlance, and are z
RMRCD94W–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. MYCOSPHAERELLA 215 tree should be cut down and burned, as it never becomes free from the disease. Farlow, G., Bull. Bessay Inst., 1875. Halsted, Neiv Jersey Agric. Coll. Expt. Station, Bull. 78. MYCOSPHAERELLA (Johans.) Perithecia as in Sphaerella, asci i6-spored, without para- physes; spores elongated, i-septate, hyaline. Pear leaf spot.—The early defoliation of pear-trees has for long been considered to be due to the presence of a fungus called Septori
RMMCKC58–. Fig. 130. — Vermiculariacircinans. i, onion attacked by fungus; 2, one of the black tufts of the fungus; 3. portion of a tuft showing the conidia borne at the apex of slender conidiophores, also the long black spines. I"it;s. 2 and 3 liighly mag. French potato scab.—Dr. Ducomet has described a disease of potatoes and tomatoes which when recurring on the tubers would come under our conception of scab, but which he terms 'dartrose.' The fungus causing the injury is VermUularia varians (Ducomet), The disease, although present, is not
RMRCD9G4–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 78 DISEASES OF CULTIVATED PLANTS the plant in obtaining the required amount of water, con- taining salts in solution. From the above statement, it becomes intelligible why, in a particular area, some plants are furnished with mycorhiza and others are not. Root-hairs are not present on those rootlets bearing. Kin. 12. I, ectotropic mycorhiza of larch, nat. size; 2, mycorhiza of same, mag. ; 3, section of root-tip of same, showing mycorhiza surrounding it,
RMMCKC90–. Yr,. 102. - Kar of barley attacktd by Lhtilago hordci. species ; Gagea lutea, also in species of Muscari, Believalia, etc. The mycelium of the fungus is perennial in the stem or cushion of the bulb, and from thence passes up the flower- stalk and into the anthers or ovary each year; hence when a plant is once infected it remains so for all time, and it is advisable to remove such bulbs, as the flowers are unsightly
RMRCD8MY–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 4o6 DISEASES OF CULTIVATED PLANTS SPHAEROPSIDIACEAE * Spores continuous PHOMA (Fries.) Perithecia subcutaneous then erumpent, globose or com- pressed, not beaked, mouth minute, conidia hyaline, continu- ous, elliptical to subglobose. A numerous genus, the species forming crowds of black microscopic dots on stems and leaves. Gooseberry shoot spot.—Numerous minute black dots nestling in the epidermis of gooseberry shoots, more especially. Fic. 126.— I, Phy
RMMCKBXP–. Fig. i6%.—Helerodera radicifola (eelworm), forming jj; tomato root; slightly reduced. the disease, are recommended by the Board of Agriculture, in Leaflet No. 75. I. To destroy these eehvorms the soil must be thoroughly
RMRCD8KN–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. DILOPHOSPORA 427 DILOPHOSPORA (Desm.) Perithecia crowded, immersed in a crustaceous weft of hyphae or stroma; spores fusiform, septate, hyaline, furnished at each end with several simple or branched, delicate hairs. Wheat ear fungus {Dilophospora gramtnis, Desm.) some- times attacks ears of wheat and arrests the development of. Fig. 132. — Cylindrosporiiirn padi. i, spots caused by fungus on a plum leaf; 2, section through a pustule of conidia of same; 3
RMMCKC93–. Pig. ioi. — Usiilago avcitac. i, a ' snuilti-d ' car of oats ; 2, spores ; 3, gi minating spores ; 4, secondary spores conjugating. Figs. 2-4 highly mag. to be of a dark olive-green colour, as seen through the tissues forming the membrane. When mature the blisters burst and liberate a dense powdery mass of black spores. The heads are most frequently attacked, and the galls may attain to the size of an apple, sometimes larger. Infection may occur at any young, growing portion of the plant. Tlie spores are irregularly globose, dark brown, delicately spinulose, 9-12 /x diam. I
RMRCD9H2–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. INJURY CAUSED BY NON-PARASITIC ORGANISMS 59 INJURY CAUSED BY NON-PARASITIC OR UN DETERMINED ORGANISMS Lichens on fruittrees.—Very frequently the trunk and branches of fruit-trees are covered with a dense growth of lichens of various kinds, which while admittedly adding to. %: Fig. 7. — Usnea harbata and Namalina fraxinea ,cens growing on branch of apple-tree. Reduced. their artistic appearance, are in other respects injurious, for although not true p
RMMCMEMM–. Fig. 29.—Cyziopus candid us. i, fungus on shepherd's purse ; 2, conidial form of fruit; 3, oospore ; 4, Cystopus portulacae, conidia and oospores in various stages of development ; 5, Cystopus trogopogonis, on leaf of goat's- beard; 6, oospore of same. Figs, i and 5, nat. size ; remainder highly mag. Lev.) attacks nearly all plants belonging to the crucifer family, in every part of the world. Among species of economic value may be enumerated : horse-radish, radish,
RMRCD946–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. Fig. dT.—Koitllinia radiciperda. i, ascigerous condition ; 2, peiilhccia : 3, section of same; 4, ascus containing 8 spores, also two parapliyso^; 5. tip of an ascus after treatment with iodine, showing the arrangement for effecting the opening of the ascus for escape of spores ; 6, a-cospores, one germinating; 7, brown mycelium with swellings; 8, black sclerotiiim bearing a cluster of conidial fruit ; 9, a single conidiophore; 10, conidia ; II, pycnidiu
RMMCKBX3–. (Afur A. (laike.) Eoot rot of tobacco. — Dr. W. ^^^ (iill)ert has just issued an exhaustive account of Thielavia basicola, which he has proved
RMRCD95N–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. VENTURIA 207 infected by spores produced on the leaves. But the leaves could not become infected except by spores produced on diseased shoots, consequently diseased shoots are the source of all the mischief, hence the most natural thing to do under the circumstances is to remove and burn all such diseased shoots. This is what I have advocated, but I have been told by a professor of mycology and a professor of agriculture independently, and in public, tha
RMMCKC20–. Fig. ii,2.—M,icrosporium nobile. i, portion of dis- eased carnation ; 2, two conidia ; 3, portion of conidium germinating; 4, Fiisarium spores, mixed with, but no proof of any relationship witii, the Macrospohum. Figs. 2, 3, and 4 highly mag. Spray with animoniacal copper sulphide, or with potassium sulphide, but as carnations will not bear too much moisture, much will depend on promptly removing leaves on the first appearance of the disease, which shows on the lowest leaves first. If the stems are attacked, and in all bad cases, the plants should be burned, not thrown on one side, otherwise
RMRCDR41–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 482 DISEASES OF CULTIVATED PLANTS fragments. On the other hand, if warm weather is suddenly followed by a chill, conidia are produced in abundance. The disease may appear during any period of the growth of the host. Conidiophores gregarious or subfasciculate on large, dry, a.. Fig. 144.—Helmiiitii.^sportuin tincuitm. i, portion of a maize leaf with fungus ; 2, a cluster of conidiophores, two bearing conidia, highly mag. brownish spots, septate, 150-180x6
RMMCKCC8–. Fig. 83.—Bulgaria pclymorpha. i, fungus on trunk ; 2, section of same ; 3, spores ; 4, asci with spores. 3 and 4 highly mag. opportunity for so doing. Tulasne has also recorded the occurrence of conidial forms of fruit, and so has Brefeld. Biffen, R. H., Ann. Bot., 15, p. 119 (1901). Brefeld, O., Heft. 10, p. 301. Ludwig, Centralbl. fi'ir Bakt., 2, p. 521, 3, p. 633. Tulasne, Ann. Sci. Nat., Ser. 3, 20, p. 164 (1853); CarJ>ol., 3, p. 192 (1863). KEITHIA (Sacc.) Ascophore immersed in the substance of the host, splitting above by a few irregular teeth; asci containing four spores, which are
RMRCD8X4–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. MELAMPSORA 325 Pine branch twist.—The aecidium phase of Melampsora pinitorqua, ^ostxn^ {=Caeoma pinitorqiaan, A. Br.), has been shown by Hartig to be very destructive to young pines, seedlings being sometimes diseased as they appear above ground. About the age of thirteen the disease dies out, and those that have not been too severely attacked, recover. Plants that are attacked when quite young are usually killed,. Fig. ()Z.—Melampsora pinito?-qua. i, to
RMMCTP39–. PJ' >-'"i;.;i
RMRCD95Y–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 202 DISEASES OF CULTIVATED PLANTS the leaves are full-grown, under the form of brownish patches which generally follow the course of the larger veins. The leaves fall long before they are dead, owirg to the mycelium of the fungus passing into the leafstalk, and cutting off the supply of food and water. Minute spore-clusters are formed. Fig. 56.- â Gnomonia veneta. 1, a diseased plane leaf, soniowliat reduced ; 2, conidia, highly mag. along the course of
RMMCKCD8–. Fio. 72.—Cyttaria gunnii. i, fungus on living branch o(/'agus Cunninghatnii, somewhat reduced ; 2, section of a fungus; 3, .iscus and spores, highly mag. All the species arc ediljlc, and closely resemble each other. All are parasitic on the southern evergreen species oi Fagus. PEZIZA(DiLi.) Ascophore sessile, fleshy and brittle, externally warted or scurfy, globose and closed when young, gradually expanding until cup-shaped or almost i)lane ; asci containing 8 spores in a single row; spores hyaline, elongated, continuous. Growing on the ground or on manure, etc. Among the
RMRCD8N3–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 400 DISEASES OF CULTIVATED PLANTS Most closely allied to Hypochtius, differing in being parasitic, with immersed mycelium, and in the basidia bearing a variable number of spores. Rhododendron galls {Exobasidium rhododetidri. Cram.) form on the living leaves of Rhododendron /lirsuium, R. fer- rugineum, R. li'ilsonianufn, etc., and vary in size from. Fig. 125.—Exobasidium rhododendri, on leaves of rhododendron, slightly reduced ; 2. basidia and spores of s
RMMCKC51–. Fig. 132. — Cylindrosporiiirn padi. i, spots caused by fungus on a plum leaf; 2, section through a pustule of conidia of same; 3, conidia of Exosforium tiliae ; 4, conidium of Sporodesmium brassicae; 5, Helminthosporium gram- inum on barley leaf; 6, conidia of same; 7, Aciinotnena rosae on rose leaf; 8, single blotch of same, showing perithecia ; 9, conidia of same; 10, conidiophores of Cercospora i-esedae; 11, single conidium of same. Figs. I, 5, and 7 about nat. size ; remainder highly mag. the grain by forming a blackish-brown, crust-like weft, which involves a portion or sometimes the wh
RMRCD8YY–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. ' PUCCINIA 309 ] circumstances, and when it occurs early in the year the leaves I fall quite early in the season, and consequently the crop is i poor in quantity and quality. As a rule the rusts can only I attack young growing leaves, but in the present case I have observed a plum-tree seriously attacked during the last week in July. A considerable amount of confusion respecting the. Fig. 90.—Piicciniapruni. i, portion of diseased plum leaf; 2, teleutosp
RMMCKC63–. I'lc. 121,. — Shrciini hirsiitiim. i, fungus; 2, section of saiiK' ; 3, basidia hi-nring spores, highly nuig. living tree it should be rut away, and the wound coaled with gas tar. Hartig, Die Zersciz. des Ho/zes, p. 129. Ward, Trans. Hoy. Soc, 189, p. 123 (1898). Partridge wood {Sierenm fnisiulosian, Fries.) is often a pure saprophyte; on the other hand, under certain conditions it assumes the nature of a destructive parasite, attacking various forest trees, more especially the oak. Dr. Hartig Ikis
RMRCD9G8–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 74 DISEASES OF CULTIVATED PLANTS should then be spread equally over the patch where it grew, and a little dry straw or litter added, and fired. By this means not only is the clover on the dodder destroyed, but also the seeds that have fallen to the ground. A French scientist, M. Garrigou, recently announced that if calcium sulphide is sprinkled over dodder, the latter blackens. Fig. II. — Dodder (Cuscuta (!ro»ovii), parasitic on a species of As/er in Kcw
RMMCM06H–. Fig. 31. I, lixoascus deformans, sliowing asci in various stages of development burslinR through the cuticle of the leaf; 2, ascus of Exoanus pruni, showing stalk-cell at base of ascus, and eight spores; 3, ascus of Taphritia aiirca filled with secondary spores produced by budding of the ascospores ; 4, surface view of niycelium of Taphrina Sadcbcckii on leaf of Almes glutinosa ; 5, differentiation of fertile or ascogenous hyphae from vegetative hyphae of Tuphrina Sadebeckii. (Figs. 4 and 5 after Sadebcck.) All highly mag. upon. The asci at first contain eight spores, but in the majority of
RMRCE2EY–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 546 DISEASES OF CULTIVATED PLANTS tiny mites feed not only on the outside of the bulbs, but they exist between the leaf scales of the bulb, feeding and laying their eggs in the interior, where they can scarcely be reached. The best plan is to burn infested bulbs, and the soil whence these have been removed should be disinfected. 2. Wash or spray the bulbs with paraffin, the treatment being repeated a fortnight later. 3. Wash the bulbs in sulphide of pota
RMMCKC2D–. I Fig. 148.—Fusariumlycopersici. , Diplocladiiim stage; 2, Fusarium stage; 3, resting spores. All highly mag. vessels, caused by the mycelium. Shortly after the plant has drooped, the portion of stem just above ground becomes more or less covered with a delicate, white film of hyphae. This is the first conidial condition of the fungus, known as the Diplocladium stage. This is followed by a second or Ftisarium stage, which originates from the same mycelium that produced the first stage. Numerous strands of mycelium spread from the roots into the soil, and there form resting- spores which rem
RMRCD8YG–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. PHRAGMIDIUM 313 dark brown, 3-8 septate, 75-100X26-30 [i, pedicel long, thickened in the middle. The infection in spring depends entirely on the presence of teleutospores present on fallen leaves, consequently all fallen leaves should be either buried by digging during the winter or by sweeping up and burning. Plants that have. Fig. 92.—Plu-agmidium stibcorticatum. i, rose branch and leaves with aecidium stage of fungus ; 2, rose leaf with teleutospores
RMMCKC77–. FiA7 arc sometimes met with growing from wounds on living trees: P. aurivella (Balsch), P. S(juarrosa (Mull.), and P. destruens (Brond.).
RMRCD942–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 243 DISEASES OF CULTIVATED PLANTS leaves, and more especially the sheathing portions, are seen to be more or less covered with rounded or elongated patches, covered with a delicate greyish-white mycelium, and bordered with brown. These patches often spread entirely over the sheath. When the fungus has reached this stage of development, the lower leaves are dead and the entire plant. Fig. 69. —I, Gibellina cenalis on wheat plant, nat. size; 2, ascuh with
RMMCKC3D–. Fig. 144.—Helmiiitii.^sportuin tincuitm. i, portion of a maize leaf with fungus ; 2, a cluster of conidiophores, two bearing conidia, highly mag. brownish spots, septate, 150-180x6-9 /x; pale olive, apex almost colourless, often nodulose; conidia spindle-shaped, ends acute, 5-8-septate, pale olive, 80-140 x 20-26 /x. A difficult disease to check, perhaps burning the stubble after corn has been gathered, if practicable, would to a certain e.tent prevent future infection. Rotation of crops, however, would be the most certain method, and as maize impoverishes the soil to a great extent, this c
RMRCD8M3–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 4i8 DISEASES OF CULTIVATED PLANTS rapidly if there is the least sign of sweating, hence tainted onions should be thoroughly dried and used at once. Spots orbicular, perithecia concentrically arranged, seated on radiating hyaline mycelium, very minute, furnished with long, rigid, black hairs; conidia oblong, hyaline, 10-14x3-4/*. Berkeley, Gard, Ckron., 1851, p. 595. Stoneman, Bot. Gaz., 1898, p. 98.. Fig. 130. — Vermiculariacircinans. i, onion attacked b
RMMCTK54–. ^'^'^ fl,. fJ â Jf f^T .7'" VG.z,o.âSpliacros(ilbeflavid<i. i, leaf showing disease ; 2, section showing conidia form ; 3, surface view of white spot bear- ing conidial stage of fungus; 4, section showing perithecia ; 5, two perithecia; 6, ascus containing eiglit spores. Fig. i reduced ; remainder nmg. had been carefully packed, and arrived in a good condition for experimenting with. These were placed in Petri dishes on sterilised damp blotting-paper. At the expiration of seven weeks dense groups of minute, bright-red perithecia
RMRCD92F–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. SCLEROTINIA 269 the death of the clover. The presence of small black sclerotia partially embedded in the substance of the stem and root indicates that the injury is due to the Sckroti?iia. As a rule, only one ascophore springs from a sclerotium, at first closed then expanding, yellowish-brown 3 mm. to i cm. across, stem elongated, slender ; spores S in an ascus, hyaline, elliptical, 16-18x8-9/^. Conidial condition unknown.. Fig. 79.—Sclerotinia ur7iula.
RMMCTPNN–. Fig. 4S.—Nec/ria solatii, figures illustrating its life-cycle, i, portion of a diseased tuber, and section through a conidial stroma ; 2, Monosporium fruit ; 3, conidia of same germinating ; 4, Fumrium stage, following the Mono^porium condition ; 5, Fusarium conidia, germinating and producing the Cephalosporiztin ?,ia.ge ; 6, stroma that has pro- duced Monosporium and Fusarhim conidia, bearing young perithecia, or the commence- ment of the ascigerous condition ; 7, section of a matureperithecium ; 8, asci containing spores, also paraphyses ; 9, ascospore germinating. The tuber in Fig. i redu
RMRCD951–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 214 DISEASES OF CULTIVATED PLANTS conidia elliptical, olive, about i6 /x long. Pycnidia resembling the perithecia, containing elliptical pale yellow, 3-septate stylospores, 10-12x6-7 /x. Spermogonia also similar to the perithecia, producing very minute spermatia. Perithecia crowded, asci cvlindric-ovate, 110-150x16-18 fx; spores. Fig. 61.—Plowrightia mcrhosa. i, portion of a plum branch, showing conidial stage of the fungus; 2, branch with ascigerous con
RMMCKBYM–. Fig. 162.—Left-hand fig., Erlophyesribis, the black currant bud mite. Middle fig., .£'r?o//;)'t'jwzV/J, the vine leaf mite. Right-hand fig., F.riophyes avellanae, the hazel bud mite. All highly mag. The anterior part is broad and short, and consists of the head and thorax fused together, constituting the cephalo thorax; the posterior portion or abdomen is elongated and tapering, and delicately transversely striated. Two pairs of legs are borne close to the rostrum. In addition to the species of economic importance, many mites form galls on our wild plants. Black currant gall mite.—^This dise
RMRCD9D1–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. io8 DISEASES OF CULTIVATED PLANTS the other hand, if the land is not infected, if the disease appears it is in one or more isolated patches, and no effort should be spared to check the spread of the disease by removing the diseased plants, and spraying the surrounding onions. As previously stated, an epidemic of disease depends. Fig. 24.—Peronospora SchUidcni. i. a conidiophore that has emerged through a stoma of an onion leaf; 2, free conidia ; 3, oospo
RMMCKC5M–. Fic. 126.— I, Phyllostula violac on violet leaf; 2, section of a perilhecium of J'/iy/losticta ; 3,' spores of same ; 4, spot on violet leaf formed by the fungus ; 5, Phoina susf>ecta, on gooseberry twig ; 6, peritheciiini of same in section ; 7, spores of same. near the tip, are exceedingly common ; in fact it is difficult to meet with a shoot of the season clear of these dots, which are the perithecia of Phoina suspecta (Mass.). This fungus is slightly, if at all, parasitic in its nature, and does no real injury, but is somewhat interesting as having been on many
RMRCE2FB–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 538 DISEASES OF CULTIVATED PLANTS caused by Eriophyes ribis (Nalepa), sometimes known as ' big bud,' is unfortunately too well known to require a detailed description. Diseased buds are known by their large size, globular form, and in remaining on the tree for a considerable. Fig. 163.—Eriophyes ribis, causing ' big bud ' of black currant. time in an unexpunded condition—in fact they arc killed by the mites, which are often present in thousands. During e
RMMCMGR9–. I'iG. 60.—P/owrij^htia riirsi.i. i, biancli of gooseberry with black knot, n;it. size ; 2, black currant branch with black knot, nat. size ; 3, sec- tion through a stroma, slightly mag; 4, asci containing spores, highly mag. The first indication o( disease is the wilting and yellowing of the foliage, which falls early in the season. As a rule a branch is not killed during the first year after infection ; during the second season the leaf-buds remain only partially expanded, and the branch dies, owing to the ascent of water being cut off by the copious development of mycelium in the conduct-
RMRCDR3A–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. FUSARIUM 491 I being prevented from ascending the stem, owing to the I vessels being filled with mycelium. The root is the part first attacked, the fungus entering through the root-hairs I and eventually forming a dense mass of mycelium in the j vascular portion of the root and stem for some distance I above the collar. If at this stage the stem is split open just above the collar, the vascular bundles are seen to be brown ! in colour, due to the presenc
RMMCKC9P–. Fig. 96.—Cronartium ribicohint. i, uredo and teleuto- spore stages on leaf of black currant; 2, uredospores, (Z, and teleutospores, b, cemented together in a column ; 3, uredospore ; 4, teleutospores, two of which are germi- nating ; 5, aecidia on bark of Weymouth pine; 6, aecidiospores. Figs, i and 5 nat. size, remainder highly mag. aggregated into a column which springs from the sorus of uredospores. Weymouth pine rust {Cronartium ribicolum, Deitr. = Peridermium sirobi, Kleb.).—The aecidium stage of this
RMRCD8JJ–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. ENTOMOSPORIUM 453 Sorauer has described an ascigerous fungus he called Stigmatea mespili, which occurred on dead leaves along with Entomosporii/m, and which he considers as being the higher form of the last-named fungus. He offers no cultural evidence, however, of this supposed relationship, which thus rests only on juxtaposition of the two. The black perithecia are flattened and have an imperfectly formed mouth. Spores several-celled, the minute, latera
RMMCKCC6–. Fig. S6. —Uromyces betae. i, portion of a mangold leaf dis- eased ; 2, portion of leaf with a cluster of aecidia; 3, section of portion of leaf with two uredospore pustules ; 4, aecidiospores ; 5, uredospores ; 6, teleutospores. Fig. i reduced, remainder mag. Uromyces betae as are our European plants. This I consider as one of the proofs that the fungus is by some means carried along with the plants to new countries. Now as beet or mangold is only introduced to new countries by means of seed, it follows that fungus spores must necessarily have been conveyed along with the seed. The disease h
RMRCE2GB–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. Fig. 159.—Spongospora scabies. 1, tuber showing wuunds made during early development of the parasite; 2, section of same potato; 3, miture spore- balls of Spongospora ; 4, amoeboid bodies of Spo>igospora in a potato cell, the starch has already disappeared; 5, showing the amoeboid bodies fused to form a Plasmodium in a ]>otato cell; 6, a more advanced stage of the Plasmodium ; 7, the ()lasmodium in a still more advanced staj;e, showing its substanc
RMMCNC0M–. Fig. 4.—Two portions of a branch of a pear-tree damaged by hail. The left-hand figure shows the injured side of the branch ; that on tlie right hand shows the uninjured side. Half nat. size. has been studied in detail by Viala, as affecting the vine. When once attacked, the branches, although yellow, do not die at once, but produce leaves which remain small and are of a yellow colour. The branches produced are numerous, very short, slender, and bear only rudimentary leaves. If the disease occurs during the flowering season, the colour of
RMRCD96M–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 194 DISEASES OF CULTIVATED PLANTS Strawberry leaf spot.—Both cultivated and wild straw- berries are often severely damaged by a fungus named Sphaerella fragariae (Tul.), the conidial form of which was at one time the only stage known, and was called Ratnularia Tulasnei (Rab.). Small reddish-brown patches first appear on the leaves, which continue to increase in size for some time and frequently encroach on each other, forming. Fig. 52.—Sphaerella fra^^ar
RMMCKBX7–. Fig. i-jo.—Apheleiichus olesistus. i, surface view of fragment of frond, showing eelworms under the surface of the epidermis. It will be observed that the size of the stomal opening is sufficiently large to admit the passage of the eelworm ; highly mag. ; 2, Pteris droog- mansiana ; 3, Adiantnm capilhis-veneris, form fissa ; 4, Lygodium voliibile. In the last three figs, the dark portions are caused by eelworms ; reduced. are placed in fairly dry air, the migration is checked. I have never seen eggs in the tissues of infested plants, and imagine that they are deposited in the soil in which t
RMRCD987–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. ^ ^ Vfc ^ i .^. m. 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.. Massee, George, 1850-1917. New York : Macmillan
RMMCKCE7–. Fig. 71. — Lophodermium pinastri. i, fungus on pine leaves; 2, ascigerous form of fungus; 3, conidial form ; 4, ascus with spores; 5, a single spore. Figs. 2-5 mag. primary leaves showing brown blotches, while other portions become purple-red. Even at this early stage the character- istic mycelium may be found in the brown blotches. During the first year after infection a large number of minute black spots, representing a conidial form of the fungus, are pro- duced, the contents of which do not appear to be capable of germination. As a rule, the ascigerous form of the fungus does not appear
RMRCD999–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 17: DISEASES OF CULTIVATED PLANTS near. After the tree is dead, the second or ascigerous form of fruit bursts through the bark in larger pustules than those formed by the conidial fruit. In all the cases I have investigated in the field, the common practice of planting too deep had been followed, and this I feel assured has something to do with the disease, more. Please note that these images are extracted from scanned page images that may have been digi
RMMCKC6Y–. ^'ir V Fig. 115.—Fames antiosiis. 1. portion of fungus; 2, sec- lion of same, showing stratified tubes in three layers ; 3, por- tion of hyn-eninni, showing tulies and tlieir openings, shglitly mag. between the bark and the wood. Soon after the mycelium has extended in the wood the latter changes to a lilac or violet colour, and afterwards to a yellowish-brown, and becomes light and sjiongy. The mycelium simultaneously extends up the trunk and towards the tips of the roots. When the roots have become thoroughly infested with mycelium, flattened, biscuit-like, pure white fruiting bodies or sp
RMRCD9HC–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 42 DISEASES OF CULTIVATED PLANTS portion of the wound. This form of injury is mostly present | on plants grown under glass, and is especially common on. Kir,. 5.—Inliimescences, or sa|)-ait.s oti stem of nn .Irai/'! ijiown in a hol-honse. Nat. size. species of Solaiium and allied jjlants. It is, howevLr, also met with on other plants, as species of Mimosa, Acacia, Camellia, etc. It is occasionally observed on plants growing outside,. Please note that t
RMMCKCB5–. Fig. 90.—Piicciniapruni. i, portion of diseased plum leaf; 2, teleutospore ; 3, paraphysis ; 4, lower cell and portion of pedicel of a teleutospore, from which the upper cell has broken away ; 5, uredospore. Fig. i reduced, remainder highly mag. nature of the various kinds of reproductive bodies produced by this species has existed until recently, when the matter has been thoroughly worked out and put right by Professor M'Alpine. Uredospores varying from almost globose to piriform, smooth, apex conspicuously thickened, 18-36 X 14-18^1; para- physes numerous. Teleutospores formed of two almos
RMRCD94A–. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. Fig 66—Koselhiiia iiciatnx. i, poiiion of root of apple-tree with whue fleecy mycelium, 2, biown hyphae with swelHngs; 3, loot with sderotia beating conidial fruit; 4, single cluster of conidiophoies; 5, branch of last beating conidia; 6, stylospores produced in pycnidia (after Viala) ; 7, perithecium surrounded by conidiophores (after Viala) ; 8, ascospores; 9, a sycamore infected witli thi^ fungus, the portion above ground enveloped in white my- celium
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