Xanthomonas campestris pv. alfalfae. [Descriptions of Fungi and Bacteria].

Author(s):  
J. F. Bradbury

Abstract A description is provided for Xanthomonas campestris pv. alfalfae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Medicago sativa, which it infects naturally. A Romanian strain naturally infects Trifolium pratense. By artificial inoculation Melilotus indica, Pisum sativum and Trigonella foenum-graecum are readily infected. Other hosts by inoculation are: Lablab purpureus, Medicago truncatula, M. scutellata, Phaseolus vulgans, Trifolium incarnatum, Vicia benghalensis and Vigna mungo (all reported by Moffett & Irwin), Clitoria ternatea and Lupinus termis (48, 3266), and Glycine max, Medicago lupulina, Melilotus alba, M. officinalis, Trifolium pratense and Vicia sativa (all reported by Stuteville & Sorensen, 1966). DISEASE: Leaf spot of lucerne. Small water-soaked spots enlarge, become brown and may coalesce to form areas of dead, dry, papery tissue. Lesions may be interveinal, along the midribs, or at the margins of the leaflets. Stem lesions also occur (36: 650; Moffett & Irwin, 1975). These start as water-soaked circular spots about 2 mm diameter. They usually coalesce to form long lesions which may extend from one node to the next. The colour of these lesions becomes dark purplish, with a greenish-yellow central region and a greasy margin. When seedlings are attacked in damp conditions post-emergence damping off occurs (Stuteville & Sorensen, 1966). GEOGRAPHICAL DISTRIBUTION: Sudan (39: 3), India (Bombay State, 35: 287), Japan (51, 1579), USSR (Republic of Georgia, 53, 3747), Australia (Queensland, 55, 789), Romania (47, 1912), USA (Wisconsin, 14: 766; Kansas, 52, 3367; Iowa, 36: 650; probably Maryland, 57, 657), Nicaragua (42: 467). TRANSMISSION: By water-splash in the nursery and by wind-blown infested soil particles in the field (53, 2931). The pathogen survives in plant debris and soil from August to June in Kansas conditions, and in dry hay for many years (52, 3367).

Author(s):  
J. F. Bradbury

Abstract A description is provided for Xanthomonas campestris pv. corylina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Corylus avellana, C. maxima and C. rostrata (syn. C. californica). On inoculation C. colurna is also infected. DISEASE: Bacterial blight or bacteriosis of filbert or hazel nut trees. Leaf spots, bud and twig necroses and stem cankers are produced. The cankers may girdle branches or even trunks of young trees and cause death above. GEOGRAPHICAL DISTRIBUTION: Turkey (Black Sea area 54, 578), Australia (Vict. 60, 6677), England (59, 3913), France (56, 86), Italy (64, 4520), Yugoslavia (37: 125), USA (OR, WA), Chile (culture received at CMI), and apparently USSR (58, 4044). TRANSMISSION: Bacteria overwinter in cankers on branches and in buds, and spread to other parts of the tree in wet weather. Limited spread from tree to tree takes place by water splash. Man is an important vector especially during pruning activities on young trees. He is also responsible for the introduction of the disease into new areas.


Author(s):  
J. F. Bradbury

Abstract A description is provided for Xanthomonas campestris pv. sesami. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Sesamum indicum (Pedaliaceae). DISEASE: Bacterial blight of sesame or simsim; known as 'Marad ed Dum' in the Sudan. Mainly a leaf spot disease, this starts as tiny dark olive green spots, which increase in size, becoming dark red-brown to black, and about 2-3 mm. They may be rounded or angular, and may coalesce to involve larger areas of leaf. Stems and capsules may also be infected, having oval, slightly raised, dark red-brown lesions. GEOGRAPHICAL DISTRIBUTION: Sudan and India (CMI Map 494, ed 2, 1973) to which must be added Venezuela, now confirmed (54, 524; 56, 2615). TRANSMISSION: Within a crop by water splash, wind-driven rain etc. ; from one area to another by seed transmission (47, 593). Survival in seed is up to 16 months (51, 400), in soil up to 6 months.


Author(s):  
M. Fitton

Abstract A description is provided for Myrothecium roridum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Plurivorous. On Antirrhinum, Coffea, Cucurbitaceae, Cyamopsis psoraloides, Gardenia, Gloxinia, Gossypium, Hibiscus esculentus, Hypocyrta, Lycopersicon esculentum, Molucella, Sesamum indicum, Solanum melongena, Trifolium pratense, Vigna unguiculata, Vinca, Viola. DISEASE: Commonly causing necrotic lesions or shot holes on leaves but can also occur on petioles, stems and fruit. Small, sometimes water-soaked, lesions increase to about 2.5 cm diam. ; they may be zonate and coalesce, defoliating the plant. On many hosts infection is most serious under nursery or glasshouse contitions. Infection leads to stem lesions, dieback of the crown and decay at soil level; this may resemble typical damping-off symptoms. Stem cankers have been reported on cotton and sunken lesions on the fruit of cantaloupe. On tomato fruit a firm, black rot develops, with a sharply delimited border between healthy and diseased tissue; the rotted part can be removed readily in one piece (25: 345; 35: 19; 36: 528; 41: 199; 44: 1586, 3367; 49: 503). GEOGRAPHICAL DISTRIBUTION: Widespread (CMI Map 458, ed. 1, 1969); possibly more serious in warmer regions. TRANSMISSION: Probably a common soil saprophyte, with the capacity to become actively parasitic under conditions not yet clearly definable. Infection of cotton bolls and carpel walls is reported (43, 3382b). Seed of C. psoraloides when inoculated gave only 16% germination compared with 93% for the uninoculated seed.


2010 ◽  
Vol 59 (2) ◽  
pp. 255-268
Author(s):  
István Harmati

Sekély humuszos szintű, erősen karbonátos réti talajon kialakult természetes (Achilleo-Festucetum pseudovinae) gyepen beállított tartamkísérletekben vizsgáltuk a műtrágyázás kérdéseit a gyep növényi összetételének megjavítása, termésének növelése és minősége javítása céljából. A kísérlet humuszban gazdag, nitrogénnel és káliummal igen jól ellátott, de foszforban szegény talaján az N- és P-műtrágya 2-2 adagját szólóban és kombinációikban alkalmaztuk. Az öntözetlen kísérletet 28, az öntözöttet 14 éven át folyamatosan, széleskörűen vizsgáltuk. Megállapításainkat a következőkben foglaljuk össze. – A gyep növényi összetételét a N- és a P-műtrágyák adagjaiktól és kombinációiktól függően megváltoztatták. A nitrogén a füvek, a foszfor a pillangósok versenyképességét fokozta és segítette elő növekedését. Az önmagában alkalmazott N-műtrágya a talaj nagyfokú P-szegénysége miatt nem gyakorolt pozitív hatást a gyepre. A P-műtrágya viszont kedvező változásokat okozott: a füvek fejlődésének elősegítése mellett nagymértékben növelte a pillangósok borítási értékét és tömegarányát, különösen az öntözött parcellákon. Öntözetlen viszonyok között a réti perje (Poa pratensis), a sovány csenkesz (Festuca pseudovina) és a komlós lucerna (Medicago lupulina) alkotta a gyep termésének túlnyomó részét, néhány egyéb fű- és pillangósvirágú komponens társaságában. Az öntözött kísérletben a pillangósok abszolút uralma mellett gyakran a réti perje jutott vezető szerephez. A pillangósok közül az eperhere (Trifolium fragiferum), a komlós lucerna (Medicago lupulina) és a vörös here (Trifolium pratense) váltakozva jutott uralomra. Az időjárás nagyban befolyásolta a gyep pillangós komponenseinek tömegarányát. Az NP kombinációkban a pillangósok tömegaránya erősen lecsökkent, különösen a nagyobb N-adag használata esetén. Öntözetlen területen a sovány csenkesz és a réti perje változó arányban alkotta a gyep termésének túlnyomó részét. Az öntözött parcellákon azonban a réti perje abszolút uralkodóvá vált és az egyre jobban előretörő tarackbúza (Agropyron repens) is jelentősen részt vett a termés kialakításában, elsősorban a nagyobb N-dózisú kombinációkban. A kísérlet 3. évtizedében a csapadékos években megjelent a francia perje (Arrhenatherum elatius) és a réti csenkesz (Festuca pratensis) is. – A gyep termését az önmagában alkalmazott N-műtrágya nem növelte jelentősen. Ezzel szemben a P-műtrágya nagy hatékonysággal 2–4-szeresére (3–5 t·ha–1-ra) növelte a gyep szénatermését, elsősorban a pillangósok nagyarányú térhódítása révén. 1 kg P2O5 öntözetlen körülmények között 43, míg öntözöttben 68 kg szénaterméstöbbletet eredményezett, sokévi átlagban. A 90 kg P2O5·ha–1 adag néhány év után soknak bizonyult. A legjobb eredményt a 200 kg N·ha–1 + 60 kg P2O5·ha–1 adaggal értük el, amellyel az öntözetlen területen – 28 év átlagában – 7,87, öntözötten – 14 év átlagában – 7,12 t·ha–1 szénatermést kaptunk. Az időjárás nagymértékben befolyásolta a termés mennyiségét és minőségét, legfőképpen a pillangósok tömegarányának változása révén, különösen az öntözetlen kísérletben. A három növedék tömegének aránya 7 évi átlagban, az öntözetlen kísérletben a szóló foszforkezeléseknél 48:37:15%, míg az NP kombinációknál 56:35:9% volt. Az öntözött területen ezek az arányok az előbbi sorrendben: 39:49:12, illetve 43:41:16%. A nitrogénből számított nyersfehérjehozam sokévi átlagban az öntözetlen kísérletben 428–550, míg az öntözöttben 560–760 kg·ha–1 volt. – A talaj felvehető tápanyagtartalma az évek során jelentősen megváltozott, különösen a talaj 0–10 cm-es rétegében. A P-trágyázás önmagában, de az NP kombinációiban is az adagoktól, illetve az ezek hatására kialakult termések mennyiségétől függő mértékben növelte a talaj P-tartalmát. A legjobbnak a 200 kg N·ha–1 + 60 kg P2O5·ha–1 kezelésű parcellákban bizonyult: a kísérlet 22. évében a talaj 0–10 cm-es rétegében a P-tartalom 260 mg P2O5·kg–1 lett, ami az erősen karbonátos talajok esetében igen jó P-ellátottságnak mondható. A K-ellátottság azonban az NP-kezeléseknél az optimális szint alá csökkent (172 mg K2O·kg–1) a termések nagyarányú K-kivonása következtében. Ezért néhány évi NP-trágyázás után K-pótlásra is szükség van.


Author(s):  
E. Punithalingam

Abstract A description is provided for Phomopsis oryzae-sativae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Oryza saliva. DISEASE: Collar rot of rice, appearing at the end of tillering stage. Visible symptoms are small dark brown lesions at the base of the auricle of the topmost fully expanded leaf. These lesions enlarge to cover the whole auricle and in the advanced stage lesions extend to the adjacent parts of the leaf sheath and leaf blade. Within 14 days the blade joint at the top of leaf sheath turns dark brown and then rots, causing the leaf blade to drop off (Kanjanasoon, 1962). GEOGRAPHICAL DISTRIBUTION: Asia (Thailand). TRANSMISSION: No studies reported. Conidia presumably dispersed by water splash.


Author(s):  

Abstract A new distribution map is provided for Xanthomonas campestris pv. musacearum (Yirgou & Bradbury) Dye. Proteobacteria: Xanthomonadales. Hosts: banana (Musa sp.), enset (Ensete ventricosum). Information is given on the geographical distribution in Africa (Burundi, Congo Democratic Republic, Ethiopia, Kenya, Rwanda, Tanzania, Uganda).


Author(s):  
E. Punithalingam

Abstract A description is provided for Ascochyta rabiei. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Cicer arietinum. DISEASE: Blight of gor chick pea (Cicer arietinum), attacks all above-ground parts of the plant; circular lesions on leaves and pods and elongate ones on petioles and stems. The pycnidia form in concentric areas on these lesions and in severe attacks the whole plant is killed. GEOGRAPHICAL DISTRIBUTION: Restricted to the Mediterranean region, S.E. Europe, S.W. Asia and also reported from Tanzania (CMI Map 151, ed. 2, 1966). Additional areas not yet mapped are: Lebanon, Turkey, USSR (Azerbaijan, Republic of Georgia, Moldavia). TRANSMISSION: Infection is carried both on and within the seed. Seed infestation in pods showing infection was 50-80%. Seed formation, size and germination and seedling growth are adversely affected (12: 264; 49, 3059). Conida are presumably dispersed by water-splash and viability is retained in host debris on the soil surface between crop seasons.


Author(s):  
C. Booth

Abstract A description is provided for Gibberella zeae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Wheat, maize, barley, carnations and other ornamentals; also reported infecting Lycopersicon, Pisum, Trifolium and Solanum DISEASE: Seedling blight, pre-emergence and post-emergence blight, root and foot rot, brown rot, culm decay, head or kernel blight (scab or ear scab) of wheat, maize, barley and other cereals. Leaf and flower rot of carnations and other ornamentals. Also reported infecting species of Lycopersicon, Pisum, Trifolium and Solanum. GEOGRAPHICAL DISTRIBUTION: Worldwide on maize and rice in the tropics. Wheat, oats, barley and rye in temperate regions. TRANSMISSION: By planting infected or infested seeds or by planting in infested soil. Secondary infection occurs widely by water droplets under moist conditions or by ascospore discharge.


Author(s):  
K. E. Reay

Abstract A description is provided for Xanthomonas campestris pv. graminis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Lolium italicum, L. multiflorum, L. perenne, Dactylis glomerata, Festuca pratensis, and Trisetum flavescens. Single cases of natural infection of Agropyron repens, Phalaris arundinacea and Phleum pratense are also recorded (62, 241), but their status in the natural host range is unknown. In inoculation tests (Egli et al., 1975; Egli & Schmidt, 1982) the following were highly susceptible: Alopecurus pratensis, Dactylis glomerata, Festuca arundinacea, F. pratensis, F. rubra, Lolium loliaceum, L. multiforum, L. parabolicae, L. perenne, L. remotum, L. temulentum, Phleum arenarium and P. bertolonii. Showing much less susceptibility were Agrostis alba, Arrhenatherum elatius, Phleum alpinum, P. phleoides, P. pratense, Poa annua, P. compressa, P. fertilis, P. memoralis, P. pratensis and P. trivialis. Leyns et al. (61, 6162) found that Agrosas tenuis and Festuca ovina were moderately susceptible when inoculated. Egli et al. (1975) recorded doubtful symptoms on Hordeum vulgare and Triacum aestivam on inoculation, but consider that they are unlikely to be naturally infected. DISEASE: Bacterial wilt of forage grasses. Symptoms usually first noticed at the heading stage, when young leaves curl and wither, and shoots remain stunted or may die. Other plants will continue to make poor growth and produce small, distorted inflorescences. Chlorotic and necrotic zones form on the older leaves along long stretches of vascular bundles, often extending into the sheaths. Bacterial streaming may be seen under the microscope from the cut ends of vascular bundles of infected tissue mounted in water. GEOGRAPHICAL DISTRIBUTION: CMI Map 533, ed. 1, 1979 lists France, Germany, Switzerland and Wales, to which must be added Scotland (63, 2925), Belgium (61, 4199), Netherlands, Norway (62, 241), and New Zealand (62, 241). Possibly in USA (IL; 61, 5045) though this disease is currently attributed to a Rickettsia- like organism. TRANSMISSION: Within the crop transmission is presumed to be by the blades of mowing machines.


Author(s):  
S. Little

Abstract A description is provided for Cercospora duddiae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Allium ascalonicum, A. cepa, A. fistulosum, A porrum, A. sativum. DISEASE: Leaf spot or withertip on onion and garlic. The symptoms vary on the different host species. On onion circular, chlorotic spots 3-5 mm diam. form mainly on the tip of the leaf, gradually decreasing in number towards the leaf base. The lesions at the leaf tip coalesce, forming a dry greyish-brown area, and in severe cases the entire leaf tip may be killed. The base of the leaf is mottled with brown necrotic leaf spots. Eventually the necrotic tissue may spread down the leaf surface, delimited by a narrow band (3 mm) of chlorotic tissue (Welles, 1923). Rarely does the disease cause much damage (Chupp & Sherf, 1960). GEOGRAPHICAL DISTRIBUTION: Africa: Mauritius, Nigeria, Sierra Leone, Somalia, Uganda; Asia: Borneo, Brunei, Burma, India, Indonesia, Oman, The Yemen; Australasia: Papua New Guinea; North America: West Indies (Barbados, Jamaica). TRANSMISSION: By air-borne or water-splash dispersed conidia, and by transportation with onion parts. The fungus is also reported to be seed borne (Chupp & Sherf, 1960).


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