Compendium of Potato Diseases - (PDF, 101 mb) - USAID

More documents

Recommendations

Info

ITURKENSTFEN. L... 1978. Tiion foliar de lapapa enelIPer: I. Especies de Phorna asociadas. Fitopatologia 13:67-69. (Prepared by L. .1. Turkensteen) Choanephora Blight Choanephora blight, caused by ('lhoinelhoracueurliturun (Berk. & Rav.) Thaxter is only known so far in hot, moist, tropical sites in Peru wh'-ere potato has recently been introduced. It is marked by long (4-5 mm). spiny spora ngiophores (Fig. 49G-.J) on initially water-so- '.ed. hut later necrotic, lesions (Fig. 52). Affected plants i. die rapidl3y or slowly. Selected Reference TURKENSITEN L..I1. 1979. Choanepliora blight of potatoes and other crops grown tinder tropical conditions in Peru. Neth. J. Plant Paihol. 85:85-86. (Prepared by 1..J.Turkensteen) Gray Mold The fungus is found on a wide range of plants throughout the world but in potato the disease is usually considered of minor economic importance. Symptoms Syvmptonls become apparent on foliage towsard the end of the growing season. Lesions on upper leaves are rare, developing Only during periods of cool weather. Lesions ate usually oi the Margins or tips of' leaves. typically wedge-shaped. often bordered by ma }jerveins,. ;ld have wide concentric /oiation. lleev may sitperficiallv resenle late blight lesions. When infected flower parts fallon leaves. the fungus may grow from the dcaying part and produce a sonewhat circular lesion (Fig. 53 B). I.\eer lea\es t liat have become chlorolic from shading break dos itwith ill ,iiv rot. Rot spreads fro infected leascs through the petiole aid into the cortex of the stei (F1ig. 53A). BOt rvtis fruits profcusely oiiaffected tissue, producing it lcu1//y appea ra ice. Spece masses and aerial mycelia wit h gray liltl)( are relati\elycleise and tff-white or gray to tiatn in contrast to those \\ith late blight. \\Iich ilresparse and white. 1Ocber inlection, which is uncommon, is not apparent at digging bit de\clops during storage and may become severe. lie surface ,olinfected tissue is wrinkled. Underlying tissue is flabby. temporarily darkened, and later becomes semiwatery w'ith browndecay. Tufts Ofthie fungus may emerge from wounds and eyes (Fig. 53C and )). A dry type of rot also develops, Fig. 52. Choanephora cucurbitarum infection on potato leaves, (Courtesy L. J. Turkensteen) 48 -usually appearing as sunken. pitted, discolored areas penetrating usuall\. less than I rin. Causal Organism Bolrvti. cin'rea 'ers. produces conidia in a grapelike cluster. conidia are ellipsoid to ovoid, one-celled, 9--15'X 6.5-jIp in,and borne on the tips of condiophores (Fig. 531-(i). 1otrytis fruits on decaying petioles, stems, flowcrs, and tuber parts, and on sclerotia. Sclcrotia are hard, black. irregularly shaped, 1~15 im long, and firmly attached to the substrate. The perfect stage. Scle'roiniia iwc'liane (de Bary) Fuckel (syi. Botr.,otiia liwkelilnu (dc Bar3,) Whet/.) is relatively rare, viih apothecia 1.5-7.0 nin in diameter and 3-15 mm high. Epidemiology Infection, sometimes initially latent, becomes apparent on senescent plant parts under stress from shading or excessive humidity. Spores are spread by wind and rain, and lesion development is limited by dry sunny conditions. Leaf infection requires high humidity and relatively cool temperatures. Pnoculum is apparently ubiquitous. High levels of K and N fertility reduce tle percentage of tuber infection. Relative maturity of tubers has little influence on incidence of infection. Tuber decay may be severe when tubers are placed immediately into storage at moderately low temperatures and high humidity without previous wound healing. Control I) Foliage protectant sprays may be useful if foliage is not severely shaded. 2) Permit tubers to wound heal before placing them in low temperature storage. Selected References Et.IJS, M. B., and .1. M. WAL.L.ER. 1974. Sc'rolinia fuckeliana (conidial state: Botrrtiscinerea). No. 431 in: Descriptions of Pathogenie Fungi and Bacteria. Comnonw. Mycol. Inst.. Kew, Surrey, England. 2 pp. HARPER, P. C., and II. WII... 1968. A response of grey mold of potatoes to fertilizer treatment. Eur. Potato .1. I11:134-136. HOLI.IOMON, I). W. 1967. Observations on the phylloplane flora of potatoes. Fur. Potato .1. 1):53-61. RAMSEY, G. B. 1941. Botri.s and Schrotinia as potato tuber pathogens. Phytopathology 31:439-448. (Prepared by W. J. Hooker) White Mold White mold is a cool temperature disease occurring in the Andes and in temperate zones nearly everywhere that potatoes are grown. Symptoms Water-soaked lesions covered by a cottony mycelial mat and sclerotia are most frequent on the main stem at the soil line or on lateral branches in contact with the soil. They may appear, however, in the angles ift secondary branches, leaves, petioles, and flower peduncles. Leaf lesions, irregularly shaped, are at the base of leaflets. First symptoms are small areas of discolored tissue that turn gray and look wet. In severely affected plants, the stem is girdled and plants die (Plate 36). Infected sterns often with zonate lesions (Fig. 54A) have mycelia and sclerotia in the pith (Fig. 5413). Tubers near the soil surface may be infected, beginning with small depressed areas sometimes located near the eyes and having a distinct demarcation between affected and healthy tissues. As lesions enlarge, flesh shrinks and becomes superficially blackened and spongy (Plate 37). Rot is wateryand soft, becoming leaky under pressure. It is whiter than normal and, even in advanced stages, discolors the tuber only slightly
d AC D A 0 Fig 53 Gray mold. A, Botrytis sporulating on stem lesion and dead petiole: B, leaf lesion; C and D, Botrytis tuber infection with feltlike mass of mycelium at arrow: E and F,Botrytis cinerea conidia on conidiophore; G, conidia. Bar in E represents rnl 50pm; bar in F represents 10 and gives no odor. Infected tissues later develop internal cavilies Ildled %kithII iceliirIr and selerotia. Ca~usal Organi~ss* Ni+h'riuloiz liuirriri (IIih.I de lirrv (svNr. IfI i:'hnia 'I %cI'roiorum(Fib.) Korl. & D)rniont ) and also S. mior lagger ~ ani .5 um1'rI,'dia Rarin sev ar. Ceauisal agents. Sclerotia (Fig. 54(*);are hard. lenticular or irregular in shacpe, and varied in si/c. [he iaV he nmirlitetor .vhe over i cerntinetei- in diameter. ouuli ., s',l'ri al i;i \ hla k c ci'nr gs arid \ hite interiu s: liter thei MIrri1 li h~CO InL' bl;I~k ;1rid 1i1i11. [I i s elCCirirnI is rite1 and 1 flu Is. MIinute. ghhose spermatia (2-3 mill)develop infre- qtmently inrinvelial mats at the base o the plant or in drying cultures. lheir role in pathogenicity is unkrnowvn. Apothecia (Fig. 55 top) orned at tlie soil surface may' he funnel-shaped to flat. Iheircolors include pale orange, pink, light tan. and white. Apothecia can he 1.5 cm, r nmre in diameter., and ore or several ma erI.iwrge frrrm a single scleroliuni. Asci are eight-spored, hyaline. cylindroclavate. 84-2510 X 4-23 pm. Ascospores unicellular, are 6-2X8 2--15.2 in, ovoid, hvaline, narrow at the base, and slightly inflated at the apex. IParaphyses are filiform and hyalirne (Fig. 55 bottono). " " .. B C Fig. 54. White mold: A, zonate lesions on stem; B, stem interior showing cavity containing Sclerotinia sclerotiorum mycelium and a sclerotium; C, sclerotia. 4P
Page 1 and 2:
, ,. ,o . ; , . o , . r. , -' .L ,
Page 3 and 4:
Compendium of Potato Diseases W. J.
Page 5 and 6:
In memory ofimy respected colleague
Page 7 and 8: Acknowledgments Planning Committee
Page 9 and 10: Introduction 1 Potato Disease 1 The
Page 11 and 12: A potato disease is an interaction
Page 13 and 14: Fig. 1.A, Lower portion of young po
Page 15 and 16: +q I B Fig 4. Natural openings in a
Page 17 and 18: Part I. Disease in the Absence of I
Page 19 and 20: more heavily in the vascular region
Page 21 and 22: the air temperature when tubers are
Page 23 and 24: iiO A B 'D C Fiq. 14 Second growth:
Page 25 and 26: identifying tissue bruised by black
Page 27 and 28: Internal Sprouting multiple sprouts
Page 29 and 30: conditions permits normal leaf deve
Page 31 and 32: Epidemiology Oxidant injury is pres
Page 33 and 34: sevritof stnting, chiorosis. loss o
Page 35 and 36: Selected Reference brown to bronze
Page 37 and 38: Part II. Disease in the Presence of
Page 39 and 40: should be planted on land with at l
Page 41 and 42: Control I) Use disease-free tubers
Page 43 and 44: FOI-SO M. D, and I. A. FRIEDMAN. )9
Page 45 and 46: Fungi Powdery Scab liberating powde
Page 47 and 48: Histopathology Sort of sporangia de
Page 49 and 50: any time but generally occurs late
Page 51 and 52: '40 ff .. . '1 f . ."L', . '1 .,. "
Page 53 and 54: A \, 2) Powdery mildew is rarely a
Page 55 and 56: R., Inst.. Kew. Surrey. ngland. 609
Page 57: TORRES, H.. E. R. FRENCH, and I.. W
Page 61 and 62: strands of pigmented hyphae. Sclero
Page 63 and 64: tuber malformation. Roots are also
Page 65 and 66: 1. Giant-hill plants, taller than n
Page 67 and 68: 13. Bacterial soft rot. Erwinia car
Page 69 and 70: 24. Wart. Synchytrium endobioticum
Page 71 and 72: 34. Pleospora herbarum (Stemphylium
Page 73 and 74: 44. Charcoal rot. Macrophomina phas
Page 75 and 76: 55. Leafroll virus. Current season
Page 77 and 78: 67. Mop-top virus. Primary tuber 68
Page 79 and 80: 77. Aster yellows mycoplasma sympto
Page 81 and 82: Symptoms Small, localized, light br
Page 83 and 84: obovoid, and 14-30 X 5-10 pm. Pycni
Page 85 and 86: invaders through the IFusarium lesi
Page 87 and 88: necrosis extending into the tuber t
Page 89 and 90: do not survive drying. Both species
Page 91 and 92: cauisal. Tesis Magister Scientiae e
Page 93 and 94: penetration, and subsequent disease
Page 95 and 96: have been demonstrated, including t
Page 97 and 98: In P..floridana,strains of PVY" and
Page 99 and 100: infects certain comnie,-cial stocks
Page 101 and 102: cytoplasm of infected potato cells
Page 103 and 104: WETTER, C. 1971. Potato virus S. No
Page 105 and 106: 3) Resistance has not been identifi
Page 107 and 108: nm), which do code for coat protein
Page 109 and 110:
Symptoms AMV may induce Other predo
Page 111 and 112:
Disease Cycle I)escriptions of Plan
Page 113 and 114:
Selected References KASSANIS, B. 19
Page 115 and 116:
Control 1)Avoid locations in wkhich
Page 117 and 118:
The "yellows" types of disease, cha
Page 119 and 120:
modifying cultural practices and by
Page 121 and 122:
immature females in the white or ye
Page 123 and 124:
l.aboratory, Control. and Quarantin
Page 125 and 126:
They attack many major crops in the
Page 127 and 128:
infested areas of North America sev
Page 129 and 130:
antennal tb l tuberce u antenna eye
Page 131 and 132:
carbon tetrachloride, applied at th
Page 133 and 134:
Diagnostic Microbial Structures Scl
Page 135 and 136:
Surface and or interior Shades of g
Page 137 and 138:
Equivalent Names of Potato Diseases
Page 139 and 140:
Common Name Causal Factor Other Nam
Page 141 and 142:
Common Name Causal Factor Other Nam
Page 143 and 144:
coalesce-union of similar structure
Page 145 and 146:
many days following removal of the
Page 147 and 148:
Index Abrasions, tuber surfaces. 14
Page 149:
Irost tolerance in. 9 aniligena. 68
show all

Compendium of Potato Diseases - (PDF, 101 mb) - USAID

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?