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

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Wk,- Fig. 22. Coiled sprout. (Courtesy M.A. Alli, J.H. Lennard, and A. E. W. Boyd) the time of planting, overmature seed tubers with long sprouts that may form tubers before sprouts emerge from the soil, and deep planting in compacted soil have been associated with the disorder. Ethylene in low concentrations as produced by sprouts induces coiled sprout characteristics. Control I) Avoid planting seed tubers with long sprouts. 2) Avoid planting in compacted soil resistant to sprout penetration. Selected References AI.l.M.A.. J. I. LENNARD. and A. . W. BOYD. 1970. Potato coiled sprout in relation to seed tuber storage treatment and to infection by 1I'rticillium nubihon Pethybr. Ann. Appl. fliol. 66:407-415. CAT(CffPOf,- A. i1., and .I. R. fIl1I IMAN. 1975. Studies of the coiled sprout disorder of the potato. Parts 2and 3. Potato Res. 18:539-545 and 597-607. COX, A. E. 1970. Early tuberisation associated with coiled sprout in Craigs Royal potatoes. Pliant Pattiol. 19 :49)-50. TIMM. I.., .1.C. BIS HOP. I. W. PERI)UE. I). W. GiRIMIES. R. E. VOSS. and 1), N. WRIGIII1. 1971. Soil crusting on potato plant emergence aid gros tli. Calif. Agric. 25(August):5-7. (Prepared by W. .1. Hooker) Hair Sprout Tubers with hair (or spindle) sprout germinate early, sometimes even before harvest, producing thin sprouts as small as 2 mm in diameter. A single produce tuber may normal 18 sprouts and hair sprouts fron d ifferent eves. Hot. dry conditiot.s in the late growing season, particularly during tuber development, favor hair sprout lormation. flair sprout has been induced in tubers of certain. but not all, culti\ars by warmrl water treatment for 2 fir at 45C. Virus infection has not been consistently associated with spindle sprouts. Early maturity foilowing attack by Colleiotrichum atramentarium may predispose to spindle sprout. Certain mvcoplasma (liseases (aster vellows) and pysllid yellows are also known to cause hair sprout. (See also genetic abnormalities -wildings and feathery wildings and internal heat necrosis.) Selected References ORAD. : A. G., and 1. P. SAN ROMAN. 1955. Conditions which dIetermine Stretntgers. spindling A. Ii. R. spotli licet'tistcr, of potto 1). Noo'daiun. in Spain. anidt .1. 1 ) . Lages 160 11. \Van dlr 171 in. :. \Want. eds. Proc. Second (onl. Potato Virus f)is.. lissc-Wagcningen, June 1954, II. Veenmnan an(f Zonen. Wageningcn. 193 pp. SNYDER. W. C., H., . I IIMAS, and S. J. I-AIRCIIl.tD Spindling 1946. or hair sprout of potato. Phytopathologv 36:897-904. STEINI-CK, 0. 1955. ntersuchungen und Bleohachtungen diber die Fadenkeimnigkeit %on 24:195-210. Kartoffelknollen. Phltopalhol. Z. SWENZI.. II. 1966. Fadenkeitnigkeit und Kallose-bildung durch Varnm\a .schearidundhg \on Kartolfelknolh.n. Re. Rourn. hiol. Ser. Ilot. 1:271-276. (prepared by W. .1. H,oker) Nonvirus Leafroll Leafrolling is a symptom with several unrelated causes. When carbohydrate translocation from the foliage is impaired, starch accumulates in the leaves, causing them to become leathery and roll upward (Fig. 23) in a way similar to that of virus lea froll. Leafroll-like symptoms, with or without chlorosis and pigmentation, red may accompany Rhiioctonia, Fusarium wilts. and other diseases; injury by mycoplasitas. and mechanical injury of stems. Leafrolling may also be genetic. Although genetic nonvirus leafroll has symptoms similar to those of' virus leafroll. its nonvirus origin was established by I'ailure of graft infect transfers suitable to indicator hosts. The recessive mutant gene (I r) causes starch accumulation in leaves, but anatomically defective phloem is not detectable. Certain nutritional soil conditions. such as nitrogen toxicity. also cause nonvirus leafroll. Rolling of leaves is uniformly intense from plant to plant. In contrast, leaf'roll severity in virus leafroll usually differs differ in considerably degree of response. between plants. Correction Cultivars of unsatisfactory soil - A4 B Fig. 23. Nonvirus leafroll: A, plant grown in calcareous muck; B, apparently normal plant grown in similar soil supplemented with sulfur. (Courtesy W.J. Hooker and G. C. Kent) :
conditions permits normal leaf development. Toproll affects the plant's apical leaves. Its symptoms are similar to those of virus leafroll, but toproll results from feeding by the potato aphid lfacrosiphum euphorhiacin the absence of thle leafroll vrus. When aphid feeding is discontinued, new growth is normal. Plants grown from progeny tubers are free from toproll and give normal yield. Selected References I)ZIEWONSKA. M. A.. and R. K. McKEE. 1965. Apparent virus infection in hcalthy potatoes. lotato Ies. 8:52. (0IBSON. R W. 11I75. Potato sced tubcrsdo not transmit lop-roll. Plant Pathol. 24:107-108. HOOKER. W. .1..and G. C. KENT. 1950. Sulfur and certain soil amendments for potato scab control in the peat soils of northern lossa. A\n. Potato .1.27:343-365. L.eCI1R(i, 1. I.. 1944. Non-s irus leafroll of Irish potatoes. Am. Potato .1.21:5-13. REESIMAN, A. l. 1973. Some observations on "toprol" in the Netherlands. Proc. Irienn, Conf.. Fur Assoc. Potato Res. 5:184. SIN NIMONIS, N. V. 1965. Mlutant expression in diploid potatoes, Ann. An'pl. Biol. 20:65-72. VOL K. G. M.. and N. (GAMMON. .r. 1954. Potato production in Florida as influenced by soil acidity and nitrogen sources. Am. Potato 1.31:83-92. (Prepared by W. J. Hooker) Hail Injury Hail tears and often perforate, leaves (Plate 4). Although the potato plant has a remarkable ability to recover from foliage damage, hail may caust defoliation sufficiently severe to impair y'ields. On stems. injury is localized at the point of impact; epidermal tissue turns gray with a paperlike sheen. Yield reduction varies with severity of injury, time of injury, and cultivar. (ireatest losses result from vine damage within 2-3 weeks after blossom set. Marketable yields are adversely affected through the relative increase in small tubers or in offshaped tubers. Specific gravity may be reduced when hail damages mature vines. Hail injury seldom predisposes foliage to infection except for the Ulocladium disease in the tropics. Selected Reference IBER .SFOR1).I.C. 1967. Effect of simulated hail damage on yield and quali.v of poiatoes. Am. Potato .. 44:347-354. (Prepared by W. .1.Hooker) Wind Injury Wind injury is evident on upper surfaces of leaves that, through wind movement, have been rubbed by other leaves, usually those directly above the affected area. Discolorid tissue is brown when dry, varies in size, has a glistening or oily appearance (Plate 5). and sometimes extends through the leaf. following severe high winds, leaves may be tattered at the edges and the plant may appear hard (non succulent). Verycold winds lasting for some time cause undersurfaces of leaves, particularly those turned over by the wind, to be brown, sometimes with a silvery or glassy leaf sheen. injur ay be more severe at the edges of the field. D uring harvest. tubers Lcafinjry e moein y rvin, sver harvest, sacks ay in attheedge tubrsi tile fied sacks m oftil av be ince fild.Am. damagedA fedtae damage by drying wind. Injury may become evident later during storage as sunken spots underlying the skinned portions of tubers. The surfaces may be overgrown with bacterial slime, causing decay in storage. Damage is greater with immature than with n,,tture tubers and with open mesh sacks than with tightly woven ones. Selected References GRACE,.. 1977. Plant Response to wind. Academic Press, New York. 204 pp. WHITEMAN, T. M.. and .1.M. LUTZ. 1954. Sunken scald spot field injury evident in stored potatoes. Am. Potato J. 31:43-49. (Prepared by W. J. Hooker) Light Injur Liggtuin Lightnir,- injury frequently accompanies severe thunderstornis, ';everity is influenced by field and plant hydration. Diagnosis of injured plants without information about the distribution of plant injury in the field is hazardous because plant symptoms may resemble those of blackleg or Rhizoctonia injury, and tuber symptoms may closely resemble those of ring rot. Bleached stems at soil line often resemble those injured by high temperatures. Symptoms Within a few minutes to a few hours following lightning, stems collapse and tops of plants irreversibly wilt. Leaves may remaiti green and turgid even though stems collapse. In most cases, injury extends 5-10 cm or more above the soil line; it rarely proceeds from the top downward. Affected portions are soft, water-soaked, and discolored black to brown. Tissues soon dry and become chocolate brown to tan, with the surfac= layer light tan to almost white. Pith collapse results in flattened, ribbed, or angular stems with longitudinal depressions of the surface. Collapsed pith forms horizontal plates, and when the stem is split longitudinally the pith pnears crosshatched or ladderlike (Fig. 24A). Leaf petioles in contact with soil are often collapsed. Belowground portions of stems and roots frequently escape injury. Water transport is often sufficient to maintain green, turgid tops, which may survive despite collapse of parenchymatous stem tissue. Injured tubers have brown to black skin necrosis with some cracking. Surfaces may be injured on opposite sides of the tuber, with intermediate cortex and pith becoming soft and remaining relatively normal in color for ashort time. Later, decay extends completely through the tuber, leaving a hole. Unaffected portions of tubers often remain solid. In some, the cortex is intact even though the pith iscompletely collapsed and watery. Tubers may resemble those affected by other diseases such as Pythium leak or bacterial ring rot (Fig. 24B). Epidemiology A field may show various patterns of injury: I ) areas in which all plants are killed adjacent to ciearly defined areas of healthy plants, 2) areas with dead plants at the center and progressively reduced injury toward the periphery, 3)poor defined arias with no focus of injury, in which plants with varying degrees of injury are scattered among dead plants and unaffected ones (Fig. 25), and 4) a number of scattered, relatively small foci containing seseral plants in various stages of injury. These variations result from differences in intensity of electrical discharge and from variations in soil hydration. Electrostatic discharge and conduction along irrigation pipes is related to field distribution of injured plants. Selected References HOOKER. W.J. 1973. Unusual aspects of lightning injury in potato. m Potato Poa oJ SAM J.50:258-269. 50 5 -69 )EL, G. 1940. Lightning injury to potato tubers. Ann. Appl. Biol. 27:196-198. WEBER. G. F. 1931. Lightning injury of potatoes. Phytopathology 21:213-218. (Prepared by W. J. Hooker) 19
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: Internal Sprouting multiple sprouts
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 and 58: TORRES, H.. E. R. FRENCH, and I.. W
Page 59 and 60: d AC D A 0 Fig 53 Gray mold. A, Bot
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
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