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

More documents

Recommendations

Info

l, I Fig. 42. Skin spot: A, on potato tuber; B, on stem and roots; C, Oolyscytalum pustulans(Oosporapustulans).Bar represents 25 jum. (A, Copyright National Institute of Agricultural Botany, Cambridge, England; B, courtesy Rothamsted Experimental Station, Harpenden, Herts, England; C, reprinted, by special permission, from More Dematiaceous Hypomycetes, by M. B. Ellis. 1976 Commonwealth Mycological Institute, Kew, Surrey, England) Control If)Skin spots aInd damnage to tuber eyes can be prevented by Leak stongueris diarl75in th) indethm.1'C) lhog h fungsn threain inectins.wherever viale 2) lDisinfection of'seed tubers soon after harvest w/ith fungi Leak, also called watery wound rot, may occur sporadically potatoes are grown. cides, including organomercurials and 2-aminobutane, is S m t m effective in preventing disease during storage. Sym p t ubs 3) Betnomyl and thiabendozole applied at harvest also appea brsarn decrease the disease. Because these materials persist inth tu ethe tuber appears r af e t d A di c l e .w t r-o k r a bie f ct on thdis n.ore d ieatrsae d e as to b ie solle au ndthe skin is mis t.sInternally skin;In prventspoulaionof P 17sitlan on eedtubrs, they greatly reduce subsequent infection of' plants and progeny tubers. diseased flesh is clearly demarcated from healthy tissue by a dark boundary line. Rotted tissue is spongy, wet, I.nd may have 4) Ther 1 fre putulns frin cn b prouce by 4) can propagating plants cr fretssvel.. from stem cuttings, although, to maintain tile health of' stocks, treatment with fungicide is needed to cavities. Oil cutting and exposure to air it changes color toogray pogsieytgrbowadfnlamstlakoc brownan. fialy almoste blcy sionally with it pink tinge. Affected tissue has the smoky gray prevent reinfection during their commercial multiplication. color of frosted tissue. After infection, at tuber may become so completely rotted (Plate 26) within ;I few days that even a slight Selected References, pressure causes the skin to rupture and large quantities of liquid to exude. In the storage pile, all that remains of infected tubers B()NA), A. F. W. 1972. IVotmo, storage dise~ases. Re~v. plant Patho)l. 5 1:297-32 1. BOYD,. A. E. W.. and .1. If. I.ENNARI). 1962. Se~asonal fluctuation in potato skin spot. Plant Pathol. I: 16 1-1 6. GRAIIAM, 1). C., G;.A. [JAMI1.T1ON, C'.F-.QUI NN. ad A. It.ittfi D R t I IV- E\ :N. 19 73. 1lfst If2-a in nobutane is a fuminiga nt for c trol of gangrene. skin spot and silver scurf diseases (it potato tube~rs. are the tuber shells with thin papery skins (Fig. 43A). Cut seed tubers may also be rotted. C u a r a i m !.'lit tli i to m r r v w,/ ,I.r lb '~ rla r a tt umH tI e se s ,a Idp d p s sil i l other P'thittm spp. cause the disease. Oospores, which are Potato Res. 16:1019-125. 11II)W. G. A.. ,1. M. IIIRS 1. and F. .1. MUIND)Y. 1969. The phonology fskin spot I0Or.spralpti~tulan.Ovn and Waktf.)and othr fungal diseass f potato tubers. Ann. Appl. Biol. 64:266-279. II. .A . M.IfIRS ,,and O.1I STIF MAN. 1973. Efftcts olskin sp t WOr sporal i.vtuha ) on potatoe~s An . Appl. Biol. 73:151-162. IIIRST,...M.. G;. A. IDE, R. L_CRI|:FIN, aInd 0. .. ";TEl)MAN. 1970. Improving the health of seecd potatoes. .1.Agric. Soc. E'ngl. smooth, thick-walled, and spherical, measure 14.2-19.5 um and are terminal on branched coenocytic hyphae. Sporangia (Fig. 43B and C) are spherical, 12-29 mam,when produced terminally and barrel-shaped, 17-27 X 14-24 mm, when intercalary. Sporangia of A.uhinum do not produce zoospores. The myceliumn is often difficult to isolate from diseased potato tissue. 131:87-106. l-RS'I, .1.M., and G. A. SAI.T. 1959. OosporaIp.tulan Owe~n and Wakefield it. ;Ipara,ite of potato ro)ot systems. Trans. H~r.Mycol. Soc. 42:59-66. K HtARAKOVA. A. 11 1961. On the biology of the causal agent f Disease Cycle The fungus lives in the soil and can enter tubers only through wounds. Infection, therefore, usually occurs at harvesting, grading, or less frequently at planting. Cut seed tubers are predisposed to infection fter planting its soil temperatures Mycpool.s 40:558. uan OenIdWaeild Myco. 40558.immature (Prepared by G. A. Hide) e. pl begin to rise. Serious crop loss does take place in bruised, tubers harvested during hot, dry weather. The rot that develops is gretly aggravated by relatively high temperatures 38
any time but generally occurs late in the season. Leaves become chlorotic, vilt. dry up, and abscise, starting at the stem base, Aerial tubers may form. Infection occurs in the roots, and all root, stolon, and stem tissues are killed as lesions develop. Stem lesions may extend up to the basal leaves, with water-soaking and light brown vascular discoloration at theadvancing margin. Necrotic stems and roots are brown to black and may be confused with blackleg. Tubers generally become infected (Plate 27) through diseased stolons, but some infections appear to occur at buds or lenticels. Rot proceeds uniformly through the tuber, with the advancing margin usually delimited by a dark line visible through the skin. Periderm over rotted portions is brownish-cream in white cultivars; tissues beneath lenticels are dark brown to black. • . Rotted tissues remain intact but are spongy. When recently or partially rotted tubers are cut, internal tissues are cream color, odorless, and rubbery or spongy in texture; if the cut tuber i, squeezed, aclear liquid appears. On exposure to air, the color of infected tissues progressively changes to salmon pink (in 20-30 4 rmin) brown, and black (in about I hr). Internal tissues of tubers 71 d rotted for somec time are black. " 3 Causal Orgarnism Pin, rot is most commonly caused by Phytophihora ert'throseptica Pethybr. Sporangia are nonpapillate, highly B C .. variable in shape, ellipsoid or obpyriform, and 43 X 26 mm. Oogonia, 30-35 mm in diameter, have smooth walls I pm thick Fig. 43. Leak: A, typical tuber shell rot. Pythium sp. from rotted and may turn faintly yellow with age. Antheridia are tuber: B, resting sporangium; C, spore with germ tube (bar amphigynous, ellipsoid orangular, and 14-16X 13pm. Oospores represents 20 pm). (Fig. 44) have walls 2.5 pm thick and nearly fill the oogonia. The fungus grows on several media but not on dilute malachite green. Optimum and maximum growth temperatures are and poor ventilation but may be completely arrested under cool 24-280 C and 340 C, respectively. Asexual structures form in conditions. mycelial mats when transferred successively to mineral solution and water or when grown in water culture with boiled hemp Other Hosts seeds. Sexual organs form abundantly in agar media. Both species of Pithium are pathogenic on an extremely wide P. cryp)togea Pethyb., P. drechseri'Fucker, P. megasp(erma range of hosts, including many market-garden crops, causing Drechsler, and P. parasitica Dastur also infect potatoes and damping-off, root rot, or soft rot disease, induce plant and or tuber symptoms similar to those caused by P. erthrosepica. Single strains of P. cr'vptogea form sexual Control organs only sparingly after a few weeks in culture but promptly I) losses can be minimized by delay in lifting the crop so that when grown with complementary strains of'. cr'tnamomi. The tuber skins may mature. dimensions of reproductive structures of P. rt*plogea are 2) Avoid mechanical injury to tubers by taking all possible similar to those of P. drechsleri,but its optimal growth temcare in harvesting. peratures (22-25 0 are lower than those (28-31"C) for P. 3) 1f rotting begins in storage, increase air movement, and drechseri.P. megaslwrma has paragynous antheridia, in concool and dry the crop as quickly as possible. trast to amphigynous antheridia in the other species, and it has larger oospores (an average of 41 pm vs. about 24-25 Pm). Selected References Sporangia of P. parasiticaare papillate, and those of the other species are nonpapillate. It I I.R,. I'.. and S. (i. .lt)NTS. 1949. IPlant Pathology. Macmillan and Co.. ltd.. London. 979 pp. MIITI)I.E-ON, .1. I. 1943. The taxonomy. host range and geographic r . " distribution ol the genus I'vthion. Wein. Torrey Iot. Cluh . i. . . 20:1-171. I)MPKINS. C. M. 1975. World literaturc on I'r'hitimand Rhi:octwi'n, Species and the IDisease% Ihey ('ause. (ontrib. No. 24. Reed lerbarium. Baltimore, 10 I). WIllIE ItAt). J.. J. I'. MINIOSII. and W. NI. FINI)LAY. 1953. The Polato ill Ilcalth and l)iscase. 3rd ed. Oliverand Boyd. London. 744 pp. (Prepared by A. R. McKenzie and C. HI.l.awrence) Pink Rot Pink rot has been reported from nine states in the United States and from II other countries in North and South America, Europe the Middle and Far East. and Australia. Symptoms Fig. 44. Pink rot. Meture oospore of Phytophthora erythroseptica Wi Iting. which issonilt imes t lie initial symptom. may occur at (bar represents 10 pm). (Courtesy R.C. Rowe and W.J. Hooker) 39
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: Histopathology Sort of sporangia de
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
show all

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

Create successful ePaper yourself

Delete template?

Save as template?