613:. These countries account for four of the top ten world producers of cocoa, CĂ´te d'Ivoire being the number one producer worldwide. In some cases, when left untreated, the pathogen has led to an 80% loss of cocoa pods. However, the infection may not always be localized on the pods. Cankers formed on the bark of the cocoa trees lead to a reduction of tree vigor and total yield, and in extreme cases, result in a 10% loss of trees annually. As the trees age pod production decreases; warnings of
37:
424:. Haustoria invade the plant intracellularly to retrieve nutrients while further dispersing the pathogen within the host. Chlamydospores that survive in the soil produce mycelia that can also infect plant structures. Infections of stems and branches lead to the formation of cankers while infections on cocoa pods cause pod rot. The development of cankers has also been associated with insects that burrow into the bark of cocoa trees.
208:. This pathogen can cause detrimental loss of yield in the economically important cocoa industry, worth approximately $ 70 billion annually. It can damage any part of the tree, causing total yield losses which can easily reach 20-25%. A mixture of chemical and cultural controls, as well as choosing resistant plant varieties, are often necessary to control this pathogen.
360:
plays an important role in the infection of the cocoa trees; mycelium found in the soil and in cankers on the bark develops into sporangia, which can then germinate. Zoospores are produced from these sporangia as secondary inoculum. They may infect the plant either directly or indirectly depending on
277:
can be seen growing on these spots 3 to 5 days following their emergence. The spots will grow and darken in color until eventually the entire pod turns black and becomes mummified. In more advanced stages, the pathogen may take over the internal tissues and cause the cocoa beans to become warped.
375:
depends heavily on the correct environmental conditions to cause disease. Primary infections usually occur in June, however, disease peaks between August and
October. Under humid conditions a single pod may produce up to 4 million sporangia. These sporangia can be dispersed by rain, movement of
524:
Cultural practices not only reduce the incidence of disease but also allow for better use of chemical control. If the disease is not causing much damage, cultural control alone may be sufficient. Removal of infected plant parts reduces sporangial inoculum and is an effective cultural control.
529:
reduces the humidity of the surrounding air which is unfavorable for the production of sporangia. Frequently harvesting the pods reduces the amount of sporangial inoculum. Another form of cultural control is the burning of the pod husk piles to destroy additional sources of chlamydospores and
585:
trees in hopes of more effectively controlling the spread of black pod disease. Growing a cocoa variety with resistance can also increase the effectiveness of chemical applications. Resistance will also reduce the quantity of infectious plants, thereby reducing the amount of cultural control
515:
which can be damaging to the environment. Spraying is recommended 4-6 times a year from the last week of May to the end of the growing period. Overuse of chemicals will result in increasing amounts of heavy metals being absorbed into the environment.
465:
survives in the soil during elongated dry periods. When the conditions are right, zoospores swim toward the surface of the soil where a fine aerosol is produced in the presence of water to transport the spores to the pods. In comparison to
361:
the availability of water. A direct infection by the zoospore results in the production of more mycelia, which may develop into sporangia capable of releasing more inoculum or chlamydospores. Chlamydospores serve as survival structures for
1071:
Opoku, Isaac Y.; Akrofi, Andrews Y.; Appiah, Alex A. (1 February 2007). "Assessment of sanitation and fungicide application directed at cocoa tree trunks for the control of
Phytophthora black pod infections in pods growing in the canopy".
556:
Though this method has shown positive results, the formulation is not practical for such a wet, tropical region. Research is being done into examining different formulations that can more effectively be applied.
282:
also readily forms stem cankers that are usually confined to the lower part of the tree, but may be present anywhere on the tree. Canker lesions may extend beneath the soil surface, providing a source of primary
457:, primarily in the forested areas of the countries. The forested regions of West Africa near the equator receive 1500mm to 2000mm of rain; cocoa is planted in these areas where the forest is cleared. Since
1194:
Ford, Tamasin, Jonathan Vit, Rupert Neate, Tania
Branigan, and Emine Saner. "The Cocoa Crisis: Why the World's Stash of Chocolate Is Melting Away." The Guardian. 21 November 2014. Web. 21 October 2015.
581:
and black pod disease is looking at the cellular processes involved in infection. Through the examination and understanding of these processes, researchers can alter the genetic makeup of
261:, can form on stems and branches as a result of disease. Infected cocoa pods rot and turn black, providing insight on the origin of the disease name. Other symptoms that may occur include
511:+Mancozeb are typically used. Mixtures of these chemicals can be used to prevent the pathogen from acquiring resistance to certain chemical compounds. Many of these fungicides contain
889:
Helliwell, Emily E.; Vega-ArreguĂn, Julio; Shi, Zi; Bailey, Bryan; Xiao, Shunyuan; Maximova, Siela N.; Tyler, Brett M.; Guiltinan, Mark J. (March 2016). "Enhanced resistance in
1405:
491:
Chemical control is often necessary to conserve yield, although it can come at a very high price. Chemical control targets the initial inoculum, reducing the amount of
1320:
245:
that can infect any part of the cacao tree at any time under optimal environmental conditions. Trees as young as seedlings may show symptoms of infection such as
1359:
1122:
Mbarga, Joseph; Begoude, Didier; Ambang, Zachee; Meboma, M; Kuate, J; Schiffers, Bruno; Ewbank, William; Dedieu, Laurence; Ten Hoopen, Gerben (1 October 2014).
474:
is able to produce greater quantities of inoculum more quickly and can distribute it earlier in the season; thus it may infect more pods in a shorter time than
235:, causing the greatest percentage of yield loss. This pathogen causes black pod disease which produces an array of symptoms throughout the host’s life cycle.
1163:
David Guest, (2006). “Black Pod: Diverse
Pathogens with a Global Impact on Cocoa Yield” Cacao Diseases: Important Threats to Chocolate Production Worldwide
956:
Latijnhouwers, Maita, Pierre J.G.M. De Wit, and
Francine Govers. "Oomycetes and Fungi: Similar Weaponry to Attack Plants." Cell Press 11.10 (2003): 462-69.
1294:
445:
dominate. West Africa’s environment is characterized by a dry season from
November until February. During this time, moisture-laden air from the
435:
spp. occur wherever cocoa is grown and is the most economically detrimental pathogen of cocoa in West Africa where the two species
36:
1333:
1212:
1364:
225:, or the cocoa tree, located in West and Central Africa. It is considered to be the most virulent species of
1410:
166:
1223:
893:
against oomycete and fungal pathogens by secretion of phosphatidylinositol-3-phosphate-binding proteins".
544:
441:
851:
M. A. Barreto et al. (2015). “Detection of genetic resistance to cocoa black pod disease caused by three
577:
will increase the plant's resistance to both pathogens simultaneously. Much of the current research into
1400:
150:
365:, in some instances surviving as long as 18 months. An indirect infection results in the formation of
1286:
1255:
242:
273:
is quite rapid. Small translucent spots on the pod can be seen 2 to 3 days after infection. Whitish
968:
Prabha, K Peter and R. Chandramohanan (2014). Integrated management of black pod disease caused by
454:
170:
1097:
936:
500:
417:
401:
31:
1325:
990:
Agriculture and
Consumer Protection. Integrating crops and wildlife in West Africa. Chapter 1.
1372:
1089:
1054:
1029:
928:
920:
868:
759:
751:
713:
705:
512:
369:
spores in the absence of water; mycelium production occurs after germination of these spores.
193:
1377:
1143:
1081:
1021:
910:
902:
743:
695:
664:
405:
221:
197:
117:
617:
shortages as soon as 2020 have been predicted based on the combination of these factors.
565:
Choosing a resistant variety of plant is an effective method of minimizing the damage of
1281:
205:
189:
107:
74:
61:
1025:
548:
is used as a biological control agent. It is applied as a wettable powder, containing
1394:
1147:
1123:
449:
moves in, providing ideal moisture conditions for the growth of both cocoa trees and
349:
337:
266:
254:
1172:"Top 10 Cocoa Producing Countries." WorldAtlas. 22 April 2015. Web. 22 October 2015.
991:
940:
1101:
413:
385:
302:
227:
127:
87:
597:
is the most important cocoa pathogen in central and west Africa. It is endemic to
1246:
1207:
1307:
1061:. Research article, International Journal of Plant Protection, Volume 7 issue 1.
972:. Research article, International Journal of Plant Protection, Volume 7 issue 1.
610:
461:
favors wet conditions, these forested regions are ideal during the wet seasons.
353:
262:
201:
1181:
Djiekpor EK, Goka K, Lucas P, Partiot M, (1981). Cocoa black pod rot caused by
495:
and sporangia present. In west Africa chemicals are applied using spray tanks.
1085:
412:
is formed during germination of the zoospore which typically gives rise to an
306:
298:
1185:
sp. in Togo: assessment and control strategies. Cafe Cacao The, 25(4):263-268
1093:
1033:
924:
755:
747:
709:
700:
683:
1268:
668:
614:
508:
496:
421:
409:
397:
329:
310:
284:
48:
1338:
932:
763:
717:
400:, and penetrate host tissues. For the pathogen to enter a plant cell, the
328:
that has a polycyclic disease cycle, producing three asexual spore types:
1346:
1240:
734:
Evans, Harry C. (December 2007). "Cacao diseases-the trilogy revisited".
598:
504:
492:
376:
planting materials, insects, rodents, and contaminated harvesting tools.
357:
333:
325:
250:
186:
97:
813:
269:, premature drop, soft rot, and shriveling. The process of infection by
1312:
1299:
1053:
Prabha, K Peter and R. Chandramohanan (2014). Integrated management of
915:
602:
549:
526:
446:
345:
906:
1351:
684:"Cacao diseases: important threats to chocolate production worldwide"
366:
258:
246:
1217:
1008:
Akrofi, A.Y; Appiah, A.A; Opoku, I.Y (1 April 2003). "Management of
1273:
606:
274:
1128:
for the biological control of cacao black pod disease caused by
530:
sporangia. These cultural practices can limit disease caused by
1260:
1221:
818:: A Review on its Status as a Pathogen on Cacao in West Africa"
453:. Cocoa is known to grow well in countries that occur in the
837:(Black Pod of Cocoa). “Invasive Species Compendium”. CABI
408:
of the plant, thereby getting carried into the cell. A
655:: A potential threat to the cocoa industry in Ghana".
651:
Opoku, IY; Appiah, AA; Akrofi, AY; Owusu, GK (2000). "
396:
need free water on plant surfaces in order to encyst,
1230:
855:
species”. Springer
Science+Business Media Dordrecht
992:http://www.fao.org/docrep/004/x6543e/x6543e01.htm
964:
962:
8:
392:. Like all oomycetes, zoospores produced by
986:
984:
982:
980:
978:
1218:
1012:pod rot disease on cocoa farms in Ghana".
609:and is present as an invasive pathogen in
404:of the pathogen must attach itself to the
20:
952:
950:
914:
699:
1406:Water mould plant pathogens and diseases
1159:
1157:
626:
1049:
1047:
1045:
1043:
863:
861:
646:
644:
642:
640:
638:
636:
634:
632:
630:
1117:
1115:
1113:
1111:
1003:
1001:
999:
847:
845:
843:
807:
805:
803:
801:
799:
797:
795:
793:
657:Ghana Journal of Agricultural Science
569:. Breeding for resistance for either
420:cells of the plant’s tissue and form
313:growing off of medium-length stalks.
7:
884:
882:
880:
878:
791:
789:
787:
785:
783:
781:
779:
777:
775:
773:
729:
727:
352:mating which requires two different
1074:European Journal of Plant Pathology
682:Ploetz, Randy C. (December 2007).
356:; so far none have been observed.
14:
416:. These structures penetrate the
16:Species of single-celled organism
1148:10.1016/j.biocontrol.2014.06.004
1124:"A new oil-based formulation of
293:can be distinguished from other
35:
542:In certain regions of Africa,
301:. These gametangia have large
1:
1026:10.1016/S0261-2194(02)00193-X
297:species by its production of
822:African Crop Science Journal
384:Not much is known about the
895:Plant Biotechnology Journal
1427:
1086:10.1007/s10658-006-9082-8
156:
149:
32:Scientific classification
30:
23:
1213:USDA ARS Fungal Database
748:10.1094/PHYTO-97-12-1640
701:10.1094/PHYTO-97-12-1634
344:can also produce sexual
869:"Phytophthora Database"
669:10.4314/gjas.v33i2.1876
340:. Although it is rare,
305:containing five to six
217:Phytophthora megakarya'
1232:Phytophthora megakarya
1130:Phytophthora megakarya
1126:Trichoderma asperellum
1059:Phytophthora palmivora
970:Phytophthora palmivora
835:Phytophthora megakarya
816:Phytophthora megakarya
812:Akrofi, A. Y. (2015).
653:Phytophthora megakarya
595:Phytophthora megakarya
545:Trichoderma asperellum
182:Phytophthora megakarya
160:Phytophthora megakarya
25:Phytophthora megakarya
219:s only known host is
265:, dieback, lesions,
243:facultative parasite
1136:Biological Control
561:Genetic resistance
538:Biological control
501:copper oxychloride
212:Hosts and symptoms
1388:
1387:
1373:Open Tree of Life
1224:Taxon identifiers
1055:black pod disease
907:10.1111/pbi.12436
742:(12): 1640–1643.
694:(12): 1634–1639.
194:black pod disease
178:
177:
142:P. megakarya
1418:
1381:
1380:
1368:
1367:
1355:
1354:
1342:
1341:
1329:
1328:
1316:
1315:
1303:
1302:
1290:
1289:
1277:
1276:
1264:
1263:
1251:
1250:
1249:
1219:
1195:
1192:
1186:
1179:
1173:
1170:
1164:
1161:
1152:
1151:
1119:
1106:
1105:
1068:
1062:
1051:
1038:
1037:
1005:
994:
988:
973:
966:
957:
954:
945:
944:
918:
886:
873:
872:
865:
856:
849:
838:
832:
826:
825:
809:
768:
767:
731:
722:
721:
703:
679:
673:
672:
648:
520:Cultural control
487:Chemical control
402:effector protein
162:
40:
39:
21:
1426:
1425:
1421:
1420:
1419:
1417:
1416:
1415:
1391:
1390:
1389:
1384:
1376:
1371:
1363:
1358:
1350:
1345:
1337:
1332:
1324:
1319:
1311:
1306:
1298:
1293:
1285:
1280:
1272:
1267:
1259:
1254:
1245:
1244:
1239:
1226:
1204:
1199:
1198:
1193:
1189:
1180:
1176:
1171:
1167:
1162:
1155:
1121:
1120:
1109:
1070:
1069:
1065:
1052:
1041:
1014:Crop Protection
1007:
1006:
997:
989:
976:
967:
960:
955:
948:
891:Theobroma cacao
888:
887:
876:
867:
866:
859:
850:
841:
833:
829:
811:
810:
771:
733:
732:
725:
681:
680:
676:
650:
649:
628:
623:
592:
563:
540:
534:significantly.
522:
489:
484:
430:
406:binding protein
382:
319:
257:wounds, called
222:Theobroma cacao
214:
174:
164:
158:
145:
118:Peronosporaceae
34:
17:
12:
11:
5:
1424:
1422:
1414:
1413:
1411:Cacao diseases
1408:
1403:
1393:
1392:
1386:
1385:
1383:
1382:
1369:
1356:
1343:
1330:
1317:
1304:
1291:
1278:
1265:
1252:
1236:
1234:
1228:
1227:
1222:
1216:
1215:
1210:
1208:Index Fungorum
1203:
1202:External links
1200:
1197:
1196:
1187:
1174:
1165:
1153:
1107:
1063:
1039:
1020:(3): 469–477.
995:
974:
958:
946:
901:(3): 875–886.
874:
857:
839:
827:
769:
736:Phytopathology
723:
688:Phytopathology
674:
625:
624:
622:
619:
591:
588:
562:
559:
554:T. asperellum.
539:
536:
521:
518:
488:
485:
483:
480:
429:
426:
381:
378:
338:chlamydospores
318:
315:
231:which infects
213:
210:
206:central Africa
190:plant pathogen
176:
175:
165:
154:
153:
147:
146:
139:
137:
133:
132:
125:
121:
120:
115:
111:
110:
108:Peronosporales
105:
101:
100:
95:
91:
90:
85:
78:
77:
72:
65:
64:
62:Diaphoretickes
59:
52:
51:
46:
42:
41:
28:
27:
15:
13:
10:
9:
6:
4:
3:
2:
1423:
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1201:
1191:
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1133:
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1127:
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1103:
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1087:
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1079:
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1060:
1056:
1050:
1048:
1046:
1044:
1040:
1035:
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1027:
1023:
1019:
1015:
1011:
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1002:
1000:
996:
993:
987:
985:
983:
981:
979:
975:
971:
965:
963:
959:
953:
951:
947:
942:
938:
934:
930:
926:
922:
917:
912:
908:
904:
900:
896:
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848:
846:
844:
840:
836:
831:
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823:
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788:
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776:
774:
770:
765:
761:
757:
753:
749:
745:
741:
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728:
724:
719:
715:
711:
707:
702:
697:
693:
689:
685:
678:
675:
670:
666:
662:
658:
654:
647:
645:
643:
641:
639:
637:
635:
633:
631:
627:
620:
618:
616:
612:
611:CĂ´te d'Ivoire
608:
604:
600:
596:
589:
587:
584:
580:
576:
572:
568:
560:
558:
555:
551:
547:
546:
537:
535:
533:
528:
519:
517:
514:
510:
506:
502:
498:
494:
486:
481:
479:
477:
473:
469:
464:
460:
456:
455:subhumid zone
452:
448:
444:
443:
438:
434:
427:
425:
423:
419:
415:
411:
407:
403:
399:
395:
391:
387:
379:
377:
374:
370:
368:
364:
359:
355:
351:
350:heterothallic
347:
343:
339:
335:
331:
327:
323:
317:Disease cycle
316:
314:
312:
308:
304:
300:
296:
292:
288:
286:
281:
276:
272:
268:
267:mummification
264:
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256:
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244:
240:
236:
234:
230:
229:
224:
223:
218:
211:
209:
207:
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199:
195:
191:
188:
184:
183:
172:
168:
163:
161:
155:
152:
151:Binomial name
148:
144:
143:
138:
135:
134:
131:
130:
126:
123:
122:
119:
116:
113:
112:
109:
106:
103:
102:
99:
96:
93:
92:
89:
88:Stramenopiles
86:
83:
80:
79:
76:
73:
70:
67:
66:
63:
60:
57:
54:
53:
50:
47:
44:
43:
38:
33:
29:
26:
22:
19:
1401:Phytophthora
1231:
1190:
1183:Phytophthora
1182:
1177:
1168:
1139:
1135:
1129:
1125:
1077:
1073:
1066:
1058:
1017:
1013:
1010:Phytophthora
1009:
969:
898:
894:
890:
853:Phytophthora
852:
834:
830:
821:
815:
739:
735:
691:
687:
677:
660:
656:
652:
594:
593:
582:
579:P. megakarya
578:
575:P. megakarya
574:
571:P. palmivora
570:
567:P. megakarya
566:
564:
553:
543:
541:
532:P. megakarya
531:
523:
513:heavy metals
490:
476:P. palmivora
475:
472:P. megakarya
471:
468:P. palmivora
467:
463:P. megakarya
462:
459:P. megakarya
458:
451:P. megakarya
450:
442:P. palmivora
440:
437:P. megakarya
436:
433:Phytophthora
432:
431:
414:appressorium
394:P. megakarya
393:
390:P. megakarya
389:
386:pathogenesis
383:
380:Pathogenesis
373:P. megakarya
372:
371:
363:P. megakarya
362:
354:mating types
342:P. megakarya
341:
322:P. megakarya
321:
320:
295:Phytophthora
294:
291:P. megakarya
290:
289:
280:P. megakarya
279:
271:P. megakarya
270:
239:P. megakarya
238:
237:
232:
228:Phytophthora
226:
220:
216:
215:
192:that causes
181:
180:
179:
171:M.J. Griffin
159:
157:
141:
140:
129:Phytophthora
128:
81:
68:
55:
24:
18:
1308:iNaturalist
916:10919/97896
428:Environment
307:chromosomes
263:damping off
1395:Categories
1080:(2): 167.
1057:caused by
621:References
590:Importance
586:required.
552:flour and
497:Fungicides
482:Management
299:gametangia
1247:Q16976160
1142:: 15–22.
1094:0929-1873
1034:0261-2194
925:1467-7652
756:0031-949X
710:0031-949X
615:chocolate
509:Metalaxyl
422:haustoria
418:epidermal
410:germ tube
398:germinate
334:zoospores
330:sporangia
311:sporangia
200:trees in
136:Species:
49:Eukaryota
1347:MycoBank
1326:10388913
1282:Fungorum
1241:Wikidata
941:25355847
933:26214158
764:18943725
718:18943724
599:Cameroon
583:T. cacao
505:Mancozeb
499:such as
493:mycelium
367:encysted
358:Mycelium
348:through
346:oospores
326:oomycete
285:inoculum
251:root rot
233:T. cacao
187:oomycete
114:Family:
98:Oomycota
94:Phylum:
45:Domain:
1313:1452519
1300:3203681
1102:6620069
603:Nigeria
550:cassava
527:Weeding
447:equator
259:cankers
167:Brasier
124:Genus:
104:Order:
1378:252692
1352:320483
1287:320483
1274:PHYTMG
1261:193296
1100:
1092:
1032:
939:
931:
923:
762:
754:
716:
708:
605:, and
507:, and
336:, and
324:is an
303:nuclei
275:spores
247:blight
185:is an
169:&
1339:40979
1321:IRMNG
1098:S2CID
937:S2CID
663:(2).
607:Ghana
241:is a
198:cocoa
173:(1979
82:Clade
69:Clade
56:Clade
1365:4795
1360:NCBI
1295:GBIF
1269:EPPO
1090:ISSN
1030:ISSN
929:PMID
921:ISSN
760:PMID
752:ISSN
714:PMID
706:ISSN
439:and
309:and
255:Bark
204:and
202:west
1334:ISC
1256:EoL
1144:doi
1082:doi
1078:117
1022:doi
911:hdl
903:doi
744:doi
696:doi
665:doi
573:or
388:of
249:or
196:in
75:SAR
1397::
1375::
1362::
1349::
1336::
1323::
1310::
1297::
1284::
1271::
1258::
1243::
1156:^
1140:77
1138:.
1134:.
1110:^
1096:.
1088:.
1076:.
1042:^
1028:.
1018:22
1016:.
998:^
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961:^
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935:.
927:.
919:.
909:.
899:14
897:.
877:^
860:^
842:^
820:.
772:^
758:.
750:.
740:97
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726:^
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704:.
692:97
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686:.
661:33
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503:,
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470:,
332:,
287:.
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1146::
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1104:.
1084::
1036:.
1024::
943:.
913::
905::
871:.
824:.
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766:.
746::
720:.
698::
671:.
667::
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