245:. Presently, it is believed that the stromata overwinter on corn and soil residue. This is the primary inoculum that must be destroyed if the cycle is to be interrupted. Providing optimal temperatures, humidity and rainfall however, ascospores and conidia will be released in a gelatinous mass on the stromata. Both wind and precipitation are used to disperse the spores; however it is solely the ascospores that infect other plants. The role of conidia in the reproductive cycle is still unknown. The ascospores are released in bunches, and can travel as much as 80 yards (73 m) with wind dispersion. Following infection, new stromata can form within 12–15 days in infected tissue, producing additional ascospores and conidia. Given the polycyclic nature of this pathogen, as well as the ability to infect corn at any developmental stage, it is extremely hard to manage.
37:
307:
the pathogen. During 2015 and 2018 when there was a high incidence of tar spot, the weather was warmer with high humidity and precipitation frequency, possibly attributing to the increased number of cases reported. Additional research is needed to understand the optimal conditions for propagation of this disease in the
Midwest.
199:. The first symptoms are yellowing spots on both upper and lower leaf surfaces. Within the spot develops the characteristic black stromata over the ascomata, along with chlorosis of surrounding tissue. The chlorotic rings may be elliptical, circular, or may conjoin to form striping up to 10 millimetres (
306:
In Latin
America, the disease propagated quickly in temperatures ranging from 60–70 °F (16–21 °C) with high humidity. Long periods of moisture on the leaf surface also increased the disease incidence. However, in the Midwest, it is still unknown as to the conditions that are preferred by
325:
by reducing lesion size due to hyperparasitism. Chemical control with one or two treatments of
Fenpropimorph or Mancozeb applied every ten days were the most effective fungicides used in field trials. Although no cultivars currently exist that are immune to this pathogen, CIMMYT has developed 14
469:
Kleczewski, Nathan M; Plewa, Diane E; Bissonnette, Kaitlyn M; Bowman, Norman D; Byrne, Jan M; LaForest, Joseph; Dalla-Lana, Felipe; Malvick, Dean K; Mueller, Daren S; Chilvers, Martin I; Paul, Pierce A; Raid, Richard N; Robertson, Alison E; Ruhl, Gail E; Smith, Damon L; Telenko, Darcy E P
315:
A basic control measure that could be implemented is residue management. By tilling the field and rotating crops, this helps reduce the primary inoculum that overwinters on stalks and other residue. A biological control method that has shown potential is the infection with
297:
in 2019. Tar spot appeared in
Wisconsin in Green and Iowa counties in 2016, and had become a serious problem by 2018. When surveyed by the university and DATCP, it was found that 33 counties had recorded cases, and 77 of 79 fields surveyed, or 97 percent, showed signs.
248:
The pathogen progresses from the lower leaves to the upper leaves and husks. As many as 4000 clypeus may form on a leaf, resulting in 80% of affected leaf area. Given optimal conditions, total leaf death can occur in as little as twenty one days.
338:, and poor kernel fill resulting in up to a 30 bushel loss per acre. Increased lodging and stalk rot have also been associated with intense cases. Losses have become severe in some areas of the USA since 2018.
175:. Identified by the distinctive development of stroma, this pathogen in itself is of little economic importance in the production of corn. However, the accompanying fungal infection of
755:
233:. Research is ongoing to determine the exact cause of these lesions. Symptoms have been recorded as early as V3, but are most commonly observed during R3-R6 on or below the ear leaves.
444:
722:
Vasal, SK; Srinivasan, G; Cordova, H; Pandey, S; Jeffers, D; Bergvinson, D; Beck, D (1999). "Inbred Line
Evaluation Nurseries and Their Role in Maize Breeding at CIMMYT".
873:
912:
958:
860:
209: in) long. Some of the chlorotic tissue around the ascomata may become necrotic with darker edges, forming the indicative 3–8 millimetres (
476:
587:
485:
381:
548:
Hock, J; Dittrich, U; Renfro, BL; Kranz, J (1992). "Sequential
Development of Pathogens in the Maize Tarspot Disease Complex".
187:
damage and subsequently yield reduction. As of 2021 there is insufficient information about this pathogen and its management.
326:
inbred lines in Latin
America that are highly resistant. However, most hybrids used in the Midwest have proven susceptible.
373:
708:
681:
Hock, J; Kranz, J; Renfro, BL (1995). "Studies on the
Epidemiology of the Tar Spot Disease Complex of Maize in Mexico".
886:
745:
36:
917:
229: in) "fish-eye". The presence of these lesions is not universal, nor is the association of these lesions with
321:
968:
963:
953:
489:
608:
Bajet, NB; Renfro, BL; Valdez
Carrasco, JM (1994). "Control of Tar Spot of Maize and its Effect on Yield".
776:
472:"Documenting the Establishment, Spread, and Severity of Phyllachora maydis on Corn, in the United States"
131:
852:
821:
565:
31:
878:
925:
808:
503:
348:
930:
690:
617:
557:
530:
493:
660:
98:
78:
847:
694:
160:
88:
947:
569:
813:
318:
799:
638:
108:
534:
621:
164:
68:
507:
834:
294:
286:
48:
891:
498:
471:
432:
401:
899:
793:
335:
290:
278:
262:
865:
561:
409:
270:
266:
904:
184:
180:
58:
770:
839:
168:
826:
521:
Liu, LJ (1973). "Incidence of Tar Spot of Corn in Puerto Rico".
282:
274:
774:
195:
This pathogen is an obligate parasite solely of the species
756:
523:
Journal of Agriculture of the University of Puerto Rico
464:
462:
460:
783:
445:
Centre for Agriculture and Bioscience International
639:"Maize Diseases: A guide for field identification"
261:appeared in the US for the first time in 2015 in
643:International Maize and Wheat Improvement Center
709:"Diagnostic Fact Sheet for Phyllachora maydis"
374:"Diagnostic Fact Sheet for Phyllachora maydis"
8:
676:
674:
257:Native to the Americas, from Mexico south,
771:
20:
497:
241:Little is known about the progression of
661:"Bureau of Plant Industry Annual Report"
610:International Journal of Pest Management
365:
171:, and is more commonly referred to as
477:Journal of Integrated Pest Management
7:
633:
631:
603:
601:
581:
579:
470:(2020-01-01). Walker, Nathan (ed.).
427:
425:
959:Fungal plant pathogens and diseases
586:Kleczewski, Nathan (January 2019).
183:, was claimed to cause significant
695:10.1111/j.1365-3059.1995.tb01671.x
14:
649:: 1–119. 2003 – via CIMMYT.
486:Entomological Society of America
382:U.S. National Fungus Collections
334:Tar spot causes low ear weight,
35:
1:
985:
535:10.46429/jaupr.v57i3.10745
622:10.1080/09670879409371868
588:"Corn Disease Management"
179:identified by "fish-eye"
137:
130:
32:Scientific classification
30:
23:
443:. Oxfordshire, England:
592:Crop Protection Network
437:(black spot of maize)"
177:Monographella maydis,
499:10.1093/jipm/pmaa012
402:"Phyllachora maydis"
330:Economic importance
785:Phyllachora maydis
748:Phyllachora maydis
562:10.1007/BF00442777
435:Phyllachora maydis
243:Phyllachora maydis
191:Symptoms and signs
156:Phyllachora maydis
141:Phyllachora maydis
25:Phyllachora maydis
941:
940:
926:Open Tree of Life
777:Taxon identifiers
349:Rhytisma acerinum
152:
151:
16:Species of fungus
976:
934:
933:
921:
920:
908:
907:
895:
894:
882:
881:
869:
868:
856:
855:
843:
842:
830:
829:
817:
816:
804:
803:
802:
772:
767:
765:
764:
732:
731:
719:
713:
712:
705:
699:
698:
678:
669:
668:
657:
651:
650:
635:
626:
625:
605:
596:
595:
583:
574:
573:
545:
539:
538:
518:
512:
511:
501:
466:
455:
454:
452:
451:
429:
420:
419:
417:
416:
398:
392:
391:
389:
388:
370:
228:
227:
223:
218:
217:
213:
208:
207:
203:
143:
40:
39:
21:
984:
983:
979:
978:
977:
975:
974:
973:
944:
943:
942:
937:
929:
924:
916:
911:
903:
898:
890:
885:
877:
872:
864:
859:
851:
846:
838:
833:
825:
820:
812:
807:
798:
797:
792:
779:
762:
760:
744:
741:
736:
735:
721:
720:
716:
707:
706:
702:
683:Plant Pathology
680:
679:
672:
665:Wisconsin DATCP
659:
658:
654:
637:
636:
629:
607:
606:
599:
585:
584:
577:
547:
546:
542:
520:
519:
515:
468:
467:
458:
449:
447:
431:
430:
423:
414:
412:
406:www.uniprot.org
400:
399:
395:
386:
384:
378:nt.ars-grin.gov
372:
371:
367:
362:
344:
332:
313:
304:
255:
239:
225:
221:
220:
215:
211:
210:
205:
201:
200:
193:
148:
145:
139:
126:
99:Phyllachoraceae
79:Sordariomycetes
34:
17:
12:
11:
5:
982:
980:
972:
971:
969:Fungus species
966:
964:Maize diseases
961:
956:
954:Phyllachorales
946:
945:
939:
938:
936:
935:
922:
909:
896:
883:
870:
857:
844:
831:
818:
805:
789:
787:
781:
780:
775:
769:
768:
740:
739:External links
737:
734:
733:
714:
700:
689:(3): 490–502.
670:
652:
627:
616:(2): 121–125.
597:
575:
556:(3): 157–161.
550:Mycopathologia
540:
513:
456:
421:
393:
364:
363:
361:
358:
357:
356:
352:, also called
343:
340:
331:
328:
312:
309:
303:
300:
254:
251:
238:
235:
192:
189:
161:plant pathogen
150:
149:
146:
135:
134:
128:
127:
123:P. maydis
120:
118:
114:
113:
106:
102:
101:
96:
92:
91:
89:Phyllachorales
86:
82:
81:
76:
72:
71:
66:
62:
61:
56:
52:
51:
46:
42:
41:
28:
27:
15:
13:
10:
9:
6:
4:
3:
2:
981:
970:
967:
965:
962:
960:
957:
955:
952:
951:
949:
932:
927:
923:
919:
914:
910:
906:
901:
897:
893:
888:
884:
880:
875:
871:
867:
862:
858:
854:
849:
845:
841:
836:
832:
828:
823:
819:
815:
810:
806:
801:
795:
791:
790:
788:
786:
782:
778:
773:
759:
757:
751:
749:
743:
742:
738:
729:
725:
718:
715:
710:
704:
701:
696:
692:
688:
684:
677:
675:
671:
666:
662:
656:
653:
648:
644:
640:
634:
632:
628:
623:
619:
615:
611:
604:
602:
598:
593:
589:
582:
580:
576:
571:
567:
563:
559:
555:
551:
544:
541:
536:
532:
528:
524:
517:
514:
509:
505:
500:
495:
491:
487:
483:
479:
478:
473:
465:
463:
461:
457:
446:
442:
438:
436:
428:
426:
422:
411:
407:
403:
397:
394:
383:
379:
375:
369:
366:
359:
355:
351:
350:
346:
345:
341:
339:
337:
329:
327:
324:
323:
320:
310:
308:
301:
299:
296:
292:
288:
284:
280:
276:
272:
268:
264:
260:
252:
250:
246:
244:
237:Disease cycle
236:
234:
232:
198:
190:
188:
186:
182:
178:
174:
170:
166:
162:
158:
157:
144:
142:
136:
133:
132:Binomial name
129:
125:
124:
119:
116:
115:
112:
111:
107:
104:
103:
100:
97:
94:
93:
90:
87:
84:
83:
80:
77:
74:
73:
70:
67:
64:
63:
60:
57:
54:
53:
50:
47:
44:
43:
38:
33:
29:
26:
22:
19:
784:
761:. Retrieved
753:
747:
727:
723:
717:
703:
686:
682:
664:
655:
646:
642:
613:
609:
591:
553:
549:
543:
526:
522:
516:
481:
475:
448:. Retrieved
441:www.cabi.org
440:
434:
413:. Retrieved
405:
396:
385:. Retrieved
377:
368:
353:
347:
333:
322:phyllochorae
319:Coniothyrium
317:
314:
305:
258:
256:
253:Distribution
247:
242:
240:
230:
196:
194:
176:
172:
167:diseases in
155:
154:
153:
140:
138:
122:
121:
109:
24:
18:
529:: 211–216.
302:Environment
110:Phyllachora
948:Categories
763:2021-11-08
730:: 341–351.
450:2020-01-11
415:2020-01-11
387:2020-01-11
360:References
311:Management
169:maize/corn
165:ascomycete
69:Ascomycota
65:Division:
800:Q10629416
508:2155-7470
295:Wisconsin
287:Minnesota
259:P. maydis
231:M. maydis
117:Species:
55:Kingdom:
49:Eukaryota
900:MycoBank
879:11102775
848:Fungorum
794:Wikidata
570:35279090
492:): 1–5.
380:. U.S.:
354:tar spot
342:See also
336:vivipary
291:Missouri
279:Michigan
263:Illinois
197:Zea mays
173:tar spot
163:causing
95:Family:
45:Domain:
931:3706033
918:1825666
866:2570319
827:1014516
724:Maydica
667:. 2018.
410:UniProt
271:Florida
269:, then
267:Indiana
224:⁄
214:⁄
204:⁄
181:lesions
105:Genus:
85:Order:
75:Class:
905:167673
853:167673
840:PHYRMA
754:EPPO (
568:
506:
293:, and
185:foliar
147:Maubl.
892:40876
874:IRMNG
814:4H292
566:S2CID
484:(1).
159:is a
59:Fungi
913:NCBI
861:GBIF
835:EPPO
504:ISSN
283:Ohio
275:Iowa
265:and
887:ISC
822:EoL
809:CoL
691:doi
618:doi
558:doi
554:117
531:doi
494:doi
490:OUP
950::
928::
915::
902::
889::
876::
863::
850::
837::
824::
811::
796::
752:.
728:44
726:.
687:44
685:.
673:^
663:.
645:.
641:.
630:^
614:40
612:.
600:^
590:.
578:^
564:.
552:.
527:57
525:.
502:.
482:11
480:.
474:.
459:^
439:.
424:^
408:.
404:.
376:.
289:,
285:,
281:,
277:,
273:,
226:16
206:32
202:13
766:.
758:)
750:"
746:"
711:.
697:.
693::
647:4
624:.
620::
594:.
572:.
560::
537:.
533::
510:.
496::
488:(
453:.
433:"
418:.
390:.
222:5
219:–
216:8
212:1
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
