b'New Disease Means Genetic Tolerance Research is UnderwayScientists are investing in research to protect cornfrom tar spot.Sonja BegemannLIKE THE SUBSTANCEfor whichIts something that continues to grow its named, tar spot is sticking around. and spread broader each year, says When tar spot blew into the MidwestShane Meis, Wyffels director of research. in 2015 from South America, farmersBut we have to remember the disease were understandably concerned abouttriangle needs to be present, like all dis-what this budding disease could mean foreases, so its not a guarantee every year.their crops. With nearly six seasons of the disease under their belts, seed companiesDiscover Genetic Tolerancesand researchers are finding what it takesNew technologies are enabling research-to protect corn from the pathogen. ers to identify solutions faster, at lower costs. This could lead to commercial solu-Understanding the Disease tions in as little as five years.Like all diseases, tar spot needs the com- If we see a small number of major plete disease triangle to infect plants. Theresistance genes that could be, in theory, spores need to be present in corn fieldstargeted for gene editing or transgenic or blow in through the air, and it favorsevents it could be [a faster route to com-cool, wet conditions. mercialization], says Addie Thompson, I have never seen a disease as crip- Michigan State Extension corn genetics pling as tar spot, says Steve Wilkens,researcher. It might have to go through Golden Harvest agronomy manager. Itsmore regulatory mechanisms though. My like, you can go to church Sunday andgoal is that using a more recent line of come home, and the crop is dead. genetics to pull from means the transition Wilkens covers most of the Midwestis much faster.and says the disease can rob the cornShes surveying thousands of corn crop of around 50% of yield potential inhybrids to identify key genetics that confer severe infestations. tolerance to tar spot. Using phenotypic Plus, if it comes in late, it might notobservations and what they know about have as big, if any, impact on yield but itgenetics, Thompson and plant patholo-can lower stalk integrity, Wilkens says.gists at MSU are finding what could Which we all know slows down harvestbecome a genetic solution to tar spot.and does lead to more harvest loss. The hybrids theyre researching are Over the past six seasons, 2018 andpublicly available, including full marker 2021 have been the most favorable forsets. Later this year or early next year, tar spot. While it can be found in othertheyll be publishing their findingsstates, Iowa, Illinois, Indiana, Michiganincluding snips that could be used as and Wisconsin have recorded the mostmolecular markers to help with tar spot instances of the disease. tolerance selection.SOURCE: STEVE WILKENS, GOLDEN HARVEST126/ SEEDWORLD.COMDECEMBER 2021'