Identifying New Sources of Alternaria Leaf Blight Resistance in Carrot
Pamela Moreno
1 and Philipp Simon
1, 2
1 Department of Horticulture, University of Wisconsin-Madison, 1575 Linden Drive,
Madison, WI 53706, USA
2 USDA-Agricultural Research Service, Vegetable Crops Unit, University of
Wisconsin-Madison, 1575 Linden Drive, Madison, WI 53706, USA
Worldwide, wherever carrots are grown the insidious fungus
Alternaria dauci
(Kühn)
Groves and Skolko can be found.
A. dauci causes
Alternaria leaf blight (ALB) and is a major problem for growers for two reasons. First, ALB
is very prolific and can rapidly colonize foliage to form lesions that greatly reduce
photosynthesis and consequently plant health. Second, and perhaps more importantly, the
lesions can weaken or kill the petioles, which can significantly reduce the effectiveness of
mechanical harvesting. Although it is difficult to tabulate the amount of yield loss by
A. dauci each year, the damage can be as severe as 40% to 60%. To date, integrated
pest management strategies stress pathogen free seeds, resistant varieties, crop rotation,
scouting and fungicide applications. Even though there are several varieties with some
resistance to ALB, higher levels of resistance have been observed in diverse
Daucus
germplasm. Thus, in this research we are evaluating germplasm from Asia, South America, and
Europe to identify new sources of resistance based on exposure to ALB in field trials in
Wisconsin over multiple years. In order to evaluate these diverse
Daucus, weekly
field observations during the growing season will provide the necessary data to identify new
sources of resistance that eventually can be incorporated into commercial cultivars.
Last updated
Friday, 02-Aug-2013 11:50:49 CDT
