Extension Plant Pathologist
Department of Plant Pathology
UW-Madison College of Agricultural and Life Sciences
New tomato varieties fight late blight
Time – 3:01 minutes
0:17 – Three new tomato varieties
0:32 – Strong resistance
1:21 – Locating resistant tomatoes
1:51 – Worth the extra cost
2:08 – Resistant tomatoes also useful
2:21 – How resistance is developed
2:50 – Lead out
New progress in the fight against tomato late blight. We’re visiting today with Amanda Gevens, Department of Plant Pathology, University of Wisconsin Extension in the College of Agricultural and Life Sciences, Madison, WI and I’m Sevie Kenyon.
Sevie Kenyon: Amanda, you have some new tomato varieties to tell us about?
Amanda Gevens: We do; we have three commercially available tomato varieties that do have substantial resistance to late blight, particularly to the new strains of late blight, that we have had in the area.
Sevie Kenyon: Amanda, how good is this new resistance?
Amanda Gevens: The resistance is quite good. We do have two varieties that are commercially available, “Mountain Magic” and “Defiant,” that have two resistance genes to fight against late blight and they work quite well against these new strains of the pathogen here in the state. “Plum Regal” is the third variety; it’s a plum tomato-type. Out of all of these that have resistance we have representative of each market type, which is nice. “Plum Regal” does have a single resistance gene to late blight and it holds up quite well but it doesn’t have a second gene, which seems to be more durable and is found in “Mountain Magic” and “Defiant.” Growers should know, home gardeners should know, that late blight resistance doesn’t mean you’ve got resistance to every other foliar disease, but you still need to manage and be watchful for others.
Sevie Kenyon: Amanda, how do people go about locating these varieties?
Amanda Gevens: If growers, or home gardeners, are shopping from Johnny’s Selected Seeds online these are readily available. The accessibility is much greater than it was two years ago when some of these were first released and so the seed should be available. There is the chance that we will see late blight in tomato and potato crops in 2013. We have had cases on both tomato and potato here in [the] state.
Sevie Kenyon: Amanda, is there any difference in cost between these resistant varieties and regular tomato varieties?
Amanda Gevens: The cost is, it’s a bit higher, but I’d say the benefit out weighs the cost when you consider the resistance that will come with these selections. Then the lack of a need to, perhaps, consider fungicide applications.
Sevie Kenyon: Amanda, these three varieties in particular, which markets are they for?
Amanda Gevens: Yeah, these can be used for canning, they can be used for slicing for salads, [and] they do have multi-purpose.
Sevie Kenyon: Amanda, can you describe how plant breeders go about developing this kind of resistance?
Amanda Gevens: Through traditional breeding efforts an identification had been made of resistance to late blight, to specific strains of late blight over the years. Once sources are identified and further characterized breeders can then begin to “stack,” as you will, or add multiple genes for resistance within these lines. So, once that’s achieved and evaluated in time, we can then fill some level of comfort and confidence that these sources of resistance are durable.
Sevie Kenyon: We’ve been visiting with Amanda Gevens, Department of Plant Pathology, University of Wisconsin Extension in the College of Agricultural and Life Sciences, Madison, WI and I’m Sevie Kenyon.