AMSEED American Seed Intelligence Platform
Tomato comparison

Defiant PhR vs Iron Lady

Two purpose-bred blight-resistant hybrids, compared on what they actually resist.

Defiant PhR Iron Lady
Breeding F1 hybrid F1 hybrid
Growth habit Determinate Determinate
Days to maturity 65-70 75-80
Fruit color red red
Fruit size class medium medium
Typical weight 6-8 oz -
Primary uses slicing slicing
Introduced - -
Documented resistances 3 3
Saves true from seed No (F1) No (F1)

Measured against each other

The table above is two descriptions placed side by side. Below are the trials that grew both varieties in the same ground, in the same season, measured by the same people. That is the only setting where a difference between them is something somebody observed rather than something we inferred.

Evaluation of Late Blight Resistant Tomato Varieties, 2013

2013 · Organic research field, Long Island · New York
MeasurementDefiant PhRIron LadyWhat the trial concluded
Late Blight severity 2.3 % 1.6 % Defiant PhR was more severely affected here. This trial published no mean separation for this measurement, so the difference is untested.
Late Blight: disease progress (AUDPC) 137.2 index 125.2 index Defiant PhR was more severely affected here. This trial published no mean separation for this measurement, so the difference is untested.

Superscript letters are the trial's own mean separation, not ours. Entries sharing a letter were not separated at the trial's significance level however far apart the two figures look, and where a trial published none we say the difference is untested rather than treating the arithmetic as the finding. Each block is one site and one season.

Disease resistance

Defiant PhR

Late BlightPh-2+Ph-3 · resistant
Early Blightintermediate

Iron Lady

Late BlightPh-2+Ph-3 · resistant
Early Blighttolerant

Traits

Only Defiant PhR

  • Early Season

Only Iron Lady

  • Mid Season

Origins

Defiant PhR

Johnny's Selected Seeds' answer to the 2009 Northeast late blight epidemic: a determinate mid-size slicer with Ph-2 + Ph-3 resistance, released so gardeners would never again lose everything to one wet August.

Iron Lady

The Cornell-NC State collaboration marketed as the first triple-resistant tomato: late blight, early blight, and septoria tolerance in one determinate package, released through High Mowing Organic Seeds.

Sources & References

Evidence: 5 sources, including 4 independent references.

  1. Johnny's Selected Seeds catalog · Johnny's Selected Seeds, Seed Catalog
  2. Vegetable MD Online · Cornell University, Plant Pathology, University or Government
  3. Evaluation of Late Blight Resistant Tomato Varieties, 2012 · Cornell Long Island Horticultural Research and Extension Center (2012), University or Government
  4. Evaluation of Late Blight Resistant Tomato Varieties, 2013 · Cornell Long Island Horticultural Research and Extension Center (2013), University or Government
  5. NC State Fresh-Market Tomato Breeding Program (Mountain series) · North Carolina State University, University or Government