AMSEED American Seed Intelligence Platform

Defiant PhR

F1 hybrid tomato · Solanum lycopersicum

Breeding
F1 hybrid
Growth habit
Determinate
Days to maturity
65-70 days
Fruit
red, medium
Weight
6-8 oz
Bred by
Johnny's Selected Seeds

Origin & history

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.

Measurements

MeasurementValueContext
Days to maturity 65-70 days Consensus range across the cited sources, which include both independent references and commercial catalogs.
Fruit weight 6-8 oz Typical range for the cultivar, as a consensus across the cited sources. Not a measured mean from any single crop: fruit weight varies with season, spacing and where on the plant the fruit set.

Trial results

What this variety did in published university trials. These are observations of a season, not properties of the seed, so they are kept separate from the measurements above and are never merged into them. Letters are each report's own mean-separation groups.

Evaluation of Late Blight Resistant Tomato Varieties, 2013

2013 · New York · full season · published as "Defiant PhR"

MeasurementResultMethod
Late Blight severity * 2.3 % Visual severity rating under natural infection
Late Blight: disease progress (AUDPC) 137.2 index Area under the disease progress curve

Evaluation of Late Blight Resistant Tomato Varieties, 2012

2012 · New York · full season · published as "Defiant PhR"

MeasurementResultMethod
Late Blight severity * 0-0.2 % Visual severity rating under natural infection

* Measured differently in different trials. disease severity varied between the trials above. AMSeed shows both figures rather than averaging them, because the difference between them is the finding: performance depends on the site, the season and the protocol, and a single blended number would hide exactly that.

Each trial states its own limits, and they are worth reading before acting on any figure here. Yields in these reports are extrapolated from small research plots and run higher than commercial farms achieve; cull rates reflect the disease pressure of one particular season.

Traits

Disease resistance

CodeDiseaseLevelBasis
Ph-2+Ph-3 Late Blight (Phytophthora infestans) resistant Independently observed
- Early Blight (Alternaria linariae (A. solani)) intermediate Breeder declared
FF Fusarium Wilt of Tomato (Fusarium oxysporum f. sp. lycopersici) resistant Breeder declared

Breeder declared means the resistance was stated by whoever breeds or sells the seed. That is not a reason to disbelieve it, and for most resistance genes it is the only evidence that exists: the breeder screens the line and publishes the result in their catalog, and no independent party re-tests it. We label it rather than quietly presenting it as though someone had checked.

Related varieties

Head to head

Sources & References

Evidence: 4 sources, including 3 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