OSU S200 is an experimental breeding line hybrid from Oregon State University. It is a determinate, red, slicing tomato that has reportedly shown good resistance to late blight. The background of this experimental line includes a former OSU breeding experiment and an accession of Solanum habrochaites, a wild tomato relative. According to the UW-Madison NOVIC report (2016), quantitative late blight resistance can be attributed to S. habrochaites and Ph-2 comes from the dropped OSU breeding line. My paper on late blight from spring quarter contains a brief discussion of genetic diversity within tomatoes (or rather domesticated crops in general) as well as the possibilities and need for introgressing desirable traits from wild relatives into domesticated crop genomes.

OSU S200 has had a mixed performance in the trial. Pre-transplant disease scores (greenhouse) were more severe than we would have liked to see, but plants seemed to bounce back fairly well in the field. This is at least true for Blocks 1 and 3, but the OSU S200 in Block 2 is certainly succumbing to disease pressure. Block 2 is the highest in disease severity across the board, but OSU S200 is actually surrounded by several varieties not showing any symptoms, so its poor performance is somewhat obvious here.

Despite variable disease performance, OSU S200 is extremely productive! Like whoa! Some of the harvest numbers blow me away compared to other varieties. I am also very partial to the fruit as well. They are beautiful; some samplers have described them as “perfect.” For me, their perfection really lies in their texture. They are firm, yet supple, with a skin that is thin enough to easily chew, but thick enough to help prevent damage post harvest.

First Ripe Fruit:

All harvest data represents two OSU S200 plants from each block, or six plants total:

Harvest 1 (September 1, 2017)

Picking Ease (5=easy, 1=difficult): 5

Marketable Fruit: 36 fruit weighing 5027g (11.08 lb.) Unmarketable Fruit: 30 fruit weighing 1996g (4.4 lb.)

Reasons why unmarketable: too small, cracking, “projections”

Harvest 2 (September 8, 2017)

Picking Ease (5=easy, 1=difficult): 4

Marketable Fruit: 52 fruit weighing 6992g (15.41 lb.) Unmarketable Fruit: 20 fruit weighing 1783g (3.93 lb.)

Reasons why unmarketable: size, zippers, divots

Average Fruit Size: 8.08 cm x 6.72 cm      (3.18″ x 2.65″)

Brix: 6.3, 7, 4.3

Harvest 3 (September 15, 2017)

Picking Ease (5=easy, 1=difficult): 5

Marketable Fruit: 37 fruit weighing 4197g (9.25 lb.) Unmarketable Fruit: 24 fruit weighing 1489g (3.28 lb.)

Reasons why unmarketable: too small, soft rot

Harvest 4 (September 22, 2017)

Picking Ease (5=easy, 1=difficult): 3

Marketable Fruit: 11 fruit weighing 988g (2.18 lb.) Unmarketable Fruit: 7 fruit weighing 314g (11.1 oz.)

Reasons why unmarketable: too small

Harvest 5 (September 29, 2017)

Picking Ease (5=easy, 1=difficult): 5

Marketable Fruit: 7 fruit weighing 606g (1.34 lb.) Unmarketable Fruit: 8 fruit weighing 469g (1.03 lb.)

Reasons why unmarketable: too small, rot