What’s New in Tomatoes

1. What’s New in Tomatoes Chuck Marr Horticulture Kansas State University

2. Don’t start too early in the season. In Manhattan, 20% chance of a freeze April 30 10% chance of a freeze May 5 5% chance of a freeze May 9 Soil temperature should be a consistent 55o F Below critical soil temperature, plant roots don’t develop and plants don’t absorb nutrients properly. Plants may survive but don’t ‘thrive’

3. ‘Modern’ tomato varieties • Semi-determinate (‘determinate’) vine • Uniform ripening genetic trait • Multiple disease resistance • Meaty, firm fruit • Heat tolerant genetic trait (Hot Set) • Long Shelf Life (LSL) genetic trait

4. What is important? • Produce lots of tomatoes • Foliage cover but easy to spray • Fairly large size and uniform • Produce early but sustained • Few culls (cracks, Blossom-End Rot, etc) • Disease resistance • Taste good

5. Semi-Determinate or “Determinate”-”Compact” Vine Habit Standard vine Determinate/Compact vine

6. Advantages of Compact Vine • Adapted to raised bed culture • Short cages or ‘stake-weave’ • More stable in wind • Use less water and fertilizer • Closer spacing-more plants per row • Yields comparable to large vined types

7. Variations in vine size:

8. Uniform Ripening (UG Gene) Fruit ripens uniformly- top to bottom and inside-outside. Uniformly ripe. No ‘green shoulder’ or waste when using.

9. Meaty Firm Fruit • Fruit holds into slices • Can be chopped or diced • Does not soften easily when stacked • Modern consumers prefer • Not irregular or rough like a ‘beefsteak’ type

10. Multiple Disease Resistance Fusarium wilt in tomato. No known control. Persists for 8-12 years. There are 2 strains or races F1 and F2. Need both resistance (A new strain F3 has been discovered in the deep south)

11. Leaf blight (Early Blight and Septoria Leaf Spot) is a different story. There is some resistance available but hasn’t proven to be very effective in the field. Both are foliar fungus diseases-spores develop on leaves and don’t enter the roots of the plant.

12. Tomato Spotted Wilt (TSW) Virus • Stunted plants, purplish color. Mottled, marbled fruit • Spread by western flower thrips-primarily in greenhouse or transplants.

13. Bacterial Spot or Speck Spots or specks on fruit, stem, and leaf. Usually a problem in cooler, wet conditions. Copper fungicides- not as effective as blight control

14. Additional Disease Resistance V,F1,2,3 N, TMV, TSWV, ASC, Bacterial Speck/Spot) • Fusarium 1 and 2 • Fusarium 3 (a few varieties) • Verticillium wilt (don’t have in KS) • Tobacco mosaic virus (TMV) • Nematodes (a problem south of I-70) • Tomato spotted wilt virus (some coming) • Bacterial speck and spot (a problem north of I-70)

15. ‘Modern’ Tomato Varieties Some that we’ve relied on for several years. Still useful to consider for their reliability and consistency over the years. Semi-determinate, F1,2 resistance, reliable production • Merced- sturdy vine, good quality • Mt. Spring-second early, good quality • Celebrity- oldest of the semi-determinates • Carnival- slightly larger than Celebrity

16. Blossom drop from excessive summer heat. Daytime 95 F, Night 75 F Excessive N; Hot, dry winds make problem worse A genetic trait- usually referred to as the Hot Set or Heat Set gene allows tomatoes to set under heat conditions. Many new varieties now are being developed with the Hot Set gene incorporated.

17. Sun Leaper and Sunmaster have done well. Several newer varieties coming along with this characteristic.

18. Long Shelf Life (LSL) Tomato When a tomato reaches a full size, green stage, it starts to produce an internal gas – ethylene- which ‘drives’ the ripening process. Continuous ethylene production continues after the tomato is fully ripe- then it becomes soft, squishy, and begins to rot.

19. LSL tomatoes can be held for a longer time after fully ripe with little loss of quality or flavor.

20. Have held tomatoes for up to 1 month after fully ripe and still edible. May not be useful to all growers but can improve shelf life of tomatoes if not sold quickly.

21. Pik Ripe 193 and Keepsake. Several newer varieties coming along with this trait as well.

22. Yes, but how do they TASTE!! 21 varieties 55 ‘tasters’ Whole tomatoes, cut slices and taste samples Appearance Color Meatiness Acidity Sweetness Texture Rated on a 1-10 scale. Varieties were named and names visible to tasters.

23. Tomato ‘Taste’ Study Factor Variety Range Taster’ Range

24. F3 Fusarium resistance Fruit size .50 lb Good quality Good fruit size .52 lb Mid season harvest Good quality Compact vine, F1,2 resistance, small ‘stylar scar’, sturdy vine

25. What’s ‘really new’- so new that we have only limited testing (1 year in several locations). Very limited seed or not released yet. Will be evaluating more in the next few years….. But have several advantages to consider when they may become more widely available

26. Heat set Good size .57 lb Mid season Now named “Red Pride” High early yield Fair size .54 lb Low culls

27. LSL type Good size .52 lb Good yield Seed increase this year Large .59 lb TSWV and F3 resistance Early-midseason Good yield

28. Early-midseason Very large fruit .67 lb Low culls Early-midseason Good size .53 lb Highest yield in our trial

29. Bacterial wilt, F 1,2, and TSWV resistance Moderate early yields Good size .56 lb Bacterial S resistance Some pointed fruit Bact S and TSWV resistance Early-midseason Very large size .68 lb A little rough More culls

30. K-State-Research & Extension “Knowledge for Life”