Growing Tomatoes

Growing Tomatoes Advanced Master Gardner Training-2005 Chuck Marr Horticulture Kansas State University

Commercial Varieties Translate well Not controversial ‘University’ Varieties Represent the state Not time consuming Tomato Names and Numbers Amelia Crista Quincy BHN 555, 543, 444 etc Mountain Fresh, “ Crest, “ Spring Florida 47, Florida 91, Florida 7514

Characteristics of tomato plant • Consistent, even watering • Consistent, even temperature • Harvest for 5-7 weeks • Hard to shift from vegetative to fruit development • Plant covered with glandular hairs filled with an alkaloid substance (greenish white)

Trichomes or Glandular hairs

Tomato roots and fertilization • Fibrous, dense root system • Effective in finding fertilizer • Easy to ‘overfertilize’

Tomato fruit develop from flowers that are open for about 3 days. Flowers almost always self-pollenized. It takes 30 days for a fruit to develop to a full sized, green- ready to ripen (another 5-7 days to ripen)

Blossom End Rot (BER) Brown leathery patch on bottom of tomato fruit. Deficiency of calcium in fruit from calcium moving in water stream bypassing the fruit. Underdeveloped root system, watering fluctuations, or lush, succulent growth are all potential causes. Avoid sidedressing with ammonium forms of N fertilizer. (common one is urea). Preferred: Calcium nitrate Liquid N Organic sources

‘Catfacing’ • Some varieties are prone • Cold nights in early in fruit development

Don’t start too early in the season. Soil temperature should be a consistent 55 F. Check soil temperature at late morning at a 2 inch depth. Below critical soil temperature, plant roots don’t develop and plants don’t absorb nutrients properly. Plants may survive but don’t ‘thrive’

Average freeze date April 18 • 50 % April 18 • 40 % April 21 • 30 % April 24 • 20% April 28 • 10% May 3 • 5% May 7 Date that soil temperatures reach 55 F is usually when average freeze date is from 10-20% chance of a freeze or 10-14 days after average freeze date.

Vine productive only 6-7 weeks • Early spring planting (early May) • Summer planting (mid-late June) June July August Sept Oct

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

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

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

Semi-determinate vine habit • More efficient in ‘partitioning carbohydrates’- leaf area supporting plant and fruit development • Slower to ‘re-grow’ following damage (hail insects etc) Semi-determinate Standard Leaf area to support fruit development (and new vine growth)

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

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

Fusarium wilt (2 Races or Strains F1 and F2) Fusarium wilt is a soil borne fungus that will persist from 8-12 years There is NO KNOWN CONTROL Race 3-some varieties

Leaf blight diseases (Early Blight and Septoria Leaf Spot) Older leaves on plant. Usually after fruit load has developed

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

Some varieties are resistant. Treatment is very difficult Nematode Damage to Tomato Roots South of I-70 where problem is most significant (over-wintering) ‘Upgraded’ varieties with nematode resistance Celebrity= Celebrity Supreme Mt Fresh= Mt Fresh Plus

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.

Average days (last 30 years) when Day >95, Night >75 Range from < 15 days to > 45 days

Sun Leaper and Sunmaster have done well. Several newer varieties coming along with this characteristic. Florida 91

Some internal characteristics of tomato fruit where flavor differences are noted Seed cavity Locular jelly Placental tissues

Firm vs ‘juicy’ fruits Tomatoes that have more flesh and less seed cavity, locular jelly are less flavorful. Internal flesh contains fewer flavor compounds Have to bite into cells to release contents. Many newer tomato varieties are firmer by consumer preference.

Tomato Ripening • Tomatoes produce an internal gas- ethylene- that ‘drives’ the ripening process…. “Mature-green’ stage

Immature green Mature green Breaker Turning Orange Red Red ripe Significant loss of flavor Some loss of flavor, sugar Less loss of flavor Very little flavor differences Tomato Ripening Stages

Turning to Ripe Stage • Significant losses of flavor if harvested before ‘mature green stage’ • Slight loss of flavor if harvested before ‘turning stage’ • Practically no loss of flavor after ‘turning’ stage • About 40-50% of commercial US tomatoes are harvested before they reach the mature green stage (estimated)

Cold injury to tomatoes influences flavor. • Mature Green-Turning tomatoes >55o F • Ripe tomatoes >50o F Tomatoes stored between 40 and 50 degrees can have significant losses of flavor. Aroma compounds decline- sourness increases Tomatoes stored at 65 F or above had little significant changes in flavor due to any cold storage treatment. Length and temperature combine to injure fruit “Preconditioning” is a current area of study

Over-fertilization can reduce tomato flavor… • Very high levels of nitrogen and potassium have been associated with poor flavor in tomatoes • Certain volatile compounds increase with increasing fertilizer levels • Higher volatile levels (of 12 measured compounds) • pH unchanged • Soluble solids (sugars) slight increase • % citric acid slight increase

Differences Among Us • Age • Youth- sweet • Older- bitter • Age dulls the senses • Illness or physical limitations (colds, etc) • Male vs female • Musk aromas sensed differently • Ethnicity or background • What we like established by what we’re exposed to • “Life Altering Experiences”

Celebrity (Supreme) Florida 47 Mt. Spring Mt. Fresh Mt. Crest Merced Floralina Florida 91 (Hot Set) Sunmaster (Hot Set) Sun Leaper (Hot Set) Amelia Untested Sebring Quincy Florida 7514 Some varieties to consider

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

Growing Tomatoes