Latin Name of Tomatoes
- Solanum lycopersicum
- Solanaceae family
- Potato Family
Latin Name of Lettuce
- Latuca sativa
- Family Asteraceae or Sunflower family
Latin Name of Onions
- Allium cepa
- Cepa group
- Alliaceae or Onion family
Latin Name of Broccoli
- Brassica oleracea
- Group italica
- Brassicaceae or Mustard family
Latin Name of Cauliflower
- Brassica oleracea
- Group botrytis
- Brassicaceae -- Mustard family
Latin Name of Sweet Corn
- Zea mays var. rugosa
- Poaceae or Grass family
Top Tomato production States
- Fresh market prod.:
- -California and Florida have 72.7% of the market:
- -The third most important state is Tennessee with 4.25% of production.
- Processing prod.:
- -California has approx. 95.8% of the market; Indiana, Ohio, Michigan are other producers of processing tomatoes
How are tomato vines separated?
- Vines are usually indeterminate, semi-determinate, or determinate.
- These designations refer to the flowering habit of the plants.
Is the tomato warm or cool season? Can it tolerate frosts?
It is a warm season crop and the fruit and vine cannot tolerate frosts.
Is the tomato an annual, biennial or perennial in the wild? How is it cultivated in the US, i.e., is it grown as an annual, biennial or perennial in the US?
- The tomato plant is a perennial vine in the wild
- cultivated as an annual in the US
Is tomato considered a shallow-, moderate- or deep-rooted crop? How does this affect fertilization practices, especially side dressing?
- Roots often reach 6 feet into the soil and may go as deep as 10-12 feet.
- However, 70% of root system may occur in top 8 inches of soil!
- Root systems also spread equally extensively away from stem of plant.
- In furrow-irrigated fields, nitrogen is applied pre plant and in one or more side dressing; late season, water-run applications are also common. If potassium is needed it is applied in a manner similar to that of nitrogen.
Is the tomato a self- or cross-pollinated crop? How does this fact affect the need for isolation when producing tomato seed? Are the flowers perfect?
- It is usually self-pollinating
- Most often pollination occurs due to wind causing disturbance of the flowers loosening pollen which then alights on stigma
What are the typical isolation distances for a crop like tomato? Broccoli? Sweet corn?
- Tomato: 25-50 ft Self pollinated
- Swt. Corn: 330-500 ft Wind pollinated
- Broccoli: 1-2 miles Insect pollinated
What does it mean to say that a plant is determinant? What are the advantages of growing a determinant crop? Disadvantages?
- With determinate plants, flowers develop but apical point also develops into flower and growth stops
- •Get more concentrated, uniform fruit set (flowers at every node)
What does it mean to say that a plant is indeterminant? What are the advantages of growing an indeterminant crop? Disadvantages?
Indeterminate vines flower and the apical or top shoot continues growing producing new flowers every 3rd node
What temperature is considered to be the threshold temperature for tomato germination, growth and root function? Why do tomatoes stop functioning/growing below this temperature?
- Direct seeding: seeds won't germinate below 50°F Optimum germination at 75°F
- top growth: 80-90F’s day; 50-70F’s at night optimal
- Temperatures >95°, <53°F, do not have good growth of tops.
Tomato transplants easily, with moderate difficulty, or with difficulty? What crops are difficult to transplant?
- Tomato is easily transplanted as it easily produces roots
- Corn is difficult to transplant
What is an adventitious root? Why are they important in tomato transplanting and tomato production?
- Secondary roots arise easily from lower stem area and are known as adventitious roots
- important during transplanting
If night temperatures are much above 72°F, and if day temperatures approach and/or exceed 100°F, poor tomato fruit set can occur -- flowers can fall off or abort from the plant. However, tomatoes are often grown in areas with extreme temperatures, such as the San Joaquin and Imperial Valleys. What factors enable tomatoes to be grown, and to produce, under such conditions?
How does low temperature affect fruit set in tomatoes? What is the name given the scarring of tomato fruit that sometimes results from exposure to cold temperature? How can this scarring be avoided? Can high temperature also cause this scarring?
How should the amount and analysis of fertilizer change with the growth of a crop of tomatoes, i.e., be able to diagram the relative amounts of N, P, and K applied to a tomato crop (through a drip system) as it grows from seed through anthesis to harvest.
- For the rapid growth stage of tomato, higher nitrogen fertilizer is used but it also contains phosphorus and potassium (though the P and K may be a little lower than for the transplant fertilizer).
- At the mature growth stage, use low nitrogen and high P and K.
- With drip irrigation, give constant rate of fertilizer even through bloom stage.
- -Steadily increase rate of fertilization then as approach maturity stage, steadily decrease. ---Therefore, the pattern is to gradually increase the fertilizer then to gradually decrease it.
What is the optimum temperature range for fruit ripening?
- Best fruit set for traditional tomato occurred when night temperatures in the 59-68°F range (15-20°C)
- Day temperatures over 100°F cause poor fruit set
How does light affect color development?
At what “ripening” stage are many fresh market tomatoes picked in California? How does this affect the temperature at which these fruit can be stored? What is considered the lowest safe temperature to store these fruit (a small temperature range is OK).
- For fresh market, fruit usually picked mature green or "pink"
- 65-70°F optimal for ripening fruit --> get best color development
- At higher temperature, ripening will be faster, but color will be poorer
What are “pink” or “vine-ripened” tomato fruit? How does being “vine-ripened” affect storability, shipability and flavor?
What is ethylene, i.e., what are common descriptors for this chemical as it relates to plants?
- Ripening is initiated by gaseous hormone, ethylene, C2H2.
- Ethylene endogenously produced by fruit
What is the chemical formula for ethylene? Do higher plants produce this chemical?
Why are harvested mature-green tomatoes often gassed with ethylene, even though they naturally produce this gas?
Gassing causes fruit to ripen much more evenly Reduces sorting, repacking costs on receiving end.
To what concentration of ethylene are tomatoes usually exposed?
~100 ppm for 24 hours or more
How does ripening affect the lowest-safe-temperature of storage of tomatoes?
65-70°F optimal for ripening fruit --> get best color development
Blossom end rot can be a common problem of tomatoes, especially those grown in greenhouses. What is considered the primary cause or culprit behind the formation of blossom end rot?
- Symptoms: water-soaked spot on blossom-end of fruit enlarges and darkens, becomes sunken and leathery.
- Cause: is related to a deficiency of calcium. Problem occurs when tomato plants have grown rapidly during the early part of the season and are subjected to hot dry weather when the fruits are in an early stage of development.
- Too much water such as with heavy irrigation ay also bring on the problem.
What are the typical, diagnostic symptoms of Fusarium infection of tomato plants? What is Fusarium? How is it normally controlled? What abbreviation is used, when buying seed, to indicate that a variety is resistant or tolerant to a particular race of Fusarium?
- Symptoms: wilting, yellowing of leaves, death of plant. Drooping and downward curvature of the oldest leaves followed by wilting and death
- Fusarium: is a pathogen that invades the host plant through the roots and plugs the water conducting tissues.
- Control: once it has infected the plant nothing can be done to control it.
What are the typical, diagnostic symptoms of Vericillium infection of tomato plants? What is Vericillium? How is it normally controlled? What abbreviation is used, when buying seed, to indicate that a variety is resistant or tolerant to a particular race of Vericillium?
- Verticillium wilt first appears as yellowing between the major veins on mature leaves.
- Plants with Verticillium wilt develop a patchy light brown discoloration in the xylem tissue.
- The fungus verticillium dahliae infects susceptible plants through the roots and invade and plugs the water conducting tissues.
- Development is favored by cool, moist spring weather, but wilting of foliage may not show up until sunny warm weather occurs and the plant is under stress.
- Controlled: avoid soils where highly susceptible crops have previously been grown. Don't transplant plants that have wilt.
- Verticillium resistant varieties indicated by the letter V following the name
What are the typical, diagnostic symptoms of Late Blight infection of tomato plants? What causes Late Blight? How is it normally controlled? What conditions promote this disease?
- Caused by the water mold fungus Phytophora infestans, which over-winters in infected tubers in the field, storage, or cull piles.
- Spread of diseases requires moisture from rainfall, sprinkler irrigation, or RH of 90% or greater. Average temp must be less than 78 F.
- Spores spread by wind
- Symptoms include small water-soaked areas on leaves that enlarge to form large purple-brown oil blotches. Leaf tissue dies and blackens.
- On the undersides of leaves, rings of grayish-white spores form around lesions. Infected fruit turn brown but remain firm
- Control using resistant varieties and fungicidal sprays; avoid sprinkler irrigation
Sunburn of tomato fruit can cause what symptoms/problems? How is sunburn normally controlled? [Try to grow plant in such a way that it holds sufficient foliage over fruit. If insufficient foliage, may use a cover spray over fruit to reflect light]
What exactly is meant by one saying that a commodity is chilling sensitive?
Chilling sensitivity refers to produce that is sensitive to cool temperatures usually below 55°F and above 32°F
What plants are most commonly found to be chilling sensitive?
In general, plants of sub-tropical and tropical origin are sensitive to cool temperatures -- tomato, eggplant, bell pepper, cucumber, sweet potato, watermelon, all citrus, bananas
What is the “chilling threshold” of a commodity?
The lowest safe storage temp-USDA
What are the symptoms of chilling injury? Why is chilling injury considered to be “cryptic” damage, i.e., when is it usually expressed? How does chilling injury differ from freezing damage?
- Pitting of the surface -- death of underlying cells with resulting collapse
- Discoloration of tissuesiii.
- Increased decay
- Uneven ripening or no ripening at all
- Increased water loss due to disruption of epidermis
What exactly does it mean to say that the development of chilling injury is time and temperature dependent?
- This means that the lower or longer the temperature and time, the more quickly injury develops
- Small doses of chilling temperature may have no real effect
How does susceptibility to chilling temperatures affect marketing? Storage?
- However, with chilling sensitive crops, the lowest safe temperature is limited to the chilling threshold, which is the lowest safe temperature at which a commodity can be stored before cold temperature (chilling) injury begins
- Practically, this means that many crops can be stored only for a few weeks instead of months
What is meant when one states that chilling injury is often “cryptic” damage?
- Chilling injury shows up at distribution
- Cryptic damage (hidden)
- Chilling can occur in the field not just after harvest
Indications of disease resistant varieties
- Letter following the names of the tomato varieties
- V: verticillium wilt
- F: fusarium wilt
- N: root knot nematodes
Be able to compare and graph the potential shelf life of a non-chilling sensitive vs. a chilling sensitive crop.