SCIENTIFIC NAME: Solanum lycopersicum
DETERMINATE (Bush): Varieties do not need pruning and may be grown with or without support; fruit ripens within a concentrated time period.
INDETERMINATE (Climbing): Varieties should be staked, trellised, or caged, and pruned for best results; fruit ripens over an extended period.
CULTURE: GROWING SEEDLINGS: Don’t start too early. Root-bound, leggy plants that have open flowers or fruit when planted out may remain stunted and produce poorly. Sow 6mm deep in flats, using a soilless peat-based mix (not potting soil), 5-6 weeks before plants can be transplanted out after frost danger. Keep temperature of the starting mix at 24-32C; tomato seeds germinate very slowly in cooler soil. When first true leaves develop, transplant into plug trays or 75mm-10mm pots for large, stocky 7-8 week transplants for earliest crops. Grow seedlings at 16-21C. Water only enough to keep the mix from drying. Fertilise with fish emulsion or a soluble, complete fertiliser.
TRANSPLANTING OUTDOORS: Transplant into medium-rich garden or field soil 30cm-60cm apart for determinate varieties, 60cm-90cm apart for indeterminate, unstaked varieties, and 25cm-50cm for staking. Plant 7.5cm to 20cm deep, covering the root ball and stem well up to the cotyledons (first leaves). If using grafted plants, take care to ensure the graft union is not touching soil. Water seedlings with a high-phosphate fertiliser solution. For earliest crops, set plants out around the last frost date under floating row covers, which will protect from frost to about -2C. If possible, avoid setting out unprotected plants until night temperatures are over 7C. Frost will cause severe damage.
FERTILISER: Abundant soil phosphorus is important for early high yields. Too much nitrogen causes rampant growth and soft fruits susceptible to rot.
DISEASES: Learn the common tomato diseases in your area. Select resistant varieties. For prevention, use young, healthy transplants, avoid overhead irrigation, plow in tomato plant refuse in the fall, rotate crops, and do not handle tobacco or smoke before handling plants. Fungicides can reduce certain diseases when properly selected and applied.
BLOSSOM END ROT: Prevent blossom end rot by providing abundant soil calcium and an even supply of soil moisture.
INSECT PESTS: Use row covers to protect young seedlings from flea beetles. Tomato hornworms can be controlled with Bacillus thuringiensis – DiPel. Use spinosad for potato beetle larvae and adults.
HARVEST: Fully vine-ripen fruit only for local retailing or use. To deliver sound fruit, pick fruit less ripe the further the distance and the longer the time between the field and the customer.
STORAGE: Store firm, ripe fruit 7-16C for 4-7 days.
DAYS TO MATURITY: From transplants.
TRANSPLANTS: Avg. 850 plants/1,000 seeds, 7,600 plants/30g, 122,000 plants/500g.
AVG. PLANTING RATE: Avg. 785 seeds/667 plants to produce 330metres. of row. Avg. 8,540 seeds/30g, to produce 1 acre of transplants, 45cm between plants in rows 1.2metres apart (7,260 plants needed).
CLIMATIC REQUIREMENTS OF TOMATOES. J.M Fortier
Tomatoes are sensitive plants. They can withstand minimum and maximum temperatures of 5C and 35C for a few hours only, before they shut down fruit production.
The optimal thermal regime is 18C to 24C during the day and 16C to 20C at night.
The difference between the day and night average temperatures should be between 1C and 4C.
Temperature below 10C will slow down or even stunt growth and development.
If we look at the average temperature over a 24-hour period (T,24 h), the optimal range is between 17C and 22C. Outside this comfort zone, the tomatoes’ fruit productivity and quality are severely affected.
As for humidity, the optimal rate is between 65% and 80%. An environment that is too humid will lead to problems related to fungal disease and to poor floral fertilization.
Excess or lack of humidity will strongly influence crop productivity.
To produce regularly, tomatoes need a great amount of light. In greenhouses where the climate is temperate, tomatoes will grow faster in summer when daylight lasts 17 to 18 hours, compared to fall when daylight decreases to 12 hours and less.
