Germination: tomato seed can remain viable for 3–4 years if it is stored cool and in
airtight containers. In real life these conditions are rarely found and seed viability
can fall dramatically, especially in warm and humid conditions. Germination
normally takes about 7–10 days. The effect of temperature on germination of tomato
Soil: should be fertile, and both compost and manure are highly beneficial. Lighter
soils usually signify shorter growing and fruiting periods than heavier, more
retentive soils. Optimum pH is about 6–7 (classified as having “intermediate
tolerance” to acidity), and tomatoes need potash as young plants and a balanced
fertiliser with more Nitrogen as they grow.
Seed rate: About 250–500 g/ha., 250–350 seeds per gram. Rarely planted in large
areas by subsistence farmers. Often two or three seeds are planted together, then
thinned to the best plant.
Plant spacing: very variable, but average spacings are 90 cm between rows and 30
cm between plants. The plants can grow very large if they have adequate space,
nutrients, light, etc.
Depth: 0.5–2 cm. The transplants should be buried well down deep to encourage
development of adventitious roots from the hypocotyl area.
GROWTH CONDITIONS
The taller, indeterminate types need support, and should be firmly supported on
poles, string, fences, etc. The side-shoots are normally pinched out, to encourage the
When the lower truss begins to ripen the lower leaves can be removed, especially
if they are showing signs of fungal disease, using a sharp knife or secateurs to
minimise wounding. This simple act not only increases the air-flow and light supply
to the lower canopy, but also makes the ripening tomatoes more easily visible to
growers when they check for weeds, pests, diseases, ripeness and readiness to
harvest.
Day length: tomatoes are day-neutral and in many parts of the world they are
cultivated 12 months of the year.
Growth period: three crops a year can be grown, in the tropics. In temperate
climates about 130 days are normally taken to produce the first ripe fruits.
Indeterminate types can then be continuously harvested over a very long period.
When winter approaches, the green fruits can be taken indoors and ripened in a
warm place.
Temperature: most varieties need 3 or 4 months of warm, frost-free weather. Some
new varieties can set fruit at low temperatures (down to about 4C), others at high
temperatures (up to about 32 C). Frost sensitive.
Rainfall: badly affected by drought periods. Best in medium or low humidity.
Pests: Cutworms can bite off the young plants at ground level. Protect them with
collars of material (cardboard, stiff paper, etc) or wood ash, as with cabbages. Root-
knot nematodes are also common, especially in nurseries. Greenflies, Whiteflies and
Red Spiders can be damaging, especially in greenhouses. Regular sprayings with a
soap solution will keep their numbers down, and both Whitefly and Red Spiders can
seed is discussed in Section 1Fa, “Germination”, page 46.
the plants have developed a certain number of trusses, 4–10 or more depending on
the quality of the growing conditions.
plant to set fruit and to make a tidy plant. The tip is also often pinched out after