| Interesting fact |
| Pests and Diseases |
| Integrated Garden Management |
| Final note |
Tomatoes
Tomatoes (Lycopersicon esculentum) belong to the Solanaceae family, which includes potatoes, capsicums (peppers), eggplant, cape gooseberry and tamarillo, as well as the nightshade weeds. Botanically, tomatoes are classified as a fruit because the edible portion is a giant berry.
Tomatoes originated from South America, most likely the Peru region, where they were cultivated as early as 700 AD. It is thought that Spanish explorers brought them to Europe, with the first mention of tomatoes in literature being in 1544. This described a pomi d'oro (golden apple) that was eaten in Italy with oil, salt and pepper. The English regarded the tomato with suspicion for many years, considering the bright red colour to be a danger signal. In New Zealand tomatoes were grown in home gardens from the late 1800s.
In the mid-1990s over 600 varieties of tomatoes were commercially available in the US and Canada, and 2500 varieties were kept as seed in a gene bank in Gatersleben, Germany.
Tomato cultivars in New Zealand
There is a bewildering assortment of tomato varieties available. Below are a number of different types of tomatoes.Select several different varieties to grow in the garden that will suit your climate and requirements for tomatoes.
Classifying tomato cultivars
Tomatoes can be categorised as determinate or indeterminate. Determinate
tomatoes (also called bush or dwarf tomatoes) grow to a certain size and
then begin to flower, producing a single crop that is harvested once.
These are very useful for commercial growers. In-determinate tomatoes
(also called vine or cordon tomatoes) grow stems and produce flowers at
the same time. They need staking and are useful in the home garden as
they produce fruit over a long period of time.
Heirlooms and hybrids
Tomatoes can also be divided into heirloom or hybrid varieties.
Heirloom tomatoes are old varieties that have been around for a long time,
and many of them have very good flavour but may have less disease resistance
and a greater tendency to develop physiological disorders than modern
varieties. The modern hybrids have been bred for characteristics such
as consistency in colour, shape and size, long shelf-life, high yield,
uniform ripening and disease resistance.
End uses
Tomato varieties can be categorised by their end use. For example,
plum tomatoes are used for canning and have thick flesh and reduced amount
of pulp. Beefsteak tomatoes (e.g. Big Beef) are very large and also have
reduced pulp, which makes them excellent for sandwiches and sauces. Salad
or classic tomatoes are juicy as they have a lot of pulp but this tends
to fall out when they are sliced.
Tomatoes are considered to be one of the most important vegetables in
the western diet, based on the amount consumed and the vitamins and minerals
supplied. Particularly important are vitamins A and C. At around 22 mg
vitamin C/100 g, tomatoes are considered to be a good source of this important
nutrient. Tomatoes are also high in carotenoids, such as beta-carotene,
which is one of the precursor molecules to
vitamin A.
Another important carotenoid in tomato is lycopene, which is responsible for the bright red colour. Lycopene is a potent antioxidant and a number of recent studies have linked high intakes of lycopene with a reduced risk of cancer, particularly prostate cancer. Lycopene is also thought to have a role in preventing degeneration of the eyes and may help in protecting the skin from ultra-violet light damage, while eating tomato-based foods has been associated with a reduced risk of heart disease.
A typical home garden may include only 5-10 tomato plants. There is no opportunity for replanting if a plant is lost in January and this will lead to the loss of a significant proportion of the crops. Therefore it is very important to monitor established tomatoes plants regularly and act quickly if there are symptoms of pests or diseases. Some of the more important pests and diseases are described below but first we will look at how the principles of Integrated Garden Management (IGM) can be used to grow healthy tomatoes.
Integrated Garden Management for tomatoes
IGM techniques initially rely on preventing pests and diseases attacking the tomato plants. This is not always possible so the tomatoes should be watched closely during growth for the first signs of pests or disease. Once the pest or disease has been identified, an appropriate control technique should be selected. This may involve more than one method and will not necessarily involve the application of chemicals. Chemical control can be very effective for large areas, e.g. a processing tomato crop, or when a pest or disease attack is particularly severe. However, in home gardens, the application of chemicals, especially insecticides, can upset the ecological balance within the garden and lead to further outbreaks of other pests and diseases. IGM techniques useful for growing tomatoes. These include crop rotation, resistant cultivars, seed treatment, weed control, fertiliser, irrigation, biological control and chemicals.
For more information an integrated garden management and specific pests and diseases, see More info.
In the home garden, especially where IGM principles are applied, pests and diseases rarely cause problems. Your tomato-growing efforts will be rewarded in the summer with bowls of fresh juicy salad tomatoes, tasty tomato sandwiches and delicious sweet treats of cherry tomatoes. In the winter, reach for the jars of dried tomatoes in olive oil, tomato chutney, tomato sauce, tomato relish and tomato soup, and plan what cultivars you will plant next year.