1.1 Background of the study
Tomato (Solanum lycopersicon L.) is one of the most widely
and important cultivated crop in Africa (Opena, et. al., 1990). Tomato is the
world’s largest vegetable crop after Potato and sweet potato, but it tops the
list chart of canned vegetables. In Nigeria Tomato is recorded as the important
vegetable after Onion and paper (Fawusi, 1987). It is an important condiment in
most diet and a few cheap source of vitamin, with a large quantity of water
(%), calcium (%), and Niacin all of great important in the metabolic process of
Tomato can be grown in a variety of geographical zones in
open filed or in greenhouses (screen house), and the fruit can be harvested
manually or by mechanical means. In 2014, the global area cultivated with
tomatoes was 5 million hectares with a population of 171 millions tones. The
major tomato producing Countries are; China and India. (FAODSTATE, 2017). Under
certain conduction such as pruning, weeding, irrigation, frost free
environment, etc, the crop can be perennial or semi-perennial, but for
commercial purpose. It is considered as annual (Geisenberg and Steward, 1986).
Although there are many types of growing system for
greenhouse tomatoes, the two principle cropping systems are: “Two crops per
year and one crop per year”, it’s significance doesn’t lie only on profit, but
also in the income generated in the local economy for farmers and agricultural
workers (Guldinez, 2013). There are several categories of protected vegetable
production methods which provide some degree of control over various
environmental factors such as: greenhouse, tunnels and covered field
(Nieves-Garcia et. al., 2011). Although there is no quantitative record about
the world’s vegetable production in greenhouse, some calculation have been
made. For example, in 2012, the greenhouse vegetable production was about 81
million kilo-gram (kg), of which 40 million kg of the total production was
tomato, and 37 million kg was cucumber. More so, In 2012, the tomato production
in Northern America Accounting for about 52% of the market in Canada and 22% of
the market in the United State (form credit Canada, 2012). But tomato
production in Nigeria is low as compared to those of temperate zones due to
differences in cropping environment conditions, lack of high yielding
varieties, and cultural practices applied to the crops in the field.
Commercially, tomato fruit can vary in colour, size and
shape (Vaughan and Heissler, 1997). The fruit contains large quantity of water,
vitamin minerals such as hycopene (which gives the fruit it’s predominantly red
colour) and beta-carotene (which contains up to 3% sugar of the fresh fruit
weight). Tomato also contains tomatine and alcocide with fungicide properties.
Tomatine concentration decreases as the fruit matures which helps to determine
the taxonomy of the species. Therefore, if can be useful (OECD, et. al., 2018).
Tomato is one of the best studied cultivated dicotyledon
plant of the molecular level and has been used as a model species for research
into gene mapping, characterization (example pathogenic resistance gene) and
gene transferred approaches. It is also useful to study other plant trait such
as fruit ripening, hormonal function and vitamin by synthesis (Chetelat, et.
1.2 Origin and distribution of tomato
The edible tomato, often red berry of the plant solanum
esculentum is a species originated from Western South America and Central
America. Its domestication and uses as a cultivated food may have it indigenous
to the Mexicans. From there, it was brought to Europe and to other part of the
European-colonized world during the 16th century. Although there is no much
history on how tomato was spread eventually introduced to Africa in the early
19th century and finally to Nigeria.
Tomato has been cultivated since prehistoric times with the
earliest agricultural techniques and its cultivation and production keeps
improving and evolving. This depends on several factors such as organoloptic
properties of the fruits, farming system, agronomic practices etc. Modern age
of commercially grown tomato started with the effort of Alexander W.
Livingston. In 2009, worldwide tomato production rose to 158.3 million tons,
surpassing the previous years by 3.7%. The largest producers were China with 24%
of world production, followed by United States, Turkey, India, Egypt and Italy.
1.3 Benefits of Tomatoes
Tomatoes are a great source of vitamins
A single tomato can provide about 40% of the daily
recommended minimum of vitamin C. What’s more, tomatoes supply vitamin A, which
supports immunity, vision, and skin health; vitamin K, which is good for your
bones; and potassium, a key nutrient for heart function, muscle contractions,
and maintaining a healthy blood pressure and fluid balance.
They protect heart health
Tomatoes contain an antioxidant called lycopene, which is
responsible for their red color. Research suggests that in terms of heart
health benefits, it’s more effective to eat tomatoes and tomato products than
take lycopene supplements. Other studies have shown that higher blood levels of
lycopene are tied to lower death rates for people with metabolic syndrome, a
cluster of risk factors that raise the chances of developing heart disease,
diabetes, and stroke.
Improve you vision
Lycopene is also good for your eyes. And that’s not the only
peeper-protective nutrient in tomatoes; they contain lutein and beta-carotene
as well. According to research, those nutrients support vision and protect
against eye conditions including cataracts and macular degeneration.
Boost digestive health
The fluid and fiber in tomatoes may be helpful if you’re
prone to constipation. (According to the USDA one large tomato contains 6
ounces of fluid, and 1.5 grams of fiber.) Just be aware that in some people,
the acidity from cooked tomatoes may trigger or worsen acid reflux and
Help with diabetes management
Tomatoes may be a protective food for people with type 2
diabetes: In one study, people with diabetes who supplemented with cooked
tomatoes for 30 days experienced a decrease in lipid peroxidation, a chain
reaction in which substances called free radicals attack fat, leading to damage
that ups the risk of heart disease. This is particularly important, because
diabetes doubles the risk of stroke and heart attack.
Guard skin health
A 2011 study found that the combination of tomato paste and
olive oil protected against sun damage, and boosted the production of
pro-collagen, a molecule that gives the skin its structure and keeps it firm
and youthful. Scientists believe that the lycopene in tomatoes is key. It’s at
its highest concentration when tomatoes have been cooked, and olive oil boosts
its absorption from your digestive system into your bloodstream.
Protect against cancer
Observational studies have found links between the superstar
compound lycopene and fewer incidences of prostate, ovarian, lung, and stomach
Tomato is a significant source of Umami flovour. This is
consumed in diverse ways; raw or cooked, sources, salad and in drinks.
Tomatoes are also one of the main ingredients in hundreds of
dishes and products that are sold in Supermarkets throughout the world.
Tomatoes serve as the best to people who wish to grow fruits
and vegetables. It is also an essential part of many recipes as well as many
produced products such as “Tomato Ketchup and Tomato Paste”. Tomato is
advantageous over other types of crops, such as:
High Yield which result in their high economic value
High nutritional value with high level of Pro-vitamin A and
C, as well as being ranked highest in their contribution to human diet.
In competition with other vegetables, tomato is a short
duration crop in term of time of production.
They are suitable in diverse cropping system used on grains
1.4 Justification of the study
Tomato is one of the most demanding vegetable in Nigeria and
Western part of the world. Mexico and India are the major supplier of tomato as
far as tomato consumption is concerned. Local production is unable to meet the
demand since most of the product is left to rot on farm sites due to poor
storage facilities, poor road network linkage to farms and the markets in the
rural and urban areas. This prevents purchasers from purchasing it from the
farmers as the cost tends to increase due to the state of the roads. The
perishable nature of the fruit also forms part of the reasons why local
production is not able to meet the market demand.
1.5 Objective of the study
The objectives of the study were to:
Determine the variability trait existing between the exotic
and local cultivars of tomato, planted in Obio Akpa.
Assess the number of fruits per plants and fruit yield per