Plant breeding for organic and sustainable, low-input agriculture

Selection of tomato cultivars for organic production
Ewa Rembiałkowska, Ewelina Hallmann
Warsaw University of Life Sciences – SGGW, Warsaw, Poland
The organic food products are recognized by the consumers as better and safer than conventional
ones. Organically produced plants have often lower yields but higher nutritive values that are
very important quality indicators for the consumers. Therefore the aim of the presented work was
to identify and to select the best cultivars of tomatoes in terms of their nutritive values. Food
quality can be understood as food safety, measured by the minimal content of harmful substances
(as nitrates, pesticide residues etc.) and nutritive quality, measured by the maximal content of
desirable substances (as vitamins, bioactive compounds etc). In the case of tomatoes the most
important is nutritive quality, because these fruits contain only low levels of the harmful
substances; the strategy of the plant protects the fruits (and seeds inside) against toxins’
accumulation. That is a high advantage for the consumers, especially in the organic sector.
Therefore in the presented study it has been decided to focus only on the nutritive values of the
tomato fruits. It’s well known that tomatoes are very good source of the antioxidant compounds
such as carotenoids (lycopene and beta-carotene), flavonoids as quercetin, and vitamin C.
In the presented experiment nine tomato cultivars have been analysed, in that seven standard
cultivars: Atol, Awizo, Etna, Gigant, Juhas, Rumba, Kmicic, and two cherry cultivars: Piko and
Koralik. The experiment has been carried out for three years in organic and conventional farms
(two pairs of farms) located in Mazovia region. A lot of quality parameters were investigated to
select the best cultivars for organic production: the content of dry matter by scale method, total
and reducing sugars, total acidity, vitamin C, carotenoids (lycopene and beta-carotene) and
quercetin.
The results obtained indicated that five of nine studied tomato cultivars had much better quality
parameters when plants were cultivated in organic way: standard cultivars Rumba, Gigant, Juhas,
Kmicic, and cherry cultivar Koralik. The last cultivar contained the highest level of the most
investigated bioactive compounds. For example Gigant cultivar from organic production
contained 8.58 mg flavonols and only 5.35 mg per 100 g.f.m. in conventional cultivation, while
the lowest level of flavonols was found in Awizo cultivar: in organic cultivation it was only 1.54
mg per 100 g.f.m, and in conventional 1.18 mg per 100 g.f.m. Similarly, the organic cultivar
Gigant contained 4.87 mg betacarotene per 100 g.f.m, and conventionally cultivated cultivar
Gigant only 0.73 mg per 100 g.f.m. Awizo cultivar contained 1.26 mg betacarotene per 100
g.f.m. when cultivated in organic way, and in conventional cultivation it contained 1.12 mg
betacarotene per 100 g.f.m.
The above data indicate that some cultivars are able to collect significantly more desirable
compounds when cultivated in organic way in comparison to other cultivars. These cultivars can
be really recommended for organic cultivation.
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