Background information of
Tomato In TANZANIA
The genus Lycopersicon of the Solanaceae
family is believed to have originated in the coastal strip of western South
America, from the equator to about 30° latitude south. The species is native to
South America, primarily in Peru and the Galapagos Islands. It is
believed that tomato was first domesticated in Mexico as seeds were taken to
Europe from Mexico after Cortez conquered Mexico City in 1519. It was not until
1533 that the Spaniards conquered Peru and Ecuador.
Ø Wild tomato plants are still found in the countries between Ecuador and
Chile as well as on the Galapagos Islands, although only two have edible fruit,
Lycopersicon esculentum (the common tomato in wide cultivation today)
and Lycopersicon pimpinellifolium, sometimes cultivated under the name
of currant tomato. The small fruited type, Lycopersicon esculentum var.
cerasiforme, cultivated under the name of cherry tomato, is widely distributed
as a wild plant in the tropics and subtropics.
Ø Tomato (Solanum
lycopersicum L.) productivity in eastern Tanzania, mainly in the coastal belt,
is low due to drought, excessive heat, declining soil fertility, pests and
diseases, and low genetic potential of available varieties. Stress-tolerant
cultivars adapted to environmental conditions in the region can increase
productivity.
Ø Field experiments were conducted at Mikocheni
Agricultural Research Institute and five on-farm sites in Kinondoni and
Bagamoyo districts during the 2008/2009 and 2009/2010 seasons to evaluate
performance and adaptability of tomato varieties. 'Tengeru 97' and 'Meru' were
the most promising varieties based on tolerance to nematodes, good fruit
characteristics, and high market acceptability, but were susceptible to early
blight. 'LBR-6' and 'LBR-11,' which are early blight resistant, were rated
excellent for taste and had high market acceptability, but were susceptible to
nematodes. Further testing of these varieties in disease hot spots along with
integrated pest management strategies that focus on nematodes and early blight
should be pursued. To increase production and quality of tomatoes in eastern
Tanzania, plant breeders must develop and introduce varieties that are heat
tolerant, resistant to nematodes, fusarium wilt, early blight, bacterial wilt
and Tomato yellow leaf curl virus. Introduction Vegetables are a good source of
carbohydrates, minerals, and vitamins (Tindall, 1983). Tomato (Solanum
lycopersicum L.) production is higher than other vegetable crops in Tanzania,
with a total annual production of 129,578 t, representing 51% of the total
vegetable production (Mwasha, 2000; de Putter et al., 2007). Vegetable
production in eastern Tanzania, covering mainly the coastal belt, has increased
due to growing demand. Average tomato yield is from 2.2 to 3.3 t/ha (URT, 2003)
which is far below the world average of 27.5 t/ha (FAO, 2005).
Ø Low productivity is caused by a combination of
factors including abiotic stress problems such as salinity, drought, excessive
heat, declining soil fertility, biotic stress from pests and diseases, poor
crop management, and a lack of well-adapted, high yielding varieties. To
increase productivity, there is a need to develop and introduce stress-tolerant
cultivars adaptable to the coastal areas. Breeding material and varieties are
available with resistance to diseases such as Tomato yellow leaf curl virus
(TYLCV), bacterial wilt (BW), fusarium wilt, gray leaf spot, early blight and
nematodes (Cornell University, 2006). However, there are no varieties with
resistance or tolerance to these stresses adapted to eastern Tanzania's agro
ecologies with largely coastal climatic conditions. This project was undertaken
to evaluate yield performance and adaptability of tomato varieties and lines in
eastern Tanzania.