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.