**2. Tomato production trends and constraints in Ghana**

which is modern day Chile, Bolivia, Ecuador, Colombia and Peru; however, the original site of domestication is unclear [2]. Two hypotheses have been expressed for the original site of tomato domestication: one stipulates Peru and the other Mexico. It is, however, presumed that Mexico is probably the site of domestication and Peru is the centre of diversity [3]. Originally, tomatoes were pea-sized berries but domestication and plant breeding have resulted in increased fruit

Tomato continues to be the most important vegetable in the world due to increasing commercial and dietary value, widespread production as well as model plant for research [5]. Tomato is utilized as a fresh crop or processed into various forms such as paste, puree and juices. Tomato is a rich source of vitamins (A and C), minerals (iron, phosphorus), lycopene, Beta-carotene, high amount of water and low calories [6]. The five leading producers of tomato in the world are China, India, United States of America, Turkey and Egypt [7]. The world's tomato produc-

According to Norman [9], tomato (*S. lycopersicum*) was introduced into the geographical area considered modern day Ghana in the sixteenth century. Although the cultivation of tomato remains a subsistent farming activity, its cultivation and trade contributes significantly to livelihoods improvement [10]. Schippers [11] asserts that tomato is the most important vegetable in Ghana, compared to all the other vegetables. This view can be justified with the continuing increase in the demand for fresh and processed tomatoes in Ghana. With an average yield of about 8.1 tonnes per hectare in 2013, an estimated 340,218 tonnes of fresh tomatoes were produced locally and 5,945 tonnes was imported. In addition, 109,513 tonnes of processed tomatoes were imported within the year 2013 [12]. In the ensuing year, reported tomatoes statistics showed that there were increases in the local production volumes (366,772 tonnes), marching the increase in output per hectare of 8.6 t/ha [13]. The high volumes of tomato produced locally as well as imported are an indication of the importance of tomato in

Despite the importance of tomato in Ghana, tomato-breeding programmes over the years have not been systematic and therefore had not led to the development of new varieties that meet the needs of consumers as well as biotic and abiotic stresses [14]. The major goals of tomato breeding worldwide are increasing yield, tolerance to biotic and abiotic stresses and improvement in sensory and nutritional value of the crop [15]. Consequently, past Ghanaian plant breeders have focused on germplasm collection, evaluation of imported and local accession for morphological and agronomic traits as well as screening accessions for their reactions to biotic and abiotic stresses. Nonetheless, there have been little published breeding programmes in the past that focussed on improving fruit-quality traits or introgression genes that will make cultivars resilient to both biotic and abiotic stresses. In 2014, the Ghana National Tomato Federation stated that the union has been pushing government to support research in the development of high yielding and quality tomato variety suitable for local and export market [16]. This chapter therefore highlights tomato production trends in Ghana, tomato production constraints, past tomato-breeding programmes in the country and future tomato-breeding objectives, which will serve as a locus for developing future tomato-breeding

tion in 2014 was 171 million tonnes with an average yield of 37 tonnes per hectare [8].

sizes [4].

50 Recent Advances in Tomato Breeding and Production

every Ghanaian meal.

programmes.

Tomato is mostly produced in seven out of the 10 regions in Ghana. These production regions include Upper East region, Northern region, Brong Ahafo region, Ashanti region, Eastern region, Greater Accra region and Volta region. The demand for both fresh tomato and tomato products is year round although tomato production in Ghana is seasonal due to the differences in the rainfall patterns as well as water availability. In the exception of the Upper East Region where tomato is produced during the dry season under furrow irrigation system and some parts of the Greater Accra region, tomato production is generally rain fed. During the rainy season, harvest is abundant, leading to glut and wastage even though there is scarcity during the dry season. The abundance of tomato during the rainy season results in low prices and low return on investment. Tomato produced during the rainy season is supplied to the market from May to October but the varieties produced during this period are poor in colour, watery, acidic and have a shorter shelf life, making them unsuitable for processing. Due to the unavailability of processing tomato varieties, all the three state-owned tomato-processing factories had to shut down. Tomato varieties that are currently grown by Ghanaian farmers are mostly imported varieties and farmers selected varieties. A very important open-pollinated variety (OPV) grown in Ghana particularly in the Brong Ahafo region is the Power Rano (a cross between Power and Laurano varieties) which was identified by the National Research Institute (NRI) researchers in the 1990s based on its good production and local processing qualities [17].

Dry season production in Ghana on the other hand is challenging, and demand is in excess of supply. This period partially coincides with the Christmas season when demand for tomato is at its peak. In order to meet the dry season demand, there is heavy importation of fresh tomato from neighbouring countries, particularly Burkina Faso to augment local supply. Some parts of the Greater Accra region such as Ashiaman, Tema and Weija grow tomato under irrigation system and mostly supply tomato unto the market from September to December, and the Upper East region then continues tomato supply from January to April**. I**mported tomato from Burkina Faso supplements local production 5–6 months of the year [18] with a peak supply from February to April [19]. It has been established that, with the availability of water and favourable night temperatures, the highest quality and fruit yield of tomato is obtained in the dry season [20]. In Ghana, the capacity for dry season tomato production lies in the savannah zones, particularly the Upper East, Volta and the Greater Accra regions since water for dry season irrigation is not a limiting factor in these regions. Tomato production halted in the Upper East region in 2002 due to Tomato Yellow Leaf Curl Disease (TYLCD) and a complex of fungal pathogens [21]. In addition, over 600 tomato farmers in the Agotime-Ziope District of the Volta region were reported to have lost virtually all their investment following the TYLCD infection (in 2014) of over 1000 hectares of tomato farms in the area [22]. A high night temperature, a high prevalence of TYLCD and inadequate irrigation facilities to channel the available water are characteristics of dry season production of tomato in the Greater Accra region. Ghana's inability to produce tomato during the dry season therefore has been attributed to a lack of irrigation facility, a high incidence of Tomato Yellow Leaf Curl Disease [23, 24] as well as high night temperatures [25].
