6. Screenhouse/greenhouse

Greenhouse tomato production utilizes techniques that are not used in the open field or other intensive cropping systems. In the greenhouse, water, carbon dioxide, artificial lighting, soilless growth medium such as hydroponics and heating systems are provided to simulate the growing conditions that occur in the open field [28]. Most greenhouses are used in association with drip irrigation systems that regulate and save the amount of water that will be required to produce the optimum yield. In some cases, only 25% of the water required in the open field is used to produce the same quantity in the greenhouse [29]. This is very useful in areas that are faced with extreme temperatures and water scarcity [28] and will be crucial in crop production especially with the imminent shortage of water that will be associated with climate change and variability. The use of greenhouse technology in tomato cultivation combines market-driven quality parameters with the production system that enhances the quality and quantity of the final product. Provision of the necessary intensive plant care is possible without the excessive use of chemical pest management. This is because better protection is achieved through the use of integrated pest management strategies that are more effective under controlled environments than in open field [30]. Cultivation of tomato under this system ensures that the high profit margins due to premium prices offered the good-quality products obtained because in addition to higher yield, the production is also free from dust, insect, disease, and pest [31]. Greenhouse-grown round and cluster tomatoes were found to contain higher levels of lycopene than field-grown tomatoes. However, the opposite was the case with cherry tomatoes which recorded lower levels of lycopene under greenhouse conditions compared with openfield cherry tomatoes. These reports suggested the presence of genotype by environment interaction effect [18]. Therefore, careful varietal selection should be done when utilizing the greenhouse technology in tomato cultivation. Besides careful varietal selection, energy consumption is also one area that needs to be considered critically when deciding the type of technology to be used for maximum profit [32].

#### 6.1. High tunnel

and high of 25C, while the warm season temperatures average low of 26C and a high of 32C. Significantly higher or lower temperatures can have negative effects on fruit set and quality. Studies have shown that temperatures above 32C for more than 3 hours a day can induce abortion of flowers resulting in low fruit yield [21]. In Ghana and most parts of West Africa, it is cultivated in the open field under field conditions, or in controlled environments such as greenhouse. The productivity of the tomato crop depends on the yield potential of the genotype, the soil as well as agronomic and management practices that are carried out. Tomatoes can be produced on a wide range of soils varying from deep, medium textured sandy loam or loamy, fertile, well-drained soils [22]. The site for growing tomatoes should be carefully selected based on the topography, soil type, soil structure, and soil management and the cropping history of the land (fields previously cropped to solanaceous crops should be avoided). Tomato plants depend on the soil for adequate nutrient and water supply as well as anchorage for physical support. For this reason, land preparation should be adequately done to ensure proper plant establishment and to provide the best soil structure for root growth and development. Tomatoes require soils that are rich in nutrients but most soils in Sub-Saharan Africa are low in nutrients due to continuous intensive cultivation without adequate application of soil amendment measure [23, 24]. The potential of organic and inorganic fertilizers can provide the needed solution for intensive tomato cultivation, but this is limited due to scarcity, cost implications, and problems with high acidity associated with over application of such fertilizers [25]. The application of green manure can also provide a viable alternative for

maintaining soil fertility but its use is limited among tomato farmers in Ghana [26].

In most parts of the tropics, tomato production is weather dependent and highly seasonal. This had led to fluctuations in glut during peak harvest and scarcity during the unfavorable periods of the season. This scenario often affects the pricing and revenue of the growers as well as consumer satisfaction [27]. The use of controlled environment in tomato cultivation can address the challenges faced by tomato farmers to provide suitable environment for growing tomatoes during the off-season and meet consumer demands. Several controlled environments

Greenhouse tomato production utilizes techniques that are not used in the open field or other intensive cropping systems. In the greenhouse, water, carbon dioxide, artificial lighting, soilless growth medium such as hydroponics and heating systems are provided to simulate the growing conditions that occur in the open field [28]. Most greenhouses are used in association with drip irrigation systems that regulate and save the amount of water that will be required to produce the optimum yield. In some cases, only 25% of the water required in the open field is used to produce the same quantity in the greenhouse [29]. This is very useful in areas that are faced with extreme temperatures and water scarcity [28] and will be crucial in crop production

5.1. Controlled environments

74 Recent Advances in Tomato Breeding and Production

are used in tomatoes cultivation.

6. Screenhouse/greenhouse

Tomatoes are well adapted to the growing conditions within a high tunnel. A high tunnel often called hoophouse is a solar-heated, manually controlled vented structure cold frame that is covered with plastic (single or double layer) for cultivation of many horticultural crops with the purpose of lengthening the growing season. Though similar in appearance to some greenhouses, they lack some features of greenhouses such as electricity for temperature and humidity regulation, and thus require no electrical connections for ventilation and supplemental heat [33–35]. However, most high tunnels have roll-up sidewalls and detachable end walls for temperature and humidity management. High tunnels can significantly increase the average daily temperature and protect the crop from wind, rain, insects, and diseases. Crops are grown directly in the soil using raised beds or mulch [36, 37]. Since high tunnels exclude natural rainfall so water must be applied through irrigation. Drip irrigation significantly improves the marketable yield and overall quality and is the best form of irrigation for tomatoes grown under high tunnels. It ensures uniform application of water to help reduce fruit cracking and other physiological problems such as blossom end rot. In most intensive cultivation using the high tunnel technology, both water and nutrients are supplied to the crops during the growing season with drip irrigation [38]. When tomatoes are cultivated in high tunnels they can be trained to grow vertically by the use of trellis or staking (Figure 1).

#### 6.2. Hydroponics

Hydroponic tomatoes are grown in a nutrient solution rather than soil. The plants are typically placed in a nonsoil material known as substrata that can support their roots and hold the nutrients. In some cases, hydroponic system utilizes absorbent substrata such as coconut fiber, perlite, rock wool, vermicompost, and their combinations [39, 40] together with a drip-irrigation

However, hydroponic gardening is labor-intensive and requires skilled training for efficient water and nutrient management under large-scale production. It has been suggested that one of the major problems of using the hydroponics systems for tomato cultivation is its requirement for highly specialized technical support in order to properly replenish the nutrient

Genotype × Environment Interaction: A Prerequisite for Tomato Variety Development

http://dx.doi.org/10.5772/intechopen.76011

77

The tomato plant like most vegetable crops requires a lot of water for optimum growth and development. Moisture stress causes abortion of flowers and young fruits, and young fruit, sun scalding, and dry rot of fruit. Water is required at most critical stages of growth of the

Figure 2. Dutch bucket hydroponic system for cultivating tomatoes (https://www.google.com.gh/search?tbm = isch&sa = 1&q = hydroponics+tomatoes&oq = hydroponics+tomatoes&gs\_l = psy-ab.3..0j0i5i30k1j0i24k1l6.202616.205468.0.206233.9.9.0

.0.0.0.384.1735.2-5j1.6.0….0…1.1.64.Psy-ab..3.6.1732…0i67k1.0.HQe-PNKGI6I#imgrc = gjqgs0WVSaQvuM).

solution in all the growing phases of the crop [43] (Figure 2).

6.3. Irrigation

Figure 1. Interior and exterior features of high tunnels for controlled vegetable cultivation.

system which supplies water at low tension and high frequency to create optimum environment for growth of the vegetable [41, 42]. By avoiding soil medium, the use of hydroponics enables the grower to prevent diseases and soil-borne pests, such as nematodes, that are difficult to control [43]. Tomato production under protected systems such as hydroponics allows cultivation in regions inappropriate for conventional agriculture by efficiently using natural resources particularly water and soil [44]. Hydroponic systems provide regulation of harvesting, avoiding crop rotation, better fruit quality, better crop handling, and better control over nutritional needs and environmental conditions. Growing tomatoes under hydroponic system allows the grower to raise them under a controlled environment with less chance of disease, faster growth, and greater fruit yield. This offers several advantages in terms of the quantity and quality of products obtained per unit land area over cultivation in soil [45]. However, hydroponic gardening is labor-intensive and requires skilled training for efficient water and nutrient management under large-scale production. It has been suggested that one of the major problems of using the hydroponics systems for tomato cultivation is its requirement for highly specialized technical support in order to properly replenish the nutrient solution in all the growing phases of the crop [43] (Figure 2).

#### 6.3. Irrigation

system which supplies water at low tension and high frequency to create optimum environment for growth of the vegetable [41, 42]. By avoiding soil medium, the use of hydroponics enables the grower to prevent diseases and soil-borne pests, such as nematodes, that are difficult to control [43]. Tomato production under protected systems such as hydroponics allows cultivation in regions inappropriate for conventional agriculture by efficiently using natural resources particularly water and soil [44]. Hydroponic systems provide regulation of harvesting, avoiding crop rotation, better fruit quality, better crop handling, and better control over nutritional needs and environmental conditions. Growing tomatoes under hydroponic system allows the grower to raise them under a controlled environment with less chance of disease, faster growth, and greater fruit yield. This offers several advantages in terms of the quantity and quality of products obtained per unit land area over cultivation in soil [45].

Figure 1. Interior and exterior features of high tunnels for controlled vegetable cultivation.

76 Recent Advances in Tomato Breeding and Production

The tomato plant like most vegetable crops requires a lot of water for optimum growth and development. Moisture stress causes abortion of flowers and young fruits, and young fruit, sun scalding, and dry rot of fruit. Water is required at most critical stages of growth of the

Figure 2. Dutch bucket hydroponic system for cultivating tomatoes (https://www.google.com.gh/search?tbm = isch&sa = 1&q = hydroponics+tomatoes&oq = hydroponics+tomatoes&gs\_l = psy-ab.3..0j0i5i30k1j0i24k1l6.202616.205468.0.206233.9.9.0 .0.0.0.384.1735.2-5j1.6.0….0…1.1.64.Psy-ab..3.6.1732…0i67k1.0.HQe-PNKGI6I#imgrc = gjqgs0WVSaQvuM).

tomato plant particularly at transplanting, flowering, and fruit development. Adequate supply of water is very essential for attaining the full potential of tomato plants under cultivation [31, 32]. However, agricultural activities in most parts of the tropics are mostly rainfed resulting in short supply of water for farming activities during the dry season. Rainfall amounts are often erratic even during the main growing season resulting in poor crop performance especially in areas where tomatoes are grown in soils with low water holding capacity. The use of irrigation schemes provides the needed water required for crop production. This makes supplemental irrigation essential for commercial tomato production to sustain consistent yields of highquality tomatoes during the off-season to meet demand of consumers. Studies have shown that irrigation increases annual tomato yields by an average of at least 60% over dryland production [32, 33]. The quality of tomatoes cultivated under irrigation has also been found to be better than nonirrigated fields [20].

the middles remain dry. Another advantage of drip irrigation is obtained when used in within a high tunnel which is equipped with the ability to inject water-soluble nutrients through the

Genotype × Environment Interaction: A Prerequisite for Tomato Variety Development

http://dx.doi.org/10.5772/intechopen.76011

79

Multilocation trials are usually performed by researchers to evaluate new or improved genotypes across multiple environments (locations and years), before they are promoted for release and commercialization. This is systematic approach undertaken to increase yield stability of new crop varieties in stress-prone environments [47]. Data generated from such trials are important for (i) accurate estimation and prediction of yield based on limited experimental data; (ii) determining yield stability and the pattern of genotypes response across environments; and (iii) providing reliable guidance for selecting the best genotypes or agronomic treatments for planting in future years and at new areas [48]. However, the performances or ranking of the genotypes in such experiments are usually not the same in the different environments. This is because of interactions between the genotypes and the environments [49, 50]. This type of interaction is known as genotype × environment interaction (GEI), and may complicate the selection and recommendation of genotypes evaluated in diverse environments [51, 52]. The importance of GEI in genotype evaluation and breeding programs has been demonstrated in almost all major crops [53–57]. The GEI reduces the association between the phenotypic and genotypic values and leads to bias in the estimation of gene effects and combining ability for various characters that are sensitive to environmental fluctuations less

Genotype × environment interactions can be classified into three broad types (Figure 3) (i) "no" GEI, (ii) non-crossover interaction, and (iii) crossover interaction [58]. The number of environments (E) and the number of genotypes (G) determine the number of GEI possible and that, the higher the number of environments and genotypes the greater the number of possible G × E interactions. Thus, with two genotypes and two environments, and with only a single criterion, at least four different types of interactions are possible. With 10 genotypes and 10 environments, 400 types of interactions are possible, which would undoubtedly make their

When there is no GEI, the effects of each of the risk factors are similar across the levels of the other risk factors. A "no" GEI occurs when one genotype (G1) constantly performs better than the other genotype (G2) by approximately the same amount across both environments. Figure 3A, B shows that G1 and G2 perform similarly in two environments, because their responses are parallel and stable. The variations in trait expression across a range of environments for the two genotypes are therefore additive. Moreover, the intergenotypic variance

implications and interpretation more difficult to comprehend [59, 60].

drip lines as the plant needs them.

reliable for selection [57].

9. No G × E interaction

8. Genotype × environment interaction
