Quantitative Growth Analysis of Tomato (Lycopersicon esculentum Mill.)

The tomato is the edible, often red, fruit/berry of the plant Lycopersicon esculentum, commonly known as a tomato plant. The plant belongs to Angiosperms of nightshade family, Solanaceae. The species originated in western South America. Its use as a cultivated food may have originated with the indigenous peoples of Mexico. The tomato (Lycopersicon esculentum Mill.) is commercially important throughout the world both for the fresh fruit market and the processed food industries. Tomato is consumed in diverse ways, including raw, as an ingredient in many dishes, sauces, salads, and drinks. While tomatoes are botanically berry-type fruits, they are considered culinary vegetables as an ingredient or side dish for savory meals. Numerous varieties of tomato are widely grown intemperate climates across the world, with greenhouses allowing its production throughout the year. In the recent decades, the consumption of tomatoes has been associated with prevention of several diseases (Willcox et al. 2003 and Sharoni et al. 2006) mainly due to the content of antioxidants including carotenes, (Lycopene as well as 𝛽-carotene), ascorbic acid, and phenolic compounds (Jesus Periago et al. 2009). The plants typically grow to 1–2.8 meters (100– 280 cm) in height and have a weak stem that sprawls. It is a perennial in its native habitat, and cultivated as an annual. Fruit size varies according to cultivar, with a width range of 0.5–4 inches (1.3–10.2 cm). Tomato (Lycopersicon esculentum Mill.) is one of the most important and has the highest acreage of any vegetable crop in the world (Jensen et al., 2010). In 2010, its global production was approximately 145.6 million tons of fresh fruit and Brazil ranks ninth, with 2.7% of the world production (Matos et al. 2012). Tomato growing is considered a high-risk activity due to the great variety of environments and systems in which it is grown, high susceptibility to pests and diseases, and high demand for inputs and services, which lead to high financial investment per unit area. Furthermore, Monte et al. (2013) remark that good productivity requires availability of water throughout the cycle, as the tomato plant is very sensitive to water stress. The commercial value of the table tomato is defined by the characteristics and quality of the fruit (Ferreira et al., 2004). All the living organisms are, at various stages in their life history, capable of growth. Given suitable conditions, this means change in size, change inform and/or change in number. These three processes together form an important part of the phenomenon of life. Among natural systems they help to distinguish the living from the non-living though, in a sense, many non-living systems also grow. Understanding the principals involved in plant growth requires a systematic approach using the tools of mathematics, physics, and other sciences along with commonsense knowledge of biological variability. This teaching resource illustrates the method of interpreting plant development referred to as growth analysis (Kuchay and Zargar, 2016). The exercise can be used jointly with a series of related problems in a crop science course. Plant growth analysis refers to a useful set of quantitative methods that describe and interpret the performance of whole plant systems grown under natural, semi-natural, or controlled conditions (Kuchay and Zargar, 2016). Plant growth analysis provides an explanatory, holistic and integrative approach to interpret plant form and function. A technique of investigating growth and yield by use of growth functions was developed by British plant physiologists and has been commonly termed growth analysis (Watson, 1952 and Williams, 1946). Plant growth analysis is considered to be a standard approach to study the plant growth and productivity (Wilson, 1981). Plant growth analysis uses simple primary data like weight, area, volumes and contents of plants or plant parts to investigate processes within and involving the whole plant or crops (Hunt, 2003). Growth analysis has proved to be highly effective in studying the reaction of particular plant species to different environmental conditions and cultivation/management practices. The growth analysis studies not only help us in understanding how plant accumulates dry matter, but also discloses the underlying principles and events which can make a plant more or less productive (Ahad, 1986). The procedure for analyzing growth in terms of dry weight changes was first made by Blackman 1919, when he pointed out that growth could be regarded as a process of continuous compound interest. Any increment produced in any interval would add to the "capital" for growth in subsequent periods. The classical approach is one of the oldest methods in plant growth analysis studies introduced in the beginning of this century (Blackman 1919, West et al. 1920, Briggs et al. 1920) where the relative growth rate (RGR) is calculated by dividing the difference in loge transformed plant weight at two harvests by the time difference between those harvests. Growth analysis parameters help in studying differences in the performance of different varieties or cultivars of crops under similar or varied conditions. The growth analysis parameters like RGR and NAR directly influence the economic yield of crops (Srivastava and Singh, 1990). Similarly, dry matter production; LAR, NAR and RGR are ultimately reflected in higher yield of crops (Thakur and Patel, 1996). Karim and Fattah (2007) reported that NAR gets increased during fruiting stage. The shading of plant populations to varied degrees can be done in order to determine the effect of light intensity and the reaction of individuals can be monitored through growth analysis, like the shading of leaves can reduce NAR (Net Assimilation Rate) but the plants becomes more leafy. The reductions of light intensity can double the leaf area ratio (LAR) and similarly, more leaf surfaces can compensate the reduction in NAR so that relative growth rate (RGR) remains more or less constant.