# Design and Comparative Analysis of a Ground-Level Trellising Tool for Greenhouse Tomato Cultivation
## 1 Introduction  
In Spain, greenhouse cultivation has experienced continuous growth since it was first established approximately 50 years ago, covering an area of 63,390 hectares currently [1]. The largest concentration is found in the province of Almeria, located in the southeast of Spain, which is one of the most outstanding production regions in the world with regard to both area and volume. This region is known as \"the sea of plastic\" due to the significant area of greenhouses that cover a large part of its territory (32,827 hectares), representing 52% of the entire wintered surface at the national level [2]. Almeria produced 80% of the total vegetables in Spain during the 2021/22 season [1, 2], which gives a clear idea of the high profitability of this agricultural production system. Almeria has managed to become one of the largest exporters of fruits and vegetables in Europe. Among all horticultural crops, greenhouse production of tomatoes in Almeria is a highly significant contributor to the economy, with approximately 8201 hectares under cultivation and a production of 730,745 tons [2]. In 2021, the Andalusian protected tomato area represented 76% of the total greenhouse area in Spain, with Almeria accounting for 76% of this [3]. This crop represents about 63% of the total value of greenhouse tomato production in Spain [4], making it a key element in the export of fresh vegetables. Almeria'stomato exports are primarily destined for European markets, including Germany, France, and the United Kingdom, for which stable and high-quality production is demanded year-round. The competitiveness of tomatoes from Almeria in the global market is attributed to the implementation of advanced production and biological control technologies, as well as the optimization of water resources through drip irrigation. The horticultural sector in Almeria employs about 75,000 people directly [2]. Of these, it is estimated that around 11,000 jobs are related to tomato cultivation in Almeria, mainly in the stages of sowing, maintenance, and harvesting of the fruit, as well as in the management and supervision of greenhouses, which have a high impact on job creation, including qualified and unqualified labor. Furthermore, there are considerable numbers of indirect jobs generated in auxiliary sectors, such as the transport, marketing, and production of phytosanitary products and agricultural machinery. Since its beginnings in the 1960s, greenhouse infrastructure has undergone a remarkable technological evolution, adapting to production, climate, and sustainability needs. Greenhouses have transformed from being a rudimentary technique with low and flat structures that did not exceed 2 m in height to complex multi-tunnel and \"scrape-and-tame\" installations, which allow for more efficient and profitable agricultural production by reaching greater heights [5]. Today, these types of greenhouses have a maximum height between 3.7 and 4.3 m and a minimum height between 2.8 and 3.5 m, depending on the area [2]. These models have several advantages that directly affect agricultural production, such as microclimate control, which provides important control over ventilation and, thus, reduces the proliferation of pests and diseases while promoting uniform plant growth and increasing yield per cultivated area. In certain horticultural products, such as tomatoes grown in greenhouses, it is necessary to carry out trellising to achieve greater productivity and quality in the crop by improving the lighting and ventilation, as well as preventing the fruits from touching the ground [6]. The trellising system that is usually used in common practice is the hanging system and, lately, a variant of this type of support has been introduced; this is also known as the \"Dutch\" or \"hanger\" technique.