*3.1. Mesh*

Cockshull et al. [5] explain that shading can reduce the average tomato size, but in turn favours a more homogeneous ripening in summer.

Araki et al. [12], in a plantation of spinach, observed that shading of 45% is optimal for growth in the months of June, August, and September, but 60% is optimal for the month of July.

Abdel-Ghanyand Al-Helal [22] claim that the diffusion of solar radiation occurring with shading mesh is related to the colour, texture, and porosity of the mesh; however, they caution that the methods used to measure the porosity of shading mesh may have an estimated error of 14% to 38% [25]. In addition, they revealed that shading mesh behaves like translucent materials, and the colour and solidity of the mesh influence heat transfer [26]. Later, they confirmed that the temperature and porosity of the mesh are more relevant parameters than texture and colour when radiative transmission and reflection are measured [29].

Chen et al. [27] developed a model to evaluate the performance of shading mesh and to predict air temperature in greenhouses.

In Serbia, Ilic et al. [31] observed that shading with coloured mesh in a tomato plantation reduced the amount of fruit with cracked skin and increased the commercial production by 35%, although the fruits had a lower beta-carotene content.

Abdel-Ghany et al. [32] compared upper exterior shading of the greenhouse with interior shading, finding that interior shading increases the thermal radiation by 147% and daytime air temperatures, whereas this increase is not seen with exterior shading.

Ahmed et al. [34] claim that shading methods reduce energy and water consumption, and increase fruit productivity and quality.

Nagy et al. [35] conducted a study of the production of pepper plants grown in a greenhouse under white, red and green shading and determined that the content of ascorbic acid increased even more in the fruits of plants grown with white shading.

Murakami et al. [36] state that the use of mesh in a melon crop reduced the leaf temperature of greenhouse plants by approximately 5 ◦C, and the size of the fruit was not affected, although the sugar accumulation in the fruit did increase.
