## 4 Control Strategies in Greenhouses  
Greenhouse control technology refers to the use of different devices and systems to monitor and regulate the environment inside greenhouses, aiming to optimize conditions for plant growth [222; 223]. This can include the use of temperature, humidity and light sensors, automated watering systems, controlled ventilation and even the use of artificial intelligence to optimize the growing environment. These technologies aim to maximize production, improve crop quality and reduce the use of resources such as water and energy [224; 225]. Just as water resources are not the main focus of this article, control strategies in greenhouses are also not part of the main scope of the discussion but deserve a brief approach. In greenhouse management there are mainly two forms of control, which are distinguished by the degree of automation and technological complexity, these two forms of control are manual control, which involves direct human intervention, and automated control, which uses technology to monitor and adjust environmental conditions, as we can see in the Figure 11.  
Figure 11: Adapted from [PERSON] et al. [226], this figure presents flowcharts that illustrate four levels of automation in the operational management of agricultural greenhouses. 1. Traditional Agriculture: Manual operations performed by farmers, such as planting and irrigation, without technological assistance. 2. Manual Control: Farmers use sensing devices to guide the manual operation of actuators. 3. Supervised Control: Low-level automatic adjustments are made with human supervision, based on sensory data and external predictions. 4. Automatic Control: A fully automated closed control system integrates sensors and actuators, significantly reducing the farmer’s role in daily greenhouse operations. In Manual Control, adjustments to the greenhouse environment, such as temperature, humidity, ventilation and irrigation, are made manually by the operator. This may include opening and closing windows or vents, turning heaters or fans on and off, and adjusting irrigation based on observation. The main advantages of this form of control are simplicity and lower initial cost. It is more adaptable to smaller greenhouses or where advanced technology may not be economically viable. On the other hand, it requires more labor, is less accurate and more susceptible to human error. May not be time and resource-efficient, especially in large-scale greenhouses [227]. In Automated Control, a variety of sensors and computer-controlled devices are used to continuously monitor and adjust the environmental conditions of the greenhouse [228]. These include automated irrigation systems, temperature and humidity control with automated ventilation and heating, controlled lighting and in some cases, automatic \(CO_{2}\) enrichment. The main advantages of this form of control are greater precision in environmental control, time and labor savings, and the potential to significantly improve efficiency and productivity. Automation allows for constant, real-time monitoring and adjustment, adapting to changes in external and internal conditions. On the other hand, it requires higher initial installation and maintenance costs [229; 230]. Requires technical knowledge to operate and maintain the system. The choice between manual and automatic control in greenhouses depends on several factors, such as the size of the operation, the type of cultivation, the available budget, and the desired level of precision and efficiency. While smaller, less technological greenhouses can operate efficiently with manual control, larger, more intensive operations often benefit significantly from automation.