By combining solar energy with intelligent, data-driven systems, this approach ensures higher-quality products and a reduced environmental footprint [35; 36]. This study aims to evaluate the optimal harvest time of two MAPs using multispectral sensors on UAVs (Figure 1). It focuses on assessing crop variability through vegetation indices (VIs), which can guide spatially tailored crop management practices through a Decision Support System (DSS). Solar dryers offer significant economic and environmental benefits, particularly in reducing drying operation costs. For instance, farmers can save up to USD 757.31 annually and increase profits by USD 15,683 [37]. In Egypt, the use of solar dryers for aromatic crops like lemongrass and oregano can save between USD 102.5 and USD 1235.44 per year, depending on the rate of utilization [38]. The payback period for solar dryers varies, with a direct solar dryer for medicinal plants having a payback period as short as 6 months, while an indirect dryer may take up to 14 months [39]. Furthermore, hybrid solar dryer models, especially those integrated with photovoltaic cells, offer enhanced energy efficiency, achieving up to 70% efficiency [40]. Environmentally, solar dryers help significantly reduce CO\({}_{2}\) emissions; for example, drying grapes in Egypt can reduce emissions by up to 407,023.8 kg annually [38], and overall, solar dryers can mitigate up to 430,714.76 tons of CO\({}_{2}\) emissions each year [37]. Solar dryers also contribute positively to sustainability indices and can earn carbon credits, providing additional financial benefits [41]. However, the initial investment required for solar dryers can be substantial, which may deter some farmers. Hybrid and mixed-mode dryers, although requiring 15-25% more initial investment, reduce drying time by 30-40% [42]. Adoption rates are also hindered by financial and operational barriers, but multi-seasonal use and financing schemes could alleviate these challenges [43]. In conclusion, solar dryers present both economic and environmental advantages, including significant cost savings, increased revenue, and reductions in CO\({}_{2}\) emissions. Despite high initial costs, long-term benefits and the potential for carbon credits make them a viable and sustainable option for agriculture, with financial incentives and multi-seasonal usage further encouraging their adoption. The use of AI and solar power not only reduces operational costs but also improves crop quality, sustainability, and overall profitability [44; 45]. Drying, a critical preservation method, helps reduce microbial growth and maintain the quality of herbs, including flavor and nutrients. Solar drying, in particular, is an effective technique for preserving the integrity of medicinal plants, aiding in the quality control of nutraceutical and aromatic products [44; 45]. The comparison between natural drying in open air and smart solar dryers (SSDs) highlights several key differences in drying efficiency, product quality, and operational  
Figure 1: Diagram of the used test protocol. reliability. Natural drying in open air relies on direct sunlight and ambient air to remove moisture from food products. It is a simple, low-cost method with minimal infrastructure requirements. However, it is highly dependent on weather conditions, making it unreliable during cloudy or rainy periods. Additionally, there is a risk of contamination from dust, insects, and animals, which can compromise the hygiene and quality of the product. The drying process is also inconsistent, leading to uneven moisture removal and potential nutrient loss, requiring large areas for spreading out the products. In contrast, the SSD uses controlled solar energy, often integrated with photovoltaic systems, thermal energy storage, and forced convection, to enhance drying efficiency. This system offers higher drying rates, more effective moisture removal, and improved product quality with less shrinkage and better color retention.