Medicinal Plant Research 2024, Vol.14, No.4, 234-244 http://hortherbpublisher.com/index.php/mpr 239 Excessive nutrient levels can be just as detrimental as deficiencies. Over-fertilization with nitrogen can lead to excessive vegetative growth at the expense of medicinal component accumulation. High phosphorus levels can cause micronutrient imbalances, particularly with zinc and iron, leading to chlorosis and poor plant health. Excess potassium can interfere with the uptake of other essential nutrients, potentially causing nutrient imbalances and toxicity symptoms (Wu et al., 2023). 5 Watering and Irrigation Techniques 5.1 Water quality and its effect on growth The quality of irrigation water, particularly its pH and mineral content, plays a crucial role in the growth and development of D. officinale. Optimal pH levels ensure the availability of essential nutrients and prevent toxicities. For instance, soil pH was identified as a key ecological factor influencing the medicinal quality of D. officinale, affecting the availability of soil nutrients such as nitrogen and phosphorus (Yuan et al., 2020). Additionally, the presence of essential minerals in irrigation water can enhance plant growth, as seen in studies where potassium supplementation improved the quality of D. officinale by optimizing transcriptomic and metabolomic alterations (Jia et al., 2022). Salinity and contaminants in irrigation water can have detrimental effects on the health of D. officinale. High salinity levels can lead to osmotic stress, ion toxicity, and nutrient imbalances, which adversely affect plant growth and productivity. For example, studies have found that under salt stress, D. officinale initiates a series of stress response mechanisms, including the inhibition of the synthesis of growth-related hormones, such as auxins and cytokinins (Zhang et al., 2022a). 5.2 Optimal watering frequency and methods The watering frequency for D. officinale should be carefully adjusted according to the plant's growth stage to ensure optimal development. During the early stages of growth, frequent watering may be necessary to support root establishment and seedling vigor. As the plant matures, the watering intervals can be extended to prevent waterlogging and promote healthy root development. The relationship between ecological factors, such as soil moisture, and the quality of D. officinale underscores the need for tailored irrigation practices (Yuan et al., 2020). Different irrigation methods can significantly impact the growth and health of D. officinale. Drip irrigation is often preferred for its efficiency in delivering water directly to the root zone, minimizing water loss and reducing the risk of foliar diseases. Sprinkler irrigation, while effective for larger areas, may lead to higher evaporation rates and potential disease spread. Manual watering allows for precise control but is labor-intensive. The choice of irrigation method should consider the specific needs of D. officinale and the cultivation environment (Elhindi et al., 2020; Yuan et al., 2020). 5.3 Impact of overwatering and drought stress Overwatering can lead to waterlogging, which deprives the roots of oxygen and promotes the growth of pathogenic fungi. Symptoms of waterlogging in D. officinale include yellowing leaves, stunted growth, and root rot. The presence of mycorrhizal fungi has been shown to enhance the plant's tolerance to water stress by improving root health and reducing the incidence of root rot caused by pathogens (Li et al., 2021a). Drought stress in D. officinale manifests as wilting, reduced leaf size, and decreased biomass. The plant's adaptive responses to drought include the accumulation of osmoprotectants and the activation of stress-responsive genes. Mycorrhizal associations can also enhance drought tolerance by improving water uptake and nutrient acquisition. Understanding these adaptive mechanisms is essential for developing effective irrigation strategies that mitigate the impact of drought stress onD. officinale. 6 Case Studies 6.1 Study on the impact of different cultivation modes on the medicinal components of D. officinale The accumulation of medicinal components in D. officinale is influenced by various ecological factors in its cultivation environment, making it essential to study how these factors impact medicinal components under
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