The relation between compositional nutrient diagnosis indices and susceptibility of Valencia orange to citrus decline

Impact of Twig-Tip Dieback on Leaf Nutrient Status and Resorption Efficiency of Mango Trees

“…It also corroborates a study showing the variable effects of diseases on the nutrient content of citrus [36], coconut palm [45], and cacao [46]. For example, in Valencia orange, the severity of the citrus decline index is negatively correlated with Ca, Mg, S, and B and positively correlated with high leaf N, P, K, Cu, and Mn indices in the leaves [36]. Moreover, healthy coconut palms had higher macronutrient (N, P, K, Ca, Mg, and S) and micronutrient (B and Cu) uptake than those with root wilt disease trees, while Mn and Zn were comparable between healthy and diseased trees [45].…”

“…This result indicates that the impact of MTTD is nutrient-specific. It also corroborates a study showing the variable effects of diseases on the nutrient content of citrus [36], coconut palm [45], and cacao [46]. For example, in Valencia orange, the severity of the citrus decline index is negatively correlated with Ca, Mg, S, and B and positively correlated with high leaf N, P, K, Cu, and Mn indices in the leaves [36].…”

“…Our study showed that HD trees experienced more pronounced nutrient imbalances (Figure 5), which may have predisposed the plants to disease susceptibility. Studies have shown that orchards with higher nutrient imbalance indices recorded higher disease severity [15,36,47,50]. The specific nutrient imbalances observed in HD trees may have implications for their health and growth, highlighting the importance of integrated nutrient and disease management strategies in mango production to address these imbalances and promote tree health.…”

“…It is a preventive measure that supports plant health, resilience, and sustainable crop management strategies [16,51]. According to Tadayon and Sadeghi [36], balanced nutrition management could reduce the severity of citrus decline in Valencia orange orchards by increasing the leaf concentrations of Ca, B, S and Mg as higher concentrations of these nutrients were positively correlated with a lower citrus decline severity index. In our earlier report, we found that the imbalance of nutrients such as Ca/Cu, B/Mn, and Fe/Zn ratios may have contributed to the development of RCD mango, a quality defect that appears during fruit ripening, reduces the market price and consumer appeal of mango fruits [7].…”

“…The DOP index of mineral elements was determined to evaluate the deviation of the nutrient concentration from the optimum level [27,[35][36][37]. Regardless of the MTTD level, most of the analyzed nutrients (N, P, Ca, Mg, S, B, Cu, Fe, and Zn) had a negative DOP index, indicating that their concentrations were below the optimum concentration (Figure 5a), and only Mg had a higher concentration than the optimum level owing to its positive DOP index.…”