Leaf area (LA) is a fundamental growth variable for understanding physiological processes and crop yield, but direct measurements are often destructive and time-consuming. This study aimed to develop non-destructive allometric models for estimating the leaf area of sweet potato (Ipomoea batatas [L.] Lam.) cultivars using leaf dimensions. Morphological data, including leaf length (L), width (W), and their product (L × W), were collected from various cultivars. Linear, power, and exponential models were tested and validated using statistical indices such as the coefficient of determination (R²), root mean square error (RMSE), and Willmott’s d-index. The results indicated that models based on the product of length and width (L × W) provided the most accurate estimations within the evaluated dataset, exhibiting high predictive accuracy (R² ≥ 0.96, RMSE ranging from 4.24 to 5.19 cm², and Willmott’s d-index ≥ 0.98). This non-destructive approach can support rapid, precise leaf area monitoring without leaf harvesting, particularly in the evaluated cultivars and experimental conditions. In conclusion, the proposed allometric equations provide practical and accurate tools for estimating sweet potato leaf area and supporting growth assessments in similar experimental contexts.

Salinity disrupts plant redox balance, ion homeostasis, and water relations, and exogenous polyamines have been widely investigated as potential mitigators of these effects. However, it remains unclear which polyamine-mediated responses are reproducible across independent studies and whether redox protection consistently translates into downstream physiological recovery. We therefore conducted an integrated systematic review, evidence map, and publication-family-aware quantitative synthesis to evaluate the effects of exogenous putrescine, spermidine, and spermine in salt-stressed plants. We systematically searched Scopus and Web of Science through 9 August 2026, and eligible studies compared exogenous-polyamine-treated plants with corresponding salt-stressed controls. The review was not prospectively registered. Of 1093 records, 647 unique records were screened, and 179 reports were assessed in full text, yielding 34 retained reports and 444 complete quantitative contrasts. Multilevel random-effects models estimated reductions of 19.2% in malondialdehyde (95% confidence interval [CI], 12.9–25.1%) and 25.6% in hydrogen peroxide (H₂O₂; 95% CI, 15.5–34.6%). Superoxide showed a protective mean response but remained uncertain because its 95% CI included the null. In contrast, antioxidant-enzyme responses varied widely across studies, with no consistent cross-family increase in superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), or peroxidase (POD/POX) activity. Conservative independent-family syntheses supported favorable ion balance, modestly higher relative water content, and greater dry biomass, whereas total chlorophyll remained uncertain and net photosynthesis was highly heterogeneous. No clear superiority of putrescine, spermidine, or spermine was detected. Overall, exogenous polyamines most consistently reduced oxidative damage and stabilized ion–water homeostasis, whereas antioxidant–enzyme activity and photosynthetic recovery were more context-dependent. Interpretation is limited by small independent-family counts, incomplete reporting in some studies, and the absence of a formal study-level risk-of-bias assessment. By integrating systematic review, evidence mapping, and family-aware quantitative synthesis, this review provides an evidence-based hierarchy that distinguishes reproducible polyamine-mediated responses from context-dependent outcomes and helps define priorities for future salinity-tolerance research.

Purple basil (Ocimum basilicum L.) is a medicinal plant widely recognized for its richness in bioactive compounds; however, its production in semi-arid regions is often constrained by soil and/or irrigation water salinity. Micronutrient fertilization may contribute to plant stress alleviation under salinity, since elements such as Mn, Mo, and Zn are involved in essential processes related to photosynthetic metabolism and physiological adjustment. This study aimed to evaluate the short-term effects of Mn, Mo, Zn, and their combinations on growth, gas exchange, and relative chlorophyll indices of purple basil plants subjected to severe NaCl stress under greenhouse conditions. The experiment was conducted under greenhouse conditions for 30 days in a randomized block design with nine treatments and four replicates: a non-saline control without micronutrients, a saline control without micronutrients, and plants exposed to 100 mM NaCl with substrate application of Mn, Mo, Zn, MoMn, ZnMo, ZnMn, or ZnMoMn. Micronutrient sources were applied to the substrate at 3.5 g kg⁻¹ according to each treatment. Fertilization with Mn, Mo, Zn, and their combinations enhanced plant stress alleviation under salinity compared with the saline control without micronutrients, with positive responses in growth and physiological performance, including increases in chlorophyll indices. The double combinations MoMn, ZnMo, and ZnMn attenuated the effects of NaCl, especially by increasing leaf area. Mn stood out for increasing net photosynthesis and water-use efficiency, whereas Mo and ZnMo were associated with higher relative chlorophyll indices. Although the triple combination ZnMoMn improved some traits compared with the saline control, its lower efficacy relative to selected single or double applications may indicate that the simultaneous supply of the three elements reduced specific synergistic effects, possibly due to nutritional imbalance or antagonistic interactions among micronutrients under severe salinity. Overall, micronutrient fertilization, particularly through specific double combinations, may contribute to short-term mitigation of NaCl-induced stress responses under controlled greenhouse conditions.