Leaf area is a critical trait in plant physiology and agronomy, yet conventional measurement approaches such as those using ImageJ remain labor-intensive, user-dependent, and difficult to scale for high-throughput phenotyping. To address these limitations, we developed a fully automated, open-source Python tool for quantifying citrus leaf area from scanned images using multi-mask HSV segmentation, contour-hierarchy filtering, and batch calibration. The tool was validated against ImageJ across 11 citrus cultivars (n = 412 leaves), representing a broad range of leaf sizes and morphologies. Agreement between methods was near perfect, with correlation coefficients exceeding 0.997, mean bias within ±0.14 cm², and error rates below 2.5%. Bland–Altman analysis confirmed narrow limits of agreement (±0.3 cm²) while scatter plots showed robust performance across both small and large leaves. Importantly, the Python tool successfully handled challenging imaging conditions, including low-contrast leaves and edge-aligned specimens, where ImageJ required manual intervention. Processing efficiency was markedly improved, with the full dataset analyzed in 7 s compared with over 3 h using ImageJ, representing a >1600-fold speed increase. By eliminating manual thresholding and reducing user variability, this tool provides a reliable, efficient, and accessible framework for high-throughput leaf area quantification, advancing reproducibility and scalability in digital phenotyping.

A field trial was conducted at the University of Georgia Hort Hill Farm in Tifton, GA, to examine the effects of biochar rate and fertilizer type on Meloidogyne incognita (root-knot nematode), Agroathelia rolfsii (southern blight), and yield in tomatoes during the 2024 growing season. Biochar significantly reduced nematode gall ratings, particularly at 20 tons/acre, while organic fertilizer lowered gall severity and increased yield compared with inorganic fertilizer. Biochar did not affect tomato yield, and southern blight mortality remained high across treatments, likely due to spring rainfall. These findings highlight biochar's potential for nematode suppression and emphasize the yield benefits of organic fertilizer in tomato production.

Biochar and poultry litter have been proposed as soil amendments to improve soil health in coarse-textured agricultural soils, yet their field performance under southeastern U.S. conditions remains inconclusive. This two-year field study evaluated five biochar application rates (0–44.8 Mg ha⁻¹) combined with inorganic fertilizer or poultry litter on selected soil health indicators in a sandy loam Ultisol under sweet corn production in the Georgia Coastal Plain. Treatments were arranged in a randomized complete block design with four replications and analyzed using linear mixed-effects models. Biochar application did not significantly affect aggregate stability, pH, cation exchange capacity, soluble salts, organic matter, active carbon, or estimated nitrogen mineralization, with only a marginal three-way interaction observed for microbial respiration. Poultry litter significantly increased microbial respiration relative to inorganic fertilizer, whereas responses for the remaining soil health indicators were broadly similar between fertilizer sources. Year was the dominant source of variation, with extreme rainfall in 2024 reducing aggregate stability, soluble salts, microbial respiration, and nitrogen mineralization while increasing organic matter and active carbon. These findings indicate that short-term soil health responses were driven primarily by environmental conditions rather than management practices. Under the conditions of this study, either fertilizer source can be used successfully, whereas longer-term studies are needed to determine whether biochar aging enhances soil function in sandy loam Ultisols.

A field trial was conducted at the University of Georgia Hort Hill Farm in Tifton, GA, to evaluate the effects of mustard cover crops, an organic mustard seed meal amendment, and a chemical nematicide on volatile organic compound (VOC) production, Meloidogyne incognita (root-knot nematode [RKN]) suppression, cucumber plant biomass, and cucumber yield. The organic mustard seed meal amendment produced the highest VOCs, as measured in isobutylene concentrations, and significantly increased cucumber yield and biomass but did not suppress nematode populations. These findings underscore the need for integrated nematode management strategies, showing that mustard-based amendments can improve crop performance even without directly reducing nematodes.