Diagnostic Assessment of Leaf Spot Severity and Damaged Leaf Area in Date Palm (Phoenix Dactylifera L.) Using Leaf Doctor and Imagej Applications
DOI:
https://doi.org/10.33866/phytopathol.037.01.1246Keywords:
Date palm, leaf spots, disease assessment, phytopathometry, agreement, precisionAbstract
Date palm leaf spot disease, caused by several fungal pathogens, manifests as spots of various shapes accompanied by dryness and chlorosis. To assess the severity of leaf damage, two tool were used. The tools were Leaf Doctor application and ImageJ, this was the aim of the study. Different shapes, sizes, and colors, indicating different infection stages were shown by the leaf spot. Fungal isolation from infected tissues revealed six fungal species: Alternaria alternata, Fusarium oxysporum, Cladosporium herbarum, Ulocladium botrytis, Aspergillus niger, and Penicillium sp. Among them, A. alternata was the most frequent (27%), while Penicillium sp. had the lowest frequency (5%). Significant differences in damage severity were found between the upper and lower leaf surfaces. The lower surface exhibited higher damage percentages (Leaf Doctor: 37.96%; ImageJ: 38.37%) compared to the upper surface (Leaf Doctor: 30.89%; ImageJ: 32.48%). Damage also varied significantly among different leaf parts, with the base (Part D) showing lower severity than the upper and middle parts (Parts A, B, and C). Between the two tools, no statistical differences were observed (p = 0.26). But, a positive correlation was shown (r = 0.65). Lin’s concordance correlation coefficient was moderate (pc = 0.41), with a bias correction factor (Cb) of 0.63 and R² = 0.43. Visual assessments by raters revealed greater variability compared to both tools. Overall, with Leaf Doctor providing user friendly and slightly more precise evaluations, both applications demonstrated reliable performance.References
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