قارن الطرق

	تألق الكلوروفيل	مؤشر مساحة الورقة
المجال	علم المحاصيل	علم المحاصيل
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1931-2004	1947
صاحب الطريقة	Hans Kautsky, Ulrich Schreiber, Reto J. Strasser	Donald J. Watson
النوع	Non-invasive photosynthetic measurement	Plant morphometric measurement
المصدر التأسيسي	Kautsky, H., & Hirsch, A. (1931). Neue Versuche zur Klärung der Assimilationstätigkeit. Naturwissenschaften, 19(48), 964-964.	Watson, D. J. (1947). Comparative physiological studies on the growth of field crops: I. Variation in net assimilation rate and leaf area between species and varieties, and within and between years. Annals of Botany, 11(43), 375-407.
الأسماء البديلة	Fluorescence, Fv/Fm, OJIP curve, PAM fluorometry	LAI, Leaf area, Canopy structure
ذات صلة	3	3
الملخص	Chlorophyll fluorescence is a non-invasive optical measurement of how efficiently the photosynthetic machinery converts absorbed light into chemical energy (photosynthesis) or heat and light (fluorescence). When photosynthesis is inhibited by stress (drought, cold, salt, pests), chlorophyll fluorescence increases because excitation energy cannot be used for photosynthesis and must be released as light or heat. Fluorescence parameters (Fv/Fm, OJIP curves) act as sensitive, rapid indicators of photosynthetic stress, enabling early detection of plant dysfunction before visible symptoms appear.	Leaf Area Index (LAI) is a dimensionless quantity that measures the total one-sided area of leaves per unit ground area covered by a canopy. It quantifies canopy density and structure: LAI = 0 for bare soil, LAI = 1 for a thin crop, LAI = 3-6 for dense cereal or grass canopies, and LAI > 8 for dense forest. LAI is a key variable in crop growth models, evapotranspiration estimation, and remote sensing because it directly controls light interception, photosynthesis, and water loss from vegetation.