Crop Science · 1978 · 50 citations · 0 references
AgriculturePlant BiologyPlant SciencesPhotosynthesisPlant NutritionPlant PhysiologyEssential NutrientsLeaf PhysiologyMineral NutritionNutrient AvailabilityZinc DeficiencyZinc NutritionCarbonic Anhydrase FunctionMicronutrient Deficiency ResponsesPhotosynthetic Adjustment Under DeficiencyPhotosynthetic ImpairmentPlant Micronutrient DeficiencyPlant Nutrient DeficiencyZinc AvailabilityZinc Deficiency Physiology
The influence of Zn status on growth, photosynthesis, dark respiration, and carbonic anhydrase was determined to establish the relationship of these growth processes to the critical deficiency level (CDL) for growth of soybean ( Glycine max (L.) Merr. cv ‘Bragg’). Soybean was grown in nutrient solution with Zn rates of 10, 20, 50, 100, 200, 500, and 1,000 µg Zn/liter for a period of 36 days after transplanting. Critical Zn deficiency level for top dry weight was determined as 12 µg/g dry weight in recently matured leaf tissue (blade 3 from the top). Maximum photosynthesis was associated with leaf blades containing also 12 µg/g. Zinc deficiency reduced photosynthesis and carbonic anhydrase activity. Minimum dark respiration was attained at the CDL for growth and severe Zn deficiency enhanced respiration.