02272naa a2200277 a 450000100080000000500110000800800410001910000170006024501110007726000090018852014940019765000210169165000200171265000090173265000130174165000220175470000180177670000130179470000250180770000180183270000200185070000190187070000220188970000180191177300650192911359932025-10-16       2025    bl uuuu     u00u1 u    #d1 aSILVA, A. S.  aCritical toxic level of zinc in tomatoes grown on Humic Cambisol and Bruno Nitisol.h[electronic resource]  c2025  aZinc (Zn) is an essential element for plants, but high levels of this element can interfere with productivity and can contaminate soil, water and food. Therefore, it is crucial to identify the critical toxicity level of Zn in plants for the correct use of this element in agriculture. This study aimed to determine the critical toxicity level of Zn for tomato plants and the effect of this element on crop parameters. For this purpose, Zn doses (0, 50, 100, 150, 200, 250, 300, and 450 mg kg−1) were applied in two soils (Humic Cambisol and Bruno Nitisol). Gas exchange parameters, SPAD index, Zn accumulation in plant organs, dry mass production, and root parameters were evaluated. The SPAD index and net photosynthetic rate decreased with increasing Zn in the soil solution for both soils. The exposure of tomato plants to the tested dose range caused a reduction in aerial and root dry mass, root length, and root volume in both soils. The critical toxicity level of Zn for tomato plants grown in Humic Cambisol was reached at a dose of 48.7 mg kg−1, while for Bruno Nitisol, it was reached at a dose of 122.8 mg kg−1. Additionally, dry mass production of roots and aerial parts decreased with increasing Zn. Therefore, it is evident that tomato plants are sensitive to the presence of Zn in both cultivated soils, making it necessary to consider the critical toxicity level of Zn for these plants in crops, especially in systems aimed at agronomic.  aBiofortification  aplant nutrition  aSPAD  atoxicity  azinc accumulation1 aMATIAS, C. A.1 aHAHN, L.1 aMASSANEIRO, H. M. A.1 aFARIAS, N. M.1 aNAVROSKI, M. C.1 aANDRADE, R. S.1 aMIQUELLUTI, D. J.1 aCAMPOS, M. L.  tJournal of Plant Nutrition, Philadelphia, PA, p. 1-17, 2025.