01857naa a2200373 a 450000100080000000500110000800800410001910000170006024500990007726000090017652009290018565000140111465000140112865000140114265000220115665000170117865000140119565000140120965000130122365000110123665000070124765000160125465300140127065300140128465300200129865300150131865300120133365300150134570000180136070000150137870000180139370000200141177300520143110757941996-01-29       1986    bl ---       0--  u    #d1 aSIMON, J. E.  aIdentification of manganese toxicity and magnesium deficiency on melons grown in low-pH soils.  c1986  aField-grown muskmelons (Cucumis melo var. reticulatus Ser.) and watermelons [Citrullus lanatus (Thunb.) Matsum and Nakai] are sensitive to nutrient stress induced by low-pH soils. Severe foliar injury observed on melons grown in low-pH soils was caused by toxic levels of Mn and/or deficient levels of Mg in the leaf tissue. Manganese toxicity symptoms in muskmelons develop as chlorotic spotting on the adaxial surface of older leaves, with water-soaked rings around necrotic spots on the abaxial surface. In watermelons, Mn toxicity develops initially on older leaves as black-brown speckling on the abaxial leaf surface. Severe vein browning develops with age. Magnesium deficiency develops first on mature muskmelon and watermelon leaves as an interveinal  bronzing, followed by a necrosis and browning  of the interveinal tissue. Muskmelons are more sensitive to both Mn toxicity and Mg deficiency than are watermelons.  amagnesium  amanganese  anutrients  aCitrullus Lanatus  aCucumis Melo  aMagnésio  aManganês  aMelancia  aMelão  aPh  aSolo Ácido  aAcid soil  aMuskmelon  aNutrient stress  aNutrientes  aSalt pH  aWatermelon1 aWILCOX, G. E.1 aSIMINI, M.1 aELAMIN, O. M.1 aDECOTEAU, D. R.  tHortsciencegv.21, n.6, p.1383-1386, dec. 1986.