RESUMEN
BACKGROUND: Iron (Fe) deficiency chlorosis, a major nutritional problem in plants growing on calcareous soils, is related to the content and reactivity of soil iron oxides and carbonates. The effects of other soil components, however, need elucidation. In this paper we tested the hypothesis that application of high doses of phosphorus (P) to the soil can aggravate Fe chlorosis. RESULTS: Lupin and sorghum were grown on 24 calcareous soils. Leaf chlorophyll concentration (LCC) in lupin decreased with increasing available P/available Fe ratio in the native soil but LCC in sorghum was unaffected by that ratio. Application of P to the soil resulted in significant reduction of LCC and dry weight in lupin. In sorghum, LCC and dry weight were positively affected by P fertilisation for soils poor in available P whereas the opposite effect was generally observed for the P-rich soils. In another experiment where olive plants were pot-grown on two soils during the 20092011 period, P fertilisation affected LCC negatively only in 2009 and 2011 and in the soil that was poorer in iron oxides. CONCLUSION: Application of fertiliser P to Fe chlorosis-inducing soils is likely to aggravate this deficiency. However, this effect depends on the plant and the Fe and P statuses of the soil.
Asunto(s)
Fosfatos de Calcio/envenenamiento , Fertilizantes/toxicidad , Deficiencias de Hierro , Lupinus/efectos de los fármacos , Enfermedades de las Plantas/inducido químicamente , Hojas de la Planta/efectos de los fármacos , Suelo/química , Fosfatos de Calcio/metabolismo , Clorofila/análisis , Clorofila/biosíntesis , Resistencia a la Enfermedad , Compuestos Férricos/análisis , Compuestos Férricos/antagonistas & inhibidores , Compuestos Férricos/química , Compuestos Férricos/metabolismo , Hierro/análisis , Hierro/metabolismo , Lupinus/crecimiento & desarrollo , Lupinus/metabolismo , Olea/efectos de los fármacos , Olea/crecimiento & desarrollo , Olea/metabolismo , Fósforo/análisis , Fósforo/metabolismo , Fósforo/toxicidad , Enfermedades de las Plantas/prevención & control , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Distribución Aleatoria , Solubilidad , Sorghum/efectos de los fármacos , Sorghum/crecimiento & desarrollo , Sorghum/metabolismo , España , Especificidad de la EspecieRESUMEN
A four-year-old girl presented with accidental ingestion of 200 tablets of Calcarea phosphorica. Although she was asymptomatic, she was found to have marked hypocalcaemia with a prolonged QTc interval on electrocardiogram. She was successfully treated with intravenous calcium, followed by oral maintenance.
Asunto(s)
Fosfatos de Calcio/envenenamiento , Hipocalcemia/inducido químicamente , Calcio/administración & dosificación , Preescolar , Electrocardiografía , Femenino , Humanos , Hipocalcemia/tratamiento farmacológico , Hipocalcemia/fisiopatología , Síndrome de QT Prolongado/inducido químicamente , Síndrome de QT Prolongado/tratamiento farmacológico , Síndrome de QT Prolongado/fisiopatología , Resultado del TratamientoRESUMEN
High mortality in 1-week-old commercial turkey poults was attributed to the accidental substitution of dicalcium phosphate in the diet for corn. At necropsy of the affected birds, lesions were observed in the upper gastrointestinal tract, suggesting acute ingestion of a caustic substance. Mortality and gross and microscopic lesions were reproduced experimentally in turkey poults fed diets similar to the diet fed in the field case. The cause of these lesions was attributed to increased pH due to the phosphoric acid content of the diet.