[Boron lack in sugar beet and sunflower crops]

agua del suelo beta vulgaris bore boro boron carbohydrate metabolism carenze di oligoelementi climatic factors deficiencia de oligoelementos drought eau du sol facteur climatique fattori climatici helianthus annuus metabolismo de carbohidratos metabolismo dei carboidrati nutrient transport racine radici roots sintomi soil chemicophysical properties soil water symptome symptoms trace element deficiencies transport des substances nutritives transporte de nutrientes trasporto di elementi nutritivi