Absorption of foliar-applied phosphorus : Significance of leaf surface and foliar solute formulation properties

Phosphorus (P) is an essential nutrient for plant growth, but its availability to plants is often limited by fixation in the soil. Furthermore, bound P can be introduced into aquatic ecosystems through surface runoff, leading to eutrophication and ecosystem damage. The application of P via foliar fertilisation could provide an opportunity to deliver less P to plants in a more targeted way, bypassing soil fixation processes and giving better consideration to the needs of plants in relation to development and environmental conditions, thereby also reducing environmental impact. However, the mechanisms of foliar P uptake under P deficiency are poorly characterised. Therefore, in studies on maize, a plant that is particularly sensitive to P deficiency in early development, the efficiency and mechanisms of foliar P uptake have been investigated, with particular emphasis on the relationship between leaf surface characteristics and foliar P uptake. Examination of the leaf surface of four maize cultivars showed that differences in the presence of epicuticular waxes determine leaf wettability, which in turn strongly influences P uptake, which is higher in wettable leaves. For unwettable leaves, the foliar spray formulation also had a significant effect on foliar P uptake. Uptake was highest for a P salt with low deliquescence and efflorescence relative humidity and the addition of a surfactant. This thesis provides detailed insights into the relationship between leaf surface and solute properties and subsequent leaf P uptake. In particular, important mechanisms of P uptake were identified for the globally important crop maize.

Rechte

Nutzung und Vervielfältigung:


CC BY 4.0

Bitte beachten Sie, dass einzelne Bestandteile der Publikation anderweitigen Lizenz- bzw. urheberrechtlichen Bedingungen unterliegen können.

Zitieren

Zitierform:
Zitierform konnte nicht geladen werden.