|
|
Transport of humic substances through plant cuticle
Smilková, Marcela ; Salaš, Petr (referee) ; Weidlich, Tomáš (referee) ; Klučáková, Martina (advisor)
Doctoral Thesis is aimed on the transport of liquid preparations chemically based on potassium lignohumate through plant cuticles commonly utilized in agricultural applications. Firstly, the thesis deals with optimization and correct mathematical description of diffusion experiments. Transport (diffusion) experiments have been realized in model hydrogel media based on linear polysaccharide – chemically inert agarose. Diffusion experiments have been realized by two independent approaches (diffusion models) – free diffusion of lignohumate in hydrogel and diffusion pair (hydrogel-hydrogel), where one of these was enriched by lignohumate in contrast with the second one. Plant cuticle, as the major barrier on the leaves, isolated from Prunus laurocerasus, was used as porous membrane in diffusion experiments. The main aim of Ph.D. thesis was the characterization of barrier properties of cuticles, which are the most limiting barrier regulating the transport of lignohumate in/out the leaves during foliar fertilization. These experimental problems have been solved by diffusion experiments and by their proper mathematical description, especially by the determination of fundamental diffusion parameters such as effective diffusion coefficients. These parameters have been used for the modelling of concentration profiles in hydrogels and comparison with experimental data. Significant part of thesis is aimed on the determination of physico-chemical properties of plant cuticles and hydrogels matrixes utilized as model diffusion environment. These characteristics are subsequently correlated with transport (diffusion) parameters. Plant cuticles have been isolated from Prunus laurocerasus leaves and then were characterized by relevant instrumentation notably with respect to their structure and penetration through of lignohumate. Hydrogels have been characterized with respect to mechanical (viscoelastic) (rheology), morphological e.g. porosimetry) and structural (scanning electron microscopy) properties. Mentioned properties have direct link to transport processes ongoing in these materials. Next part of doctoral thesis is aimed on the proper and correct interpretation of experimental results obtained from glass-house experiments. During these experiments, hydrogels based on superabsorbent polymers developed on Faculty of Chemistry, Brno University of Technology, have been used together with commercial preparation – potassium lignohumate kindly provided by co-working commercial subject – Amagro s.r.o. The main aim was the application of lignohumate directly on plants through root system. Results of these experiments should confirm the positive effect on plant growth as well as their positive development. Results obtained from transport/diffusion experiments confirm that the penetration of active compounds (lignohumate) is more efficient in comparison with adaxial cuticles. The kinetics of lignohumate transport is faster for abaxial cuticles. From superabsorbent experiments it is obvious that these play significant role in growth and development of plant and simultaneously positively contribute to creation of suitable conditions for proper microbiological and bacterial activity, which is essential for health soil.
|
|
|
Transport of humic substances through plant cuticle
Smilková, Marcela ; Salaš, Petr (referee) ; Weidlich, Tomáš (referee) ; Klučáková, Martina (advisor)
Doctoral Thesis is aimed on the transport of liquid preparations chemically based on potassium lignohumate through plant cuticles commonly utilized in agricultural applications. Firstly, the thesis deals with optimization and correct mathematical description of diffusion experiments. Transport (diffusion) experiments have been realized in model hydrogel media based on linear polysaccharide – chemically inert agarose. Diffusion experiments have been realized by two independent approaches (diffusion models) – free diffusion of lignohumate in hydrogel and diffusion pair (hydrogel-hydrogel), where one of these was enriched by lignohumate in contrast with the second one. Plant cuticle, as the major barrier on the leaves, isolated from Prunus laurocerasus, was used as porous membrane in diffusion experiments. The main aim of Ph.D. thesis was the characterization of barrier properties of cuticles, which are the most limiting barrier regulating the transport of lignohumate in/out the leaves during foliar fertilization. These experimental problems have been solved by diffusion experiments and by their proper mathematical description, especially by the determination of fundamental diffusion parameters such as effective diffusion coefficients. These parameters have been used for the modelling of concentration profiles in hydrogels and comparison with experimental data. Significant part of thesis is aimed on the determination of physico-chemical properties of plant cuticles and hydrogels matrixes utilized as model diffusion environment. These characteristics are subsequently correlated with transport (diffusion) parameters. Plant cuticles have been isolated from Prunus laurocerasus leaves and then were characterized by relevant instrumentation notably with respect to their structure and penetration through of lignohumate. Hydrogels have been characterized with respect to mechanical (viscoelastic) (rheology), morphological e.g. porosimetry) and structural (scanning electron microscopy) properties. Mentioned properties have direct link to transport processes ongoing in these materials. Next part of doctoral thesis is aimed on the proper and correct interpretation of experimental results obtained from glass-house experiments. During these experiments, hydrogels based on superabsorbent polymers developed on Faculty of Chemistry, Brno University of Technology, have been used together with commercial preparation – potassium lignohumate kindly provided by co-working commercial subject – Amagro s.r.o. The main aim was the application of lignohumate directly on plants through root system. Results of these experiments should confirm the positive effect on plant growth as well as their positive development. Results obtained from transport/diffusion experiments confirm that the penetration of active compounds (lignohumate) is more efficient in comparison with adaxial cuticles. The kinetics of lignohumate transport is faster for abaxial cuticles. From superabsorbent experiments it is obvious that these play significant role in growth and development of plant and simultaneously positively contribute to creation of suitable conditions for proper microbiological and bacterial activity, which is essential for health soil.
|
guest ::
