Use this URL to cite or link to this record in EThOS:
Title: Development of an organic botanical plant protection product from larix by-products
Author: James, Emily E.
ISNI:       0000 0004 7425 365X
Awarding Body: University of Surrey
Current Institution: University of Surrey
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Access from Institution:
Control of pathogens by means of plant-derived plant protection products (PPPs) can be an effective, sustainable and environmentally friendly method of crop protection in organic agriculture. Larix decidua (European larch) bark is a by-product of the wood processing industry and provides a readily available, low cost and sustainable raw material. It was therefore planned to commercialise Larix extracts, containing two highly active diterpenoids (larixyl acetate and larixol) into a marketable PPP, Larixyne®, to combat grapevine downy mildew (Plasmopara viticola) in organic farming. This thesis outlines the processes and knowledge developed in order to facilitate the commercialisation of Larixyne®: (i) Analytical protocols using high-performance liquid chromatography (HPLC) and gas chromatography (GC-FID) techniques to quantify larixyl acetate, larixol and epimanool (the primary impurity) in Larix extracts were developed. (ii) Methods for large scale extraction and purification of active compounds from Larix were optimised in line with EU specifications for products with organic agricultural use. Through extraction with 2-amino-2-methyl-1-propanol (AMP), Larix bark contained extract compositions of up to 30.53% larixyl acetate and 8.45% larixol. Larixyl acetate and larixol extracts were isolated in sufficient quantity (8.0 kg) for large scale field trials. (iii) High-yield sources of larixyl acetate and larixol were evaluated and identified through screening a range of plant samples from central and northern Europe. Larix samples were found to vary in content of larixyl acetate (median 0.017% w/w, range 0.000 – 4.544% w/w), larixol (median 0.003% w/w, range 0.000 – 0.578% w/w), and epimanool (median 0.009% w/w, range 0.000 –0.752% w/w). (iv) The activity of larixyl acetate, larixol, epimanool and formulated products of Larix extracts against P. viticola on Vitis vinifera were demonstrated. Larixyl acetate and larixol exhibited excellent activity in vitro (mean MIC100 of 7 and 16 μg/mL) and in planta (EC50 0.2 – 0.7 mg/mL).
Supervisor: Mulholland, Dulcie Sponsor: University of Surrey ; European Research Council
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available