Evaluation of new means of sugarcane protection against fungal diseases under in vitro conditions.

Gabriel Laar

Master's thesis

Abstract:

Sugarcane (Saccharum officinarum) is one of the major commercial crops grown in tropical and subtropical regions of the world. The crop's industrial capacity for producing goods like crystal white sugar, bagasse, power, pressmud, etc. gives it economic significance. Fungal diseases are considered to be one of the main threats to sugarcane productivity among the crop's many production restrictions. This research aimed to assess essential oils' viability as a novel method for safeguarding sugarcane against fungal infections in a controlled laboratory environment. The study examined the effectiveness of essential oils in impeding the proliferation of fungal pathogens known to afflict sugarcane crops. Eight (8) fungal pathogens strains (Rhizoctonia solani 2, Rhizoctonia solani 5, Fusarium spp, Setophoma terrestris, Schizophyllum commune, Alternaria alternata, Chalara spp, and Fusarium verticillioides) were obtained from the Czech Collection of Microorganisms in Brno, Czech Republic. The fungal pathogens were sub-cultured and allowed to incubate for 14 days in an incubation chamber to facilitate their growth. The newly grown fungi were used in the experiment. Five already extracted essential oils: Thymus vulgaris oil, Origanumm vulgare oil, Saturea montana oil, Thymus serpillum oil, and Cinnamomum camphora oil were purchased from Saloos Naturcosmetics and used for the experiment. The study found that Origanum vulgare and Thymus vulgaris essential oils exhibited exceptional inhibitory effects against all pathogen isolates. In stage two, fungal pathogens were subjected to different concentrations of essential oils for evaluation aimed at establishing the minimum inhibitory concentration (MIC) of the effective essential oils. In the case of OV, the MIC was determined to be between 0.02 % and 0.001 % (EO) with a range of 90.17-100 % inhibition for each pathogen isolate tested. In the case of TV, the MIC was also determined to be in the range of 0.02% and 0.001% (EO) with an average pathogen growth inhibition of 25.9-75.9 % which is a significantly lower efficacy for growth inhibition compared to OV. The results underscore their potential as natural fungicides for safeguarding sugarcane crops against fungal diseases.

Keywords

Origanum vulgare, sugarcane, plant protection, essential oils, fungal pathogens, Thymus vulgaris

Language used: English

Date on which the thesis was submitted / produced: 28. 4. 2024

Thesis defence

• Supervisor: doc. Ing. Miloslav Zouhar, Ph.D.
• Reader: Jana Mazáková, Ph.D.

Czech University of Life Sciences Prague

Faculty of Tropical AgriSciences

Master programme:
Tropical Crop Management and Ecology