IN VITRО АND IN VIVО EVАLUАTIОN ОF АNTIFUNGАL АCTIVITY ОF BОTАNICАL EXTRАCTS IN THE CОNTRОL ОF LАTE BLIGHT (Phythоpthоrа infestаns) ОF TОMАTО (Solanum esculentum)

Abstract: 
Late blight caused by Phythopthora infestans establishes quickly in tomato (Solanum esculentum) as a result, it is one of the most devastating plant diseases across the world. The control of late blight is not easy because P.infestans has an advanced and complicated weaponry such as enzymes and effecter molecules coded by avirulence genes. The objective of the study was to evaluate the efficacy of botanical extracts as bio-fungicides on late blight development on tomato. The in vitro study evaluated the effect of different concentrations of neem (Azadirachta indica), moringa (Moringa oleifera), gumtree (Eucalyptus nigra) and lantana (Lantana camara) on radial growth and percent inhibition of P. infestans. The in vivo experiment was conducted to evaluate the effectiveness of botanicals to control late blight disease on tomato plants. Data on chlorophyll content, chlorophyll florescence, and plant height, number of nodes, number of flowers, and number of fruits, disease incidence and disease severity were collected and analysed. Increasing concentration of the botanical extracts significantly (p<0.05) reduced radial growth and increased percent inhibition of P. infestans in vitro. On the other hand, increasing botanical extract concentration significantly (p<0.05) increased chlorophyll content, chlorophyll fluorescence, activity of defence enzyme peroxidase (POD), Phenyalalanine ammonia lyse (PAL) and Polyphenol oxidase (PPO). Disease incidence and severity significantly (p<0.05) decreasedas the concentration of the botanical extracts increased. Similarly, plant height, number of nodes, number of flowers and number of fruits significantly (p<0.05) increased with increase in the botanical extract concentration. Gas Chromatography Mass Spectrometry (GCMS) revealed the presence of furfural, 5-Methyl-4- (trifluoromethyl) pyrido, dodecanamide, cyclopentasiloxane and decamethyl. From the research, it can be concluded that neem acetone, neem water, moringa ethyl acetate and lantana water extracts contain antifungal compounds and can therefore be used as biofungicides in Intergrated Disease Management (IDM) of late blight.
Language: 
Date of publication: 
2019
Country: 
Region Focus: 
Southern Africa
Author/Editor(s): 
Collection: 
RUFORUM Theses and Dissertations
Agris Subject Categories: 
Licence conditions: 
Open Access
Access restriction: 
Supervisor: 
Dr E. Ngаdze; Dr J T. Rugаre
Form: 
Web resource
ISSN: 
E_ISSN: 
Edition: 
Extent: 
xiii,90