Biocontrol of Postharvest Diseases of Solanaceous Vegitables
By: Rajkumar T.
Contributor(s): Susamma Phillip (Guide).
Material type:
BookPublisher: Vellayani Department of Plant Pathology, College of Agriculture 2000DDC classification: 632.3 Online resources: Click here to access online Dissertation note: MSc Abstract: The fungi commonly associated with the spoilage of solanceous vegetables viz., brinjal, chilli and tomato under storage conditions were isolated and identified.
Based on the frequency of occurrence Phomopsis vexans was selected in brinjal, Colletotrichum capsici in chilli and Fusarium solani, Rhizoctonia solani and Geotrichum candidum in tomato. These fungi were used for the further study.
The studies on epiphytic mycoflora of the fruits yielded maximum epiphytes for brinjal followed by tomato and chilli. These included several fungi, yeast and many other saprophytes.
Yeasts like Cryptococcus sp. and Sporobolomyces roseus and fungi like Aspergillus niger, Pencillium wortmanni and Fusarium solani were common to all the three vegetables. All the epiphytes were subjected to in vitro studies and tested against each pathogen. Gliocladium virens and Trichoderma harzianum were found to be effective from the in vitro test
The mechanism of G. virens and T. harzianum was studied in detail and was found to be through coiling and penetration, coiling and granulation, coiling and vacuolation, disiegration of mycelia and formation of infection pegs.
The role of T. harzianum and G. virens as biocontrol agents was studied in vivo. It was found that T. harzianum was effective in reducing the rots for brinjal in all the pathogens under study. G. virens however was found to infect the tomato fruits.
T. harzianum was formulated in talc, coir pith, charcoal and wheat flour. Among these, maximum viability was recorded in talc. The number of spores increased initially only in the case of flour while for the rest it registered a steep decline and a stagnation after fifth week.
T. harzianum was thus formulated in talc at 25 per cent concentration.
The viable spore count at the end of the seventh week was of the order of 106 c.f.u./g of the formulation.
The formulated antagonist was applied on the fruit by dipping as well as dusting. For the chilli anthracnose (C. capsici) neither of the methods were effective. In the case of brinjal rot (P.vexans) dusting was as effective as dipping in controlling the rot, for tomato dusting was slightly better than dipping in controlling sour rot (G. candidum). Both the methods were ineffective in controlling Fusarium rot (F. solani) of tomato while Rhizoctonia rot was controlled better by dusting than dipping in the formulation of the antagonist.
| Item type | Current location | Call number | Status | Date due | Barcode |
|---|---|---|---|---|---|
Theses
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KAU Central Library, Thrissur Theses | 632.3 RAJ/BI (Browse shelf) | Available | 171653 |
MSc
The fungi commonly associated with the spoilage of solanceous vegetables viz., brinjal, chilli and tomato under storage conditions were isolated and identified.
Based on the frequency of occurrence Phomopsis vexans was selected in brinjal, Colletotrichum capsici in chilli and Fusarium solani, Rhizoctonia solani and Geotrichum candidum in tomato. These fungi were used for the further study.
The studies on epiphytic mycoflora of the fruits yielded maximum epiphytes for brinjal followed by tomato and chilli. These included several fungi, yeast and many other saprophytes.
Yeasts like Cryptococcus sp. and Sporobolomyces roseus and fungi like Aspergillus niger, Pencillium wortmanni and Fusarium solani were common to all the three vegetables. All the epiphytes were subjected to in vitro studies and tested against each pathogen. Gliocladium virens and Trichoderma harzianum were found to be effective from the in vitro test
The mechanism of G. virens and T. harzianum was studied in detail and was found to be through coiling and penetration, coiling and granulation, coiling and vacuolation, disiegration of mycelia and formation of infection pegs.
The role of T. harzianum and G. virens as biocontrol agents was studied in vivo. It was found that T. harzianum was effective in reducing the rots for brinjal in all the pathogens under study. G. virens however was found to infect the tomato fruits.
T. harzianum was formulated in talc, coir pith, charcoal and wheat flour. Among these, maximum viability was recorded in talc. The number of spores increased initially only in the case of flour while for the rest it registered a steep decline and a stagnation after fifth week.
T. harzianum was thus formulated in talc at 25 per cent concentration.
The viable spore count at the end of the seventh week was of the order of 106 c.f.u./g of the formulation.
The formulated antagonist was applied on the fruit by dipping as well as dusting. For the chilli anthracnose (C. capsici) neither of the methods were effective. In the case of brinjal rot (P.vexans) dusting was as effective as dipping in controlling the rot, for tomato dusting was slightly better than dipping in controlling sour rot (G. candidum). Both the methods were ineffective in controlling Fusarium rot (F. solani) of tomato while Rhizoctonia rot was controlled better by dusting than dipping in the formulation of the antagonist.
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