Identification and evaluation of the plant growth promoting and biological control potential of fungi isolated from vermicompost-treated orchids

Date

8-2014

Degree

Bachelor of Science in Agriculture

Major Course

Major in Plant Pathology

College

College of Agriculture and Food Science (CAFS)

Adviser/Committee Chair

Johnny F. Balidion

Abstract

The presence of beneficial microorganisms in vermicomposts is one of the main reasons behind its plant growth promoting ability but little is known on the microbial community of this increasingly used technology. Characterization, partial identification, and evaluation of the plant growth promoting and biological control potential of two fungal isolates from vermicompost-treated orchids are reported. This study identified two unknown isolates from vermicompost treated Dendrobium orchids that were associated with vigorous plant growth. The plant growth promoting potential of these isolates was evaluated in the greenhouse on two hosts namely, Dendrobium sp. and Lycopersicon esculentum. Results showed that the fungal isolates were able to enhance growth of tomato (by 31%) and Dendrobium (by 64%) plants relative to the negative control (α = 0.05). Furthermore, the degree of growth enhancement was similar or better to that of normal chemical fertilization and the commercial Trichoderma inoculants at the dosage rates used ( α = 0.05). Application of the isolates also increased the yield of tomato plants in terms of fruit weight by 34% with isolate A and 20% with isolate B. Test for antagonism was also done to determine if the isolates possess biological control potential against selected plant pathogens. Both isolates possess antagonistic effects on Rhizoctonia sp., Colletotrichum sp., Fusarium sp., and Sclerotium sp., through competition and mycoparasitism. Results indicate evidence of mycoparasitism by the antagonistic activity relied mainly on competition with space and nutrients. Test for competition shows that the radial growth of the pathogens is inhibited by cocultivating it with the unknown fungal isolates by 44 ? 68% compared to the pure cultures. No evidence of volatile or non-volatile antimicrobial compounds was observed with the experimental assays done. Colony characteristics on different growth media and morphometrics of selected fungal structures suggest that the two isolates belong to the genus Trichoderma. These results suggest that vermicompost and possibly its derivatives may harbor beneficial microbes which does not only promote plant growth but may also possess inhibitory or antagonistic effects against plant pathogens and thus, decrease disease incidence in the field.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2014 A3 /M46

Document Type

Thesis

This document is currently not available here.

Share

COinS