Abstract:
Globally, Phytophthora infestans causes annual potato losses estimated at over $6 billion with fungicides
alone accounting for over $1 billion. In Kenya, potato yield loss estimates reach 119,500 tons annually.
Several fungicides recommended for late blight have raised health concerns and have led to emergence
of more aggressive strains of the pathogen. These concerns have led to the need for safer alternative
which can best be offered by bio-pesticides. Bio-pesticides are classified into biochemical, microbial
and plant derivatives derived from natural living organisms. The aim of this study was to source, identify
and screen for the bioactive potential of selected plant species against Phytophthora infestans in vitro.
Phytophthora infestans was isolated from infected potato leaves and bioactive plants were sourced
from the Kenyatta University surroundings, identified and phytochemical compounds extracted through
maceration. Bioassays involved food poisoning technique using the aqueous plant extracts. Data were
subjected to analysis of variance using SAS software version 9.1. Tukey’s Studentized Range (HSD) at
P<0.05 was used for mean separations where treatment effects were significant. All the plant extracts
showed significant effect (P<0.05) on reducing mycelial growth of P. infestans. Azadirachta indica
showed the highest overall percentage mycelia growth suppression with a mean of 54.3% at (P d” 0.05)
at ten days after inoculation (DAI) which significantly differed from Callistermon citrinus which had the
least overall suppressive effect with a mean of 26.75% at (P< 0.05). These findings show that potential
for managing late blight exist in local plants.
Date of publication:
2018
Country:
Region Focus:
East Africa
Conference:
Volume:
17
Number:
2
Pagination:
503-508.
Collection:
RUFORUM Working document series
Agris Subject Categories:
Agrovoc terms:
Licence conditions:
Open Access
Access restriction:
Form:
Web resource
ISSN:
1607-9345