TITLE:
Impact of Three Isolates of Cercosporidium personatum (Berk. Et M.A Curt.), a Pathogen of Late Leaf Spot, on Defoliation and Yield in Groundnut (Arachis hypogaea L.) under Controlled Conditions
AUTHORS:
Bawomon Fidèle Neya, Tobdem Gaston Dabire, Alassane Ouattara, Amado Sawadogo, Diariétou Sambakhe, Kouka Hamidou Sogoba, Tounwendsida Abel Nana, Ibié Gilles Thio, Frank Essem, Kadidia Koita
KEYWORDS:
Arachis hypogaea, Isolate, Late Leaf Spot, Cercosporidum personatum, Yield, Defoliation
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.14 No.10,
October
11,
2023
ABSTRACT: Late leaf spot caused by Cercosporidium personatum is one of the
most widespread groundnut leaf diseases. Along with early leaf spot and rust,
it is one of the main fungal diseases hampering groundnut production worldwide.
Late leaf spot accounts for significant yield losses throughout the world where
groundnuts are grown. This reduction in yield caused by the disease could
result in yield losses of between 50% and 70%.
In Burkina Faso, the disease is present throughout the country, with incidence
varying according to region and season. Could the variability in the incidence
of the disease be linked to the nature of the isolates or to the conditions
from each agro-ecological zone? In this study, the aim was to assess the
capacity of three isolates from three agroclimatic zones of the country to
defoliate and reduce groundnut yield. To this end, three isolates of Cercosporidium
personatum (Berk. Et M.A Curt.) were collected in these zones and evaluated
on three contrasting groundnut varieties. A split-splot design was used for the
experiment. Isolates were prepared from samples collected in farmers’ fields.
After incubation in the laboratory, leaf spots showing good sporulation were
scraped off with a scalpel after immersing the leaves in distilled water.
Inoculations were carried out under controlled environment. After inoculation
with the isolate, the percentage of defoliation and the reduction in yield of
these varieties were then evaluated. Inoculation was carried out from the 30th
day after sowing with Cercosporidium
personatum spore suspensions at
105 spores/ml. The study showed that the percentage of defoliation (P = 0.0001)
and the reduction in yield (P = 0.0001) were significant. The study revealed that,
whatever the variety, isolate I3TF from the Upper Basins region in the South
Sudanese zone caused the greatest defoliation and the greatest reduction in
yield. The variety TS32-1, regardless of the isolate used for the treatment,
recorded the best yield. The variety PC79-79, regardless of the isolate used
for the treatment, recorded the lowest percentage of defoliation. The highest
defoliation recorded under the effect of the isolates was of the order of
72.20%; the highest yield reduction was of the order of 87.20% compared with
the water control.