Citation
Mohammad Seri, Ainnur Atira
(2022)
Evaluation of silicon and salicylic acid for controlling basal stem rot disease on oil palm (Elaeis guineensis Jacq.) caused by Ganoderma boninense.
Masters thesis, Universiti Putra Malaysia.
Abstract
Basal stem rot (BSR) disease, caused by Ganoderma boninense, is the most
destructive disease that causes decay of the root system before ultimately rotting
the lower stem of the oil palm (Elaies guineensis) which reduces the weight of
fruit bunches. Repeated use of fungicides to control the disease develops fungal
resistance and it is costly and environmentally unfriendly. The objectives of this
study were to evaluate in vitro antifungal activity of salicylic acid (SA) and silicon
(Si) in inhibiting mycelial growth of boninense and to evaluate the in vivo efficacy
of Si treatment on the growth and oil palm seedlings resistance to G. boninense.
For in vitro evaluation, 50, 100, 150, 200 and 250 mg/L of salicylic acid (SA),
silicon dioxide (SiO2) and pure silicon (Si) were added individually to sterilized
potato dextrose agar (PDA) to investigate the in vitro efficacy on the mycelial
growth of Ganoderma boninense under laboratory conditions. The highest
percentage inhibition of radial growth (PIRG) was observed for Si treatment
followed by silicon dioxide (SiO2). Si treatment showed the highest percentage,
100% growth inhibition of boninense at concentration of 200 and 250 mg/L. Si
can inhibit the mycelial growth of boninense significantly (p<0.05) at a lower
concentration compared to SA and SiO2. The treatment also showed a significant
difference compared to the other two treatments as even at a concentration of
100 mg/L, the Si treatment inhibited the mycelial growth of boninense better than
the rest of the other treatments tested. There was a significant difference
(p<0.05) in almost all concentrations tested for both Si and SiO2 except for PIRG
at 200 and 250 mg/L which did not show a significant difference. The half
maximal effective concentration (EC50) that inhibited mycelial growth of
boninense was 68.57 mg/L, while for SiO2 and SA were 273.95 mg/L and 381.33
mg/L, respectively. For in vivo evaluation in the greenhouse, oil palm seedlings
were pre-treated with 50, 100, 150, 200 and 250 mg/L of silicon (Si) respectively
before being inoculated with Ganoderma boninense using the Dip, Place, and
Drench (DPD) method and observed for five consecutive months. The group of
inoculated seedlings that received no Si treatments were labelled as untreated
control seedlings (UTC). Seedlings treated with Si showed a significant (p<0.05)
reduction in disease severity against BSR where the concentrations of 150, 200
and 250 mg/L showed the lowest severity in leaf symptoms which were 7.36%,
6.49% and 4.05%, respectively with healthier and green leaves while the
seedlings without Si showed the highest severity of leaf symptoms with multiple
leaves turning yellow and dying. At five months after inoculation, examination of
internal bole tissues of oil palm seedlings treated with Si at a concentration of
250 mg/L was the most effective in suppressing BSR and recorded a 3.0% mean
percentage disease severity compared to other treatments as well as the
untreated infected seedlings that showed 35.0% mean percentage disease
severity. Si treatment plays an important role in keeping boninense infection
below threshold by restricting the pathogen’s ability to penetrate host tissues.
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Additional Metadata
Item Type: |
Thesis
(Masters)
|
Subject: |
Oil palm - Diseases |
Subject: |
Plant diseases - Fungal |
Subject: |
Silicon (Plants) |
Call Number: |
FP 2022 83 |
Chairman Supervisor: |
Siti Izera binti Ismail, PhD |
Divisions: |
Faculty of Agriculture |
Keywords: |
Basal stem rot disease, Ganoderma boninense, oil palm, salicylic
acid, silicon |
Depositing User: |
Ms. Rohana Alias
|
Date Deposited: |
02 Sep 2025 07:49 |
Last Modified: |
02 Sep 2025 07:49 |
URI: |
http://psasir.upm.edu.my/id/eprint/119412 |
Statistic Details: |
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