Abstract: Acute and chronic effects of biopesticide from entomopathogenic nematode (Steinernema thailandensis n. sp.), bacteria ISR (Pseudomonas fluorescens), wood vinegar and fermented organic substances from plants: (neem Azadirachta indica + citronella grass Cymbopogon nardus Rendle + bitter bush Chromolaena odorata L.) were tested on culantro (Eryngium foetidum L.). The biopesticide was investigated for infestation reduction of the major insect pest whitefly (Bemisia tabaci (Gennadius)). The experimental plots were located at a farm in Nakhon Sawan Province, Thailand. This study was undertaken during the drought season (late November to May). Effectiveness of the treatment was evaluated in terms of acute and chronic effect. The populations of whitefly were observed and recorded every hour up to 3 hours with insect nets and yellow sticky traps after the treatments were applied for the acute effect. The results showed that bacteria ISR had the highest effectiveness for controlling whitefly infestation on culantro; the whitefly numbers on insect nets were 12.5, 10.0 and 7.5 after 1 hr, 2 hr, and 3 hr, respectively while the whitefly on yellow sticky traps showed 15.0, 10.0 and 10.0 after 1 hr, 2 hr, and 3 hr, respectively. For chronic effect, the whitefly was continuously collected and recorded at weekly intervals; the result showed that treatment of bacteria ISR found the average whitefly numbers only 8.06 and 11.0 on insect nets and sticky traps respectively, followed by treatment of nematode where the average whitefly was 9.87 and 11.43 on the insect nets and sticky traps, respectively. In addition, the minor insect pests were also observed and collected. The biopesticide influenced the reduction number of minor insect pests (red spider mites, beet armyworm, short-horned grasshopper, pygmy locusts, etc.) with only a few found on the culantro cultivation.
Abstract: Effect of biopesticide from wood vinegar and
extracted substances from 3 medicinal plants such as: non taai yak
(Stemona tuberosa Lour), boraphet (Tinospora crispa Mier) and
derris (Derris elliptica Roxb) were tested on the age five years of
pomelo. The selected pomelo was carried out for insects’ pest control
and its quality. The experimental site was located at farmer’s orchard
in Phichit Province, Thailand. This study was undertaken during the
drought season (December to March). The extracted from plants and
wood vinegar were evaluated in 6 treatments: 1) water as control; 2)
wood vinegar; 3) S. tuberosa Lour; 4) T. crispa Mier; 5) D. elliptica
Roxb; 6) mixed (wood vinegar + S. tuberosa Lour + T. crispa Mier +
D. elliptica Roxb). The experiment was RCB with 6 treatments and 3
replications per treatment. The results showed that T. crispa Mier was
the highest effectiveness for reduction population of thrips
(Scirtothrips dorsalis Hood) and citrus leaf miner (Phyllocnistis
citrella Stainton) at 14.10 and 15.37 respectively, followed by
treatment of mixed, D. elliptica Roxb, S. tuberosa Lour and wood
vinegar with significance different. Additionally, T. crispa Mier
promoted the high quality of harvested pomelo in term of thickness
of skin at 12.45 mm and S. tuberosa Lour gave the high quality of the
pomelo in term of firmness (276.5 kg/cm2) and brix (11.0%).
Abstract: This research was conducted in the Mae Sot
Watershed where located in the Moei River Basin at the Upper
Salween River Basin in Tak Province, Thailand. The Mae Sot
Municipality is the largest urban area in Tak Province and situated in
the midstream of the Mae Sot Watershed. It usually faces flash flood
problem after heavy rain due to poor flood management has been
reported since economic rapidly bloom up in recent years. Its
catchment can be classified as ungauged basin with lack of rainfall
data and no any stream gaging station was reported. It was attached
by most severely flood events in 2013 as the worst studied case for
all those communities in this municipality. Moreover, other problems
are also faced in this watershed, such shortage water supply for
domestic consumption and agriculture utilizations including a
deterioration of water quality and landslide as well. The research
aimed to increase capability building and strengthening the
participation of those local community leaders and related agencies to
conduct better water management in urban area was started by mean
of the data collection and illustration of the appropriated application
of some short period rainfall forecasting model as they aim for better
flood relief plan and management through the hydrologic model
system and river analysis system programs. The authors intended to
apply the global rainfall data via the integrated data viewer (IDV)
program from the Unidata with the aim for rainfall forecasting in a
short period of 7-10 days in advance during rainy season instead of
real time record. The IDV product can be present in an advance
period of rainfall with time step of 3-6 hours was introduced to the
communities. The result can be used as input data to the hydrologic
modeling system model (HEC-HMS) for synthesizing flood
hydrographs and use for flood forecasting as well. The authors
applied the river analysis system model (HEC-RAS) to present flood
flow behaviors in the reach of the Mae Sot stream via the downtown
of the Mae Sot City as flood extents as the water surface level at
every cross-sectional profiles of the stream. Both models of HMS and
RAS were tested in 2013 with observed rainfall and inflow-outflow
data from the Mae Sot Dam. The result of HMS showed fit to the
observed data at the dam and applied at upstream boundary discharge
to RAS in order to simulate flood extents and tested in the field, and
the result found satisfying. The product of rainfall from IDV was fair
while compared with observed data. However, it is an appropriate
tool to use in the ungauged catchment to use with flood hydrograph
and river analysis models for future efficient flood relief plan and
management.
Abstract: The efficiency of wood vinegar mixed with each
individual of three plants extract such as: citronella grass
(Cymbopogon nardus), neem seed (Azadirachta indica A. Juss), and
yam bean seed (Pachyrhizus erosus Urb.) were tested against the
second instar larvae of housefly (Musca domestica L.). Steam
distillation was used for extraction of the citronella grass while neem
and yam bean were simple extracted by fermentation with ethyl
alcohol. Toxicity test was evaluated in laboratory based on two
methods of larvicidal bioassay: topical application method (contact
poison) and feeding method (stomach poison). Larval mortality was
observed daily and larval survivability was recorded until the
survived larvae developed to pupae and adults. The study resulted
that treatment of wood vinegar mixed with citronella grass showed
the highest larval mortality by topical application method (50.0%)
and by feeding method (80.0%). However, treatment of mixed wood
vinegar and neem seed showed the longest pupal duration to 25 day
and 32 days for topical application method and feeding method
respectively. Additional, larval duration on treated M. domestica
larvae was extended to 13 days for topical application method and 11
days for feeding method. Thus, the feeding method gave higher
efficiency compared with the topical application method.
Abstract: The effect of wood vinegar, entomopathogenic
nematodes ((Steinernema thailandensis n. sp.) and fermented organic
substances from four plants such as: Derris elliptica Roxb, Stemona
tuberosa Lour, Tinospora crispa Mier and Azadirachta indica J. were
tested on the five varieties of sweetpotato with potential for
bioethanol production ie. Taiwan, China, PROC No.65-16, Phichit
166-5, and Phichit 129-6. The experimental plots were located at
Faculty of Agriculture, Natural Resources and Environment,
Naresuan University, Phitsanulok, Thailand. The aim of this study
was to compare the efficiency of the five treatments for growth, yield
and insect infestation on the five varieties of sweetpotato. Treatment
with entomopathogenic nematodes gave the highest average weight
of sweetpotato tubers (1.3 kg/tuber), followed by wood vinegar,
fermented organic substances and mixed treatment with yields of
0.88, 0.46 and 0.43 kg/tuber, respectively. Also the
entomopathogenic nematode treatment gave significantly higher
average width and length of sweet potato (9.82 cm and 9.45 cm,
respectively). Additionally, the entomopathogenic nematode
provided the best control of insect infestation on sweetpotato leaves
and tubers. Comparison among the varieties of sweetpotato, PROC
NO.65-16 showed the highest weight and length. However, Phichit
129-6 gave significantly higher weight of 0.94 kg/tuber. Lastly, the
lowest sweet potato weevil infestation on leaves and tubers occurred
on Taiwan and Phichit 129-6.
Abstract: Raw wood vinegar was purified by both standing and
filtering methods. Toxicity tests were conducted under laboratory
conditions by the topical application method (contact poison) and
feeding method (stomach poison). Larvicidal activities of wood
vinegar at four different concentrations (10, 15, 20, 25 and 30 %)
were studied against second instar larvae of housefly (Musca
domestica L.). Four replicates were maintained for all treatments and
controls. Larval mortality was recorded up to 96 hours and compared
with the larval survivability by two methods of larvicidal bioassay.
Percent pupation and percent adult emergence were observed in
treated M. domestica. The study revealed that the feeding method
gave higher efficiency compared with the topical application method.
Larval mortality increased with increasing concentration of wood
vinegar and the duration of exposure. No mortality was found in
treated M. domestica larvae at minimum 10% concentration of wood
vinegar through the experiments. The treated larvae were maintained
up to pupa and adult emergence. At 30% maximum concentration
larval duration was extended to 11 days in M. domestica for topical
application method and 9 days for feeding method. Similarly the
pupal durations were also increased with increased concentrations
(16 and 24 days for topical application method and feeding method
respectively at 30% concentration) of the treatments.