Preface - kmutt

KMUTT Annual Research Abstracts 2005
Nantipa Keawpet, Pongphen Jitareerat,
Sirichai Kanlayanarat
APEC Symposium on Assuring Quality and
Safety of Fresh Produce, August 1-3, 2005,
Radisson Hotel, Bangkok, Thailand
Asparagus (Asparagus officinalis)
spears cv. 'Brock Improve' were fumigated with
0, 50, 250, 500 or 1000 ppb 1-MCP for 12 hr at
20°C and then held at 20°C with 90% RH. Fiber
and lignin contents increased with storage
corresponding to the increasing toughness of the
spears indicated by increasing shear-press force.
1-MCP reduced fiber and lignin formation and
toughening. Such inhibitory effect of 1-MCP
increased with increasing concentration of up to
500 ppb. The effectiveness of 1-MCP declined
at higher concentration of 1,000 ppb. Peroxidase
activity followed similar trend as fiber and
lignin content. It was also inhibited by 1-MCP
which was most effective at 500 ppb. However,
peroxidase activity did not coincide with lignin
content during the first 2 days of storage.
IC-261 ANTIFUNGAL ACTIVITY OF
CINNAMON (Cinnamonmum zeylanicum)
EXTRACT ON BANANA CROWN ROTTING
FUNGI
Nang Kyu Kyu Win, Pongphen Jitareerat,
Sirichai Kanlayanarat
APEC Symposium on Assuring Quality and
Safety of Fresh Produce, August 1-3, 2005,
Radisson Hotel, Bangkok, Thailand
Crown rot is the important postharvest
disease of banana caused by complex fungi; C.
musae, Lasiodiplodia theobromae, and
Fusarium spp. are ubiquitous in postharvest
storage. Due to the consumer concern on
fungicide residue therefore, alternative methods
for controlling of postharvest diseases were
required. The antifungal activity of cinnamon
extracts on these pathogens was observed in
vitro at room temperature. Inhibition of conidial
germination and mycelial growth was
investigated on potato dextrose agar with 0, 100,
500, 1,000, 5,000 and 10,000 ppm of cinnamon
extract in compared with 750 ppm carbendazim.
The results revealed that cinnamon extracts at
5000 ppm completely arrested the conidial
germination and growth of all pathogenic fungi.
Conidia of L. theobromae was the most sensitive
to cinnamon extract at the lowest concentration
(100 ppm) with 18.33% of inhibition while C.
167
musae and Fusarium spp. were 46.67 and
78.33% respectively. However, mycelial growth
of Fusarium spp. was affected by 1,000 ppm
with the inhibition percent of 75.71% but
77.18% and 33.35% for C. musae and L.
theobromae. The ED 50 values of cinnamon
extracts were 588, 1,950, and 692 ppm for
mycelial growth of C. musae, L. theobromae and
Fusarium spp. and were 91, 50 and 758 ppm for
their conidia. This study indicated that the ED 50
value of cinnamon extracts for mycelial growth
was higher than that of conidia germination,
excepted Fusarium spp. and the cinnamon
extract at 5,000 ppm has a potential to be used as
biological control to reduce crown rot disease of
banana.
IC-262 PREHARVEST CHITOSAN SPRAYING
ON LEAF SPOT DISEASE AND GROWTH OF
ORCHID (Dendrobium missteen)
Nang Kyu Kyu Win, Pongphen Jitareerat,
Sirichai Kanlayanarat
APEC Symposium on Assuring Quality and
Safety of Fresh Produce, August 1-3, 2005,
Radisson Hotel, Bangkok, Thailand
Leaf spot disease on mature orchid
plants caused by Colletotrichum gloeosporioides
is commonly a problem of flower quality.
Avoidance of chemical residue on the
environment and human safety, natural
substance as chitosan was used to control leaf
spot disease in this experiment. Chitosan was
sprayed on orchid plants which had leaf spot
disease at the concentration of 0, 0.6, 1.2, 1.8
and 2.4% every week for 10 weeks under natural
condition. Disease development, quality of
flower and growth of shoot were assessed during
preharvesting. The results revealed that chitosan
spraying significantly reduced leaf spot disease
severity at the concentration of 1.2, 1.8 and
2.4% compared to control and 0.6% chitosan
sprayed plants. However, quality characteristic
such as number of flowers, flower size and also
growth of plant (new shoot emergence and
length of shoots) were not significant different
among treatments excepted the shoot length of
1.8% and 2.4% chitosan sprayed plants were
significantly higher than that of other treatments.
The results suggested that preharvest spraying of
chitosan can be used to reduce leaf spot disease
severity on mature orchid plants although it
could not influence on the quality of flowers and
growth of orchid plants.
International Conference