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Papers by Niwooti Whangchai

Thesis (Ph. D. in Agriculture)--University of Tsukuba, (A), no. 2812, 2002.3.25 Includes bibliogr... more Thesis (Ph. D. in Agriculture)--University of Tsukuba, (A), no. 2812, 2002.3.25 Includes bibliographical references

Chiang Mai Journal of Science

Chiang Mai Journal of Science

International Journal of Bioscience, Biochemistry and Bioinformatics

International Journal of Bioscience, Biochemistry and Bioinformatics

Maejo international journal of science and technology

This study evaluated the effects of culture season and different stocking density on productivity... more This study evaluated the effects of culture season and different stocking density on productivity of freshwater prawn that was raised in northern Thailand. The experiment was conducted at the Faculty of Fisheries Technology and Aquatic Resources, Maejo University, Chiang Mai, Thailand. This study was divided into two experiments; each treatment was replicated three times. The first experiment investigated the effect of climatic condition on the culture and production of freshwater prawn post larvae (PL 10; mean weight of 0.02 g) stocked in 400m2 ponds. Results of the first experiment revealed freshwater prawn raised during the dry season to summer obtained higher growth rate (0.19 g and 0.15 g/day) and survival rate (34.27% and 24.49%) than that of summer to rainy season (p<0.05). The second experiment investigated the effect of 2 different socking densities (25 and 50 individuals/m2) on the production survival of freshwater prawn. Results showed that the rate of growth, survival...

Chiang Mai Journal of Science

ABSTRACT

日本水処理生物学会誌 別巻 Journal Japan Biological Society of Water and Waste, Oct 15, 2011

Journal of Applied Aquaculture, 2016

Maejo International Journal of Science and Technology, Mar 19, 2013

International Aquatic Research, 2015

ABSTRACT

International Journal of Global Warming, 2015

ABSTRACT This paper analyses the direct impacts of extreme weather, high and low flow events, sea... more ABSTRACT This paper analyses the direct impacts of extreme weather, high and low flow events, seasonality and other climate-related phenomena on river-based tilapia cage aquaculture in Northern Thailand. An interdisciplinary approach was taken, which included analysis of secondary water flow and meteorological data, quantitative and qualitative surveys of farmers experiences with extreme events, and direct observations during critical periods. Findings show that extreme high and low flows adversely impact a substantial fraction of farms, causing damage to cages, fish deaths, slow growth and disease problems. Economic losses are significant and result in financial debt. Compensation and assistance following floods is modest relative to losses, and coverage is incomplete. Probability of extreme flows and impacts vary among locations, are highly seasonal, and vary inter-annually. These findings are important to improving management of climate-related risks, under both current and future climatic conditions.

International Journal of Climate Change Strategies and Management, 2015

Thai Journal of Agricultural Science

ABSTRACT

Chiang Mai Journal of Science

This study investigated the effects of using plastic film shelters on the survival, growth and pr... more This study investigated the effects of using plastic film shelters on the survival, growth and production cost of giant freshwater prawn (Macrobrachium rosenbergii). Three ponds were covered with plastic shelters, whilst three other were left unsheltered as controls. The surface area of all ponds was 100 square meters (6x16.7),with a water depth of 1.0 meter. Post larvae (0.012 g. mean initial weight) were raised with a stocking density of 100 individuals/ m2. They were grown for 75 days in both treatments. The average temperature of the pond water beneath the film was 3.4 oC higher than that of unsheltered ponds. In sheltered ponds, the lowest temperature recorded was 23 oC, where as in non-sheltered ponds the lowest recorded temperature was 18 oC. The minimum and maximum temperatures (on average) in the non-sheltered ponds and sheltered ponds were 23.8-27.4 oC and 27.7-30.3 oC, respectively. Although there was no significant difference in the prawn's survival rate, the growth rate and food conversion ratio between treatments were significantly different (P<0.05). Weight gain of post larvae reared in non-sheltered ponds was 0.037±0.002 gram per day, compared with 0.062±0.002 gram per day for larvae in sheltered ponds. The mean final weight of the prawns raised in sheltered ponds was higher (5.42+0.18g) than that of prawns raised in non- sheltered ponds (2.70±0.16 g). The production cost of using sheltered ponds was lower compared to the cost using non-sheltered ponds. Variation in size of the prawns among ponds with plastic covering was lower than the non-sheltered ponds. Therefore, using plastic film covering over nursing ponds resulted in higher growth performance and lower production cost. It is therefore a promising method for farmers to rear post larvae during the cold season.

International Journal of Agriculture and Biology

Maejo international journal of science and technology

The cyanobacterium Spirulina platensis is an attractive source of valuable protein for both human... more The cyanobacterium Spirulina platensis is an attractive source of valuable protein for both human and animal consumption. The conventional nitrogen source for S. platensis is nitrate. However, recent research has evaluated the potential of using animal waste as a low-cost nitrogen source. In this work, the cultivation of S. platensis was done using dry chicken manure (DCM), collected from a closed-system poultry house, as nitrogen source. The experiment was carried out in open concrete tanks with 100 litres of culture medium and an initial biomass concentration of 0.5 g/L. The culture media were prepared to test the effect of unsupplemented DCM, DCM supplemented with 2.0 mg/L of urea (DCM+U), and/or 40 mg/L of sodium bicarbonate (DCM+U+B or DCM+B). The best cellular growth and highest protein production were observed for S. platensis in the biomass harvested from the culture medium containing DCM supplemented with 2.0 mg/L of urea (DCM+U). © 2009 by Maejo University, San Sai, Chiang...

Thesis (Ph. D. in Agriculture)--University of Tsukuba, (A), no. 2812, 2002.3.25 Includes bibliogr... more Thesis (Ph. D. in Agriculture)--University of Tsukuba, (A), no. 2812, 2002.3.25 Includes bibliographical references

Chiang Mai Journal of Science

Chiang Mai Journal of Science

International Journal of Bioscience, Biochemistry and Bioinformatics

International Journal of Bioscience, Biochemistry and Bioinformatics

Maejo international journal of science and technology

This study evaluated the effects of culture season and different stocking density on productivity... more This study evaluated the effects of culture season and different stocking density on productivity of freshwater prawn that was raised in northern Thailand. The experiment was conducted at the Faculty of Fisheries Technology and Aquatic Resources, Maejo University, Chiang Mai, Thailand. This study was divided into two experiments; each treatment was replicated three times. The first experiment investigated the effect of climatic condition on the culture and production of freshwater prawn post larvae (PL 10; mean weight of 0.02 g) stocked in 400m2 ponds. Results of the first experiment revealed freshwater prawn raised during the dry season to summer obtained higher growth rate (0.19 g and 0.15 g/day) and survival rate (34.27% and 24.49%) than that of summer to rainy season (p<0.05). The second experiment investigated the effect of 2 different socking densities (25 and 50 individuals/m2) on the production survival of freshwater prawn. Results showed that the rate of growth, survival...

Chiang Mai Journal of Science

ABSTRACT

日本水処理生物学会誌 別巻 Journal Japan Biological Society of Water and Waste, Oct 15, 2011

Journal of Applied Aquaculture, 2016

Maejo International Journal of Science and Technology, Mar 19, 2013

International Aquatic Research, 2015

ABSTRACT

International Journal of Global Warming, 2015

ABSTRACT This paper analyses the direct impacts of extreme weather, high and low flow events, sea... more ABSTRACT This paper analyses the direct impacts of extreme weather, high and low flow events, seasonality and other climate-related phenomena on river-based tilapia cage aquaculture in Northern Thailand. An interdisciplinary approach was taken, which included analysis of secondary water flow and meteorological data, quantitative and qualitative surveys of farmers experiences with extreme events, and direct observations during critical periods. Findings show that extreme high and low flows adversely impact a substantial fraction of farms, causing damage to cages, fish deaths, slow growth and disease problems. Economic losses are significant and result in financial debt. Compensation and assistance following floods is modest relative to losses, and coverage is incomplete. Probability of extreme flows and impacts vary among locations, are highly seasonal, and vary inter-annually. These findings are important to improving management of climate-related risks, under both current and future climatic conditions.

International Journal of Climate Change Strategies and Management, 2015

Thai Journal of Agricultural Science

ABSTRACT

Chiang Mai Journal of Science

This study investigated the effects of using plastic film shelters on the survival, growth and pr... more This study investigated the effects of using plastic film shelters on the survival, growth and production cost of giant freshwater prawn (Macrobrachium rosenbergii). Three ponds were covered with plastic shelters, whilst three other were left unsheltered as controls. The surface area of all ponds was 100 square meters (6x16.7),with a water depth of 1.0 meter. Post larvae (0.012 g. mean initial weight) were raised with a stocking density of 100 individuals/ m2. They were grown for 75 days in both treatments. The average temperature of the pond water beneath the film was 3.4 oC higher than that of unsheltered ponds. In sheltered ponds, the lowest temperature recorded was 23 oC, where as in non-sheltered ponds the lowest recorded temperature was 18 oC. The minimum and maximum temperatures (on average) in the non-sheltered ponds and sheltered ponds were 23.8-27.4 oC and 27.7-30.3 oC, respectively. Although there was no significant difference in the prawn's survival rate, the growth rate and food conversion ratio between treatments were significantly different (P<0.05). Weight gain of post larvae reared in non-sheltered ponds was 0.037±0.002 gram per day, compared with 0.062±0.002 gram per day for larvae in sheltered ponds. The mean final weight of the prawns raised in sheltered ponds was higher (5.42+0.18g) than that of prawns raised in non- sheltered ponds (2.70±0.16 g). The production cost of using sheltered ponds was lower compared to the cost using non-sheltered ponds. Variation in size of the prawns among ponds with plastic covering was lower than the non-sheltered ponds. Therefore, using plastic film covering over nursing ponds resulted in higher growth performance and lower production cost. It is therefore a promising method for farmers to rear post larvae during the cold season.

International Journal of Agriculture and Biology

Maejo international journal of science and technology

The cyanobacterium Spirulina platensis is an attractive source of valuable protein for both human... more The cyanobacterium Spirulina platensis is an attractive source of valuable protein for both human and animal consumption. The conventional nitrogen source for S. platensis is nitrate. However, recent research has evaluated the potential of using animal waste as a low-cost nitrogen source. In this work, the cultivation of S. platensis was done using dry chicken manure (DCM), collected from a closed-system poultry house, as nitrogen source. The experiment was carried out in open concrete tanks with 100 litres of culture medium and an initial biomass concentration of 0.5 g/L. The culture media were prepared to test the effect of unsupplemented DCM, DCM supplemented with 2.0 mg/L of urea (DCM+U), and/or 40 mg/L of sodium bicarbonate (DCM+U+B or DCM+B). The best cellular growth and highest protein production were observed for S. platensis in the biomass harvested from the culture medium containing DCM supplemented with 2.0 mg/L of urea (DCM+U). © 2009 by Maejo University, San Sai, Chiang...

Chiang Mai Journal of Science