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UPV Theses and Dissertations

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Degree: search.filters.degree.Bachelor of Science in BiologySDG: search.filters.sdg.SDG 2 - Zero hunger

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    The growth and yield performance of oyster mushroom (Pleurotus ostreatus Fries) using fish wastewater as fertilizer
    Arroyo, Karen T. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2000-04)
    Oyster mushroom, Pleurotus ostreatus, is an edible wood-inhabiting fungi that continues to gain popularity in the Philippines, as well as in other tropical countries. With the use of modern technology, this mushroom can be grown in the Philippines, provided sufficient moisture is present. Its present cultivation is limited, perhaps due to insufficiency of planting materials and the limited knowledge about its culture. The main objective of the study was to establish the possibility of the replacement of urea, the commonly used fertilizer for mushroom cultivation by fish wastewater. The study also aimed to compare the effects of different concentrations of fish wastewater on the growth of mushrooms and determine which treatment produced the best results. A total of five groups were used: two control groups (positive and negative - using urea and water, respectively) and three experimental groups, the latter with different concentrations of fish wastewater serving as alternative fertilizer (A: 10%, B: 20%, C: 30%). Fruiting bags were inoculated with oyster mushroom spawn, and after a month of incubation, the growing mushrooms were assessed using the parameters of number, weight, length, and diameter. Results showed that the weight of oyster mushrooms was heaviest when the substrate was sprayed with plain water. However, the number of mushrooms harvested, their length, and the width of the pilei were not affected by spraying the substrate with urea or moistening these with up to 30% fish wastewater. The conclusions reached were: 1) when using sawdust as substrate for oyster mushroom cultivation, it is best to simply use water to maintain the moisture of the material; 2) sawdust used in combination with low concentration of fish wastewater (10%) can result in good production; 3) neither nitrogen nor urea may be a critical factor for the growth of oyster mushroom on sawdust; and 4) high amount of phosphorus and low potassium content of fish wastewater are favorable for oyster mushroom growth.
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    Molluscicidal effect of quicklime, CaO on golden snail (Pomacea canaliculata)
    Baibado, Joewel Tarra (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1998-03)
    The golden snail (Pomacea canaliculata) is presently a major pest of rice in lowland and rainfed areas through out the Philippines . The problem of golden snail infestation in rice farming system includes damage to the rice plants, rice yield losses, additional expense, side effects of chemicals and destructive effect on native snails . The study was conducted to evaluate the molluscicidal effect of calcium oxide for the control of golden snails in farmlands and to determine the 96hour LC50 in order to know the lethal concentration of calcium oxide to golden snails. Calcium oxide was found to have a molluscicidal activity on golden snails The golden snails were exposed to different concentrations namely. 100 ppm. 200 ppm. 300 ppm .400 ppm. and 500 ppm Remarkable lethal effects of calcium oxide (p<0.05) has been found in 4(H) and 500 ppm concentrations which has reached 60-100 % after the 96 hour treatment. The 96-hour LC50 within the 95% confidence interval was 322.02 ppm as computed Calcium oxide is safe on rice when used as a molluscicide It performs dual function as fertilizer/soil stabilizer and molluscide. These dual effects are very significant because it means big savings on the part of the rice farmers. Considering the prevalence of this pest, farmers spend much on molluscicides and their application. With calcium oxide, the farmer has a molluscicide and soil stabilizer in one application.
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    Salinity tolerance of the angelwing clam, Pholas orientalis larvae
    Aguaras, Lovie Grace P. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2011-03)
    Pholas orientalis, locally known as “diwal” is one of the commercially important bivalves in the Philippines due to its delicate and sweet taste. An experiment was conducted to determine the salinity tolerance of the 24-hour-old larvae of this clam when reared in different salinity levels of 25, 30, 35, and 40 ppt. The experiment lasted for 15 days at a rearing temperature of 25° C - 27° C. Determination of survival rates and water change were done twice every week. The data gathered were then analyzed using one-way ANOVA. Results showed that survival rates were significantly high at salinities of 30-35 ppt and were significantly low at salinity levels of 25 and 40 ppt. It was also observed that there was an increasing trend of mortality with prolonged exposure to different salinity levels. This could be attributed to the limited osmoregulatory capabilities of the larvae. When reared at low salinity levels, larvae were faced with the danger of too much water entry which eventually led to death. Meanwhile, when reared at high salinity levels, the larvae died due to outward movement of water which resulted to dehydration. Information on the salinity levels that could be tolerated by diwal larvae will be an important factor in the development of larval rearing techniques for successful hatchery operations. The juveniles or seeds produced in the hatchery could be used to restock the depleted resources in the wild.