UPV Digital RepositoryUPV-DRUniversity of the Philippines Visayas
 

Undergraduate Theses

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/13

Browse

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Community structure of riverine mangrove stand in Brgy. Talokgangan, Municipality of Banate, Iloilo Province
    Belaño, Keith Dominador L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2001-04)
    The community structure of riverine mangrove stand in Brgy. Talokgangan, Municipality of Banate, Iloilo was studied. Ten “true” mangrove species representing seven families were encountered in the “mangals” of Balandra creek community in Brgy. Talokgangan. They were Avicennia marina, Avicennia lanata and Avicennia alba representing Family Avicenniaceae; Rhizophora apiculata and Rhizophora mucronata under Family Rhizophoraceae; Sonneratia alba of the Family Sonneratiaceae; Excoecaria agallocha under Family Euphorbiaceae; Camptostemon philippinense of the Family Bombacaceae; one from the Family Meliaceae namely Xylocarpus granatum, and Family Palmae represented by Nypa fruticans. Stand Basal Area was computed highest in Station 1 with 10.22 m2/ha. Station 1 was also the densest among the four stations with a density value of 2533 trees/ha. In terms of data evaluated per zone, the landward zone has a Stand Basal Area of 10.87 m2/ha which is slightly higher than the middle and riverward zones. The middle zone, however, was found to be the densest with 1850 trees/ha. The most dominant station was Station 1 with the highest Index of Dominance of 0.3319, however, was found to be the least diverse station. The highest Index of Diversity was computed in Stations 2 and 3, with diversity indices of 0.8976 and 0.8989 respectively. Avicennia marina was found common in all stations and the most dominant, making it the most important mangrove species. They were found to occupy the whole site, growing abundantly in wide range of conditions from areas frequently inundated by tidal flow in Station 1 to the firmer muddy substratum in the back mangrove areas. Rhizophora apiculata and Rhizophora mucronata was observed to occupy waterlogged soil conditions. Excoecaria agaliocha tend to flourish in firmer muddy substratum in open sites, whereas, Xylocarpus granatum was observed to occupy zones where salinity is lowest in areas rarely affected by tidal flow. Sonneratia alba and Camptostemon philippinense tend to grow in zones directly inundated by tidal flow.
  • Thumbnail Image
    Item
    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.