Genetically modified (GM) corn in the Philippines : Ecological impacts on agroecosystems, effects on the economic status and farmers’ experiences

Leiden Repository

Genetically modified (GM) corn in the Philippines : Ecological impacts on agroecosystems, effects on the economic status and farmers’ experiences

Title: Genetically modified (GM) corn in the Philippines : Ecological impacts on agroecosystems, effects on the economic status and farmers’ experiences
Author: Mabutol-Afidchao, Miladis B.
Publisher: Conservation Biology Department, Faculty of Science, Leiden University
Issue Date: 2013-11-20
Keywords: Bacillus thuringiensis (Bt) corn
Herbicide-tolerant (HT) corn
BtHT corn
Decomposition analysis
Farm economics
Non-GM corn
Genetically modified (GM) corn
Secondary pest
Asian corn borer
Species richness
Abundance
Abstract: To seek answers to the issues on GM corn adoption in the Philippines, the thesis focused to find answers on the general question: How can genetically modified (GM) corn and its attributed changes in agricultural practices affect the agro-ecosystem’s biodiversity and the economic status and social life of the farmers? Survey of Asian corn borer (ACB) in Chapter2 showed that Bt corn efficiently reduce borer pest problem and damage to plants by 44%. No secondary pest outbreak was found in Bt cornfields yet, occurrence of ACB though at an insignificant level, could imply potential development of Bt toxin resistance. On biodiversity (Chapters3 and 4), the total invertebrate abundance, surface dwellers and soil dwellers were significantly higher in non-GM cornfields than in Bt and BtHT cornfields. Insecticide-sprayed non-GM cornfields harbored more invertebrates than unsprayed Bt or BtHT cornfield. Surveyed cornfields with a minimum of two years cultivation of GM corn manifested that non-Bt cornfields had significantly higher abundance and species richness of non-target invertebrates than the Bt and BtHT fields. On economic aspect (Chapter5), the non-GM corn was not statistically different from Bt, BtHT and HT corn in terms of production output(PO), net income(NI), production-cost ratio(M) and return on investments(ROI). Results of econometric and Blinder-Oaxaca analyses demonstrate that at present GM corn hybrids do not explicitly manifest economic advantage compared to non-GM corn. On social aspect (Chapter6), GM corn adoption proved to be influenced by the perceived economic advantage, extent of knowledge, level of satisfaction and extent of first-hand experience. The foremost reason for not adopting GM corn was the cost of seed. Herbicide-tolerant (HT) corn, Bacillus thuringiensis (Bt) corn, BtHT corn, abundance, species richness, Asian corn borer, secondary pest, genetically modified (GM) corn, non-GM corn, farm economics, decomposition analysis
Description: Promotor: G.R. de Snoo, Co-promotor: C.J.M. Musters
With summary in Dutch
Faculty: Faculteit der Wiskunde en Natuurwetenschappen
Citation: Mabutol-Afidchao, M.B., 2013, Doctoral thesis, Leiden University
ISBN: 9789462034693
Sponsor: Louwes scholarship programme- Research for Water and Food jointly administered by the Cagayan Valley Programme for Environment and Development (CVPED), Isabela State University, Cabagan, Isabela, Philippines and Institute for Environmental Sciences-Conservation Biology Department (CML- CBD), Leiden University, The Netherlands
Handle: http://hdl.handle.net/1887/22273
 

Files in this item

Description Size View
application/pdf Full text 3.889Mb View/Open
application/pdf Cover 1.124Mb View/Open
application/pdf Title page_Contents 139.1Kb View/Open
application/pdf Chapter 1 General introduction 379.7Kb View/Open
application/pdf Chapter 2 705.1Kb View/Open Full text at publisher site
application/pdf Chapter 3 493.0Kb View/Open
application/pdf Chapter 4 424.1Kb View/Open
application/pdf Chapter 5 1.700Mb View/Open
application/pdf Chapter 6 613.9Kb View/Open
application/pdf Chapter 7 Concl ... atians and future research 220.0Kb View/Open
application/pdf Summary 154.8Kb View/Open
application/pdf Summary in Dutch 154.6Kb View/Open
application/pdf Curriculum Vitae 138.7Kb View/Open
application/pdf Propositions 137.0Kb View/Open

This item appears in the following Collection(s)