THE Department of Agriculture’s Philippine Center for Postharvest Development and Mechanization (PhilMech) is conducting tests on a transparent biodegradable bag for use in farms to help reduce the amount of plastic waste which is harmful to the environment.
“What farmers and agriculture commodity traders use today are still plastics and those that are left undisposed after use can present problems to the environment,” Rex Bingabing, executive director of PhilMech, said in a statement.
Plastic bags and products take years to degrade and can impede plant growth if left to rot in soil.
Fruit farms also use plastic bags to protect fruits under development from pests and the outside elements, while plastic film is used for mulcting in farming, which helps reduce moisture loss from the soil.
Collaborating with the National Mango Research and Development Center in Jordan, Guimaras and a private plastic firm, PhilMech is currently testing a biodegradable bag made from cassava starch and polybutylene succinate (PBS).
The PBS and starch were melt-blended in a twin-screw extruder and then blown into a film extrusion machine.
PhilMech first developed a transparent biodegradable fruit bag for testing. The biodegradable fruit bag measures 6 x 8 inches with a thickness of 150 microns. The tensile strength is within the range of low-density polyethylene (LDPE) while the elongation is within the range of high-density polyethylene (HDPE). However, the biodegradable bag has higher density and absorbs more water.
PhilMech projects that the biodegradable fruit bag would completely degrade after 36 weeks.
When the biodegradable bag was tested as packaging on fruits, the quality of harvested fruits in terms of percent marketable, non-marketable and export, peel color at ripe stage, flesh color and percent edible portion were comparable with the existing bagging materials such as a Chinese brown paper bag and old newspaper.
The development of a biodegradable bag was done under the project “Utilization of Biodegradable Composites Material on the Production of Fruit Bag” by PhilMech researchers Andres Tuates Jr. and Ofero Caparino, PhD.
“Plastics have achieved a dominant position in agriculture because of their transparency, lightness in weight, impermeability to water and their resistance to microbial attack. It is used as food and fruit packaging, fruit bag, food container, seedling bag, mulching film, protective for greenhouse, dryer shed and among others. However, this generates higher quantity of wastes that are difficult to dispose by the user farmers,” the researchers said.
“The plastic residues remain on the soil for some years as large pieces and they are an impediment to plant growth and also a potential hazard to animals if the land is subsequently put down to grass,” they added.