Photodegradation of crop trellising plastic twine.

摘要

In Guatemala, snow peas and broccoli share the same field and are planted in alternating cycles. Snow peas are a creeping plant and need to have support on a number of lines that actually are currently made from black polypropylene twine. After some time, when the twine photodegrades, hair-shaped twine fragments get entangled in the growing heads of the broccoli. When the growers want to pack the broccoli they have to remove all these filaments because they are considered a contaminant and not allowed in exports. This study aims to find replacement for the existing twine to avoid a packing problem after harvesting.; Experiments were conducted in a QUV apparatus where UV light was produced to simulate photodegradation in the field. Black and white polypropylene twine and four different nylon monofilaments were tested.; Two of the nylon samples performed best and can be considered as a solution for the problem. A field study is recommended to validate the results and correlate the behavior of the twines and monofilaments exposed in the UV apparatus with those exposed outdoors.