This post is written by Sara Hendery, Communications Coordinator for the Feed the Future Innovation Lab for Integrated Pest Management.

Vietnam is a major exporter of tropical fruits, and yet, the Southeast Asian country experiences incredibly high post-harvest losses. Up to 25 percent of fruit alone is lost due to inadequate storing, post-harvest processing, and other factors.

The excessive application of pesticides also leads to high incidences of post-harvest losses in Vietnam. Pesticide residues can tarnish the quality, nutritional value, safety, and even export potential of food crops.

This is especially true for the export of dragon fruit in Vietnam. While the country is the world’s leading exporter of the sweet, highly nutritious fruit, the fungal disease Neoscytalidium dimidiatum – also known as canker disease – makes dragon fruit susceptible to rot, and impedes the fruit’s marketability and exportability. To address the disease, farmers apply such exorbitant amounts of fungicides that numerous shipments of the fruit sent to the U.S. and other countries get rejected and incinerated every year, causing major food and economic losses.

The Feed the Future Innovation Lab for Integrated Pest Management (IPM Innovation Lab) partners with the Southern Horticultural Research Institute (SOFRI) in Vietnam to address canker disease and over-reliance on chemical pesticides to reduce those post-harvest losses. By implementing a simple fruit bagging technique, where each dragon fruit in a farmer’s orchard is wrapped in a malleable, open plastic bag, the team significantly boosts the crop’s defense mechanisms against threats.  

“Dragon fruit bagging has had a significant impact on post-harvest losses,” said Muni Muniappan, IPM Innovation Lab Director. “Our testing of the technique has shown significant reduction in canker disease incidence and severity, as well as a decrease in attacks by insect pests such as fruit flies. The shape, structure, and material are all intentional to ensure less fungicide is necessary for dragon fruit growth, and therefore, less losses occur during export.”

The IPM Innovation Lab-SOFRI team ran a series of tests to evaluate effectiveness of different types of bags, looking at both fruit quality and cost to farmers. The approved bag costs just one cent, and keeps its shape in the event that farmers need to apply additional foliar sprays. The bag is also transparent, allowing farmers to monitor fruit growth and quality.

Canker disease can spread quickly – first recorded in Vietnam in 2009, it took just four years for it to spread to over 10,000 hectares – and causes yield losses ranging from 30-70 percent. The disease, which leaves small red dots on the cactus of the fruit, is most severe during the wet season, when fruit is not yet ready for harvesting.

In addition to reducing canker disease incidence, implementation of dragon fruit bagging has farmers reporting other significant changes – 60 percent less pesticide sprays, 30 percent more marketable fruit, decreased labor, and savings from not purchasing additional chemical pesticides. Ultimately, a reduction in pesticides means a reduction in rejected dragon fruit shipments.

“The farmers were very scared,” said Dang Thuy Linh, a plant pathologist at SOFRI, referring to the problems dragon fruit farmers have faced. “Dragon fruit supports people’s entire income, so now they are relieved to see problems being reduced.”

The IPM Innovation Lab-SOFRI team implements fruit bagging for three other exportable crops in addition to dragon fruit – longan, lychee, and mango – significantly reducing pesticide sprays and increasing yields of those fruits as well.