Dissipation and risk assessment of fluopyram and trifloxystrobin on banana, mango, grape, pomegranate and soil at harvest
This study evaluated the dissipation kinetics and dietary risk of fluopyram and trifloxystrobin fungicides on banana, mango, grape, and pomegranate crops in India, finding that their residues degrade within 2.43 to 22.74 days and pose no significant public health concern as daily intakes remain well below acceptable limits.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Every time a farmer sprays a crop to protect it from disease, a silent race begins between the pesticide and the environment. The chemicals are designed to stop fungi that can rot fruit, but they must also disappear before the harvest so that the food on our tables remains safe. This process, known as dissipation, is not a simple fade-out; it is a complex interaction where weather, the shape of the plant, and the chemistry of the spray all determine how long a residue lingers. For decades, scientists have studied how single chemicals break down, but modern agriculture increasingly relies on mixing two different fungicides together to fight tougher diseases and prevent the pests from becoming resistant. When two chemicals are combined, their behavior can change in ways that are hard to predict. The question for consumers and regulators is straightforward: if these mixed sprays are used on fruit, how much of the chemical remains when the fruit is picked, and is that amount safe to eat?
Researchers at the Indian Institute of Horticultural Research set out to answer this question for four popular fruits: banana, mango, grape, and pomegranate. They focused on a specific combination of two fungicides, fluopyram and trifloxystrobin, which are often mixed in a suspension concentrate to treat a wide range of fungal infections. The team conducted a supervised field study in the dry zone of Karnataka, India, where they sprayed the fruit trees and vines with the mixture at both the standard recommended dose and a slightly higher dose to see if the results changed. They did not just wait for the fruit to ripen; they tracked the chemicals day by day, taking samples from the moment of the final spray until the fifteenth day, which was the harvest time. They also collected soil samples from under the trees to see if the spray had drifted down and settled on the ground.
The scientists used a highly sensitive method to extract and measure the tiny amounts of chemicals remaining in the fruit and soil. They looked at the whole fruit, but crucially, they also peeled and processed the edible parts, such as the pulp of the mango, the flesh of the banana, and the juice of the pomegranate. This distinction is vital because a thick skin might hold most of the chemical, leaving the inside clean. The results showed that the two fungicides behaved differently depending on the fruit. In mangoes, the chemicals disappeared relatively quickly, and by the time the fruit was harvested, the amount found in the edible pulp was drastically lower than what was found on the peel. The peel acted as a shield, trapping the residue while the inside remained nearly free of the chemicals. Pomegranates showed a similar pattern; the thick rind held the majority of the residue, while the juicy arils and the juice contained only trace amounts, often too small to measure.
Bananas told a slightly different story. The chemicals did not linger in the fruit at all; by harvest time, the residues in both the whole fruit and the edible pulp had dropped to levels so low they were effectively undetectable. Grapes, however, were the most persistent. The chemicals stayed in the grape berries longer than in any of the other crops, with measurable amounts remaining even after fifteen days. This difference was not due to a failure of the spray but rather the nature of the grape itself, which retained the chemicals on its surface more than the other fruits. The study also found that while the chemicals were present in the soil under the mango, grape, and pomegranate trees, they were not found in the soil under the banana trees, likely because the banana plant's large leaves caught most of the spray before it could reach the ground.
To understand the long-term safety of eating these fruits, the researchers calculated the daily intake a person would have if they ate these fruits every day for a lifetime. They compared this estimated intake against the safe daily limit established by international food safety authorities. The numbers were reassuringly small. Even when assuming a person ate the highest possible amount of fruit with the highest possible residue levels, the risk was negligible. The amount of chemical a person would consume was far below the threshold that could cause harm. The study concluded that using this specific combination of fungicides on these four fruits is safe for consumers. The chemicals break down or stay on the skin in a way that protects the edible part of the fruit, and the tiny amounts that might remain do not pose a health risk. The findings provide a clear picture of how these modern agricultural tools work in the real world, offering reassurance that the fruit on the shelf is safe to enjoy.
Drowning in papers in your field?
Get daily digests of the most novel papers matching your research keywords — with technical summaries, in your language.