Spraying Rice With Zinc Oxide Nanoparticles Protects Yields During Heat Waves, Study Finds

By Bob Yirka

A small team of horticulturists in China and the U.S. has found that spraying rice plants with a zinc oxide nanoparticle solution helps them better handle the stress of a heat wave. In their study, published in Proceedings of the National Academy of Sciences, the group conducted experiments involving spraying rice plants in a heated greenhouse.

Prior research has shown that heat waves can reduce rice yields or kill plants altogether, depending on the severity of the heat wave. Because of that, plant scientists have been looking for ways to help plants survive the likely increase in number and severity of heat waves expected due to global warming. The research team found that zinc oxide nanoparticles may be one such tool.

Prior research has also shown that zinc oxide is a natural part of plant metabolism—rice farmers have used it as a form of fertilizer for many years. More recently, researchers have found that applying zinc nanoparticles is a much more efficient approach—it allows the particles to pass through the pores in leaves. The team wondered if zinc oxide might also help rice plants maintain their yields during heat waves.

To find out, the researchers planted rice in a climate-controlled greenhouse. Once the plants were grown, the team raised the temperature to 37°C for six consecutive days. During the induced heat wave, they sprayed some of the plants with a zinc oxide nanoparticle solution, while the other plants were only watered.