Dwarf plants could reduce demands for water, fertilizer, nutrients and pesticides

Aside from arable land, most farm crops require significant amounts of water, fertilizer, nutrients and pesticides to grow. While specialized breeding is often used to help produce plants that require less of these inputs, Purdue University researcher Burkhard Schulz has found a way to create tiny versions of plants that suffer no reduction in yield through the addition of a cheap and widely available chemical.

In previous research, Schulz, an assistant professor of plant biochemical and molecular genetics, had found that using the chemical brassinazole to inhibit the steroid function in corn plants resulted in tiny versions that had only female sex characteristics. But at a cost of as much as US$25,000 a gram, the chemical was prohibitively expensive, prompting him to search for a cheaper alternative.

He found a much cheaper option in the form of propiconazole, a fungicide used to treat fungal dollar spot disease on golf courses. Not only does it cost around just 10 cents a gram, but it is also more potent than the much more expensive brassinazole. It is also recognized as a safe chemical for humans with Schulz pointing out that, "they treat golf courses with it. People are around it every day."

Schulz’s previous work adding brassinazole and altering genes to disrupt steroid production produced short, feminized versions of corn plants that developed more kernels where pollen would normally grow. His new findings show that the same results can be achieved using the cheaper and widely available fungicide propiconazole.

"We can change the architecture of a plant the same way that has been done through breeding. We can treat plants with this substance throughout the plant's life and it will never be able to produce steroids," said Schulz. "Any research where you needed to treat large plants for long periods of time would have been impossible. Those tests before would have cost us millions of dollars. Now, they cost us $25. This will open up research in crops that was not possible before."

Aside from the benefits to researchers, Schulz’s approach could also be used to produce shorter plants that not only produce the same amount of grain using less water, fertilizer and nutrients, but are also sturdier against the elements thanks to their reduced height. The technique could also be used to slow grass growth on golf courses, reducing the amount of mowing required and cutting costs.

The findings could also prove significant for seed producers who must usually perform the labor-intensive task of mechanically removing the male portion of the plants so they don’t pollinate themselves.

Schulz and his team are working to determine which genes propiconazole affects and they plans to test if the chemical will also retard steroid production in grain crops other than maize. The team's recent findings were published in the journal PLoS One.

Schulz explains his technique and its benefits in the following video.