Creating Strong Roots – An Intricate Balance Act


Countless variables factor into our overall health and well-being – balancing the right amounts of vitamins, nutrition, exercise and sleep determines how healthy we are. We can adjust one or more of these, if needed, to ensure our health is at an optimum level, which aids in our ability to fend off sicknesses.

Similarly, wheat growers have the responsibility of ensuring their crops produce a healthy root system that’s able to defend against soilborne, yield-robbing diseases. Fertilizers and nutrient management play a vital role in root health, but sometimes we forget the outside factors, such as crop rotation and tillage, that both factor into the health of developing root systems.

A diverse crop rotation can play a key role in reducing root-damaging disease competition by eliminating the “green bridge” effect, in which diseases carry over from season to season due to lack of crop rotation. But, while certain diseases thrive in conditions provided by a continuous cropping system, such as wheat on wheat, others will thrive in any field, regardless of the crop grown, so crop rotation isn’t always a workable solution.

“Take-all can be controlled in wheat by rotating with broadleaf crops such as canola or pea, which are resistant to take-all, but Rhizoctonia solani AG-8 [cause of Rhizoctonia root rot and bare patch] has a broad host range, and crop rotation does not reduce disease levels,” explains Tim Paulitz, Ph.D., research plant pathologist with the USDA-ARS.         

In addition, crop rotation isn’t always an economically feasible disease management solution, depending on geography. “In other areas of the country, crop rotation is recommended to help minimize disease pressure. However, because of the economic and climatic constraints on cereal growers, crop rotation isn’t generally practiced in low-rainfall regions of the Pacific Northwest (PNW),” says Richard Smiley, Ph.D., professor of plant pathology at Oregon State University.

Because certain diseases have the ability to exist in fields regardless of whether a grower has a continuous wheat rotation or is rotating with other crops, growers need to consider other management options such as seed treatment fungicides.

“Seed treatments are essential components of many growers’ operations in the Pacific Northwest (PNW), in part because of the challenges growers encounter with crop rotation options and tillage practices,” Smiley explains.

While there are many economic and environmental benefits of direct seeding or no-till in cereal production, the increase in adoption of reduced and zero tillage farming methods has resulted in an increase of potential soilborne and root diseases, as well as insect pressure. Some of the potential pest pressures that coincide with implementing a reduced or zero tillage program and can impact root health include soilborne disease pathogens, such as Rhizoctonia, Pythium and Fusarium.

“I believe no-till is the future of sustainability in cropping systems here in the PNW,” Paulitz explains. “However, less than 20 percent of growers in the PNW practice no-till or direct seeding, in part due to the increased potential for some soilborne pathogens, namely Rhizoctonia and Pythium, which damage root systems and decrease yield potential.”

For winter wheat growers in particular, a strong root system is critical to surviving winter dormancy. “A healthy root system is particularly important in no-till operations,” Smiley explains. “No-till winter wheat is planted later in the fall than wheat planted in cultivated fields. This means there is less time for the crop to emerge and develop a healthy stand before winter dormancy. It also means cooler temperatures, which are conducive to Pythium development.”

No-till is a generally more economical and efficient method of farming. But, because reduced tillage systems increase the potential for root-damaging disease pathogens, no-tillers need to ensure seedlings are protected from the beginning with quality seed treatments. 

“I’ve been in this area for about a decade now, and my trials – even those in fields completely infested with Rhizoctonia – clearly show that seed treatment fungicides will help protect young seedlings against this and other soilborne diseases,” Paulitz says.

By protecting against yield-robbing diseases, seed treatment fungicides enable healthier, stronger root systems to develop, which ultimately means increased yield and profit potential for the grower.

Wheat growers have come to rely on Dividend Extreme® seed treatment fungicideto protect their crop from more than 16 seedborne and soilborne diseases. “Dividend Extreme delivers proven disease protection, which leads to better seedling germination, stronger stands and more heads, because it forms a protective barrier around the roots,” explains Kiran Shetty, Ph.D., crop expert, Syngenta. “As a result, roots are healthier and able to power the crop maximize yield. Later this year, Syngenta is set to introduce a new seed treatment fungicide that will deliver a heightened level of disease protection and root health.”

Helping crops develop strong root systems is an intricate, often overlooked, component of crop production. Along with proper fertilizer and nutrient management, it’s essential to also consider how crop rotation and tillage decisions are affecting the health of developing wheat root systems. Growers who integrate agronomic practices with carefully chosen wheat genetics, seed treatments and crop protection products are better able to harvest the best return on investment.