Early Weed Scouting Helps Protect Hay Quality

Aug 06, 2026
By Farms.com

Scouting Roadside Ditches Reduces Weed Contamination and Protects Valuable Forage Supplies

Farmers who harvest hay from roadside ditches should inspect these areas carefully before mowing. While ditch hay provides valuable forage, harvesting weeds along with the crop can spread invasive plants and reduce the overall quality of the hay.

Eric Jones, Assistant Professor and SDSU Extension Weed Management Specialist, along with Graig Reicks and Philip Rozeboom, encourage producers to scout roadside ditches before harvesting.

Different States may have different laws governing right-of-way ditch harvesting. For example, the South Dakota Department of Transportation permits mowing and haying of highway right-of-way ditches after June 15 or July 10, depending on the location. Check your state laws before you begin.

Before harvesting begins, producers should walk the ditch and check for weed patches throughout the entire area.

Many noxious weeds produce large numbers of seeds that can easily spread during mowing and baling. Once the plants have reached the seed stage, harvesting them may scatter seeds across nearby land, creating new weed problems in future growing seasons.

Weed seeds can also become mixed with harvested hay. During hauling, storage, or livestock feeding, these seeds may fall onto clean land and establish new infestations. This can increase weed management costs and reduce forage production over time.

If noxious weeds have already developed mature seed heads, producers should avoid mowing those areas until proper weed control measures are completed. Leaving infested patches unharvested helps prevent unnecessary seed movement.

For small infestations, removing seed heads by hand before harvest can be an effective management practice. Destroying the seed heads limits future spread and helps keep surrounding land cleaner.

Photo Credit: gettyimages-ianchrisgraham

Video: Turning Plant Defense Into a Management Strategy

Turning Plant Defense Into a Management Strategy

Understanding how a plant responds to stress is one thing.

Using that knowledge to make better management decisions is another.

Systemic acquired resistance, or SAR, is the plant's more direct defense response. When stress or infection occurs, the plant begins signaling throughout its system and preparing defensive compounds.

But if we know that response exists, can we help prepare the plant before the stress arrives?

The answer starts with understanding what triggers the response and what the plant needs to carry it out.

The Trigger and the Fuel

Salicylic acid plays an important role in triggering the SAR pathway.

Think of it as turning the truck on.

The engine may be running, but it still needs fuel to do the work.

In this case, manganese plays an important role in supporting the enzyme systems involved in the plant's defensive response.

This makes manganese status an important part of the conversation. Whether a producer is using tissue testing, sap analysis, or simply scouting for visible deficiency symptoms, the goal is to make sure the plant has adequate manganese available.

Manganese is required in relatively small amounts, but that does not make its role small.

If the plant receives a signal to defend itself but lacks the nutrition needed to support that response, it may struggle to carry out the process efficiently.

The trigger matters.

The fuel matters too.

Prepare Before the Stress Arrives

The best time to think about stress management is before the plant is overwhelmed.

Once a crop is already struggling, management can quickly turn into a game of catch-up.

This is similar to nitrogen management. Once a plant becomes severely deficient, correcting the problem does not necessarily erase the time and yield potential already lost.

Plant defense can work the same way.

Low-rate, targeted approaches designed to support the SAR pathway may fit best ahead of an expected stress event rather than after significant damage has already occurred.

That requires producers to think about predictable stress.

We may not know exactly what the weather will do tomorrow, but we generally know summer heat is coming. We know certain field conditions increase disease pressure. We know a herbicide application can temporarily stress a crop as the plant processes the chemistry.

Even a properly timed and labeled herbicide application can create a temporary response in the plant.

That does not mean the herbicide is bad.

Weeds can create significantly more yield loss than the temporary stress caused by controlling them.

The question is not whether we should eliminate every stressor.

The question is whether we can better prepare the plant to manage necessary and predictable stress.

Not All Stress Is Bad

Stress is a normal part of plant growth.

A perfectly stress-free environment does not exist in the field.

In fact, some stress is necessary for normal plant development. A plant responds to wind, temperature, moisture, sunlight, and countless other environmental signals throughout the season.

The environment is stress.

The plant's job is to manage it.

Problems begin when the stress load becomes greater than the plant's ability to respond.

Extreme heat, drought, high salt concentrations, disease pressure, and even certain management practices can add to that load.

This is where understanding SAR becomes useful.

Instead of waiting until the plant is visibly struggling, producers can begin identifying periods when stress is likely and make management decisions around those windows.

ISR Starts With the Soil

While SAR is a more direct defense response, induced systemic resistance, or ISR, brings the conversation back to soil health.

The longevity of a farm is closely connected to the health of its soil.

Carbon plays a major role because it supports biological life within the soil. Bacteria, fungi, and other organisms interact with plant roots and influence how the plant grows, accesses nutrients, and prepares for stress.

This is why soil health cannot be reduced to one product or one application.

It is a system.

Keeping living plants in the field longer can support biological activity. Cover crops may fit some operations. Better water management can improve soil conditions.