WHAT ARE PRE-EMERGENCE HERBICIDES?

A pr-eemergence herbicide is an herbicide that is designed to control weeds by interfering with seedling germination and emergence. Conversely, post-emergence herbicides will control established weeds that have already germinated and emerged.

HOW DO THEY WORK?

Different pre-emergence herbicides may have different sites of action or manners in which they work. These products inhibit cell division, resulting in seedlings that are stunted, deformed, and unable to emerge as healthy plants.

WHAT ARE THE POTENTIAL BENEFITS OF USING A PRE-EMERGENCE HERBICIDE?

These herbicides provide protection during critical seasons when turfgrass may be less able to compete with weeds (spring and fall).

Pre-emergence herbicides are generally the most effective chemical option for controlling challenging annual weeds like crabgrass (Digitaria spp.) and annual bluegrass

(Poa annua L.).

WHAT OTHER FACTORS SHOULD I CONSIDER BEFORE PURCHASING AND USING AND PRE-EMERGENCE HERBICIDE?

Pre-emergence herbicides can injure newly established or over seeded turfgrass lawns. Follow label recommendations and consult your AgriLife County Extension Agent when in doubt.

Weed and feed products used for other purposes in the landscape may already contain pre-emergence herbicides.

Application of separate pre-emergence herbicides in addition to these products may lead to over-application that can be harmful to your lawn.

Avoid using and feed products.

WHEN DO I APPLY MY PRE-EMERGENCE HERBICIDE?

For best results, we recommend that you make two pre-emergence herbicide applications each year: one in the spring to target summer annual weeds and one in the fall to target winter annual weeds. Pre-emergence herbicides will often be the most effective when applied based on soil temperature, because soil temperatures play a critical role in weed seed germination. Per the recommendations above, apply your spring pre-emergence herbicide when soil temperatures reach approximately 55°F for several days.

MONITORING SOIL TEMPERATURE

You can monitor soil temperature yourself using a soil thermometer or even a household meat thermometer. Measure the soil temperature for the uppermost 1" of soil, where most weed seeds will be concentrated.

Check out aggieturf.tamu.edu/turfgrass-weeds/ for assistance with weed identification.

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TIRE TERMS HAVE CHANGED

Whether you are involved in agriculture or simply have a utility tractor they all have tires that will eventually need to be replaced. Tire terms have changed, bias, radial, VF, IF, and CFO. So which one do you buy? The following information is from ag industry experts who represent Goodyear and Firestone ag tires.

You’re ready to buy new tractor tires. Your dealer talks about bias versus radial tires, VF, IF and CFO.

Here is a “dictionary” of tire terms, followed by some explanation from these experts:

Bias ply: This is older tire technology.

Harris: This tire construction features body plies that are placed on a diagonal to the bead. Bias tires have limited sidewall deflection and are stiffer than a radial tire.

Sloan: The design gives it extra stiffness and penetration resistance, but also means a rougher ride and generally a shorter life span than radials. However, they’re typically less expensive than radials.

Radial tires: This technology has been available for ag tires for over a decade.

Harris: This tire construction features body plies that are perpendicular to the bead, and belts in the tread area that are placed on a diagonal.

Sloan: This construction is generally more durable and longer lasting than bias tires, but also more expensive.

Ply rating: This was the standard system for decades.

Harris: This is an old system of classifying bias tires based on the number of body plies based on the strength of the cotton fabric used as body plies.

Load index: This is an important measure of the load a tire can carry today.

Harris: It’s a number that indicates the rated load of a tire. This value has replaced the ply rating because it provides the load of the tire in pounds and kilograms.

IF tire: The letters stand for increased flexion.

Harris: An IF tire is a radial agriculture tire that is designed to carry 20% more load, will have more sidewall deflection and a larger footprint compared to a standard radial at the same inflation pressure. The larger footprint allows for more traction.

Sloan:  IF technology is only effective if inflation pressure is adequately maintained by application and weight.

VF tire: The letters stand for very high flexion.

Harris: A VF tire is a radial agriculture tire that is designed to carry 40% more load. It will have more sidewall deflection and a larger footprint compared to a standard radial at the same inflation pressure. The larger footprint allows for more traction.

Sloan:  Just like IF tires, VF technology is only effective if inflation pressure is adequately maintained by application and weight.

CFO designation: CFO stands for cyclic field operation. Expect to find this on combine or grain cart tires.

Sloan: CFO tires can handle loads 55% heavier than IF load ratings when traveling less than 10 miles per hour in a cyclic application. Additionally, CFO gets a 30% load bonus from IF load for cycling applications under 20 mph.

Advanced Deflection Design technology: This is also known as AD2 technology, and it’s from Firestone.

Harris: This design lets producers carry the same load, or as much as 20% on IF tires or 40% on VF tires more load, as a standard radial tire, but at a lower tire pressure, offering a smoother ride.

LSW: The letters stand for Low Sidewall Technology. It’s exclusive to Goodyear.

Sloan: LSW tires feature a larger rim diameter than standard tires, while maintaining the same outside diameter of tire. LSW tires meet all the same load and inflation capabilities as VF and CFO tires, meaning they can also help reduce soil compaction.