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2005 Spartan Supply in Doubt

Monday, November 15, 2004
filed under: Weeds

Many agricultural retailers and crop producers were surprised this fall with an announcement by FMC Corporation of a glitch in the production of Spartan„µ herbicide 75DF (active ingredient, sulfentrazone).

In an October 1 memo to ag retailers, the Philadelphia-based company that markets Spartan blamed the shortfall of the dry flowable product on ¡§manufacturing constraints and increased demand in other parts of the world.¡¨

¡§We are currently in a sold-out position with Spartan 75DF and have low inventory levels at all FMC distributors,¡¨ said FMC, in the announcement. ¡§While we expect our supply position to improve for the 2006 season, it will not occur in time for the 2005 season. We will be able to offer a limited amount of Spartan 4F (the company¡¦s liquid formulation) for the 2005 season to meet some of the grower demand. However, FMC will not be accepting orders for Spartan 4F until after January 10, 2005. Please also note the price of Spartan 4F is approximately 50% higher than the price of Spartan 75DF on a per acre basis.¡¨

The shortfall affects the availability of sulfentrazone sold under different trade names as well. FMC owns the rights to the chemistry, and licenses it to two other chemical companies that market sulfentrazone under different trade names (Authority, marketed by DuPont, and Blanket, marketed by Tenkoz) for broadleaf weed control in soybeans and other broadleaf crops. Sulfentrazone for all three products (Spartan, Authority, Blanket) is made at the same manufacturing plant in Baltimore. Thus, problems with making the product there affect supply of all three sulfentrazone products.

With few options for controlling kochia and other small-seeded broadleaf weeds in sunflower, and no Roundup-Ready technology, the announcement of a sulfentrazone shortfall came as a shock to the sunflower industry. No-till sunflower producers in particular will be affected. Producers of field peas, also rely heavily on Spartan for broadleaf weed control, and the product is used for weed control in flax, chick peas (garbanzo beans) and dry edible beans as well.

The National Sunflower Association, which played a key role in EPA¡¦s regulatory approval of Spartan, minced no words in expressing the industry¡¦s dismay about losing such a key crop input.

¡§It is inconceivable to me that manufacturing cannot be geared up to supply an existing market. All of the research, marketing and labeling costs have already been absorbed. You literally just need to produce and distribute the product,¡¨ said Larry Kleingartner, executive director of the NSA, in a letter to FMC concerning the product shortfall.

The NSA was fervently communicating with FMC, other chemical companies, and others in the ag industry following the FMC announcement, trying to find ways that might help alleviate the effects of a sulfentrazone shortage in 2005. At the very least, the NSA wants to ensure that supplies of the more affordable dry flowable formulation of sulfentrazone will be back up to speed by 2006, and that measures are put in place to avert a crunch in product availability in the future.

Some speculate that FMC aims to phase out the dry flowable formulation of sulfentrazone in favor of a more profitable product; perhaps the company¡¦s liquid formulation. Bob West, the company¡¦s west region business manager, says that¡¦s not the case. ¡§It¡¦s not a marketing ploy. It has nothing to do with pricing. It¡¦s an inventory situation.¡¨ Similar, perhaps, to the unexpected supply snafu of a major vaccine-producing laboratory in Great Britain, which leaves the U.S. with only about half the supply of flu vaccine it expected this winter. Supply simply will not be enough to meet demand.

West explains that an inventory run thin by commitments of sulfentrazone to other markets, combined with unexpected production constraints at the Baltimore plant that makes the chemical, led to the product shortage. ¡§The best we can do now is take action to manage the crisis.¡¨ To that end, he says FMC is working with distributors to determine how much sulfentrazone is available in supply warehouse and retailer channels, and where it¡¦s at. As much as possible, FMC will also funnel as much of the liquid formulation (used more in the tobacco market) to have available in the sunflower market.

He says FMC will also establish a better handle of year-to-year product usage volume. ¡§It¡¦s our intention to be back into production (of sulfentrazone) for 2006,¡¨ says West.

Producer options

It¡¦s always recommended to plant sunflower on clean fields that don¡¦t have problem weeds such as kochia in their recent history, and this will be even more important if Spartan isn¡¦t available as a preplant option. Weed control in the previous crop becomes a greater consideration ¡V it might make sense to plant sunflower on the previous year¡¦s Roundup-Ready corn or soybean ground.

Remember that beginning with this crop season in all sunflower-producing states, sunflower can be grown on fields planted to soybeans (or peas or lentils) the previous year, without affecting federal crop insurance coverage. In the absence of weather conditions favorable for disease, there is no risk in sunflower yield or quality planted on the previous year¡¦s soybean ground, says NDSU extension agronomist Duane Berglund. In fact, he says there may be an agronomic benefit with less weed pressure, and the sunflower crop would also take advantage of a 40-lb/ac nitrogen credit following soybeans, peas, or lentils.

A number of broadleaf herbicides labeled for wheat and corn have excellent activity on kochia and other weeds that are problematic in sunflower. But keep herbicide carryover in mind, as some broadleaf weed control products have residual activity that may not allow sunflower as a subsequent crop.

To help plan your crop rotations for next year, see the North Dakota State University Extension Service 2004 Weed Control Guide online at In the index on the left-hand side, click on the link ¡§Herbicide Carryover,¡¨ scrolling down for a table that lists a number of herbicides and crop rotation intervals. At the same web site, click on ¡§Weed Control Ratings¡¨ for herbicide efficacy ratings.

Those ratings point out that among soil-applied herbicides labeled for use on sunflower, only Spartan is rated as providing excellent kochia control. Others are rated fair to good. NDSU rates glyphosate fair to excellent on kochia, and gives a qualified excellent rating to the efficacy of Beyond in controlling kochia, as the ¡§IMI¡¨ chemistry (imazamox is the active ingredient of Beyond, labeled for use only on Clearfield sunflower) may not give complete control of ALS-resistant kochia.

IMI products are ALS inhibitors. This herbicide group kills weeds by preventing the plants from producing essential amino acids needed for growth and development. Some weed types have survived and developed tolerance to this mode of action, becoming ALS-resistant.

Sonalan and Trifluralin provide a measure of kochia control, but need to be incorporated. Doing that correctly, and getting moisture for chemical activation, can be half the battle, says Agriliance agronomist Jason Hanson. He points out that working the soil too deep or too shallow, or with the wrong tillage equipment, can result in less-than optimal weed control with soil-incorporated herbicides.

He recommends the use of granular products in the fall (for timely early spring activation) and liquid products in the spring. That makes Spartan 4F an option next spring. Since the liquid product can be tank-mixed with other soil-applied preplant herbicides labeled for sunflower, Hanson predicts producers will try stretching Spartan 4F by tank mixing it with another soil-applied product. The shortfall in the sunflower crop itself, setting up healthy prices to bid for sunflower acres next spring, would also help producers offset the higher cost of the liquid product.

Leon Wrage, South Dakota State University extension weed specialist, says that some producers apply half the rate of the dry flowable Spartan 75DF in the fall (about 2 oz) and the other half in the spring. This may not be advisable given a product shortfall. ¡§Growers should plan a complete program that will cover the acres for which there is product, rather than chancing a half rate alone,¡¨ he says.

Reduced rates may be considered in fields where kochia infestations are expected to be light, or if used with other herbicide programs.

Kochia is an early weed that competes well with sunflower if it¡¦s not controlled ¡V that¡¦s why the weed can give sunflower producers fits. Consider an early burndown prior to planting, and again at planting if needed, followed by a post treatment under no-till, or a burndown and preplant/pre-emerge treatments followed by the post-emerge herbicide. That¡¦s an extra trip around the field, but it may give the best opportunity for success in weedy fields, especially where Spartan is short.

Where tillage or incorporation is an option, Wrage suggests an early glyphosate burndown prior to planting followed by a preplant incorporated product such as Sonalan.

Using a burndown and planting sunflower a bit later to allow the crop to escape the early kochia flush may help. That doesn¡¦t always work, however. Take this year: the cool conditions resulted in slower kochia emergence that extended the weed¡¦s development.

Not only are other soil-applied herbicides labeled for use on sunflower less effective against kochia than Spartan, but most also need to be incorporated into the soil ¡Vnot worth the tradeoff in soil moisture, yield potential, and the extra trip around the field for no-till producers.

If Spartan isn¡¦t available, Wrage suggests no-till producers might want to consider the burndown coupled with Clearfield sunflower. Where kochia has a history, consider using a split glyphosate application early and again at planting, followed by Beyond post-emerge.

Or in the case of conventional till, a glyphosate burndown followed by a soil-applied herbicide, then Beyond on Clearfield sunflower to catch weed flushes that escaped the soil-applied herbicide. Beyond, which can only be used on Clearfield hybrids, is recommended to be applied to sunflower in the 2 to 8 leaf stage, when broadleaf weeds are less than 3¡¨ tall, and when grassy weeds have less than 4 to 5 leaves.

No-till producers might also want to consider Prowl H20, tankmixed with reduced rates of either formulation of Spartan, or Prowl H20 by itself.

Certainly, Prowl H20 doesn¡¦t provide the same level of control against kochia as Spartan. However, this formulation of the BASF soil-applied herbicide, new in 2004, results in less odor, staining, and volatility compared to the conventional formulation. It has essentially the same weed control spectrum as Prowl, but observations indicate that it may be a bit more effective in high-residue situations, such as no-till, because it doesn't bind as readily to stalks and other debris.

Observations also indicate efficacy on kochia with Prowl plus reduced rates (1-2 oz/ac) of Spartan 75DF, with residual activity on a number of grasses and broadleaf weeds. This tankmixing approach, as indicated earlier, could stretch the limited Spartan 75DF supplies a bit further, or at least reduce the cost relative to a Spartan liquid treatment.

Sunflower producers in the High Plains have the advantage of a longer planting window, allowing them to plant earlier or later to help avoid certain weed pressures, and to help with timing to gauge and take advantage of spring rains. Before Spartan, some no-till sunflower producers used hooded sprayers to control weeds between the rows, says Ron Meyer, Colorado State University agronomist. If Spartan is unavailable, some producers may use hooded sprayers again.

Meyer says some sunflower producers might also bump up their planting rate, or go to solid seeding, to thicken the plant canopy and give the crop a better chance to out-compete weeds. If solid seeding is chose, Meyer suggests planting earlier or later than normal as a weed control strategy.

Conversely, unavailability of Spartan may prompt other growers to switch from solid seeding to rows. Byron Richard, a Belfield, N.D. grower and a seed and chemical supplier, explains that more growers are looking at dual purpose hybrids that can be sold into the hulling or crushing markets. A row-planted crop has better uniformity and seed size, and better marketability. Planting in rows also leaves the door open for cultivation or a between-the-row application of glyphosate with a hooded sprayer.

Richard points out that years before the arrival of Spartan, there were many more sunflower acres around than there are now. Many of these same growers dealt with the challenges of weed control in sunflower then, and will now, with the added benefit of more sophisticated options for weed control and residue management with minimal soil disturbance. The profit potential of sunflower also means growers will consider producing the crop, regardless of Spartan¡¦s supply situation.

Growers should consult with their local farm input suppliers and agronomists for more details on the availability of Spartan, and recommended alternative weed control options. ¡V Tracy Sayler

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