What is a Class K herbicide?

The grasses determine the herbicide strategy

The choice of remedies against grasses is limited, especially in the case of resistance. So it is not only important to have a good effect, but also to preserve active ingredients. This is only possible with a change of active ingredient class.

Herbicidal measures in spring can be tailored to the respective situation. However, there is only scope for planning for the weeds. In the case of grasses, resistances are increasingly in the foreground. So far, this topic seemed to apply only to certain regions with problems with the black foxtail.

Resistance increases

In the last two years, however, it has been shown at Windhalm locations that resistance can establish itself and take effect very quickly. In addition to the reduced effectiveness of IPU / CTU, which is particularly known in the western federal states, the reduced effectiveness of sulfonylureas is now coming to the fore. Resistant windstalk plants were even detected for the usual quantities of 0.3 kg / ha Atlantis WG or 0.1 kg / ha Attribute. In the spring, only Axial 50 can achieve a sufficient effect on such surfaces.

In order to maintain the effectiveness of the grass products for as long as possible, in addition to plant cultivation measures, changing herbicides with different mechanisms of action (identified by the letters A, K 1 etc.) is important. This applies in particular to classes A, B and C 2 at risk of resistance. The classification of the active ingredients in the various herbicides can also be found in the overview (pages 88 to 91).

In spring, only active ingredients from the three classes at risk of resistance are available for combating grasses in cereals.

Few remedies in barley

In barley, there are few remedies to choose from against black foxtail. With Axial 50 (1.2 l / ha) and Ralon Super (1.0 l / ha + Monfast 0.4 l / ha), the two most effective herbicides also belong to the same class of active ingredients. While Axial 50 can also be used as early as possible in cooler temperatures, Ralon Super achieves higher levels of efficiency with increasing weather conditions.

In general, the following applies: Higher air humidity and a less developed wax layer support the effect. The smaller the grass weeds, the better the control successes are usually. Depending on the existing weeds, the two grass herbicides can be combined with Primus, Starane XL, Hoestar Super or Biathlon. If speedwell or field pansies are to be combated, the mixture of Foxtril Super with Primus should be used, which can only be added to the grass treatment every eight to ten days due to its compatibility.

Ariane C (1.0 to 1.5 l / ha) can also be used as a broadly effective replenishment if speedwell and pansy are not a problem. The advantage of the product lies in the long application window up to the flag leaf stage, so that thistles can also be combated.

Axial 50 (0.9 l / ha) plus mixed partners, if necessary, can be recommended against wind stalks in winter barley. IPU-containing herbicides are an interesting option in terms of price, provided that sufficient degrees of effectiveness can still be achieved. With Isofox, an IPU-containing herbicide without a drainage layer has been available in spring since this year. A mixture of Isofox (3.0 l per ha) with Duplosan KV (1.0 l / ha) and Primus (0.05 l / ha) is then recommended.

More active ingredients in wheat

With the group of sulfonylureas (active ingredient class B), the range of herbicides against grasses is expanded in wheat. This also makes it possible to change the class of active ingredients in post-treatments, especially against black oxtail, if there were autumn presentations with active ingredients of class A (e.g. Axial 50). Of course, this is only possible if all groups of active ingredients are still effective.

Follow-up treatments against the black foxtail should be carried out solo if possible, in order to be able to exploit the full grass effect. Atlantis WG is the strongest product for this. In problematic locations, it is usually the only herbicide that is still effective. For successful control, the application rate must be adjusted to the level of resistance (300 - 500 g / ha + FHS).

To optimize the effect, the applications should be carried out at higher air humidity (over 60%) and the onset of vigorous weather. The addition of 30 liters of AHL should be mandatory. Alternatively, 10 kg / ha of SSA can be added. If a sulphonylurea was presented in autumn, the use of Topik 100 plus Oel (0.6 + 1.0 l / ha) is recommended on sites without FOP resistance. Otherwise only AtlantisWG remains according to the described model.

The weeds should then only be combated after about ten days. For post-treatment of burdock, chamomile and rape seed, Primus (0.075 l / ha) or Hoestar Super (0.100 - 0.150 kg / ha) or Starane XL (0.5 - 1.0 l / ha) or Tomigan (only burdock = 0.3 - 0.5 l / ha) can be used at higher temperatures. Mixtures with CCC or - if used later in BBCH 31 - with fungicides and growth regulators are possible. If the autumn measures against wind stalk (with a herbicide of class B, e.g. falcon) have not had an adequate effect, there is a suspicion of resistance to this class. In this case, it is essential to post-treat with a class A product (e.g. Axial 50).

In most cases, no follow-up treatments are necessary for autumn treatments with herbicides containing Flufenacet against wind stalks. Weeds such as B. Burdock can, as described above, be treated in combination with other measures.

If there was no treatment in the fall

Atlantis WG + Genapol (0.3-0.4 kg / ha + 0.6-0.8 l / ha) is also suitable for the initial treatment of the foxtail in winter wheat. If the sulfonylureas are weak to medium-sized and are still fully effective, the early use of Attribute (80 to 100 g / ha), especially in combination with AHL, is also conceivable. The FOPs Axial 50, Topik 100 and Ralon Super can also be used with low to medium weed populations. To close the gaps against weeds, combinations with Biathlon, Starane XL or Primus are possible, depending on the weeds.

If the weather is favorable, you can combine Atlantis WG and Attribute with Artus and Foxtril Super + Primus to additionally safeguard against pansies or speedwell (with Atlantis, however, without the AHL addition).

Broadway (active ingredient class B) with 220 g / ha + FHS 1.0 l / ha offers the broadest spectrum against weeds as a "complete solution" for weak to medium foxtail pressure. In combination with 10 g / ha Gropper SX, the effect against pansies is secured. Alister and Caliban Duo as well as the new Atlantis Complete Pack (Atlantis OD + Husar OD) are also available with a limited coverage (all active ingredient class B).

Which grass herbicides can be used for the first application against wind stalks in wheat depends on the resistance situation on the respective areas. Where IPU is still effective, a mixture of 2 to 3 l per hectare of IPU / CTU and Foxtril Super (1.5 l / ha) plus Primus (0.05 l / ha) or the mixture with Isofox, Duplosan KV and Use Primus. Otherwise, mixtures of Axial 50 (0.7-0.9 l / ha) and Primus or Starane XL or biathlon have proven effective against burdock, chamomile, chickweed and rapeseed.

If speedwell and pansies appear, the aforementioned Foxtril Super + Primus should follow after about 10 days after the earlier Axial 50 presentation. If the weather is favorable, this supplement can also be applied as a tank mix with Atlantis WG (0.18-0.2 kg / ha + FHS) or Attribute (0.06 kg / ha). As an alternative, Artus (0.05 kg / ha) can also be added to the grass herbicides in order to achieve the necessary widespread effect. Here, however, the typical lightening is possible.

Broadway is also a complete solution against Windhalm. With the lower amount of 0.13 kg / ha + FHS, the effect against one or the other weed (e.g. speedwell) decreases. Husar OD can only be recommended for regions where the sensitivity of the wind stalk to sulfonylureas has been established.

Recommendations for rye and triticale

In winter rye and triticale, the combinations of Axial plus Partner mentioned in the Winter wheat section or the strategy of pre- and post-planting of the herbicides mentioned are available against wind stalks. Broadway (possibly plus Gropper) is also possible. The same goes for Husar OD.

We do not recommend Atlantis WG and Attribute in winter rye, as the tolerance is not always given. In triticale, however, you can use Atlantis WG up to 0.3 kg / ha against foxtail. Against the various weeds, the same partners as mentioned in the wheat section can be added.

Other grass herbicides are Axial 50 (1.2 l / ha), Topik 100 plus Oel (0.6 + 1.0 l / ha) or Ralon Super plus Monfast (1.2 + 0.4 l / ha) in triticale and rye for foxtail control possible. In combination with Primus (0.075 to 0.1 l / ha) or Biathlon (0.07 kg / ha) or Starane XL (0.8 to 1.0 l / ha), burdock, chamomile and chickweed can be adequately controlled. If pansies appear at the same time, 10 g Gropper SX should be added.

If the honorary award is more represented, the FOPs should again be used as a template and Primus (0.05 l / ha) plus Foxtril Super (1.5 l / ha) or plus Artus (0.04 to 0.05 kg per ha) as a supplement be applied.

Strategies for summer crops

Summer cereals are very competitive because of their rapid development. However, high application rates and late treatments can lead to severe yield losses. At the optimal date in the early tillering phase, the small weeds can be removed well and safely with reduced quantities in warm weather.

The control is mostly carried out with herbicide combinations of growth substance (Duplosan DP 1.0 l / ha) and the compatible sulfonylureas. Agents from this group such as Pointer SX 30 g / ha, Gropper SX 20 g / ha to Concert SX 60 - 80 g / ha or Husar OD Power Set 75 ml / ha + wetting agent are easily interchangeable. Combination products have proven their worth on locations with weeds that are difficult to control. These include: Amario, Ariane C, Biathlon, Loredo, Starane XL, Foxtril Super and others.

In the event of late emergence of climbing weeds such as knotweed and burdock after the end of tillering, Ariane C with 1.0 to 1.5 l / ha is recommended up to the flag leaf stage, if thistles also have to be controlled at the same time. Basagran DP 1.5 to 2 l / ha could even be used up to EC 49, but must not be applied to soil types that are described by an S for sand (NG 411).

Black foxtail, stalks of wind and wild oats can be removed most safely with the leaf herbicides Axial 50 (0.7-0.9 l per ha) and Ralon Super Power Plus (0.6-1.0 l / ha), with Axial 50 being good Compatibility is to be emphasized. Damage to spring barley is possible with Ralon Super. These preparations should be applied solo if possible. Combinations can quickly lead to strain on the culture.

If only wind stalk is to be combated, from the 3-leaf stage onwards, the Husar OD Power Set (75 ml / ha + 0.45 l / ha) or Concert SC (70 - 100 g / ha) can be used, provided the wind stalk is sensitive to it which is sulfonylureas. You can take action against wind stalks in oats with 70 - 100 g / ha Concert SX. Only 20 g / ha Lexus can be used against foxtail.