Roundup pre-harvest treatment

Roundup pre-harvest treatment

Roundup pre-harvest treatment

Achieve the most reliable OSR harvest results


When it comes to OSR hybrid traits, DEKALB’s genetic tolerance to pod shatter can dramatically reduce seed losses during harvest and help to protect yields. When it is about facilitating harvest management and controlling weed burdens within and beneath the canopy, Roundup treatment before OSR harvest is highly effective.


The combination of the two - DEKALB’s strong OSR hybrids and the pre-harvest treatment with Roundup - offers a great opportunity to improve the timeliness and efficiency of OSR harvesting, controlling a range of late season problem weeds and capturing full OSR output value. Learn more about the main benefits of Roundup treatment before OSR harvest, use recommendations and DEKALB’s hybrids for successful harvest results.

Benefit 1: Saves time, money and CO2 emissions

Unless the weather is ideal for rapid, even ripening, effective harvest management with Roundup products invariably allows earlier and more efficient combining than natural drying as well as giving good control over what can be very substantial weed burdens within and beneath the canopy. Studies by Claas (2014) showed significant savings in time, money and carbon emissions when harvesting Roundup treated crops (Table 1).


Untreated crop

Roundup treated crop

Combining speed

4 km/hour

6 km/hour, 50% faster


3.6 ha/hour

5.4 ha/hour, 50% more hectares per hour

Fuel consumption

16 liters/ha

12,5 liters/ha, 20% less fuel used and CO2

Labour requirement for the driver)

16,5 min./ha

11min./ha, 33% less labor costs

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Source: Claas UK, Lexion 580 with 9m cutter bar; 2014.

Benefit 2: Optimal harvest management

The OSR treatment with Roundup before harvest is particularly valuable in reliably drying down today’s most productive thick-stemmed, well-branched rape crops that have profited from stay-green agronomy. These thick-stems are a lot more demanding to desiccate than those of the past due to their much higher stem volume to surface area; especially where they have profited from effective chemistry at flowering or late nitrogen for pod fill. The pre-harvest management with Roundup also contributes to reduce OSR seed moisture and increase yield potential.

Systemic drying effect of Roundup pre-harvest treatment in OSR

Figure 1. Untreated, with green stem and leaves.

Figure 2. Homogenous impact of Roundup on the whole plant, crop ready for harvest. The light green color confirms the gentle effect

Figure 3. The pods are evenly desiccated ready for harvest

Source: Roundup 720, at 1,5 kg/ha). Source: Monsanto Trials. Kolare, Slovakia, 2011.

Benefit 3: Effective weed control in OSR

Pre-harvest is also an ideal opportunity for the control of problematic grass and broad-leaved weeds, especially troublesome perennials. Long-term control of perennial weeds is optimised at this timing. Roundup products deliver at least 90% 1 year after treatment of a wide range of perennial weeds including perennial grasses (such as common couch (Elymus repens), bent grasses (Agrostis spp.), Yorkshire Fog (Holcus lanatus) and Onion Couch(Arrhenatherum elatius var. bulbosum) and perennial broad-leaved weeds (including docks (Rumex spp.), thistles (Cirsium spp.), perennial sowthistle (Sonchus arvensis), Field Bindweed (Convolvulus arvensis) and volunteer potatoes) (Source: Monsanto trials: 1980-2002). Weed desiccation also results in less green material- being harvested and so easier harvesting and lower grain moisture content.


Roundup OSR pre-harvest spraying timing

Select several areas of the field representative of the crop. In each area pick 20 pods from the part of the canopy carrying the bulk of the yield.

If at least two thirds of the seeds have changed from green to brown in at least 15 pods the earliest stage for spraying has been reached.

Only start combining once stems as well as pods are fully fit which may be up to 3 weeks after spraying under some conditions. Remember, the statutory 14-day minimum interval between glyphosate treatment and combining must be observed.


DEKALB recommends:




DK EXSTAR combines high yields and oil content with the best agronomy package ever seen in a mainstream OSR variety.




DK IMPERIAL CL is the most widely grown Clearfield variety in the UK with a leading combination of yield protecting traits.




DK IMPRESSARIO CL is a new Clearfield variety for 2017 combining high yield potential with solid combined disease resistance and pod shatter resistance.

Use pesticides safely. Always read the label and product information before use. Roundup® is a trademark of Bayer Group.