Wheat top-dressing by drone and Fusarium control

Urea top-dressing of wheat by drone

The best time to apply urea is the first half of February, and 20 February at the latest. The reason is simple: urea takes 20 to 30 days to turn into a form of nitrogen wheat can take up, so a later application cuts yield directly (PSS Zrenjanin, Agrosava). After 20 February, agricultural advisory services usually recommend switching to CAN or AN, where half the nitrogen is available to the wheat straight away. We spread both by drone.

This critical window often falls when the ground is soaked from snow and rain, and heavy spreaders leave deep ruts in the mud. Because the drone flies above the field, mud does not push top-dressing back into March.

For spreading we use the DJI Agras T70P fitted with a separate system that replaces the sprayer: a 100-litre hopper carries up to 70 kg of fertiliser per flight, for granules of 0.5 to 10 mm. The spreading width is 3 to 10 metres, depending on the fertiliser, disc speed and flight height (manufacturer's data). At 100 kg of urea per hectare, one flight covers 0.7 ha, so spreading takes more short flights than spraying.

You set the exact rate (kg/ha) with your agronomist, ideally from a soil test for mineral nitrogen (the Nmin method). Measurements by PSS Zrenjanin show large differences between fields (from 23 to 235 kg N/ha), so working without a test is guesswork. Our drone spreads exactly the amount you set.

Urea spreading by drone costs €40 per hectare, whatever the area. Just tell us how many kilograms per hectare you plan to apply. More on timing and splitting nitrogen: Urea top-dressing of wheat: when and how much.

Second top-dressing and foliar feeding

The corrective (second) top-dressing usually goes on 3 to 4 weeks after the first, and no later than the start of stem elongation. This is a key moment, because yield potential is being set and the nitrogen has to be available to the plant straight away (Agrosava). We spread granular fertiliser for the second top-dressing the same way as urea.

For foliar feeding we apply 15 to 20 litres of water per hectare, at the standard spraying price. Details and timing for the second top-dressing and foliar treatments: Second top-dressing of wheat and foliar feeding.

Fusarium control in wheat at flowering

Fusarium head blight has to be stopped with a fungicide right at the start of flowering (when only about 5% of ears show anthers), and always before forecast rain. Several days of rain at flowering carry a high risk of infection, and on infected grain the fungus produces mycotoxins that are very dangerous to people and livestock (Forecasting and Warning Service, via AgroSmart). This window lasts only a few days, so we time the treatment day carefully with the agronomist, following the weather forecast.

The flowering fungicide is also the most important wheat treatment we do by drone. When it rains in those days, tractor operators are stuck: they have to wait 2 to 5 days for the ground to dry and the window is lost. We only need the access road to dry, and if there is a tarmac approach, we work the same day the rain stops. On grouped fields we cover 20 ha an hour, using 15 to 20 litres of water per hectare.

In dense wheat without tramlines, a tractor permanently destroys 5 to 6% of the crop.

Before flowering, wheat is attacked by leaf diseases (powdery mildew, Septoria, rusts). Fungicide protection starts from stem elongation, either preventively or at the first symptoms (Agrosava). If cereal leaf beetle appears in the crop, we also apply an insecticide to protect the yield (after notifying local beekeepers).

Your agronomist chooses the product and rate from the label, and Nikola mixes it precisely in our tank at the field. More on diseases: Wheat diseases: when to spray against Fusarium head blight.

Weed control in wheat

We apply herbicide to wheat by drone as part of the first spring spray (tillering to the start of stem elongation), often together with a fungicide (Agrosava), on the strict condition that there are no herbicide-sensitive crops right next to the field. If a sensitive crop is across the boundary, we leave the job to the tractor, because its nozzles run closer to the ground and drift less. The tractor is also always the better choice for early herbicides aimed at small weeds just after emergence.

Wheat treatment calendar

These timings are standard practice, but the exact day always depends on the weather and the agronomist's advice.

For a side-by-side comparison of drone and tractor output and capabilities, see drone or tractor.

How much wheat top-dressing by drone costs

Every drone spraying treatment on wheat (including foliar feeding) costs €25/ha up to 20 ha, €22/ha from 20 to 100 ha and €20/ha over 100 ha. Urea spreading is a flat €40 per hectare. Travel within 50 km of Opovo is free. You supply the product and the water.

Worked example: 50 ha of wheat near Crepaja (26 km from Opovo), a new client's first order, flowering fungicide. 50 ha × €22 = €1,100, minus €22 for the free first hectare = €1,078 in total. Travel is free. Jobs of 50 ha or more need a 30% advance (€323.40 in this case), and the rest is paid when the job is done.

If you agree a package of three treatments on the same field in a season (for example herbicide and fungicide in spring, foliar feeding and the flowering fungicide), you get 5% off; a package of five or more treatments gets 10% off. You pay after each treatment, and clients with a package get priority when booking. Full prices are in the price list.