Crop Watch: Heat reveals limitations of spring cropping

Our agronomists are largely upbeat about the recent heat, with Sean Sparling saying the risk of botrytis will be lower in peas and beans.

Grass growers in the North have been busy making hay while the sun shines, and Andy Goulding recommends a timely application of fertiliser and herbicide to help and protect regrowth.

Stephen Harrison says crops of winter barley in the west could be ready for the combine by mid-July, and there will be no serious crop lodging to contend with.

See also: New feed wheat variety offers SDHI fungicide savings

However, Iain Richards says that the previous dry spell back in the spring is showing the limitations of spring cropping, with rain coming too late for many spring barley crops.

Sean Sparling

Sean Sparling

East: Sean Sparling

AICC/SAS Agronomy (Lincolnshire)

Winter wheat T3 has now been complete for around 10 days and no further fungicides will be applied to any of my crops.

I should get a comfortable three-and-a-half to four weeks’ foliar disease protection out of that by which time these crops will be starting to think about senescing because grain fill will be largely complete.

It’s worth remembering the growth stage cut-off timings for many of our fungicides – once you get into grain fill that’s your lot, so don’t be tempted to waste your money by putting T4 and T5s on.

Spring wheat and spring barley have now received their flag leaf fungicides, and both weed and disease control have been very good, although Propino appeared to struggle far more than other spring barley varieties in the drought.

Peas and beans have received their first flowering fungicide and insecticide and will be receiving their second fungicide over the next 10 days if conditions dictate.

If it stays hot and dry the risk of botrytis will be minimal but close attention will be paid to the bug and disease situation because once we have missed the timing that’s that if we didn’t act.

Sugar beet surging

Sugar beet looks phenomenal in the main, although on some of the lighter fields which were hit hard by the drought crops look pretty moth-eaten because of growth stage differences, but there are no sign of black aphids or Silver Y moth causing any problems yet.

Linseed struggled more than other crops on the lighter fields, and wash through of nitrogen after four inches of rain when the linseed was barely two inches tall created issues with widespread nitrogen deficiency, as well as highlighting the problems with compaction and soil structure issues in many cases.

Regrowth of broadleaved weeds is also an issue in some fields but, hopefully, we will get away with it.

South: Iain Richards

Iain Richards

Iain Richards

Agrii (Oxfordshire)

The driest April for many years has reminded us all of the risks involved in spring cropping – especially on thin ground and where too much soil is moved ahead of drilling. Despite going into good seed-beds with sufficient moisture, the rain came too late for many earlier-drilled spring barleys.  

April-sown crops on heavier ground are faring much better, though, having taken off rapidly in early May and tillered well. While the barleys were clean early on, the bone dry first half of April got in the way of pre-em activity – letting the flush of May-germinating blackgrass off the hook.

Without this support the thin early-sown crops, in particular, have really suffered. Blackgrass populations are also surprisingly high in spring peas and beans although they too have fared better through later drilling.

Winter cropping stamps out blackgrass

In complete contrast, blackgrass control in the vast majority of our winter wheats has been good – except for a few fields drilled in the first half of October.

The difference between these and all those sown late in the month after really good stale seed-bed control is outstanding.

Like winter rape and barley, our wheats came through the spring in good shape, enjoyed minimal stress at flowering and are now accessing plenty of moisture and nitrogen, leaving us cautiously optimistic for the harvest.

We stuck firmly to wheat growth stage timings for our T3’s even though they were barely two weeks after T2’s in many cases, using prothioconazole/tebuconazole combinations for the best fusarium protection.

And thank heavens we did, as 40mm or more of rain during flowering really heightened the risk here. Robust early treatment, the dry spring and almost no stretched intervals means we’ve kept well on top of foliar diseases.

So we haven’t needed highly curative activity and have been able to make good use of multi-site protectants.

This gives us valuable leeway within budgets for a T4 to deal with any late septoria or brown rust if needed.

Stephen Harrison

Stephen Harrison

West: Stephen Harrison

AICC/Southwest Agronomy (Avon)

We are rapidly reaching the stage where, apart from pre-harvest treatment, the sprayer is being given a rest.

Aphids have failed to reach thresholds. Crops look in good order with only sporadic areas of blackgrass, brome and ryegrass spoiling the picture. 

It is now very rare to find any fields with no blackgrass whatsoever. Flying in the face of reports of total contact material failure, we have had better results this spring with Atlantis (mesosulfuron+iodosulfuron) and the like. 

Disease levels are low with even yellow rust on susceptible varieties being well contained.

Winter barley on light land looks like it could be fit for the combine by mid-July. It remains to be seen how much effect the dry April will have on yield.

I am still reeling from the announcement that pesticides will be disallowed on pulse crops for greening. Many clients are saying that their response will be fallow. 

Pea and bean crops I have looked at over the last few weeks have been alive with bees and hover flies while swallows and martins have been hunting in the skies above. In contrast, fallow areas seem barren; yet another example of policy ignoring science.

Oilseed rape is on the turn and pod sealants are currently being applied. As usual I haven’t a clue how the crop will perform. Sparrows and finches are taking seed on the headlands.

A little winter barley has lodged on overlaps during the wind and rain in early June – nothing that will cause serious headaches.

We are currently digesting the new Fertiliser Manual and considering how this will affect our plans for the next growing season.  Following early announcement of nitrogen pricing, much of next season’s requirement has been booked.

Andy Goulding

Andy Goulding

North: Andy Goulding

CAS/Hutchinsons (Cheshire)

The sun has been shining so we have been making plenty of hay over in the shire. The next task is to ensure sulphur-containing fertiliser is used for good nitrogen utilisation, and to keep protein levels of forage up.

The regrowth could bring some weed issues back to the fore, so this is a good time for herbicide use as the regrowth will be less waxed and should be at a healthy consistent growth stage.

Timing needs to be quick as maximum translocation to roots will occur before stem extension of the weeds.

Get blight control right

Blight pressure of varying degree has been somewhat of a constant according to the forecasts I have received, with full Hutton criteria being met on several occasions.

Seven-day schedules will remain throughout the rapid canopy stage where vulnerable new growth will need constantly protecting with the systemic active propamocarb, and those which will move in the wax of the leaf such as cyazofamid and mandipropamid.

Foliar nutrition of the crop should be maintained – especially magnesium. However, don’t be fooled into thinking that more grams of a given element applied will always mean more will be utilised.

Tissue analysis is good way of capturing plant status at any given time and can help identify any potential deficiencies.

I am reluctant to spray insecticides for aphid control (especially non-selective chemistry), but thankfully most crops have not reached threshold before the threat has passed.

Where crops are due treatment, I am using feeding blockers when possible as the preferred mode of action.

Maize weed control is drawing to an end, but where still due it is useful to combine products with a crop-safening effect.

Some crops are purpling with the dry soils and low solubility of phosphorus, making it harder to access this vital nutrient and would justify foliar intervention.

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