17 October 1998


Its the moment of truth in the Crops Challenge. Gilly Johnson finds out which team generated the best return from our wheat plots – and how.

Its the moment of truth in the Crops Challenge. Gilly Johnson finds out which team generated the best return from our wheat plots – and how.

THREE cheers for the AICC crop consultants. The combine has been through the Crops Challenge field and the final costs have been totted up. In three plots out of four, the best gross margins are from the consultants input recipes.

The Novartis team put up a valiant fight, but admit defeat. A look at the figures shows where they came adrift; their input spend was not targeted at the most rewarding plots.

Only in the third wheat slot did the Novartis strategy pay off. The company kicked off with a hefty dose of early nitrogen, which with hindsight was the right choice. Then an extra £40/ha (£16/acre) on fungicides – including the strobilurin Amistar – and a belt-and-braces growth promoter programme which added £20/ha (£8/acre) extra to costs, generated a massive 1t/ha additional yield. It also carried specific weights over 76kg/hl, which added a £2/t quality bonus to the market value.

Given the increasing squeeze on their farming clients, it isnt surprising that the consultants were more cautious about spending on inputs throughout the Challenge. Only in the plot in the first wheat after beans slot did the consultants manage to spend more than the Novartis team – and that was mainly down to problems keeping on top of blackgrass.

Autumn IPU didnt do as good a job as a December treatment with Hawk (clodinafop-propargyl and trifluralin), Novartis own product, which came through with flying colours. That meant a catching up job for the consultants in the spring – leaving a £20/ha (£8/acre) hole in the budget.

For this post beans plot, the initial challenge for both teams was to come up with a programme for under £200/ha (£81/acre). Neither team could keep within this target – though Novartis was nearer.

Lessons can be learnt from this experience. Both teams agree that "you need to spend money to earn money". AICC consultant Peter Taylor suggested that without this nominal lid on spending, yields could have been taken higher on this plot.

How you spend the money is also important. The post beans yields were widely different – the consultants extracted an extra 0.7t/ha (6cwt/acre) from their recipe. Lodging was less, despite more nitrogen fertiliser and a cheaper growth promoter programme.

However, the star performance came from the consultants programme on first wheat after set-aside. The yield expectations were highest from this plot for both teams, and so this is where the focus was on fungicide choice. There was the additional challenge of piecing together strob/triazole programmes.

The consultants Rolls-Royce strategy was based on two half-rate applications of Landmark (kresoxim-methyl with epoxiconazole) at T1 and T2, with half-rate Amistar (azoxystrobin) as an ear wash, while the Novartis team kept with Amistar, pulling in Alto (cyproconazole) as the T1 and T2 triazole partner, adding in Plover (difenoconazole) to pep up a final low-dose Amistar ear wash. Both sides used Unix (cyprodinil) to eliminate eyespot.

The Landmark programme came through with 0.4t/ha (3cwt/acre) higher yield, though both plots easily broke the 10t/ha (4t/acre) barrier. Was this down to a difference in performance between the two strobilurins? "Its possibly part of the answer," says AICC consultant Jamie Mackay.

"But there are other factors such as the inherent fertility following set-aside and the lack of take-all," adds colleague David Nicholls.

There was also a degree of lodging in the Novartis plot – a result of site variation, or was it due to higher nitrogen – at 221kg N/ha (179 units/acre)? The companys growth promoter strategy was uniform across the field, based on split Moddus with 5C Cycocel added to the second spray. In the post beans plot the second spray was not used, and Cycocel went on earlier.

Wide yield gap

The yield gap between first and second wheat plots is wide – a reflection of whats happened in commercial practice, particularly on heavy land, this year. Most agronomists consider take-all to be the chief suspect, but on this site it wasnt a major feature. For example, at over 10t/ha (4t/acre) the yields from the third wheat plot are significantly higher than both teams were forecasting, and this is where the impact of take-all was expected to have shown up most. Good soil structure might have been the key factor here, says Andrew Cottrell of Novartis.

Novartis chose a strobilurin programme on its second wheat, unlike the consultants, but the first/second wheat gap still exists.

On weed control for all the plots, the Novartis team had the edge. The late Hawk/IPU programme worked well, with a cleaver top-up where needed (Starane, or fluroxypyr) in spring. It also proved that mistakes with weed control were expensive to rectify later.

Average yield over the whole field, and not just the trial area, was just 8.3t/ha (3.3t/acre). So both teams can congratulate themselves at doing so much better.

Final conclusions? The Novartis team used a low risk philosophy, which necessarily cost more, though it provided guarantees against disaster. The consultants were canny with costs, but perhaps made a few mistakes through cutting corners. But they got it right more often than not – meaning they win the Challenge. Well done!