Calculating yield responses to fungicide applications – Farmers Guardian
Trials at Helix Farm North in Yorkshire have investigated responses to nitrogen and fungicide inputs in winter wheat and barley crops. Ash Burbidge reports ...
Agronomy advice firm Hutchinsons shared findings from a number of trials at its Helix Farm North, hosted by Nick and Liz Wilson at Hundayfield Farm, York, at a recent open event.
Response to fungicides, Septoria infection levels on key leaves and nitrogen uptake by wheat crops, were among the topics discussed. Fungicide response trials in winter barley and winter wheat explored the yield difference between treated and untreated crops.
The trial compared the performance of 21 varieties of winter barley, with the untreated yield averaging 9.16 tonnes per hectare and the treated yield averaging 10.16 t/ha, giving an average response of lt/hato Revysol (mefentrifluconazole)across the different varieties. LG Dazzle produced the largest fungicide treated yield at 12.2t/ha.
The largest untreated yield was10t/ha, yielded equally by Valerie, Bolton and Tardis. The winter wheat trial compared 31 varieties and produced an untreated yield average of8.56t/ha and fungicide-treated yield average of 10.37t/ha, showing an average response of 1.81t/ha.
York-based Hutchinsons agronomist Sam Hugill, said: “LG Sky-scraper came out on top of the treated varieties [13.1t/ha], with KWS Extase [12t/ha] coming in second,f ollowed closely by Gleam and Graham. This shows how cereal genetics are improving.”
Septoria infections were assessed in early July in terms of percentage coverage on leaf 2 and flag leaf.
The trial compared 30 untreated varieties of winter wheat. “The flag leaf is able to contribute 40-45 per cent of yield, so if we are seeing Septoria infection, this can result in significant change in yield and return on investment,” said Mr Hugill.
Flag leaf infection results ranged from 2 per cent to 40 per cent and leaf 2 ranged from 2 per cent to 25 per cent, showing a large variance in infection levels.
Hutchinsons fertiliser and crop nutrition specialist Rob Jewers discussed the nitrogen response curve, where previous trials conducted with Yara showed how many kilos of nitrogen were required to reach a yield plateau.
Trials in wheat conducted across sites in Suffolk, Northamptonshire and Yorkshire suggested the plateau starts at 160kg N per hectare.
“From zero nitrogen right up to 160kg N, we have almost got a straight-line response [comparing yield with nitrogen application]. “For each 50kg you apply, you can expect 1.5 tonnes of yield, so the first 160kg is the absolute minimum, I would suggest,” said Mr Jewers.
Interpreting this knowledge at Hundayfield Farm, the trial’s objective was to replace a traditional amount of nitrogen with a form of methylated urea, called UTrisha N-a nutrient efficiency biostimulant which contains the natural bacteria methylobacterium symbioticum, which fixes nitrogen from the air and converts it for the plant.
The trial was conducted over five plots incorporating different rates of nitrogen, ranging from 67kg N/ha to 240kg N/ha. The plot that received 130kgN/ha performed the best, yielding 10.75t/ha.
This provides evidence of the plateau effect, as the plot that received 240kg N/ha yielded 9.65t/ha, which shows the efficiency reducing.
“From adding additional nitrogen we did not see a further response, in fact we saw almost a detrimental response.
“The biostimulant UTrisha held its own using 130kg N/ha plus UTrisha N. The bacteria fixed the nitrogen from the atmosphere so it yielded over and above the control,” said Mr Jewers.
Email Us