For this month’s crop walk and talk we joined Agrii agronomist, Iain Sanderson for an insight into crop development in East Lothian , Scotland. Abby Kellett reports.
Colder temperatures had finally hit the UK prior to this month’s Crop Walk and Talk and these were expected to knock-back some of the disease present in crops of wheat, barley and oilseed rape, most of which are boasting a large crop mass, both below and above ground, due to mild winter temperatures so far, according to Agrii agronomist, Iain Sanderson.
Oilseed rape crops were averaging around 70 per cent establishment.
Mr Sanderson said: “This crop of Anastasia was drilled on August 16 at 50 seeds per sq.m, it’s wintered well and the plant population currently stands at around 35 plants per square metre.”
Crop development is advanced for the time of year, according to Mr Sanderson, who identified signs of early spring growth on several plants.
“There are some 10 or 12 leaves on this plant and in the middle we’ve got the onset of fresh spring growth and it’s only the end of January. This ,combined with the cooler weather , is leading to increased pigeon grazing on crops locally”
Because the crop has a large green area index, it is still a few weeks away from requiring its first nitrogen application. “At the moment, crops are not displaying any major nutrient deficiencies and leaves are looking relatively healthy and green.
“I will be looking to fine tune nitrogen and sulphur plans and rates when we re- assess the green area index of the crop in the second half of February and when spring growth is properly underway.”
While there was little sign of light leaf spot, Mr Sanderson advises growers to assess crops for disease symptoms over the coming weeks.
“Light leaf spot can be an issue in this area and phoma increasingly so. Although crops currently look clean it’s important to keep on the lookout for disease as new spring growth appears, particularly on more susceptible varieties.”
On inspection, crop roots displayed good overall health, according to Mr Sanderson. “We have nice strong tap roots and when the plant is cut open there is no sign of root browning, which would indicate boron deficiency and no sign of larvae, whether that be flea beetle larvae or stem weevil larvae.”
An autumn application of molybdenum and boron had contributed to the health and winter hardiness of this crop, he added.
With most wheat plants presenting between three and four sizable tillers, warm winter temperatures had also boosted crop growth.
Plant populations of crops drilled in early September averaged around 300 plants per sq.m, which was plenty for the time of year, said Mr Sanderson.
Further tillering would have to be controlled in order to optimise final crop yields, he suggested.
“Given how forward crops are, I would be holding back on applying early nitrogen to prevent crops getting too thick and producing too many tillers. In fact, this particular crop will need to lose some tillers in order to maximise its final yield.”
Looking at a crop of Zulu , it appeared generally free of disease other than some septoria which was present on the lower leaves.
But since many varieties are becoming increasingly susceptible to yellow rust, Mr Sanderson said he would be continually assessing all crops for signs of this disease, particularly in vulnerable varieties.
Barley crops drilled on September 20 were sitting at around 320 plants per sq.m with three or four tillers each, giving just over 1000 tillers per sq.m.
Given winter is not over, Mr Sanderson suggested current tiller numbers are sufficient but further tillering would have to be encouraged at the first nitrogen application in order to ensure survival of an adequate number.
“Unlike wheat, barley doesn’t have the same ability to compensate later on so providing conditions are right, in the second half of February onwards this crop will be looking for its first 60 to 80kg of nitrogen.”
Mr Sanderson encouraged growers to continue to assess crops for mildew activity, something which was identified on the crop of Glacier being inspected.
However he anticipates the recent change in temperatures will keep disease at bay.
“As a variety, Glacier is quite susceptible to mildew and in fact there is some mildew within the crop and it’s not entirely inactive.”
However he anticipates the recent change in temperature will help keep the disease at bay.
“ It was minus 4 here last night [Jan 25] and that will hopefully keep it under control in the meantime. If not, there may be a need to bring forward an early fungicide application,” he said.