End of season round up – Crop development
7 Aug 2018
As year 2 of our Real Results OSR site monitoring and in-season updates comes to a close, we look back at the season with our ADAS experts. First up, some comments on crop development and yields from Dr Pete Berry.
2017/18 crop development
At the three monitoring sites, good plant establishment and a mild autumn, resulted in rapid autumn growth, with medium to large canopies of GAI 1.5 to 2.5 achieved by winter.
The cold spring then caused these canopies to almost halve in size, reaching a low point in late February / early March. GAI then increased rapidly from mid-March.
At early stem extension, the GAI was modest in size at between 1 and 1.5 units. The crops therefore had a good chance of not exceeding the optimum canopy size at flowering of GAI 3.5.
The crops reached 20 cm (Hereford and Cambridge) and 10 cm (Yorkshire) by early November, from when height remained relatively constant until spring.
“Crops were probably about two to three weeks behind normal in April”
True stem extension was late, starting in late March at Hereford and Cambridge, and early April in Yorkshire. Note that in previous seasons, some crops have been flowering at this time. Crops were probably about two to three weeks behind normal in April.
Almost all stem extension occurred over a six-week period between the start of April and mid-May. Final crop height was typical at between 1.2m and 1.4m. Caryx® reduced crop height by up to 14cm.
OSR yields this year are mixed. Many good to very high yields have been reported for crops on water retentive soils, and further north, where summer temperatures have been cooler. Whereas moderate to low yields have been seen further south and on lighter soils.
“OSR yields this year are mixed”
The high summer temperatures shortened the seed filling period, but this was partly compensated by the very sunny June. Reasonable spring rainfall was sufficient to see crops through the dry summer on heavier textured soils, and where roots were able to grow deep.