Strip Trials Underline Overall Establishment Importance

Yields analysed from the bulk of the field-scale Dekalb grower trials now harvested across the country are underlining the clear relationship between hybrid performance and establishment success at a standard 50 seeds/m2 sowing rate. Average yields across the eight hybrids grown at the nine sites without excessive variation from other influences generally increased with initial establishment rates. However, the relationship was far from perfect, with at least two sites having good relative rates of autumn establishment seeing rather disappointing yields. Those trials with autumn establishment rates of greater than 75%, indeed, only yielded an average 0.16t/ha more than those with rates of 75% of less.

In contrast, a much closer relationship was evident between performance and overall  establishment (measured in plants/m2 in the spring as a percentage of seeds sown). To such an extent that the average yield difference between those achieving overall rates greater than and less than 60% was 0.72t/ha (Figure).

Seed yield by overall establishment rate in field-scale farm trialling published

“Regardless of all the other things that can effect yield, this underlines just how important it is to establish the right spring plant population,” observes Bayer trials manager, Richard Williams. “The average spring count on those sites with lower overall establishment and performance levels was only just over 20 plants/m2, for instance, against a much more optimal 35 plants/m2 for those achieving greater success. “Across our entire trial set there was relatively little variation in average spring populations amongst the varieties grown – from just 24 to 30 plants/m2 – enabling the best possible comparison between them,“ he adds. “DK Exposé, DK Excited and DK Extremus are standing out as the top performers here, all delivering seed yields 10% or more ahead of the mainstream Recommended List double low hybrid included as a comparator. At 5% ahead of the RL comparator, DK Exbury is also performing satisfyingly ahead of DK Exstar overall.

“Interestingly too, we are seeing an average 0.6t/ha yield advantage from sowing in the second half of August compared to September, with DK Excited and V367OL showing the least yield reduction from delayed sowing.”