Don’t say it too loud but it is shaping up to be a high-yield year

AFEW weeks ago I suggested that for winter cereals, the 2016/2017 growing season had been textbook in terms of ideal growing conditions.

Since then, its fair to say that the ideal conditions have continued. While the full story of the current growing season will only be apparent when trailers cross the weighbridge, the omens at this point still look good.

Good establishment last autumn, adequate but not too much soil moisture levels, and generally low levels of wet weather diseases such as septoria or rhynchosporium, coupled with plenty of opportunity for applications, should add up to a good clean canopy to adequately fill the abundant available grain sites.

The only outstanding variable is if the weather over the past few weeks has been such to maximise growing conditions of our temperate crops.

That is bright enough to maximise photosynthesis but cool enough that the plant hasn’t to close down for most of the day to conserve moisture losses.

Prevailing conditions during grain fill can turn crops of good potential into bumper (think 2015) or disaster (think 2012) harvests.

Grain yield is made up of the number of grains per unit area (heads of grain per unit area multiplied by the number of grains in each head) and the weight of these grains.

The number of grains per unit area is determined by prevailing conditions during establishment, through the winter into early spring until stem extension and even towards grain fill.

Cereal crops, in particular winter wheat, have huge capacity to manipulate the number of grains per unit area in response to prevailing conditions.

For example, in a very fertile site, the number of plants per unit area is high, the number of tillers per plant can be high and the number of viable grains on each head is also high, so there is a huge number of grains per unit area to fill and potential for high yield.

If establishment is poor and there is a limit on the plants per unit area, more tillers can be established and more grains per head can remain viable, to overcome the impediment of a low plant stand. If fertility is poor, tillers can be resorbed or eliminated, or the number of grains per head can be reduced.

In the absence of impediments such as pest attack or