How to increase wheat grain numbers
The grain number is itself a function of the number of fertile shoots per unit area and the number of grains per ear. The grower therefore needs to consider how nutrition can have an impact on the grain numbers per ear.
Nitrogen increases grain numbers
Nitrogen will affect the number of grains that are set on individual ears/spikes. A high yielding crop of wheat will have approximately 45-50 grains / ear, however if nitrogen supply is limiting this will be reduced.
The timing of the applied nitrogen is important as grain numbers are determined early from double ridge to floret initiation.
Potassium influences grain numbers
Potassium will influence the numbers of grains per ear.
This study from the Potash Development Association shows a clear relationship between potassium supply and the number of grains per ear with potassium deficiency preventing some potential grain sites from developing and reducing grain set.
Micronutrients influence grain numbers
Other crop management practices influencing wheat grain numbers
The number of eventual grains per spike (ear) varies from season to season and is affected by a number of factors including:
- Varietal choice
- Disease control during flowering
- Weather conditions during flowering
- Temperature and day length before terminal spikelet (Zadoks GS 30)
This variability enables high yields to be achieved through two ways:
- Low shoot numbers and high grain numbers/spike
- High shoot numbers and low grain numbers/spike
Recommended Yara fertilisers for wheat
Related articles
How to maintain wheat green leaf canopy
The key to achieving high wheat yields, having established the correct canopy structure, is to maintain the green area right through to the final grain filling period, capturing as much of the incident light as possible and converting it to yield.
How to increase wheat leaf and tiller numbers
The number of leaves determines the size of the crop canopy and its photosynthetic potential. The number of shoots and how many of these survive through to harvest also determines the number of ears at harvest and so the potential yield.
How to increase wheat grain size and weight
Wheat grain size is strongly influenced by plant nutrition particularly during the important grain filling period. Nitrogen, phosphate, potassium, magnesium and zinc are particularly important.
