# What is the optimum plant density for your barley variety?

Page last updated: Monday, 10 April 2017 - 3:05pm

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Recent research from the Department of Agriculture and Food, Western Australia's barley agronomy team has busted the myth that increasing the seed rate of barley will significantly decrease the quality of barley crops in medium to high rainfall areas. But how can you accurately work out the seed rate for your chosen barley variety? The target seed rate in kilogram per hectare differs between varieties due to kernel weight and response to increasing plant density.

This page shows you how to work out kernel weight and how to convert this to the most productive seed rate.

What is your target plant denisty?

In 2013, surveys carried out by the barley agronomy project found that only 15% of growers counted the number of established plants per metre to determine the plant density in their paddocks and potential yield from this density. In order to optimise your production we suggest you count your establishment (per square metre) to know if you are hitting your targets.

The recommended number of established plants (per m2) for food and malt varieties is either 120 or 150 plants/m2, depending on the variety you are growing (see Figure 1). For feed varieties, the suggested plant density is 180 plants/m2.

Conversion rates for target barley seedings of 120, 150 and 180 plants per square metre

To achieve the correct plant density, the right seed rate should be applied. Selecting the most profitable seed rate for your variety comes down to knowing the 1000 kernel weight of your particular variety. To find out this figure simply count out 1000 grains from your particular variety. It's easiest to do this in lots of 20. You will need 50 lots of 20 grains. Once you have the 1000 grains, weigh them using your kitchen scales. Take this number and using Table 1 find the seed rate you will need to achieve the target plant density. If your expected germination is less than 98%, you will need to use the formula to convert kernel weight to seed rate in kilograms per hectare. The suggested plant density for commonly grown varieties can be found in Figure 1.

Figure 1 Suggested plant density per m2 by variety
Figure 2 Suggested seed rate in kg/ha by variety if kernel weight is not known

For more information see DAFWA Senior Research Officer Blakely Paynter's 2016 Research Updates paper How much does seed rate influence barley’s performance?

## Contact information

Blakely Paynter
+61 (0)8 9690 2115
Raj Malik
+61 (0)8 9821 3247
+61 (0)8 9083 1160

Georgia Trainor
Blakely Paynter