Sowing and Varieties

The current Winter Cereal Recommended Variety lists are available from the DAFM website: DAFM Winter Cereal Variety List

The Teagasc current recommended seeding rates see below: Winter Cereal Seed Rate Calculator - 2024 (Excel format)

Sowing Date

For maximum yield, winter varieties should be sown from the end of September to early November. The potential yield will gradually decline and harvesting will be later if sowing is later than this. With modern varieties, sowing can occur up to February, but in practice crops sown from December onwards usually suffer from poor or slow establishment and yield potential is reduced.Remember: early sowing on its own does not guarantee the maximum yield; it just means that you should have the potential to achieve the maximum yield.

Sowing too early can bring its own problems, namely

• The soil may be too dry for rapid establishment,
• Young plants may be at risk from diseases existing in old stubbles
• Volunteers from previous crops may not have been killed off and,
• Risk from late spring frosts

In general, the results from many trials suggest that the best time for sowing winter cereals is between the last 10 days of September and the first 10 days of October, providing that soil and weather conditions are suitable.

Sowing rate

If you are seeking to get the maximum yield you need to establish the right number of plants to produce enough good sized ears of grain at harvest time. In order to do this, you need to sow the correct number of seeds. If you sow too few seeds, you are then depending on the tillering capacity (i.e. the ability to produce a number of seed heads from the one seed) of the crop to achieve this. Sow too many seeds and inter plant competition will result in a crop of tall and weak plants, and a lot of small ears at harvest time.

• Seed quality (germination%, Thousand Grain Weight, variety)
• Soil conditions
• Time of year
• Anticipated pest problems
• Previous experience
• Sowing method (Drilling or broadcast)

The minimum standard for germination is 85%, but it must be remembered that this is laboratory testing under ideal conditions. You can expect the germination % to fall under normal field conditions. In practice, it is not uncommon for only 60 –70% of seeds to germinate.Once we know the germination%, we then need to know the Thousand Grain Weight (T.G.W.) of the seed in order to calculate how much seed (in kg/ha) we need to sow. As you can guess, this measurement is the weight of a thousand grains and is expressed in grams. It varies according to seed size. Typical figures for T.G.W. are:

• Winter wheat: 40 – 55 grams
• Winter barley: 40 – 55 grams
• Winter oats: 30 – 40 grams

When estimating the seed rate, we must decide on the plant population we want to achieve. The table below shows typical values for the three main winter cereal crops.

Now that we have all the information we need, we can calculate the seeding rate using the following formula:

T.G.W. x Target Plant Population/square metre
                     % Establishment

= Required seeding rate ( in kg/ha)

Example: Let’s assume -

T.G.W. = 50;
Target Plant Population = 280;
% Establishment = 70.

Then,         50 x 280 = 200 kg/ha
                        70

When choosing which variety to grow, you should have a copy of the latest Department of Agriculture, Fisheries and Food (DAFF) List of Recommended Cereal Varieties , as this contains most of the information you need. It gives a score to each variety for each of the important characteristics such as yield, disease resistance, straw length and strength, grain quality and so on. Thus, you can compare the different varieties and decide which ones would suit you.

As a general rule, you should go for a high yielding variety which has good resistance to disease and lodging, and has the quality of grain you want.

Local knowledge is also very important when choosing a variety. Each variety is evaluated for a number of yield, quality and agronomic characteristics.

The yield capacity of each variety is given as a percentage of the control varieties (which themselves are proven varieties of a number of years standing), which is rated as 100. So, a variety which has a yielding capacity of 104 is deemed to be 4% better yielding than the control varieties.

Other characteristics assessed include shortness of straw, strength of straw, earliness of ripening, resistance to sprouting, resistance to disease, hectolitre weight, grain protein, 1000 grain weight, Hagberg Falling Number, milling quality, baking quality and grain hardness.

Assessment of these characteristics are based on a scale of 1 to 9: a high figure is desirable and indicates possession of that characteristic to a high degree.

Providing good seedbed conditions is essential if you want to get your crop off to a good vigorous start.

Crop Establishment

A fine firm seedbed is required for a quick and even germination. Only the top 15cm of soil need be cultivated for good root development, but compaction must be avoided at all costs. Roots need to penetrate soil to a depth of about 1 meter in order to obtain enough moisture for crop growth throughout the season.The seedbed should be prepared with the minimum number of passes.