Winter weather: The severe frost may be gone for the moment but it looks like wintry weather for a while yet. This type of weather is traditionally the reason why we are slow to spray and apply nitrogen in January or early February as we can never depend on what will still come.

The heavy frost that many got last week could do some damage to advanced winter crops. It is always good to remember that very forward crops are vulnerable to frost as well as pests and diseases. This is always a good reason not to have a big area of a single variety or crop sown early.

Once a crop moves into stem extension and the developing ear rises above ground level (GS30) the head is much more vulnerable to frost kill. While spring oat varieties are worst affected, we have also seen this happen to winter wheat and barley in the past.

Low temperatures can kill the developing ear, effectively ending apical dominance and handing the full potential of the crop back to the tillers. And if for some reason the crop does not have many tillers its potential may be badly hit. You may not even realise the main stem ear is dead for many weeks.

Hopefully this will not have happened but we must be aware of the risk and watch out for it in very forward crops. Slice the stem open along its length in 2-3 weeks and look for signs of brown tissue where the ear is. Even if this has not happened yet it could still occur in another frosty spell. We lost wheat in an April frost back in the 1990s.

Planting: Recent rainfall amounts continue to be very variable and some areas may soon be dry enough for planting. Seedbed conditions dictate such decisions but beans and possibly spring wheat and oats might be considered where crows are not be a huge concern.

Seed rate for beans should be based on target plant population and seedbed conditions. Aim to plant between 35 and 40 seeds/m2. You need to know seed size to get this right as it can easily vary from 500 to 650 grams per 1,000 seeds.

A 500g sample needs 170, 185 or 200 kg/ha to give 30, 33 or 36 established plants/m2, respectively, based on 90% establishment. So seed rate could vary from 180-250 kg/ha (12-16 st/ac) depending on seed size.

Seed size should also be used for cereals and these can vary considerable also. Push spring wheat and oats up close to 400 seeds/m2 for planting now as establishment could be hit by weather and crows.

Nitrogen: Once things warm up and we get back to growth conditions it will be important to have some nitrogen (plus P and K) on winter crops, especially rape and barley. Depending on your land you could go for just a little or a normal first split now.

Be guided by the current condition of your crop with a bit less (or later) on more advanced and dense crops. Use the GAI score to guide the quantity for rape. Include sulphur in the first split on all worn land.