Harvest underway

The quick summary to date is that this is not a bin buster. There were reports during the season that crops were a bit thin but it seems that grain fill is the major cause of the missing tonnes.

The recent hot spell combined with fresh breezes helped bring crops to maturity more quickly than expected and now harvest is underway from the south to the north of the country.

Yield reports are variable to disappointing, but some of these early crops are not a major surprise. Virus infection has been a concern from the word go and then take-all and dryness issues became apparent in some fields.

But high levels of virus infection must impact on the roots as well as the plants and I am always inclined to put this down as a likely precursor to take-all and drought issues. We will watch Joyau closely in this regard.

Early yield reports vary from 2.5 t/ac to above 4.1 t/ac but most early crops seem to be in the 3.0-3.5 t/ac range. Lower yields report poor grain fill and growers indicate that this was not a foliar disease issue.

The likelihood of some poor crops had been flagged prior to harvest so we must now hope that the bulk of remaining crops will pull up this average substantially.

Rape desiccation

Desiccation of winter oilseed rape crops has been particularly slow due to slower development. Some crops are now sprayed off but many remain to be desiccated.

I have seen recent sprayer tracks through rape crops which look to have been sprayed off too early.

The recent heat may speed things up now. Check seed colour in the pods wherever you can manage to get into your crop. Pull 20 pods on the main raceme (the main and tallest stem) in a number of places.

When more than two-thirds of the seeds in at least 15 of the pods have turned brown or black, the crop is about ready for desiccation.

Check every two to three days once seed colour begins to change. Burning off too early will reduce yield but timing is a compromise in an uneven crop.

Straw and stubbles

If there is no active local demand for straw do not be afraid to chop at least some of it as it will benefit your ground in the longer term.

The nutrient value of straw has more than doubled with the fertiliser cost increases so it is worth more than double the value in the ground.

The official value of the P and K removal alone is over €40/ac at average grain and straw yield.

Against that must go the cost of diesel and metal to chop and incorporate. But there is also the cost of baling and the frequent cost of turning straw to dry it out, the big cost associated with delayed planting of the next crop and the new issue of not having stubbles cultivated for nitrates compliance.

It is my belief that nutrient offtake in Ireland is higher than official figures indicate because our straw is seldom mature at harvest and greener straw contains more nutrients. This is the main reason why oats remove much more P and K. Straw will also contain a level of trace elements.