Monday, December 10, 2018

Growers deserve well-earned rest after unsettling year

December 3, 2018 by  
Filed under Crops

Better autumn weather and means most crops are off to good start, says Richard Overthrow.

Most fields are closed for winter now but relatively kind weather meant cereals went in and established well and generally autumn agronomy is complete.

The nightmare of oilseed rape establishment is behind us but we must be resigned to whatever natural shock awaits the crop. Increasingly growers around the country are looking to reduce their reliance on rape and in this area we are well ahead in this, having suffered from flea beetle for much longer.

A few issues may cause us to break our winter slumber over the next couple of months. Aphid flight into crops has slowed down now and although mild weather may extend this it’s driven by day length as well as temperature so doesn’t normally change much.

Late flights

What will be of concern are any mild spells during winter which don’t necessarily encourage late flights into the crop, but help the very few aphids which survived the autumn control programme to breed and spread virus across large areas.

This has happened recently, in 2015/16, and we need to look out for similar conditions with a view to spraying a pyrethroid at the earliest opportunity in late winter or early spring, to crops thought to be at risk.

Mildew and rust

Mild weather and soft growth seen last month has generated some reports of mildew and yellow rust in earlier sown wheat crops and in barley, rhynchosporium and net blotch. Cold weather should sort these out but it wouldn’t hurt to check crops every now and then. Winter fungicides are hardly ever worthwhile but we still need to monitor anything developing.

To return to the thorny oilseed rape issue, around now we should be seeing larvae if they are present. There are no control measures available for these so don’t be tempted into ‘revenge spraying’.

But it is surprising how crops can come back from intense infestations. An assessment of numbers needn’t decide whether to keep the crop or write it off, but should guide you as to how much more to invest in the crop pending such a recovery.

Phoma and leaf spot

In stark contrast to last season, phoma was very slow to get going and any new infections now are unlikely to threaten yield, so the emphasis must be on light leaf spot. A warm wet winter will encourage this though many growers used a robust fungicide in mix with a propyzamide application last month, and this should protect the crop at least until stem extension.

Where single or final fungicides were applied early, then protection may run out during winter, also if less-robust products were used, the disease may develop early in the New Year.

That said, the latest predictions from the AHDB show the overall disease risk locally remains lower than in recent peak years so we may find crops stay fairly clean and early spring treatment is unnecessary.

The benign late autumn allowed timely sowing of winter bean crops. But if there are any still to plant they can produce respectable yields when sown in December or January, though they will mature later than earlier sowings. Similarly, spring beans can be sown from early January onwards if desired.

Best wishes for Christmas and New Year.

Richard Overthrow is a regional agronomist with NIAB TAG, the UK’s largest independent agronomy organisation with several research centres in East Anglia. For more details, call 01223 342495.

Speak Your Mind

Tell us what you're thinking...
and oh, if you want a pic to show with your comment, go get a gravatar!

 
barbour pas cher barbour pas cher barbour pas cher barbour pas cher barbour pas cher golden goose saldi golden goose saldi golden goose saldi golden goose saldi golden goose saldi doudoune moncler pas cher doudoune moncler pas cher doudoune moncler pas cher doudoune moncler pas cher doudoune moncler pas cher moncler outlet online moncler outlet online moncler outlet online moncler outlet online moncler outlet online