Thursday, November 15, 2018

Fingers crossed for a straightforward harvest

June 29, 2018 by  
Filed under Crops

An unpredictable year makes cereal yields hard to forecast – even now, says Richard Overthrow.

Harvest is just around the corner and even at this late stage it is difficult to assess yield potential of any crop, such has been the vagaries of the season. As ever, whatever the outcome we will carry on into next season and hope to repeat or improve as appropriate.

Pre-harvest farm tours, even from the combine cab are a good opportunity to map any areas of surviving grass weeds. It is too late to rogue or spray off surviving plants now but this monitoring exercise will allow next season’s campaign to be planned.

There may also be broad leaved weeds which have come through herbicide treatment. Resistance in some species, poppies and mayweeds in particularly, to some ALS-inhibitor herbicides is spreading and any such cases should be noted to allow adjustment of future herbicide strategies.

Straw use will again be an important decision to make. Growers also need to be aware of the P & K value of crop residues, data for which are available in RB209, but the concern in the run-up to harvest was of possible straw shortages due to lack of crop growth so its value may rise and this may influence this year’s policy.

Crop management

Glyphosate treatment is still the most common method of harvest management in winter rape. Check recommended timings carefully to avoid immature seed or delayed harvest. Although many crops showed a short flowering period this year, possibly giving a more uniform maturity, this is unlikely to significantly increase the number of crops not desiccated.

Post-harvest cultivations are still an important part of grass weed control programmes, both to encourage weed emergence pre-sowing and to provide suitable seedbeds for optimum residual herbicide performance.

Stale seedbeds, where the stubble is cultivated and rolled or pressed to encourage grass weed emergence, can be effective against black-grass, rye-grass and sterile and great bromes, and should be created as soon after harvest as possible. Delayed drilling in the worst affected fields will also give more time to get a good flush of grass weeds before sowing the next crop.

It is important, at a time of year when glyphosate applications are made, that we follow stewardship guidelines for this valuable herbicide.

Weeds and seeds

Meadow and soft bromes have very different stubble management requirements. Seeds of these will be encouraged to germinate by leaving exposed on the surface, so if either of these is the main target leave stubbles untouched for as long as possible.

Where a stale seedbed follows an oilseed rape crop then, if possible, wait for shed rape seed to be wetted by rain before cultivating and burying. Oilseed rape volunteers are becoming a widespread problem, particularly with the shorter rotations and seed shed during harvest can become dormant for several years if buried in dry conditions.

Volunteer rape has also been implicated in the recent erucic acid problems many growers have encountered. Stale seedbeds have less value prior to oilseed rape due to the shorter cultivation window but it is still worth trying where grass weed populations are high.

Richard Overthrow is a regional agronomist with NIAB TAG, the UK’s largest independent agronomy organisation with several research centres in the Midlands. 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