Early harvest offers grassweed control opportunity

An early harvest and rain in the past week means growers across the country have the ideal opportunity to get on top of annual grassweeds ahead of drilling this autumn, ProCam’s David Ellerton says.

The hot, dry summer is resulting in notably low levels of black-grass seed dormancy, he notes.

“For the first time in many years, most people should have both the time and moisture to achieve good stale seedbed weed control.

“The recent rain has been far too limited to replenish soil reserves. But it has largely fallen on standing crops so it should provide sufficient upper soil moisture for a good chit of blackgrass seed, because the soil surface is well protected from the drying effects of sun and wind.

“The secret of success, though, will be to retain the precious moisture as fully as possible through the primary cultivation and use it to best effect with careful glyphosate applications.”

Dr Ellerton recommends cultivations as soon after harvesting as possible where blackgrass and sterile brome are the key targets. With meadow, soft and rye bromes, on the other hand, he advises delaying cultivations for a couple of weeks to encourage dormancy breaking.

Shallow tillage, he notes, is preferable to ploughing or deeper discing wherever moisture preservation is critical.  And he insists good rolling or pressing immediately after cultivation will pay dividends in optimising weed seed-to-soil contact as well as moisture preservation.

“By consolidating the ground the same day as cultivating it you’ll really preserve its moisture and stimulate the fastest possible weed growth,” he stresses.  “I’d be surprised if you didn’t get a flush of weeds you can spray off with Roundup in seven to 10 days with the soil temperatures as high as they are.”

Growers might even have the opportunity to spray off two flushes of annual weed growth ahead of cereal drilling, he concludes.