NovaChem > Industry News > 2021 > Scout weeds pre-harvest, & make next season easier.

Scout weeds pre-harvest, & make next season easier.

Published on 23/11/2021

But before you do, consider that this is the perfect time to work alongside your customers to map their weed problems for next season.

Grassweeds especially, but also some larger broad-leaved weeds, are very easy to see when they poke out above the crop. So, get out there now, take your customers with you, and note and map those difficult to control weeds.

And while you are doing this try and establish based on your knowledge of the season just ending: Are these weeds likely to be escapes for some reason or is this the start of a herbicide resistance problem?

Finally start to plan your herbicide programmes for this autumn.

As well as deciding whether to use Sakura® or Firebird® as your pre-emergence herbicide, consider reducing the weed burden by creating a stale seedbed to use with Round-up Ultra® MAX.

With a wealth of practical knowledge, the Bayer field team is there to assist whenever required.

Which weeds am I looking for?

The key grass weed species you should be looking out for when scouting paddocks are ryegrass, wild oats, vulpia hair grass and canary grass. Just occasionally you may also find barley grass.

All of these grass weeds are prolific seed producers with individual plants capable of producing hundreds, even thousands of viable seeds.

While autumn germinating weeds tend to produce more seed, even spring germinating plants can easily produce hundreds of seeds per plant.

With the viability of seed measured in years, poor control in the short term leads to a problem for many years to come. The age old saying “one year’s seeding leads to seven years’ weeding” is very true!

And while noting grass weeds, keep an eye open for broadleaf weeds as well. Look for mayweeds, cleavers, polygonum species such as redshank and the new kid on the block, beaked parsley, (Anthriscus caucalis M. Bieb).

It goes without saying that as well as noting which weeds are present in each paddock you should also map where they are. This will allow efficient, targeted applications for the following season.

Herbicide resistance is a growing threat.

Recent surveys in the arable growing areas have shown that herbicide resistance is a growing threat and testing carried out by Bayer in NZ reinforces this finding.

The number of species, the geographical area and the number of paddocks affected are all increasing.
How do you know whether herbicide resistance is the reason for you finding weeds in your customers’ paddocks?

The first stage is to rule out the obvious - Was the right herbicide used? Were weeds at the right size when they were sprayed? Was it a competitive crop? Did the weeds germinate after application? Was the seedbed structure and moisture content good? Can I rule out application technique issues?

If the answer to these questions is yes, and especially if the weeds remain in patches in the main part of the paddock, the issue could well be that herbicide resistance is developing.

To be sure, try and organise a resistance test. Again, now is the time to collect seed for testing.

Plan for the autumn.

Now you have a weed plan to work with, the next step with your customers is to discuss their autumn herbicide programme, plan your post-harvest operations to ensure you reduce the weed burden as much as possible and put steps in place to create the ideal seedbed for successful weed control with Sakura and Firebird.

Words: Neil Waddingham, customer marketing manager, Bayer NZ

This page is best viewed in an up-to-date web browser with stylesheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so. The latest version of Firefox, Safari, Google Chrome or Internet Explorer will work best if you're after a new browser.