Drew Pfitzner and his dad Michael Pfitzner manage a mixed arable farm in New South Wales, Australia. They are very interested in agri-tech; using yield maps, variable rate fertilizer and seed applications. For the last year they have used fieldmargin for mapping locations of weeds as part of their defence strategy against feathertop Rhodes grass.
Feathertop Rhodes grass is a tufted annual grass up to 1 m tall. The grass is increasingly displaying tolerance to herbicides, in particular glyphosate. It is spread easily and can grow in very dry conditions. Plants mature quickly, with large numbers of viable seeds produced in just four weeks. This image shows a new seedling from Hill End farms on a very hot and dry track.
Although feathertop rhodes grass is a difficult weed to manage, seeds are viable for less than 12 months so if you are able to limit seed production for even one season the seedbank will rapidly drop and effective weed control can be achieved (Source). Potential strategies to achieve this include patch spraying, tillage, burning and pulling up (‘chipping’) plants.
At Hill End they use fieldmargin to record locations of the weeds while they are in their machines scouting.
“The problem with feathertop rhodes grass has been getting worse and worse on our land. Last year, we went a bit mad and we recorded the location of every individual weed using fieldmargin app. This season we recorded more than 300 weed sites on over 3000 ha of land.”
The app has also helped them by allowing the team to share locations of the weeds when they are out chipping on foot. It has meant the team could share and monitor progress much more efficiently so that they can understand the scale of the weed problem.
“Currently we are using a camera sprayer (WeedIT) to patch spray weeds based on colour differences, green on brown. Naturally that uses a lot less herbicide, around 8 to 10 % of the paddock will get sprayed. They do respond to glyphosate but it won’t kill it alone. We then have to go out and remove some weeds manually by chipping ”
They have found fieldmargin much easier to use for tracking weed problems then other systems they tried.
“Previously we sort of recorded the locations of things in our GPS but it’s hard to use that data as it’s a pain to grab it out of it and put it on a computer and no real easy way to use your phone. So in this way, using fieldmargin app has helped us heaps in tracking weeds. We have also noted where we have done trials, fox holes and spray locations. I know of a University developing a tool that chips out weeds using a WeedIT camera and a tine that’s lowers quickly to chip out the weed. That’d be an interesting option to try in the future”
Having a map of their weeds allows Drew and Michael to monitor the spread of the problem and determine what will be the most effective control strategy.
“Now because we have all our maps and data in the same place we can turn our records into useful information. Using the located markers we will be able to see which weeds return next season. Strategic tillage would be something to consider but we are in no-till so we would rather avoid working up paddocks. The main aim was to track where the weeds are each year and work out a trend.”
The farm has used map uploader on fieldmargin to store and view fertiliser and yield maps.
“We use yield maps for variable rate seeding and fertiliser application. Using fieldmargin we have put in our variable rate lime applications in two of our paddocks and compared this information with satellite data. Knowing the locations where we have high levels of weeds mean that we can analyze yield data to see effects and see the difference from season-season.”
“Feather top rhodes grass is a massive issue for us. fieldmargin has allowed us to map our fields for free using our mobile phones. I have enjoyed using the app and It really does offers a workable solution. I’ve got a few neighbours onto it as well.”