Australia's sorghum belt faces a grass weed crisis. Johnson grass, feathertop Rhodes grass, and barnyard grass are outrunning every herbicide in the toolbox. WeedBot Pro targets them mechanically — resistance is irrelevant.
Grass-on-grass weed competition in sorghum is the hardest weed management challenge in Australian agriculture. The chemistry is running out.
Grain sorghum occupies over 2 million hectares of Australia's northern cropping zone, from the Darling Downs through central Queensland. It's the cornerstone of summer cropping rotations, providing both grain income and stubble cover for following winter crops. But the weed problem in sorghum is uniquely difficult because the crop and its worst weeds are all grasses.
Johnson grass (Sorghum halepense) is sorghum's evil cousin — literally a wild relative that cross-hybridises with the crop. It produces rhizomes that persist for years, and populations with confirmed resistance to Group A (fops and dims) herbicides are now widespread across the northern grains region. Feathertop Rhodes grass (Chloris virgata) has exploded across central and southern Queensland, with glyphosate-resistant biotypes now the norm rather than the exception. Barnyard grass (Echinochloa crus-galli) dominates irrigated sorghum in the Lachlan and Namoi valleys.
Selective herbicide options in sorghum are limited. Atrazine provides some broadleaf control but does nothing for grass weeds. Group A herbicides are increasingly ineffective due to resistance. This leaves growers with inter-row cultivation (which destroys stubble and risks soil erosion) or hand-chipping (which costs $200-400/ha and requires workers who simply aren't available). WeedBot Pro offers a third path: precision mechanical removal that's selective, non-chemical, and preserves soil structure.
Solving the grass-on-grass identification challenge with deep learning.
WeedBot's deep-learning model is trained on 50,000+ annotated images from sorghum systems. It distinguishes crop from Johnson grass by analysing leaf width, vein patterns, and tillering habit with 97% accuracy from the 2-leaf stage.
For perennial grasses like Johnson grass, surface removal isn't enough. WeedBot's precision blade targets the root crown and upper rhizome nodes, disrupting the regenerative tissue that allows these weeds to persist between seasons.
Configured for all sorghum row configurations: solid plant (75cm), single skip, and double skip. The AI maps your planting pattern on the first pass and adjusts navigation for the wider skip rows.
GPS-tagged weed density maps show exactly where Johnson grass rhizome banks are building. Target these zones with deep ripping or intensive fallow management before they explode in the next summer crop.
Unlike conventional inter-row cultivation that buries or destroys crop stubble, WeedBot operates above the soil surface. Stubble cover is maintained for moisture conservation and erosion protection — critical in dryland sorghum systems.
Post-emergence weed control in sorghum has a narrow window — typically 2-4 weeks. WeedBot covers 40-60 ha/day per unit, operating 24/7 to hit the entire crop during the optimal timing window.
How WeedBot Pro stacks up against current options for a 2,000 ha sorghum program.
| Method | Cost/ha | Efficacy on Resistant Grasses | Stubble Impact |
|---|---|---|---|
| Atrazine + Group A herbicides | $35-55 | Failing (60% resistance) | None |
| Inter-row cultivation | $25-40 | Good (non-selective) | Severe — destroys stubble |
| Hand chipping crews | $200-400 | Good (when workers available) | Minimal |
| WeedBot Pro | $8-15 | Excellent (mechanical) | None — preserves stubble |
Yes. This is one of WeedBot's most technically demanding applications. Sorghum, Johnson grass, and barnyard grass are all grasses with similar early morphology. WeedBot's deep-learning vision system is trained on over 50,000 annotated images specific to sorghum cropping systems and achieves 97% classification accuracy from the 2-leaf stage onward by analysing leaf width, colour gradients, and growth habit.
A single WeedBot Pro unit covers 40-60 hectares per day in standard 75cm row sorghum. For wider 1-metre row or skip-row configurations, coverage increases to 50-70 hectares per day. The unit operates 24 hours on a single charge cycle, making it practical for the time-critical post-emergence weeding window.
Absolutely. Skip-row sorghum (plant-skip or plant-plant-skip) is ideal for WeedBot because the wider skip rows give the robot more operating space. The AI maps the planting configuration on the first pass and adapts its navigation pattern accordingly. Skip-row configurations actually increase daily coverage because the robot spends less time on tight turns.