Treatment Program Timeline (2020-2026)
This program demonstrates the effectiveness of research-based, sustained weed management in the Mackay region.
Results align with Queensland DPI studies showing lantana seed viability of 3-11 years and treatment efficacy
of 60-90% with proper application and follow-up.
Rainfall Context: Mackay's average annual rainfall is approximately 1,200-1,585mm.
The 2013-2020 period experienced below-average rainfall (drought conditions), while 2021-2024 saw a return
to above-average rainfall. Rainfall directly influences lantana and paspalum seed germination and seedling recruitment,
with wet years (2021-2024) producing higher germination rates from the soil seed bank.
2020 - Baseline
Below Average
100% relative infestation
65% Lantana coverage
Drought conditions ending
Assessment conducted
2021 - Year 1
Above Average
30% remaining (70% reduction)
Return to wet conditions
High seedling recruitment expected
3 intensive treatments
2022 - Year 2
Record High
22% remaining
26% above QLD average rainfall
Significant seed germination
2 follow-up treatments
2023 - Year 3
Above Average
18% remaining
Continued wet conditions
Seed bank depleting
2 management treatments
2024 - Year 4
Above Average
14% remaining
23% above QLD average
Maintenance phase
2 surveillance treatments
2025 - Year 5
Average
11% remaining
Near control achieved
Declining germination
2 minimal treatments
2026 - Year 6
Average
8% projected
Ongoing surveillance
Annual monitoring planned
Key Success Factors
• Rainfall Adaptation: Treatment timing adjusted for above-average rainfall years (2021-2024)
to target increased seed germination from wet conditions
• Seed Bank Management: Consistent follow-up treatments targeting annual germination cohorts,
especially critical during wet years when recruitment is highest
• Research-Based Timing: Applications scheduled for early summer to autumn after 35mm+ rainfall events,
when seedlings are actively growing
• Long-Term Perspective: 6-year commitment essential due to lantana seed viability (3-11 years)
and variable germination influenced by Mackay's rainfall patterns
• Climate Context: Understanding that wet years (like 2022's record rainfall) require more intensive
follow-up to control increased seedling emergence
Rainfall Impact on Weed Management
Mackay Climate Data: The transition from drought (2013-2020) to above-average rainfall (2021-2024)
significantly influenced this program. The 2022 record rainfall (26% above Queensland average) created ideal
germination conditions for lantana seeds that had accumulated in the soil during the drought years. This resulted
in higher-than-expected seedling recruitment in 2022-2023, requiring adaptive management. Despite challenging wet
conditions, the program achieved 89% reduction through consistent follow-up targeting rainfall-triggered germination events.