Tactics for integrated weed management
There are many tactics that should be considered when developing an integrated plan to manage annual ryegrass (Lolium rigidum). These include: improving crop competition; burning residues; inversion ploughing; autumn tickle; using herbicides and more.
| Tactic | Most likely % control (range) | Comments on use |
|---|---|---|
| Improving crop competition | 50 (20-80) | Optimum sowing rates essential. Row spacing >250mm will reduce crop competitiveness. Sow on time |
| Burning residues | 50 (0-90) | Avoid grazing crop residues. Use a hot fire back-burning into the wind |
| Inversion ploughing | 95 (80-99) | Bury seed 100mm deep. Use of skimmers on plough is essential for good results |
| Autumn tickle | 15 (0-50) | Only effective on previous year's seed-set |
| Fallow and pre-sowing cultivation | 60 (0-90) | Cultivation may lead to increased ryegrass in the crop. Use in combination with a knockdown herbicide. Use cultivators that bury seed. Cultivate during dry weather to reduce transplanting |
| Knockdown (non-selective) herbicides for fallow and pre-sowing control | 80 (30-95) | Avoid overuse of the one herbicide group. Add carfentrazone if annual ryegrass has less than two leaves |
| Double knockdown or ‘doubleknock’ | 95 (80-99) | Reduces the likelihood of glyphosate resistance. Use glyphosate followed by SpraySeed® 3-14 days later |
| Pre-emergent herbicides | 70 (50-90) | Note incorporation requirements for different products and planting systems. Rotate between herbicide groups |
| Selective post-emergent herbicides | 90 (80-95) | Apply as early as possible after the annual ryegrass has two leaves to reduce yield losses in cereals |
| Spray-topping with selective herbicides | 80 (60-90) | Apply before milk dough stage of annual ryegrass |
| Crop-topping with non-selective herbicides | 70 (50-90) | Note stage of crop compared to stage of annual ryegrass. Often not possible to achieve without crop loss |
| Pasture spray-topping | 80 (30-99) | Graze heavily in spring to synchronise flowering |
| Silage and hay – crops and pastures | 80 (50-95) | Most commonly used where there is a mass of resistant annual ryegrass growth. Follow up with herbicides or grazing to control regrowth |
| Renovation crops and pastures – green manuring, brown manuring, mulching and hay freezing | 90 (70-95) | Most commonly used where there is a mass of resistant annual ryegrass growth. Follow up with herbicides or grazing to control regrowth |
| Grazing – actively managing weeds in pastures | 50 (20-80) | Graze heavily in autumn to reduce annual ryegrass plant numbers. Graze heavily in spring to reduce seed-set |
| Weed seed collection at harvest | 65 (40-80) | Best results where crop is harvested as soon as possible before weeds lodge or shatter |
| Sow weed-free seed | 85 (50-99) | Reduces the risk of introducing resistant annual ryegrass to the paddock with crop seed |