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Leaf stage, in ryegrass pasture management, is an indicator for optimal grazing times. Monitoring the leaf stage helps you understand when a paddock is ready for grazing and if your rotation length is suitable for current growth conditions. For instance, grazing between the 2 and 3 leaf stages maximises the quality and quantity of your pasture. Keep in mind, if you graze too early or too late, it could affect the pasture's growth and yield. Using leaf stage as a guide, adjust your grazing practices to maintain a balance between tiller energy status and pasture recovery. By doing so, you ensure your pasture's health and productivity.
Leaf stage can be used to maximise pasture performance. Monitoring ryegrass leaf stage is an effective indicator of when a paddock is ready to graze. The optimal time to graze ryegrass pastures is between the 2 and 3 leaf stage.
Leaf stage helps to identify when a paddock is ready to be grazed and indicates how well rotation length fits with current pasture growth conditions. In spring, using leaf stage will impact on the amount and quality of pasture grown later in the season. Further, good grazing management in spring increases tillering in perennial ryegrass.
The leaf stage takes into consideration:
Rotation length is a practical way to manage pasture growth and quality. Through rotation length we can manage leaf stage and through leaf stage we can evaluate if the rotation length is optimal.
Rotation length can be adjusted to different times of year and pasture situation.
Leaf appearance rates depend on soil temperature and moisture availability, with leaves taking longer to appear when it is cooler or when soil water is limited.
|Average temperature||13 - 16oC||18 - 20oC||14 - 20oC||10 - 13oC|
|Time taken for one leaf to fully grow||9 - 11 days||8 - 10 days||8 - 12 days||11 - 15 days|
|Average temperature||11 - 16oC||16 - 20oC||12 - 20oC||9 - 12oC|
|Time taken for one leaf to fully grow||9 - 13 days||8 - 11 days||8 - 14 days||12 - 16 days|
|Average temperature||9 - 16oC||16 - 19oC||10 - 18oC||7 - 10oC|
|Time taken for one leaf to fully grow||9 - 16 days||9 - 11 days||10 - 17 days||15 - 21 days|
|Bay of Plenty|
|Average temperature||10 - 16oC||16 - 20oC||11 - 20oC||7 - 12oC|
|Time taken for one leaf to fully grow||9 - 15 days||8 - 11 days||8 – 16 days||12 - 21 days|
|Average temperature||10 - 16oC||14 - 18oC||10 - 18oC||8 - 10oC|
|Time taken for one leaf to fully grow||9 - 15 days||10 - 12 days||10 - 17 days||15 - 18 days|
|Lower North Island|
|Average temperature||10 - 16oC||14 - 20oC||10 - 18oC||8 - 10oC|
|Time taken for one leaf to fully grow||9 - 15 days||8 - 12 days||10 - 17 days||15 - 18 days|
|Top of South Island/Westland|
|Average temperature||10 - 16oC||14 - 18oC||10 - 18oC||7 - 9oC|
|Time taken for one leaf to fully grow||9 - 15 days||10 - 12 days||10 - 17 days||16 - 21 days|
|Average temperature||7 - 14oC||13 - 18oC||6 - 16oC||2 - 8oC|
|Time taken for one leaf to fully grow||10 - 21 days||10 - 13 days||11 - 28 days||18 - 72 days|
|Average temperature||7 - 13oC||13 - 18oC||6 - 15oC||2 - 8oC|
|Time taken for one leaf to fully grow||11 - 21 days||10 - 13 days||12 - 28 days||18 - 72 days|
The table presents approximate leaf appearance rates for different regions based on average temperatures and soil water availability of at least 40%.
This can be used as a guide but it is important to determine the leaf stage of your own pastures using the ryegrass picture outlined above
Leaf stage should be used in combination with yield measurements and feed demand information
Rather than rigid adherence to a single leaf stage grazing target, grazing management must also consider needs such as pasture cover targets, feed demand requirements and pasture quality. For example, during periods of high growth rates in spring, lower stocked-farms may graze closer to the 2-leaf stage to control pastures covers and maintain pasture quality.