Stamina GT6 combines useful winter growth, great persistence and the ability to tolerate set stocking of sheep (though not recommended for lamb finishing). It provides excellent yield and quality during warmer growing months. Stamina GT6 was the first lucerne released for Australian farmers trialled under the internationally recognised Standard Test Protocol for grazing tolerant lucernes.
PGG Wrightson Seeds have developed three Stamina lucernes, Stamina Torrens GT8, Stamina GT6, Stamina 5. Our Stamina lucernes have forced a rethink on how lucerne is used by farmers in mixed farming zones. The reality is that the demands of sheep grazing, such as set stocking for lengthy periods and hot dry seasons, are not conducive to lucerne persistence. The PGG Wrightson Seeds Stamina lucernes aim to change that.
Most growers require a longer term lucerne stand that is productive through the warmer months when quality feed is in short supply. In addition they require a lucerne stand that tolerates the rigours of dryland sheep grazing for up to 10 years. The Stamina range of lucernes will persist and produce better if rotationally grazed. Once established, they tolerate continuous and close grazing better than most other lucerne varieties. Stamina lucernes are also good companions for phalaris, winter-active tall fescues and sub and annual clovers, producing a robust year-round legume based pasture.
The Stamina lucernes have low broad crowns and naturally have high forage quality with fine stems and high leaf/stem ratio. Stamina lucernes are able to maintain this quality by remaining a dense, leafy stand rather than opening up and becoming stalky and weedy. Stamina® lucernes are suitable for grazing, or production of quality hay.
Developing grazing tolerant lucernes for Australia’s dryland farms has taken nearly two decades and was a collaboration between PGG Wrightson Seeds and Cal/West Seeds in the USA. The products were initially developed in the US after a 6 year screening programme in which elite breeding lines and successful commercial varieties were set stocked by both sheep and beef cattle for a period of 6-7 months per year. Paddocks were maintained at a constant vegetative height of 2-5cm throughout the grazing periods.
Further screening was conducted in Australia by PGG Wrightson Seeds who evaluated 24 advanced lines in trials that ran for 7 years. Plots were grazed for two 10 month periods at a stocking rate of 40 sheep/ha equivalent. Lucerne varieties bearing the Stamina designation were selected as ‘best of the best’ in these ultra-rigorous evaluations.
There are a number of seed companies claiming their lucernes are grazing tolerant, we encourage farmers to ask how they were developed, how they were tested and if they were evaluated according to the standard test protocols. Farmers who want persistent lucerne standards advised to plant, proven grazing tolerant (GT) varieties from PGG Wrightson Seeds.
Stamina GT6 like all other lucerne is small seeded, so therefore it is important to ensure that the sowing of Stamina GT6 is done correctly to ensure the best results for establishment. There are some key fundamentals to get right when sowing lucerne including seedbed preparation, weed control, sowing depth and sowing technique. Following these key steps will help achieve a good establishment of lucerne.
Preparing the seedbed takes into consideration the soil type and cultivation of the soil to ensure the soil is fine. This will aid the seed to soil contact at the time of sowing as well as supporting good moisture infiltration around the seed either after a rainfall event or irrigation.
Poor weed control is one of the most common issues that can lead to poor lucerne establishment. Weed control must start the year prior to sowing the lucerne to ensure adequate time and opportunity to control any weeds that are present in the paddock. This should also reduce the need for post emergent herbicides to be used in the young lucerne crop as this can retard growth.
The sowing depth needs to be managed as lucerne is a small seed and therefore only needs to be sown at no more the 15mm deep. This will enable the lucerne to germinate and the seedlings to rise above the soil to begin photosynthesis.
The sowing technique is the method of actually getting the seed into the soil. With so many different options for sowing equipment, it is important to understand the impact this can have when sowing lucerne. Accuracy of sowing rate, equipment condition (shears, knife points or discs) and final compaction (press wheels, harrows or tyre roller) are all important when looking to successfully establish lucerne.
In the development and evaluation of Stamina GT6 it underwent a very tough protocol to establish grazing tolerance. While Stamina GT6 will survive better than most other lucernes if treated in less than ideal management for lucerne persistence, it is not recommended to treat it any differently to managing other lucerne stands.
Stamina GT6 should be grazed in a rotational grazing system. It is recommended that the rotation period is between 30 – 35 days following grazing during the growing period (rotation lengths may need to be extended during the cooler months due to slower growth).
When grazing lucerne it is ideal to graze the plant down to 5cm in height and then have the stock taken out. This typical management will ensure a strong lucerne stand for many years which will make Stamina GT6 a very sound investment.
Minimum 350mm rainfall per annum unless irrigated