Native Seeds sells a range different grass types, but there are different ways that the seed is prepared for sale.
Seed is sold as:
• clean seed
• floretted seed
• pelletised seed
• seeds and awns (kangaroo grass)
• seed in thatch form
The method used is usually the result of the different characteristics of the seed.
Australian native grass seeds have notbeen modified by years of selective breeding and usually come wrapped in fluffy appendages or with long awns or with awns that make them form asmall ball like steel wool.
So what are the advantages and limitations of these various seed forms?
These are seeds that have been cleaned of their appendages to expose the caryopsis, or kernel of the seed. These seeds are easy to sow through conventional equipment as they flow easily and can be sown to the desired depth.
The disadvantage of using cleaned seed is that it is not able to bury itself, relies on human activity for dispersal and needs to be sown into the soil under controlled conditions. Sometimes these seeds will germinate faster than floretted seed, but this only occurs when conditions are ideal – the soil is well cultivated, the temperature is correct and there is a regular and constant moisture level.
Native Seeds sometimes prepares seed in the cleaned form for use by specific clients such as turf farms where conditions are guaranteed to be ideal, otherwise we usually recommend sowing seed in the floretted form or the pelletised form.
This means seed that is still enclosed in its various appendages such as fluffy lemmas or glumes or even twisted awns. For some seeds such as wallaby grass, this means that it is very hairy and wide; for others such as spear grass it means long awns that twist and interlock; while for others like weeping grass this means interlocking awns. All of these appendages make these seeds impossible to sow through conventional equipment.
They do offer advantages for establishment in some conditions. Often the appendages help to disperse the seed, often they help to help bury the seed in the ground and in many cases the appendages help to hold moisture around the seeds which aids germination.
Recent technological advances have seen the development of pelletising processes that wrap the entire floretted seed in a coating. This has dramatically improved the ability of the seed to be sown by conventional equipment as the seed, once pelletised, is able to flow freely. It also offers other potential advantages through the capacity to include other ingredients into the pelletising material. It is possible to add in some plant protection factors such as a fungicide for protection against seedling diseases, an insecticide for control of sucking pests in the early plant stages and even beneficial fungi to help to promote plant growth on difficult or sterile soils. It may even be possible to add small amounts of specific plant nutrients on soils that are known to be limited by the availability of the ingredient.
Seed pelletizing does add weight to each seed and hence there are fewer seeds per kilogram. But there are many compensating advantages through higher rates of seedling establishment. However, the sowing rate usually needs to be doubled for pelletised seed.
Native Seeds is continuing to investigate the use of seed pelletising for our native grasses and will incorporate new technologies once they have been proven to be advantageous to seedling establishment.
Seeds and Awns
This form applies mainly to Kangaroo grass as it is a particularly difficult grass to clean down to cleanseed. We have been spending considerable time on our efforts to develop a successful cleaning method, developing new machinery in the process. At this stage, all our top end Kangaroo grass product is sold in this form. It consist of seed and awns with a small amount of mulched straw. It is easy to sow, as the seed will flow through commercial seeding equipment.
Kangaroo grass has been sold in the thatch form for some years and occasionally Native Seeds keeps a smallpart of its crop for cutting and sale in the thatch form. To produce thatched seed, the entire stem of the kangaroo grass plant is cut about 150mm (6 inches) off the ground and gathered together. Sometimes these stems are simply laid flat on the areas to be sown; while at other times they are stacked and stored prior to dispersal.
The advantages of this process are that seed is not lost through the harvesting process and that there is an amount of mulch material available for protection of the prepared ground. There is also a potential gain from ongoing maturation of some partially ripe seeds while in the thatch, though this is somewhat unreliable.
The disadvantages are that the amount of seed included cannot be precisely known, the viability of the seed cannot be tested, the rate of spread of the seed cannot be controlledand the evenness of sowing is very poor.
Clients should contact Native Seeds to see what seed form is the most appropriate for the application.