The results of an applied science study led by Associate ProfessorSingarayer Florentine at Federation University have been published in the Online Journal PLoS ONE. The objective of this study was to identify how the environmental factors of light, temperature, heat, salinity, drought, soil pH, and seed burial influence germination and seedling emergence of two serrated tussock populations. Studies have shown that light and alternating temperature regimes have been identified as two of the most important environmental factors in triggering seed germination.
The results of this study highlight that serrated tussock seeds are non-photoblastic, and dormancy break can be triggered by favourable of alternating temperatures of approximately 25/15°C and ample water availability. Radiant heat was also observed to have a positive effect on total germination yields. Interestingly, the study found that germination was not enhanced or inhibited by pH level, suggesting that soil pH is not a limiting factor on this species recruitment.
These findings suggest that light reducing management techniques will be unsuccessful for preventing germination. Tilling the seeds to a depth of at least 4cm may reduce the emergence of seedlings, and because the seeds still germinate when buried, this may quickly reduce the seedbank.
(image 1: The effect of seed burial (cm) under field conditions on seed germination (%)
Land managers should look for serrated tussock recruitment after good rainfall events and suitable temperature regimes, particularly after fire treatments. By understanding the climatic conditions that significantly enhance recruitment, management techniques can be applied accordingly to maximise their productivity.
The full journal article can be viewed for free by clicking here:
Citation: Humphries T, Chauhan BS, Florentine SK (2018) Environmental factors effecting the germination and seedling emergence of two populations of an aggressive agricultural weed; Nassella trichotoma. PLoS ONE 13(7): e0199491. https://doi.org/10.1371/journal.pone.0199491