Influence of various environmental factors on seed germination and seedling emergence of a noxious environmental weed: Green Galenia (Galenia pubescens)
- Authors: Mahmood, Ako , Florentine, Singarayer , Chauhan, Bhagirath , McLaren, David , Palmer, Grant , Wright, Wendy
- Date: 2016
- Type: Text , Journal article
- Relation: Weed Science Vol. 64, no. 3 (2016), p. 486-494
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- Description: Green galenia is a South African woody prostrate perennial that was first recorded in Australia in the early 1900s and has since become a serious threat to indigenous temperate grasslands and surrounding agricultural areas. Laboratory and field based experiments were conducted to examine the effect of environmental factors on the germination and viability of green galenia seed. It was shown that green galenia was able to germinate over a broad range of temperatures, but short bursts (5 min) of high temperatures (80 C to 120 C replicating possible exposures to a fire) reduced seed germination. Seed germination was positively favored by light, declined rapidly in darkness, and decreased by >80% at a depth of only 0.5 cm in soil. Water stress greatly reduced seed germination (45% germination at osmotic potentials below -0.2 MPa). Germination was completely inhibited at water potentials of -0.4 to -1.0 MPa. This species is moderately tolerant to salinity, with over 50% of seeds germinating at low levels of salinity (60 mM NaCl), and moderate germination (49%) occurring at 120 mM NaCl, it can germinate well in both alkaline (pH 10-83%) and acidic (pH 4-80%) conditions. The results of this study have contributed to our understanding of the germination and emergence of green galenia, and this will assist in developing tools and strategies for the long term management of this noxious weed in Victoria and other parts of Australia. Nomenclature: Green galenia, Galenia pubescens (Eckl. & Zeyh.) Druce.
Investigations into the effects of elevated carbon dioxide and drought on the growth and physiology of carpet weed (Galenia pubescens Eckl. & Zeyh.)
- Authors: Mahmood, Ako , Florentine, Singarayer , Fernando, Nimesha , Wright, Wendy , Palmer, Grant , McLaren, David , Sillitoe, Jim
- Date: 2016
- Type: Text , Conference proceedings
- Relation: 20th Australasian Weeds Conference 2016; Perth, Western Australia; 11th-15th September 2016 p. 347-350
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- Description: The present study aimed to examine the interactive effects of elevated atmospheric CO2 concentration and drought stress on the growth and some of the physiological processes of Galenia pubescens. Photosynthetic rate of plants increased under elevated CO2 concentration, however drought caused significant reduction in net photosynthetic rate by (45% in 400 ppm CO2) and (27% in 700 ppm CO2) after five days simulating the drought treatment when compared with well-watered plants. Plants grown under elevated CO2 level and well-watered produced a greater biomass (17.5 ± 0.5 g per plant) compared to the plants which were grown under the ambient CO2 concentration.