scholarly journals Effects of Gall Induction by Epiblema Strenuana on Gas Exchange, Nutrients, and Energetics in Parthenium Hysterophorus

BioControl ◽  
2005 ◽  
Vol 50 (5) ◽  
pp. 787-801 ◽  
Author(s):  
S. K. Florentine ◽  
A. Raman ◽  
K. Dhileepan
Keyword(s):  
Gas Exchange ◽  
Parthenium Hysterophorus ◽  
Epiblema Strenuana ◽  
Gall Induction

Seasonal variation in the effectiveness of the leaf-feeding beetle Zygogramma bicolorata (Coleoptera: Chrysomelidae) and stem-galling moth Epiblema strenuana (Lepidoptera: Tortricidae) as biocontrol agents on the weed Parthenium hysterophorus (Asteraceae)

2003 ◽  
Vol 93 (5) ◽  
pp. 393-401 ◽  
Author(s):  
K. Dhileepan
Keyword(s):  
Seed Bank ◽  
Negative Impact ◽  
Soil Seed Bank ◽  
Summer Rainfall ◽  
Biocontrol Agents ◽  
Parthenium Hysterophorus ◽  
Exclusion Experiment ◽  
Limited Impact ◽  
Zygogramma Bicolorata ◽  
Epiblema Strenuana

AbstractVariation in the effectiveness of biocontrol agents on the weed Parthenium hysterophorus L. was evaluated at two properties (Mount Panorama and Plain Creek) in Queensland, Australia for four years (1996–2000) using a pesticide exclusion experiment. At Mount Panorama, higher levels of defoliation by the leaf-feeding beetle Zygogramma bicolorata Pallister and galling by the moth Epiblema strenuana Walker in 1996–97 coincided with an above average summer rainfall, but in the following three years with below average summer rainfall the defoliation and galling levels were significantly lower. Biocontrol had significant negative impact on the weed only in 1996–97 with no major impact in the following three years. At Plain Creek, galling by E. strenuana was evident in all the four years, but varied significantly between years due to non-synchrony between P. hysterophorus germination and E. strenuana emergence. At Plain Creek biocontrol had limited impact on the weed in 1996–97 and 1997–98, with no significant impact in the following two years. Over the 4-year period, defoliation and galling resulted in 70% reduction in the soil seed bank at Mount Panorama, but the reduction in the soil seed bank at Plain Creek due to galling was not significant. Effectiveness of Z. bicolorata and E. strenuana was dependent on weather conditions and as a result had only limited impact on the weed in three out of four years.

Parthenium weed (Parthenium hysterophorus L.): gas exchange characteristics as a basis for prediction of its geographical distribution

1977 ◽  
Vol 28 (3) ◽  
pp. 449 ◽  
Author(s):  
D Doley
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Gas Phase ◽  
Leaf Water Potential ◽  
Dark Respiration ◽  
Leaf Water ◽  
Parthenium Hysterophorus ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Very High

Gas exchange studies in Parthenium hysterophorus L., a weed recently introduced into central Queensland, indicate that its limits of distribution may be very wide in the humid and subhumid regions of Australia. Under conditions of high leaf water potential, the maximum rate of apparent photosynthesis of cabinet-grown plants was 77 ng cm-2 sec-1, with a temperature optimum of 28°C. Gas phase diffusive resistances were very low and insensitive to photosynthetic photon flux density at high water potentials (–5.0 bars), but became greater and quite sensitive to photon flux as the leaf water potential approached –20 bars. At temperatures between 10 and 40°C, transpiration increased slightly, and the dark respiration rate was almost constant, owing to a steady and considerable increase in gas phase diffusive resistance with temperature. The control of gas exchange broke down at about 42°C, so that transpiration in the light and dark proceeded at equal rates, and dark respiration rates were very high. Gas exchange in P. hysterophorus appears to be no more sensitive to reduced water potential than it is in several favoured crop and pasture species, but the distribution of this weed may be limited by even brief exposure to very high temperatures, or by prolonged drought.

Sign in / Sign up

Export Citation Format

Share Document