Population Dynamics of Broadleaf Weeds in Turfgrass as Influenced by Chemical and Biological Control Methods

Weed Science ◽  
2007 ◽  
Vol 55 (4) ◽  
pp. 371-380 ◽  
Author(s):  
Mohammed H. Abu-Dieyeh ◽  
Alan K. Watson
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Weed Control ◽  
Seed Bank ◽  
Biological Control Agent ◽  
Control Agent ◽  
Weed Species ◽  
Early Autumn ◽  
Herbicide Treatment ◽  
Broadleaf Species

A 3-yr field study was conducted to determine the effect of a biological control agent,Sclerotinia minorJagger, and a common herbicide, Killex, on the population dynamics of dandelion and other broadleaf species and on the dandelion seed bank. Treatments were applied as one spring, one early autumn, or a spring plus an early autumn treatment per year. The response of the dandelion population to a spring herbicide treatment was similar to two applications per year (spring and early autumn). Significantly less dandelion control occurred after the first early autumn application of the herbicide. Two weeks after application, spring or early autumn treatments withS. minorwere equally effective in suppressing dandelions. In the second year of the two applications per year ofS. minortreatment, weed control was equivalent to the herbicide. By the third year of the one spring application ofS. minor, weed control was equivalent to the herbicide. Generally over the study period, the early autumn application ofS. minorwas less effective than the spring or the spring and early autumn applications. TheS. minortreatments significantly reduced the dandelion seed bank, and this effect was not significantly different from the Killex herbicide treatment. The rate, frequency, and seasonal timing of application had no effect on the dandelion seed-bank size, but terminating the application would gradually replenish the seed bank. Populations of white clover, broadleaf plantain, birdsfoot trefoil, and common ragweed were similarly suppressed by either theS. minoror the herbicide treatments. Yellow woodsorrel significantly increased after 1 yr of herbicide treatment compared with theS. minorand untreated control treatments, indicating a possible weed species shift. Turf quality was improved because of the herbicide andS. minortreatments, but grass injury and smooth crabgrass invasion were recorded in 17% of herbicide-treated plots.

A process-based population dynamics model to explore target and non-target impacts of a biological control agent

2009 ◽  
Vol 220 (17) ◽  
pp. 2035-2050 ◽  
Author(s):  
Darren J. Kriticos ◽  
Michael S. Watt ◽  
Toni M. Withers ◽  
Agathe Leriche ◽  
Michelle C. Watson
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Biological Control Agent ◽  
Control Agent ◽  
Dynamics Model ◽  
Population Dynamics Model

Hybridization between Dactylopius tomentosus (Hemiptera: Dactylopiidae) biotypes and its effects on host specificity

2010 ◽  
Vol 100 (3) ◽  
pp. 331-338 ◽  
Author(s):  
C.W. Mathenge ◽  
P. Holford ◽  
J.H. Hoffmann ◽  
H.G. Zimmermann ◽  
R.N. Spooner-Hart ◽  
...  
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Host Specificity ◽  
Biological Control Agent ◽  
Control Agent ◽  
Weed Species ◽  
Maternal Parent ◽  
Control Programs ◽  
Fitness Index ◽  
Biological Performance

AbstractDactylopius tomentosus is composed of biotypes adapted to different Cylindropuntia species. One biotype is an important biological control agent of C. imbricata in South Africa while another has the potential for the control of C. fulgida var. fulgida. These two weed species occur in sympatry in some areas of South Africa, so the introduction of the second biotype could result in hybridization, which, in turn, could impact on the biological control programs through altered host specificity and fitness of the hybrids. To anticipate what might happen, reciprocal crosses were made between the two biotypes, and the biological performance of the resultant hybrids was compared with that of each parental lineage on C. imbricata and C. f. var. fulgida. The biotypes interbred freely and reciprocally in the laboratory. Comparisons of crawler and adult female traits showed differences in performance that were dependent on the origin of the maternal and paternal genomes. However, when all traits were combined into a ‘fitness index’, both hybrids clearly outperformed the parental lineages. The increase in fitness shown by the hybrids over their maternal lineage was greater on the alternative host of the maternal parent than on the natural host of the maternal parent. Therefore, in areas where the two cacti occur in sympatry, hybridization between the biotypes is not expected to be detrimental to the biological control of either weed.

scholarly journals Host Range of Herpetogramma basalis (Lepidoptera: Crambidae), a Biological Control Agent for the Invasive Weed Alternanthera philoxeroides (Centrospermae: Amaranthaceae) in China

2019 ◽  
Vol 19 (6) ◽  
Author(s):  
Shihai Chu ◽  
Shengbo Cong ◽  
Ruhai Li ◽  
Youming Hou
Keyword(s):  
Biological Control ◽  
Host Range ◽  
Biological Control Agent ◽  
Oviposition Preference ◽  
Multiple Choice ◽  
Control Agent ◽  
Alternanthera Philoxeroides ◽  
Weed Species ◽  
Amaranthus Tricolor ◽  
Invasive Weed

Abstract Alternanthera philoxeroides (Mart.) Griseb. is an invasive herbaceous amphibious weed species in China. A pyralid moth Herpetogramma basalis (Walker) was discovered feeding on A. philoxeroides through field surveys and may be a potentially useful biocontrol agent. To determine the host range of H. basalis and evaluate its potential to control A. philoxeroides, no-choice and multiple-choice tests were conducted. Herpetogramma basalis fed on target weeds and 29 nontarget plant species. In addition to the target weed A. philoxeroides, H. basalis developed to adult on eight other nontarget species. Herpetogramma basalis survived to adulthood successfully on A. philoxeroides and less successfully on several other Amaranthaceae species. In multiple-choice studies, H. basalis showed a strong oviposition preference for A. philoxeroides over Amaranthus tricolor L. (Centrospermae: Amaranthaceae). Amaranthus tricolor was the only crop plant that supported the complete development of H. basalis. We cautiously recommend H. basalis for the biological control of A. philoxeroides in China.

Field Evaluation of a Bioeconomic Model for Weed Management in Corn (Zea mays)

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 915-923 ◽  
Author(s):  
Douglas D. Buhler ◽  
Robert P. King ◽  
Scott M. Swinton ◽  
Jeffery L. Gunsolus ◽  
Frank Forcella
Keyword(s):  
Weed Control ◽  
Seed Bank ◽  
Active Ingredient ◽  
Weed Management ◽  
Corn Yield ◽  
Bioeconomic Model ◽  
Weed Species ◽  
Economic Return ◽  
Soybean Yield ◽  
Herbicide Treatment

A bioeconomic weed management model was tested as a decision aid for weed control in corn at Rosemount, MN, from 1991 to 1994. The model makes recommendations for preemergence control tactics based on the weed seed content of the soil and postemergence decisions based on weed seedling densities. Weed control, corn yield, herbicide active ingredient applied, and economic return with model-generated treatments were compared to standard herbicide and mechanical control treatments. Effects of these treatments on weed populations and soybean yield the following year were also determined. In most cases, the model-generated treatments controlled weeds as well as the standard herbicide treatment. The quantity of herbicide active ingredient applied decreased 27% with the seed bank model and 68% with the seedling model relative to the standard herbicide treatment. However, the frequency of herbicide application was not reduced. In 1 yr, seed bank model treatments did not control weeds as well as the standard herbicide or seedling model treatments. Corn yields reflected differences in weed control. Net economic return to weed control was not increased by using model-generated control recommendations. Weed control treatments the previous year affected weed density in the following soybean crop. In 2 of 3 yr, these differences did not after weed control or soybean yield. Although tactics differed, the bioeconomic model generally resulted in weed control and corn yield similar to the standard herbicide. The model was responsive to differing weed populations, but did not greatly after economic returns under the weed species and densities in this research.

scholarly journals Chondrostereum purpureum as an inundative biological control agent for invasive woody weeds in New Zealand

2010 ◽  
Vol 63 ◽  
pp. 274-274
Author(s):  
T.D. Ramsfield ◽  
C.A. Carlson ◽  
M.W.P. Power ◽  
D. Skudder
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Populus Trichocarpa ◽  
Control Agent ◽  
Lesion Length ◽  
Weed Species ◽  
Buddleja Davidii ◽  
Inundative Biological Control ◽  
Salix Matsudana ◽  
Chondrostereum Purpureum

Chondrostereum purpureum is a basidiomycete fungus that is being investigated as an inundative biological control agent for invasive woody weeds This study was conducted to assess the susceptibility of seven species of weeds to C purpureum The species that were inoculated in this trial were broom (Cytisus scoparius) gorse (Ulex europeaus) buddleia (Buddleja davidii) Himalayan honeysuckle (Leycesteria formosa) hawthorne (Crataegus monogyna) poplar (Populus trichocarpa) and willow (Salix matsudana) Two isolates of C purpureum and a control were used and were each replicated 12 times All plants were potted and the trial took place under nursery conditions Mortality and canker size were measured 6 months after inoculation Data were analysed using SAS The highest mortality (50) was recorded for broom with one isolate but very little mortality was observed across the other species A highly significant weed by isolate interaction was observed with regards to lesion length with weed species susceptibility varying with respect to one of the C purpureum isolates Hawthorn and willow had greater lesion lengths after inoculation with the same isolate that had caused mortality in broom The results from this trial are being used to direct a larger field trial

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