Interactions betweenBactra verutanaand the Development of Purple Nutsedge(Cyperus rotundus)Grown Under Three Temperature Regimes

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 550-553 ◽  
Author(s):  
K. E. Frick ◽  
R. D. Williams ◽  
R. F. Wilson

For effective biological control through augmentation,Bactra verutanaZeller, would have to be released against purple nutsedge(Cyperus rotundusL.) in May and June when temperatures are cooler than they are from late July through September when maximal natural populations of this biological control agent occur.Bactralarvae exposed to simulated mid-May (24/13 C) and mid-June (29/18 C) temperature regimes developed more slowly than larvae exposed to the mid-July (32/26 C) temperature regime, but nutsedge plant growth was also slower. Thus, the relative amounts of feeding injury were similar at all three regimes. Larval feeding generally increased the number of shoots slightly, but not significantly, reduced significantly the production of inflorescences, and reduced the weight of total dry matter produced between 28 and 49%.

2015 ◽  
Vol 33 (2) ◽  
pp. 165-173 ◽  
Author(s):  
R.S.O. Lima ◽  
E.C.R. Machado ◽  
A.P.P. Silva ◽  
B.S. Marques ◽  
M.F. Gonçalves ◽  
...  

This work was carried out with the objective of elaborating mathematical models to predict growth and development of purple nutsedge (Cyperus rotundus) based on days or accumulated thermal units (growing degree days). Thus, two independent trials were developed, the first with a decreasing photoperiod (March to July) and the second with an increasing photoperiod (August to November). In each trial, ten assessments of plant growth and development were performed, quantifying total dry matter and the species phenology. After that, phenology was fit to first degree equations, considering individual trials or their grouping. In the same way, the total dry matter was fit to logistic-type models. In all regressions four temporal scales possibilities were assessed for the x axis: accumulated days or growing degree days (GDD) with base temperatures (Tb) of 10, 12 and 15 oC. For both photoperiod conditions, growth and development of purple nutsedge were adequately fit to prediction mathematical models based on accumulated thermal units, highlighting Tb = 12 oC. Considering GDD calculated with Tb = 12 oC, purple nutsedge phenology may be predicted by y = 0.113x, while species growth may be predicted by y = 37.678/(1+(x/509.353)-7.047).


2016 ◽  
Vol 9 (2) ◽  
pp. 78-88 ◽  
Author(s):  
A. Mohammadi-Khoramabadi ◽  
H. Alipanah ◽  
S. Belokobylskij ◽  
M.R. Nematollahi

Summary Prosopis farcta (Fabaceae) is a native and common perennial weed plant in Iran. In search of environmental-friendly control methods against P. farcta, we discovered the seed feeder moth Nephopterygia austeritella (Lepidoptera; Pyralidae) in central Iran and studied its bioecology for the first time from 2008 through 2009. Infestation pattern, larval feeding behaviour, developmental period, seasonal occurrence and the adverse impact of the moth on the reproductive organs of P. farcta were investigated. Diagnostic morphological characters of the fifth larval instar of N. austeritella are provided. Two gregarious ectoparasitoids were reared and identified as Apanteles subcamilla and Phanerotoma leucobasis (Hymenoptera: Braconidae). Mortality rates of the larvae were 3.03 and 13.44% in 2008 and 2009, respectively. Larvae destroyed 29.6-38.4% of the pods of their host plants. The potential of N. austeritella as an efficient biological control agent in IPM programs against P. farcta is discussed.


Author(s):  
Randall W. Long ◽  
Carla M. D’Antonio ◽  
Tom L. Dudley ◽  
Kevin R. Hultine ◽  
Adam M. Lambert

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 438
Author(s):  
Sonja Stutz ◽  
Rosemarie De Clerck-Floate ◽  
Hariet L. Hinz ◽  
Alec McClay ◽  
Andrew J. McConnachie ◽  
...  

We evaluated the potential of the European root-feeding moth Dichrorampha aeratana as a biological control agent for the invasive weed Leucanthemum vulgare (oxeye daisy) in North America and Australia. The taxonomic proximity of the ornamental Shasta daisy (Leucanthemum × superbum) to L. vulgare and its popularity in North America made finding sufficiently host-specific biological control agents a challenge. No-choice tests conducted with 74 non-target species revealed partial or complete larval development on 11 species. In multiple-choice oviposition and larval development tests that were conducted in field cages, larvae were found on five of these, however in multiple-choice tests conducted under open-field conditions, larvae were only found on the ornamentals Shasta daisy and creeping daisy (Mauranthemum paludosum). Larval feeding by D. aeratana had no measurable impact on Shasta daisy, but larval feeding and plant competition reduced the biomass and number of flower heads of L. vulgare. We conclude that D. aeratana is a suitable biological control agent because it will not affect the ornamental value of Shasta or creeping daisies and because it is unlikely to feed on any other economically important or native species. We also expect D. aeratana to contribute to the suppression of L. vulgare populations.


2021 ◽  
Vol 12 (01) ◽  
pp. 1-8
Author(s):  
Duangkhaetita Kanjanasopa ◽  
Wanthakarn Aiedhet ◽  
Suraphon Thitithanakul ◽  
Chanyarat Paungfoo-Lonhienne

2021 ◽  
Vol 22 (6) ◽  
Author(s):  
MAYA SARI ◽  
ABDJAD ASIH NAWANGSIH ◽  
Aris Tri Wahyudi

Abstract. Sari M, Nawangsih AA, Wahyudi AT. 2021. Rhizosphere Streptomyces formulas as the biological control agent of phytopathogenic fungi Fusarium oxysporum and plant growth promoter of soybean. Biodiversitas 22: 3015-3023. Rhizosphere Streptomyces are considered as promising sources of plant growth-promoting rhizobacteria (PGPR) and biocontrol agents against pathogenic fungi, particularly Fusarium oxysporum causing root rot, cotyledon rot, hypocotyl rot, and stunted growth in soybean. Formulation of rhizosphere Streptomyces with appropriate carrier materials is necessary to facilitate storage and application in plants. This study aimed to develop a formulation of rhizosphere Streptomyces, apply the formula to control F. oxysporum, and promote soybean plant growth. Five Streptomyces isolates, i.e., Streptomyces panaciradicis ARK 13, Streptomyces tritolerans ARK 17, Streptomyces recifensis ARK 63, Streptomyces tendae ARK 91, and Streptomyces manipurensis ARK 94 were used in this study. All of the isolates could grow in potato broth, rice bran extract, and molasses as alternative media. The highest biomass produced from the molasses growth medium. All five isolates had antifungal activity against F. oxysporum with the inhibition percentage ranging from 41% to 76%, and all of them were detected to have the iaaM gene. Indole-3-acetic acid (IAA) hormone produced by these isolates were ranging from 8.99-15.14 mg L-1, with the phosphate solubilization index of 2.13-2.47. Five rhizosphere Streptomyces formulas with the main carrier of peat could maintain the viability with the population density of 108 CFU g-1 for 8 weeks of storage at room temperature. Two formulas, F17 and F94, were the best formulas to control disease caused by F. oxysporum with disease suppression of 74% in sterile soil and 80-85% in non-sterile soil. Formula F17 and F94 significantly increased soybean growth in sterile and non-sterile soils. Therefore, these formulas could be recommended as biocontrol and plant growth promoters of soybean.


2017 ◽  
Vol 17 (2) ◽  
pp. 170 ◽  
Author(s):  
Nur Prihatiningsih ◽  
Heru Adi Djatmiko ◽  
Puji Lestari

Siderophore activity of Bacillus subtilis as plant growth promoters and biological control agent of eggplants pathogens. The aims of this research were to identify the siderophores of B. subtilis, to assess its activities as plant growth promoters and biological control agent of eggplants pathogens. Five isolates of B. subtilis i.e.B46, B209, B211, B298 and B 315 grown on SDCASA medium. The isolate which showed the best siderophores production was then further studied on its ability as a growth promoter on eggplants in two soil types with different Fe content. The inhibitory test was conducted against two kinds of pathogens, namely Colletotrichum sp. and Ralstonia solanacearum. The greenhouse experiment was arranged using a factorial completely randomized block design. The first factor was the B. subtilis (B. subtilis B298 and without B. subtilis B298), second factor was the type of soil (Ultisol and Andisol). The variables measured were Fe uptake by plants, plant growth parameters on eggplant i.e. height, leaf number, root length, root volume, weight of fresh and dried shoot as well as fresh and dry root, percentage of inhibition to fungal and bacterial eggplant pathogens. The results showed that the five isolates of B. subtilis were able to produce siderophores as catecholate and hydroxamate types. The best siderophore production was showed by B. subtilis B298. The ability of B. subtilis B298 in accelerating the growth of plants was indicated by the increased of uptake Fe, plant height, leaf number, root volume, weight of dried plants by 45.62%, 25.48%, 19.45%, 41.10% and 34.89% respectively. The inhibition to the fungal and bacterial eggplant pathogens best shown by the isolates of B. subtilis B298 with 55.4% and 22 mm respectively.


2022 ◽  
Vol 951 (1) ◽  
pp. 012106
Author(s):  
R Sriwati ◽  
T Chamzurni ◽  
F Razi ◽  
Syaifullah ◽  
Yunita ◽  
...  

Abstract To increase plant resistance from an early age, it is necessary to introduce biological control agents from groups of fungi and bacteria. This study aims to determine the effect of Trichoderma harziaunum and Bacillus thuringiensis Aceh isolates in increasing the superiority of Aceh patchouli plants that are resistant to pests and plant diseases. The study used non-factorial RAL method with cover and uncovered seedling methods. Both series were treated with the same biological control agent, the control without any treatment, the treatment of T. harzianum and B. thuringiensis while the observations were made when the seedling covered was opened. Observations included plant morphological characters, plant growth development and peroxidase enzymes. The results showed that morphologically the original patchouli growing in Lhoong district had similar morphological characters to the Lhokseumawe variety. The application of biological control agents of the T. harzianum and B. thuringiensis groups was more effective in increasing plant growth in the closed seedling treatment compared to the uncovered seedling. T. harzianum gave the best effect at a dose range of 1-1.5 while B. thuringensis showed a better effect at a concentration of 10-15 ml. Both treatments increased the growth of patchouli seedlings as indicated by the better plant height and number of shoots. Furthermore, higher peroxidation enzymes were found in the closed seedling treatment with 1.5 g T harzianum and 15 ml B. thuringiensis. The high peroxidase enzyme as an indicator of the more resistant plants have been induced to pests and diseases. From the screen house experiment, T. harzianum and B. thuringiensis were more efficient in inducing plant growth and disease resistance of local varieties of patchouli using the closed seedling method.


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