Effects of Simulated Rainfall on Disease Development and Weed Control of the Bioherbicidal FungiAlternaria cassiaeandColletotrichum truncatum

2012 ◽  
Vol 26 (1) ◽  
pp. 117-121 ◽  
Author(s):  
C. Douglas Boyette ◽  
Charles T. Bryson ◽  
Robert E. Hoagland ◽  
Mark A. Weaver
Keyword(s):  
Weed Control ◽  
Disease Severity ◽  
Rainfall Amount ◽  
Rainfall Event ◽  
Disease Development ◽  
Simulated Rainfall ◽  
Colletotrichum Truncatum ◽  
Weed Host ◽  
Hemp Sesbania ◽  
And Control

Alternaria cassiaeandColletotrichum truncatumare bioherbicidal pathogens of sicklepod, and hemp sesbania, respectively. The effects of simulated rainfall followed by 12 h simulated dew application, immediately or delayed by 1 to 4 h, on disease severity and weed control were studied for each pathogen on its weed host under greenhouse conditions. After each simulated rainfall event, treated plants were placed in a dew chamber for 12 h. Regardless of rainfall amount and/or timing, only slight differences occurred onA. cassiaedisease severity and sicklepod control (85 to 100% for both parameters). However, when similar tests were imposed onC. truncatum, disease severity and hemp sesbania control were highly variable, ranging from 5 to 100%. Regardless of rainfall amount, disease development and control of hemp sesbania were greatly reduced (60%) when dew application was delayed by only 1 h following inoculation, regardless of rainfall treatment. Rainfall at 1.27 and 2.58 cm had little effect on disease development and control in hemp sesbania, but the effect of transfer time to dew application exhibited a greater role on these parameters. Thus the time between bioherbicide application and dew application was more important forC. truncatumthan forA. cassiae. These results indicate that rainfall amounts and the timing of dew application caused differential effects on disease severity and weed control after application of these bioherbicides to their target weeds.

Acetanilide Activity and Dissipation as Influenced by Formulation and Wheat Stubble

Weed Science ◽  
1988 ◽  
Vol 36 (2) ◽  
pp. 243-249 ◽  
Author(s):  
B. B. Petersen ◽  
P. J. Shea ◽  
G. A. Wicks
Keyword(s):  
Soil Moisture ◽  
Weed Control ◽  
Field Research ◽  
Rainfall Event ◽  
Silty Clay ◽  
Simulated Rainfall ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Wheat Stubble ◽  
Increasing Temperature

Laboratory and field research was conducted to determine the influence of winter wheat (Triticum aestivumL.) stubble on weed control and the dissipation of emulsifiable concentrate formulations (EC) of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide], alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide], and acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide]; and microencapsulated formulations (ME) of alachlor and acetochlor. EC metolachlor provided better weed control than EC alachlor when applied 28 days before planting sorghum (Sorghum bicolorL.) and similar weed control when applied at 1 or 14 days before planting. This difference was attributed to more rapid EC alachlor dissipation. The order of relative herbicide persistence at 24 C and 33% (w/w) soil moisture in a silty clay loam was ME acetochlor = ME alachlor > EC metolachlor > EC acetochlor = EC alachlor. Acetanilide degradation was affected more by increasing temperature from 15 to 24 C than by increasing soil moisture from 15 to 33%. More herbicide was washed from overwintered than fresh straw in the first 1 cm of simulated rainfall. In the first simulated rainfall event, more herbicide was removed from straw that had been dry than wet at application, but the amount of herbicide remaining on dry and wet straw was similar after four events. Formulation generally did not affect herbicide wash-off.

Biological Control of Hemp Sesbania (Sesbania exaltata) Under Field Conditions withColletotrichum truncatumFormulated in an Invert Emulsion

Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 497-500 ◽  
Author(s):  
C. Douglas Boyette ◽  
Paul C. Quimby ◽  
Charles T. Bryson ◽  
Grant H. Egley ◽  
Floyd E. Fulgham
Keyword(s):  
Biological Control ◽  
Weed Control ◽  
Field Experiments ◽  
Field Conditions ◽  
Colletotrichum Truncatum ◽  
Greenhouse Experiments ◽  
Sesbania Exaltata ◽  
Invert Emulsion ◽  
Emulsion Formulation ◽  
Hemp Sesbania

In greenhouse experiments, conidia ofColletotrichum truncatumapplied in an invert emulsion formulation controlled hemp sesbania 100% in the absence of a dew treatment. In field experiments, hemp sesbania control averaged 95 and 97% in 1989 and 1990, respectively, when this formulation was applied to hemp sesbania seedlings using tractor-mounted, air-assist nozzles. This level of weed control was comparable to that achieved from the herbicide acifluorfen. These results indicate thatC. truncatumhas excellent potential as a mycoherbicide for controlling hemp sesbania and that this potential can be augmented by formulating the pathogen as an invert emulsion.

scholarly journals Indaziflam: Leaching and control of Urochloa plantaginea in applications on coffee litter with different rainfall simulations

2020 ◽  
Vol 15 ◽  
pp. 1-8
Author(s):  
Paulo Vinicius Da Silva ◽  
Mack José dos Santos ◽  
Sergio Mateus Tronquini ◽  
Ana Lígia Giraldeli ◽  
Roque Dias de Carvalho ◽  
...  
Keyword(s):  
Weed Control ◽  
Active Ingredient ◽  
Soil Surface ◽  
Simulated Rainfall ◽  
High Susceptibility ◽  
Control Effectiveness ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
And Control

Coffee litter and the rain that occurs after the application of pre-emergence herbicides impact on their leaching and weed control effectiveness. The objective of this study was to evaluate the leaching and control effectiveness of indaziflam, applied on coffee litter, and under simulations of different amounts of rainfall. Two experiments in greenhouse were conducted with the application of indaziflam (0.1 kg of active ingredient - a.i. - ha-1), in a completely randomized design. The first involved the leaching of the herbicide using Urochloa plantaginea as a bioindicator, in a 8 x 4 factorial arrangement, with eight depths in the PVC column (0-0.05; 0.05-0.1; 0.1-0.15; 0.15-0.2; 0.2-0.25; 0.25-0.3; 0.3-0.35; 0.35-0.4 m) and four amounts of straw (0; 1; 3 and 5 t ha-1), this factor was isolated for rainfall simulations (10, 20 and 40 mm). The second experiment tested the effectiveness in controlling U. plantaginea, in a 4 x 3 factorial arrangement, with four amounts of litter (0; 1; 3 and 5 t ha-1) and three amounts of rainfall (10, 20 and 40 mm). Both experiments had four repetitions and controls without application of the herbicide. In leaching, a greater effect of indaziflam was found at a depth of 0-0.05 m, and the higher the simulated rainfall, the greater the phytotoxicity observed in U. plantaginea, with 39.75%, 52.50% and 92.06%, for rainfall amounts of 10, 20 and 40 mm, respectively. U. plantaginea showed high susceptibility to control by the herbicide indaziflam, and the lowest control, 82%, was observed when indaziflam was applied on 5 t ha-1 with simulation of rainfall at 10 mm. The increase in the amount of litter on the soil surface, combined with lower amounts of rainfall can reduce the leaching of indaziflam and the control of U. plantaginea.

Weed Control in a Conservation Tillage Rotation in the Texas Blacklands

Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 695-699 ◽  
Author(s):  
Steven M. Brown ◽  
James M. Chandler ◽  
John E. Morrison
Keyword(s):  
Control Systems ◽  
Weed Control ◽  
Conservation Tillage ◽  
Grain Sorghum ◽  
Control Measures ◽  
Sorghum Halepense ◽  
Low Intensity ◽  
No Till ◽  
Primary Tillage ◽  
And Control

A field experiment was conducted to evaluate weed control systems in a conservation tillage rotation of grain sorghum [Sorghum bicolor(L.) Moench.] – cotton (Gossypium hirsutumL.) – wheat (Triticum aestivumL.). Herbicide systems included fall and spring/summer inputs of high and low intensity. Tillage regimes were no-till (NT) and reduced-till (RT) systems; the latter included fall primary tillage followed by spring stale seedbed planting. Both tillage systems utilized controlled traffic lanes and wide, raised beds. Effective johnsongrass [Sorghum halepense(L.) Pers. # SORHA] control required intense herbicide inputs at one or both application periods, i.e., in the fall and/or spring/summer. Grain sorghum and cotton yields for the most intense weed control system, which included high inputs in both the fall and spring/summer, were not superior to systems that included high inputs in only one of the two application periods. Seedling johnsongrass emergence occurred before spring planting in RT (but not in NT) in 2 of 3 yr, and control measures were ineffective. After 3 yr, the predominant weeds were johnsongrass and browntop panicum (Panicum fasciculatumSw. # PANFA).

Evaluation of weed control in acetyl coA carboxylase-resistant rice with mixtures of quizalofop and auxinic herbicides

2019 ◽  
Vol 34 (4) ◽  
pp. 498-505
Author(s):  
Tameka L. Sanders ◽  
Jason A. Bond ◽  
Benjamin H. Lawrence ◽  
Bobby R. Golden ◽  
Thomas W. Allen ◽  
...  
Keyword(s):  
Weed Control ◽  
Rice Yield ◽  
Field Studies ◽  
Growth Stages ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Herbicide Treatments ◽  
Herbicide Mixture ◽  
Sequential Treatments ◽  
And Control

AbstractRice with enhanced tolerance to herbicides that inhibit acetyl coA carboxylase (ACCase) allows POST application of quizalofop, an ACCase-inhibiting herbicide. Two concurrent field studies were conducted in 2017 and 2018 near Stoneville, MS, to evaluate control of grass (Grass Study) and broadleaf (Broadleaf Study) weeds with sequential applications of quizalofop alone and in mixtures with auxinic herbicides applied in the first or second application. Sequential treatments of quizalofop were applied at 119 g ai ha−1 alone and in mixtures with labeled rates of auxinic herbicides to rice at the two- to three-leaf (EPOST) or four-leaf to one-tiller (LPOST) growth stages. In the Grass Study, no differences in rice injury or control of volunteer rice (‘CL151’ and ‘Rex’) were detected 14 and 28 d after last application (DA-LPOST). Barnyardgrass control at 14 and 28 DA-LPOST with quizalofop applied alone or with auxinic herbicides EPOST was ≥93% for all auxinic herbicide treatments except penoxsulam plus triclopyr. Barnyardgrass control was ≥96% with quizalofop applied alone and with auxinic herbicides LPOST. In the Broadleaf Study, quizalofop plus florpyrauxifen-benzyl controlled more Palmer amaranth 14 DA-LPOST than other mixtures with auxinic herbicides, and control with this treatment was greater EPOST compared with LPOST. Hemp sesbania control 14 DA-LPOST was ≤90% with quizalofop plus quinclorac LPOST, orthosulfamuron plus quinclorac LPOST, and triclopyr EPOST or LPOST. All mixtures except quinclorac and orthosulfamuron plus quinclorac LPOST controlled ivyleaf morningglory ≥91% 14 DA-LPOST. Florpyrauxifen-benzyl or triclopyr were required for volunteer soybean control >63% 14 DA-LPOST. To optimize barnyardgrass control and rice yield, penoxsulam plus triclopyr and orthosulfamuron plus quinclorac should not be mixed with quizalofop. Quizalofop mixtures with auxinic herbicides are safe and effective for controlling barnyardgrass, volunteer rice, and broadleaf weeds in ACCase-resistant rice, and the choice of herbicide mixture could be adjusted based on weed spectrum in the treated field.

scholarly journals Erosion and Subsequent Transport State of Escherichia coli from Cowpats

2005 ◽  
Vol 71 (6) ◽  
pp. 2875-2879 ◽  
Author(s):  
Richard William Muirhead ◽  
Robert Peter Collins ◽  
Philip James Bremer
Keyword(s):  
Escherichia Coli ◽  
Surface Waters ◽  
Overland Flow ◽  
Single Cells ◽  
Rainfall Event ◽  
Buffer Strips ◽  
Simulated Rainfall ◽  
E Coli ◽  
Unattached Fraction ◽  
Over Time

ABSTRACT Processes by which fecal bacteria enter overland flow and their transportation state to surface waters are poorly understood, making the effectiveness of measures designed to intercept this pathway, such as vegetated buffer strips, difficult to predict. Freshly made and aged (up to 30 days) cowpats were exposed to simulated rainfall, and samples of the cowpat material and runoff were collected. Escherichia coli in the runoff samples were separated into attached (to particles) and unattached fractions, and the unattached fraction was analyzed to determine if the cells were clumped. Within cowpats, E. coli grew for 6 to 14 days, rather than following a typical logarithmic die-off curve. E. coli numbers in the runoff correlated with numbers inside the cowpat. Most of the E. coli organisms eroded from the cowpats were transported as single cells, and only a small percentage (about 8%) attached to particles. The erosion of E. coli from cowpats and the state in which the cells were transported did not vary with time within a single rainfall event or over time as the cowpats aged and dried out. These findings indicate that cowpats can remain a significant source of E. coli in overland flow for more than 30 days. As well, most of the E. coli organisms eroded from cowpats will occur as readily transportable single cells.

Efficacy of Different Level of Systemic Fungicides on Management of Rice Blast at Baitadi, Nepal

2020 ◽  
Vol 7 ◽  
pp. 33-42
Author(s):  
Ashok Acharya ◽  
Prabin Ghimire ◽  
Dhurba Raj Joshi ◽  
Kishor Shrestha ◽  
Govinda Sijapati ◽  
...  
Keyword(s):  
Disease Severity ◽  
Rice Blast ◽  
Fungal Pathogens ◽  
Block Design ◽  
Rice Variety ◽  
Disease Suppression ◽  
Systemic Fungicide ◽  
Disease Development ◽  
Systemic Fungicides ◽  
Different Levels

Rice blast (Pyriculariaoryzae Cavara) is one of the most devastating diseases affecting the rice crop in across the world. Systemic fungicides are used for the suppression of blast diseases caused by fungal pathogens. Propiconazole and Carbendazim are commercial chemical control products available in markets for the control of the fungal pathogen. An experiment was conducted to examine the effectiveness of systemic fungicide on suppression of rice blast incidence in farmers' field during wet seasons in 2016. The treatments consisted of the use of different levels of propiconazole and Carbendazim on ‘Rato Basmati’ a landrace rice variety. The experiments were arranged in a randomized complete block design with three replications. The disease was scored according to the standard scale developed by the International Rice Research Institute (IRRI). Disease severity and Area under Disease Progressive curve (AUDPC) was computed based on that scale score. Propiconazole and Carbendazim at different levels reduce disease development than no treatment (control). But its efficacy was not consistent. The magnitude of disease suppression by Propiconazole was high as compared to Carbendazim. The application of propiconazole at the rate of 1.5 ml effectively reduced disease severity and AUDPC at different dates. So propiconazole at the rate of 1.5 ml thrice at weekly intervals is effective to reduce the disease development

The Effect of Trifluralin Applied Preplant on Grass Weed Control and Establishment and Yield of Barley (Hordeum vulgare)

1997 ◽  
Vol 11 (3) ◽  
pp. 515-519 ◽  
Author(s):  
Julio A. Scursoni ◽  
Emilio H. Satorre
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Herbicide Application ◽  
Planting Pattern ◽  
Weed Density ◽  
Time Of Application ◽  
Density And Biomass ◽  
And Control ◽  
Crop Planting ◽  
Grass Weed

The objective of this paper was to evaluate the effect of preplant applications of trifluralin on barley stand and yield, and control of grass weeds in field experiments during 1992 and 1993. Factors examined were: (1) crop planting patterns (conventional drill with rows 15 cm apart and deep-seeder drill with rows 25 cm apart), (2) herbicide application times (22 d before sowing and immediately before sowing), and (3) herbicide application. During 1993, hand-weeded plots also were established. Trifluralin applied preplant at 528 g ai/ha reduced weed density and biomass. Weed control was higher under conventional planting than under the deep planting pattern, and there was no effect of the time of application on herbicide efficacy. There was no herbicide injury to the crop, and grain yield was higher in treated than in untreated plots due to successful weed control.

Sign in / Sign up

Export Citation Format

Share Document