scholarly journals Sensitivity of sunflower cultivar PR63E82 to tribenuron and propaquizafop in different weather conditions

2018 ◽  
Vol 64 (No. 10) ◽  
pp. 479-483
Author(s):  
Tichý Lukáš ◽  
Jursík Miroslav ◽  
Kolářová Michaela ◽  
Hejnák Václav ◽  
Andr Jiří ◽  
...  
Keyword(s):  
Czech Republic ◽  
Growth Retardation ◽  
Weather Conditions ◽  
Field Trials ◽  
Ionic Surfactant ◽  
Leaf Chlorosis ◽  
Herbicide Treatments ◽  
Small Plot ◽  
Plant Injury

The aim of this work was to verify and assess the tolerance of the PR63E82 (ExpressSun) sunflower cultivar to tribenuron, propaquizafop and their tank-mix combination in two rates under various weather conditions. Three small-plot field trials were carried out on sunflower in Prague, Czech Republic, from 2015 to 2017. High phytotoxicity (25–56%) of tribenuron (TBM) + non-ionic surfactant was observed in 2015 and 2016 when the sunflower was sown in mid-April. In 2017, phytotoxicity was significantly lower (4–6%), probably due to a later sowing of sunflower (May), and hence higher temperatures. The main symptoms of TBM phytotoxicity were leaf chlorosis, necrosis and growth retardation. Propaquizafop (PQF) injury was minimal in 2015 and 2017. A higher phytotoxicity (10–13%) was recorded in 2016, probably due to a hail which occurred 2 days after T2 (second application term (sunflower BBCH 14)) application. Plant injury had puckered leaves and also made more side branches. TBM + PQF damaged sunflower plants most of the tested herbicide treatments (phytotoxicity 3–62%). High phytotoxicity caused stem branching, increased number of sunflower heads and decreased yield.  

scholarly journals Effect of adjuvants on the dissipation, efficacy and selectivity of three different pre-emergent sunflower herbicides

2017 ◽  
Vol 63 (No. 9) ◽  
pp. 409-415 ◽  
Author(s):  
Andr Jiří ◽  
Kočárek Martin ◽  
Jursík Miroslav ◽  
Fendrychová Veronika ◽  
Tichý Lukáš
Keyword(s):  
Weather Conditions ◽  
Field Trials ◽  
Active Ingredients ◽  
Residual Concentration ◽  
High Rainfall ◽  
Paraffin Oil ◽  
Dry Conditions ◽  
Small Plot ◽  
Silicon Based

The aim of this work was to compare the efficacy, selectivity to sunflower and dissipation of three pre-emergent herbicides. Flurochloridone, linuron and oxyfluorfen were applied individually and each herbicide was also applied in a tank mix with two different adjuvants (a silicon-based adjuvant and paraffin oil). Small-plot field trials were carried out with sunflower in Central Bohemia in 2012 and 2015. Around 25–35% of the active ingredients in the applied herbicides were detected in soil 60 days after application in both years, except for oxyfluorfen in 2012, whose residual concentration was 60%. The tested soil adjuvants did not affect the dissipation of any of the tested herbicide in soil in either experimental year. Oxyfluorfen exhibited the highest mobility and caused the greatest degree of sunflower injury (18%), especially in the year with high rainfall shortly after application. None of the tested adjuvants significantly affected sunflower injury by any tested herbicide. The efficacy of flurochloridone and linuron on Fallopia convolvulus was strongly affected by weather conditions shortly after application. The efficacy of oxyfluorfen was around 85% and was not affected by weather conditions. The effect of adjuvant on herbicide efficacy was positive only in dry conditions, where the efficacy of flurochloridone on F. convolvulus was positively affected by the silicon-based adjuvant.

scholarly journals Efficacy and selectivity of post-emergent application of flumioxazin and oxyfluorfen in sunflower

2011 ◽  
Vol 57 (No. 11) ◽  
pp. 532-539 ◽  
Author(s):  
M. Jursík ◽  
J. Andr ◽  
J. Holec ◽  
J. Soukup
Keyword(s):  
Chenopodium Album ◽  
Field Trials ◽  
Amaranthus Retroflexus ◽  
Alcohol Ethoxylate ◽  
Thlaspi Arvense ◽  
Full Control ◽  
Application Rates ◽  
Herbicide Treatments ◽  
Small Plot ◽  
Mercurialis Annua

Four efficacy and selectivity small plot field trials were carried out in four sunflower hybrids at two localities in Middle Bohemia during 2008 and 2009 with herbicides containing the active ingredients flumioxazin and fluorochloridone. For Chenopodium album, an efficacy of 97% was found after pre-emergent application of fluorochloridone + acetochlor; the efficacy of oxyfluorfen was 88–95%; the efficacy of flumioxazin was below 50% at both tested application rates (30 and 60 g/ha) and application timings (2 sunflower leaves and 4 to 6 sunflower leaves); efficacy of flumioxazin increased to 67% and 69%, when surfactants were added (isodecyl alcohol ethoxylate and heptamethyltrisiloxan). Full control of Amaranthus retroflexus was found after all pre-emergent and early post-emergent herbicide treatments; efficacy of late post-emergent herbicide treatments was below 93%. Full control of Mercurialis annua was found only after application of oxyfluorfen. Thlaspi arvense was fully controlled by fluorochloridone + acetochlor (pre-emergent) and oxyfluorfen (in both application terms). Selectivity of the four tested sunflower hybrids to fluorochloridone + acetochlor, bifenox and flumioxazin was acceptable (phytotoxicity 6 to 27%). Higher phytotoxicity (23–45%) was recorded when surfactants were added to flumioxazin. The highest phytotoxicity (68–81%) was recorded after the application of oxyfluorfen.  

Adjuvant comparison for postemergence weed control in corn

2010 ◽  
Vol 90 (4) ◽  
pp. 543-547 ◽  
Author(s):  
N. Soltani ◽  
C. Shropshire ◽  
P H Sikkema
Keyword(s):  
Zea Mays ◽  
Weed Control ◽  
Zea Mays L ◽  
Field Trials ◽  
Ionic Surfactants ◽  
Ionic Surfactant ◽  
Corn Yield ◽  
Common Lambsquarters ◽  
Green Foxtail ◽  
Herbicide Treatments

Six field trials were conducted over a 2-yr period (2004 and 2005) at Exeter and Ridgetown, ON, Canada, to evaluate the effect of postemergence application of rimsulfuron plus dicamba plus S-metolachlor/benoxacor, nicosulfuron/rimsulfuron plus dicamba/diflufenzopyr and nicosulfuron plus dicamba/diflufenzopyr with and without Agral 90® or Liberate® non-ionic surfactants on weed control and yield of corn. There was no difference between Agral 90® and Liberate® adjuvant in respect to control of velvetleaf, common ragweed, common lambsquarters and green foxtail. All herbicide treatments provided significantly higher yield than the untreated control. There was also no difference between Agral 90® and Liberate® in respect to corn yield when added to rimsulfuron plus dicamba plus S-metolachlor/benoxacor, nicosulfuron/rimsulfuron plus dicamba/diflufenzopyr and nicosulfuron plus dicamba/diflufenzopyr. Based on these results, Liberate® can be used as an alternative non-ionic surfactant for Agral 90® with the herbicides evaluated.Key words: Agral 90®, benoxacor, dicamba, diflufenzopyr, Liberate®, nicosulfuron, rimsulfuron, S-metolachlor, Zea mays L.

scholarly journals Dynamics of the Degradation of Acetyl-CoA Carboxylase Herbicides in Vegetables

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 405
Author(s):  
Miroslav Jursík ◽  
Kateřina Hamouzová ◽  
Jana Hajšlová
Keyword(s):  
Linear Models ◽  
Growing Season ◽  
Field Trials ◽  
Baby Food ◽  
Vegetable Production ◽  
The Czech Republic ◽  
Herbicide Residues ◽  
Harvest Intervals ◽  
Small Plot

(1) Background: Aryloxyphenoxy-propionates and cyclohexanediones are herbicides most widely used in dicot crops worldwide. The main objective of the study was to determine the dynamics of herbicide residues in carrot, lettuce, cauliflower, and onion in order to suggest a low level of residues in harvested vegetables. (2) Methods: Small plot field trials were carried out in four vegetables in the Czech Republic. The samples of vegetables were collected continuously during the growing season. Multiresidue methods for the determination of herbicide residues by LC-MS/MS were used. Non-linear models of degradation of individual herbicides in vegetables were calculated using the exponential decay formula. Action GAP pre-harvest intervals for the 25% and 50% maximum residue limit (MRL) and 10 µg kg−1 limit (baby food) were established for all tested herbicides. (3) Results: The degradation dynamics of fluazifop in carrot, onion, and cauliflower was significantly slower compared to quizalofop and haloxyfop. The highest amount (2796 µg kg−1) of fluazifop residues was detected in cauliflower 11 days after application. No residue of propaquizafop and cycloxydim was detected in any vegetable samples. (4) Conclusions: Aryloxyphenoxy-propionate herbicide (except propaquizafop) could contaminate vegetables easily, especially vegetables with a short growing season. Vegetables treated with fluazifop are not suitable for baby food. Lettuce and cauliflower treated by quizalofop are not suitable for baby food, but in onion and carrot, quizalofop could be used. Propaquizafop and cycloxydim are prospective herbicides for non-residual (baby food) vegetable production.

Septoria antirrhini. [Descriptions of Fungi and Bacteria].

2004 ◽  
Author(s):  
T. V. Andrianova
Keyword(s):  
South Africa ◽  
Czech Republic ◽  
New Zealand ◽  
Great Britain ◽  
South America ◽  
Geographical Distribution ◽  
Infected Plant ◽  
Weather Conditions ◽  
Plant Debris ◽  
Wet Weather

Abstract A description is provided for Septoria antirrhini. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Leaf spot, leaf drying, defoliation. HOSTS: Antirrhinum antirrhiniflorum, A. majus, A. siculum (Scrophulariaceae). GEOGRAPHICAL DISTRIBUTION: AFRICA: South Africa. NORTH AMERICA: Canada, USA. SOUTH AMERICA: Chile, Colombia. ASIA: Armenia, Azerbaijan, China, Iran, Israel. AUSTRALASIA: Australia, New Zealand. EUROPE: Bulgaria, Czech Republic, Estonia, France, Germany, Great Britain, Hungary, Ireland, Italy, Netherlands, Portugal, Romania, Ukraine, former Yugoslavia. TRANSMISSION: Not reported, but almost certainly by airborne, splash-dispersed conidia from infected plant debris and seed stocks. The disease is significantly more severe under wet weather conditions (SINADSKIY et al., 1985).

Response of dry grassland vegetation to fluctuations in weather conditions: a 9-year case study in Prague (Czech Republic)

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Jiří Dostálek ◽  
Tomáš Frantík
Keyword(s):  
Species Richness ◽  
Czech Republic ◽  
Weather Conditions ◽  
Grass Species ◽  
Individual Species ◽  
Weather Variability ◽  
Grassland Vegetation ◽  
Dry Grassland ◽  
Local Climate ◽  
The Impact

AbstractThe extreme habitats of dry grasslands are suitable for investigations of the response of vegetation to local climate changes. The impact of weather variability on the dynamics of a plant community in a dry grassland was studied. Correlations were found between different functional groups of species and individual species and weather variability. During a 9-year study in five nature reserves in Prague (Czech Republic), the following responses of dry grassland vegetation to weather conditions were observed: (i) wetter conditions, especially in the winter, affected the dominance and species richness of perennial grass species and the decline of rosette plants; (ii) the year-to-year higher temperatures in the winter produced a decline in the dominance of short graminoids and creeping forbs; (iii) spring drought adversely impacted the overall abundance, especially the abundance of dicotyledonous species, and the species richness. However, these relationships may be manifested in different ways in different locations, and in some cases the vegetation of different locations may respond to weather conditions in opposite manners.

scholarly journals Managing Bees for Delivering Biological Control Agents and Improved Pollination in Berry and Fruit Cultivation

2015 ◽  
Vol 4 (3) ◽  
pp. 89 ◽  
Author(s):  
Heikki M. T. Hokkanen ◽  
Ingeborg Menzler-Hokkanen ◽  
Marja-Leena Lahdenpera
Keyword(s):  
Crop Protection ◽  
Field Tests ◽  
Weather Conditions ◽  
Field Studies ◽  
Field Trials ◽  
Marketable Yield ◽  
Dissemination Activity ◽  
Grey Mold ◽  
Commercial Farms ◽  
Disease Pressure

<p>Targeted precision biocontrol and improved pollination were studied Europe-wide in the EU ERA-NET CORE ORGANIC 2 project BICOPOLL (Biocontrol and Pollination). A case study was conducted on the management of strawberry grey mold <em>Botrytis cinerea</em>, with the biocontrol fungus, <em>Gliocladium catenulatum</em>, vectored by honey bees or bumble bees. A joint field trial carried out in five countries targeted strawberry cultivations in open field, and included four treatments: untreated control, chemical fungicide, entomovectored biocontrol, and chemical and biocontrol combined. In organic fields, no pesticide treatments were included. The proportion of moldy berries, and/or the marketable yield of healthy berries were recorded from each treatment, along with other parameters of local interest. A pilot study was started in Finland in 2006, and, by 2012, large commercial farms were using entomovectoring. In 2012, field trials were started in Estonia and in Italy, and in 2013-14, these experiments were expanded to Slovenia and Turkey. In total, 26 field tests were conducted using entomovectoring and <em>Gliocladium catenulatum</em> (Prestop<sup>®</sup> Mix) on strawberry, with five additional trials on raspberry. Efficacy results have been excellent throughout the field studies. The results show crop protection equalling or exceeding that provided by a full chemical fungicide program, under all weather conditions, and over a wide geographical range (from Finland to Turkey). Under heavy disease pressure, entomovectoring provided on average a 47% disease reduction, which was the same as multiple fungicide sprays. Under light disease pressure, biocontrol decreased grey mold by an average of 66%, which was greater than fungicide sprays. The concept has proven to be effective on strawberries, raspberries, pears, apples, blueberries, cherries, and grapes. A conservative estimate for Finland is that over 500 ha of strawberry cultivation currently use the technique (≈15% of the strawberry growing area). To make full use of the entomovectoring technique, organic berry and fruit growers are encouraged to (i) keep bees, or to hire the service from local beekeepers for entomovectoring; and (ii) manage vegetation within and around the target crop to support the activity of bees and other pollinators, which can help to disseminate the beneficial microbial populations within the crop. Beekeepers are encouraged to (i) market pollination and biocontrol services to fruit and berry growers, and (ii) ensure that all operations are effective in mananging bees and their microbe dissemination activity. Biocontrol product manufacturers are encouraged to further develop products and their formulations specifically for entomovectoring, because current formulations are suboptimal as they are initially optimized for other uses (e.g., mixing into the soil).</p>

scholarly journals Differences in rainfall and temperature define the use of different types of nitrogen fertilizer on managed grassland in UK, NL [Netherlands] and Eire

1996 ◽  
Vol 44 (4) ◽  
pp. 317-338 ◽  
Author(s):  
D.W. Bussink ◽  
O. Oenema
Keyword(s):  
Decision Support ◽  
Ammonium Nitrate ◽  
Weather Conditions ◽  
Field Trials ◽  
Temperature Pattern ◽  
Decision Support Model ◽  
Agronomic Efficiency ◽  
Calcium Ammonium Nitrate ◽  
N Yield ◽  
Support Model

There are distinct differences between the Netherlands (NL) and the United Kingdom (UK) in the use of urea and calcium ammonium nitrate (Ca-AmmN) fertilizers on grassland. It has been known for some time that rainfall and temperature affect NH3 volatilization from urea and its agronomic efficiency. This study aimed (i) to examine rainfall and temperature pattern in NL and UK in relation to the observed urea efficiency, and (ii) to provide a simple decision support model for farmers to enable them to choose the most appropriate N fertilizer. A statistical analysis (residual maximum likelihood) of existing data from numerous field trials was undertaken. The agronomic efficiency of urea compared to Ca-AmmN in field trials was expressed as (i) urea relative N yield (Urel-N-y), and (ii) apparent-urea relative (N) yield (Uarel-(N)-y). In NL, (Urel-N-y) did not significantly differ from 100% on peat grassland. Mean (Urel-N-y) on sand and clay was 95%, in both cases. Mean seasonal Uarel-y and Uarel-N-y for the summed data of sand and clay soils was 92.3 and 86.4%, respectively, without significant differences between first and later cuts. There was no significant improvement of UNapp-relY in the last decades. In the first cut, mean Uarel-y was lower than in UK (100.9%) and Eire (100.2%). Differences in efficiency between countries could be described by short-term rainfall and temperature. By aggregating NL, UK and Eire data a simple regression equation was derived: Uarel-y= 89.48(+or-0.78) +[2.188(+or-0.15)xR3] -[1.091(+or-0.07)xT3], where R3 and T3 are rainfall amount and average temperature within three days after fertilizer application, respectively. The decision support model based on this equation showed that under prevailing NL weather conditions it will be profitable for the farmer to apply urea instead of calcium ammonium nitrate, for the first and second cut, only once every 5 and 7 years, respectively, because R3's exceeding 6 and 9.5 mm are required.

Mycotoxins in organically versus conventionally produced cereal grains and some other crops in temperate regions

2016 ◽  
Vol 9 (5) ◽  
pp. 755-770 ◽  
Author(s):  
G. Brodal ◽  
I.S. Hofgaard ◽  
G.S. Eriksen ◽  
A. Bernhoft ◽  
L. Sundheim
Keyword(s):  
Farming Systems ◽  
Weather Conditions ◽  
Field Trials ◽  
Cereal Grains ◽  
Organic System ◽  
Mycotoxin Contamination ◽  
Significant Difference ◽  
Apple Products ◽  
Low Levels ◽  
The Difference

This paper presents peer-reviewed studies comparing the content of deoxynivalenol (DON), HT-2+T-2 toxins, zearalenone (ZEA), nivalenol (NIV), ochratoxin A (OTA) and fumonisins in cereal grains, and patulin (PAT) in apple and apple-based products, produced in organically and conventionally grown crops in temperate regions. Some of the studies are based on data from controlled field trials, however, most are farm surveys and some are food basket surveys. Almost half of the studies focused on DON in cereals. The majority of these studies found no significant difference in DON content in grain from the two farming systems, but several studies showed lower DON content in organically than in conventionally produced cereals. A number of the investigations reported low DON levels in grain, far below the EU limits for food. Many authors suggested that weather conditions, years, locations, tillage practice and crop rotation are more important for the development of DON than the type of farming. Organically produced oats contained mainly lower levels of HT-2+T-2 toxins than conventionally produced oats. Most studies on ZEA reported no differences between farming systems, or lower concentrations in organically produced grain. For the other mycotoxins in cereals, mainly low levels and no differences between the two farming systems were reported. Some studies showed higher PAT contamination in organically than in conventionally produced apple and apple products. The difference may be due to more efficient disease control in conventional orchards. It cannot be concluded that any of the two farming systems increases the risk of mycotoxin contamination. Despite no use of fungicides, an organic system appears generally able to maintain mycotoxin contamination at low levels. More systematic comparisons from scientifically controlled field trials and surveys are needed to clarify if there are differences in the risk of mycotoxin contamination between organically and conventionally produced crops.

Chemical control of bacterial canker (Pseudomonas syringae pv. syringae) of apricot and cherry in Victoria

1991 ◽  
Vol 31 (5) ◽  
pp. 705 ◽  
Author(s):  
DLS Wimalajeewa ◽  
R Cahill ◽  
G Hepworth ◽  
HG Schneider ◽  
JW Washbourne
Keyword(s):  
Pseudomonas Syringae ◽  
Chemical Control ◽  
Bordeaux Mixture ◽  
Weather Conditions ◽  
Hydrated Lime ◽  
Field Trials ◽  
Bacterial Canker ◽  
Copper Hydroxide ◽  
Low Concentrations ◽  
Excellent Control

Field trials were conducted during 1982-85, to develop a comprehensive spray program for the control of bacterial canker (Pseudomonas syringae pv, syringae) of apricot and cherry. Five spray schedules were evaluated as measures to reduce disease levels. Copper hydroxide at 2.5 g/L in water was applied to apricot, and bordeaux mixture at 6 g copper sulfate + 8 g hydrated lime/L in water was applied to cherry, during autumn, winter and pre-bloom spring. The effectiveness of copper sprays in reducing epiphytic populations of the pathogen during post-bloom spring was also tested. Copper hydroxide was applied to apricot, and a foliar copper nutrient and copper hydroxide were applied to cherry at low concentrations. Most spray schedules tested significantly (P<0.05) reduced canker incidence relative to controls. Excellent control of epiphytic populations of the pathogen on apricot and cherry was achieved with copper sprays applied at post-bloom in spring. A spray schedule consisting of 2 autumn, 1 winter and 2 pre-bloom spring sprays with copper hydroxide on apricot or bordeaux mixture on cherry was successful in reducing canker (>67% reduction) and is recommended for control of the disease. Two applications of copper hydroxide at 1.0 g/L in water in post-bloom spring considerably reduced (>9 1 %) epiphytic populations (P. syringae pv. syringae) on apricot and cherry leaves. Later sprays are recommended for use in combination with the autumn-winter-spring (pre-bloom) spray schedule, especially under excessively wet and cool weather conditions in spring.

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