THE EFFECTS OF APPLICATION RATE AND SPRAY VOLUME ON EFFICACY OF TWO FORMULATIONS OF BACILLUS THURINGIENSIS BERLINER VAR. KURSTAKI AGAINST CHORISTONEURA ROSACEANA (HARRIS) (LEPIDOPTERA: TORTRICIDAE) ON RASPBERRIES

1996 ◽  
Vol 128 (4) ◽  
pp. 605-612 ◽  
Author(s):  
S.Y. Li ◽  
S.M. Fitzpatrick
Keyword(s):  
Bacillus Thuringiensis ◽  
Residual Activity ◽  
Life Time ◽  
Field Studies ◽  
Application Rate ◽  
Choristoneura Rosaceana ◽  
Original Activity ◽  
Obliquebanded Leafroller ◽  
Application Rates ◽  
Spray Volume

AbstractThe relative toxicities of two formulations (Dipel WP and Foray 48B) of Bacillus thuringiensis Berliner var. kurstaki to the obliquebanded leafroller, Choristoneura rosaceana (Harris), were determined in the laboratory. The effects of application rate (BIU per hectare) and spray volume (litres per hectare) on the efficacy of Dipel WP and Foray 48B against C. rosaceana were determined in raspberry fields. Mortality of C. rosaceana increased with application rate, and decreased with an increase in spray volume. Bacillus thuringiensis exhibited significantly longer residual activity al higher application rates and at lower spray volumes. The half-life (time at which 50% of original activity remains) of B. thuringiensis ranged from 2.45 to 6.68 days, depending upon application rate and spray volume. Laboratory and field studies indicate that Dipel WP and Foray 48B are highly and equally effective in killing larvae of C. rosaceana.

Response of LibertyLink and WideStrike Cotton to Varying Rates of Glufosinate

2015 ◽  
Vol 29 (4) ◽  
pp. 665-674 ◽  
Author(s):  
Darrin M. Dodds ◽  
Christopher L. Main ◽  
L. Thomas Barber ◽  
Charles Burmester ◽  
Guy D. Collins ◽  
...  
Keyword(s):  
North Carolina ◽  
Growth Parameters ◽  
Fiber Quality ◽  
Field Studies ◽  
Application Rate ◽  
Yield Reduction ◽  
Single Application ◽  
Application Rates ◽  
Growth Development

Field studies were conducted in Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, and Tennessee during 2010 and 2011 to determine the effect of glufosinate application rate on LibertyLink and WideStrike cotton. Glufosinate was applied in a single application (three-leaf cotton) or sequential application (three-leaf followed by eight-leaf cotton) at 0.6, 1.2, 1.8, and 2.4 kg ai ha−1. Glufosinate application rate did not affect visual injury or growth parameters measured in LibertyLink cotton. No differences in LibertyLink cotton yield were observed because of glufosinate application rate; however, LibertyLink cotton treated with glufosinate yielded slightly more cotton than the nontreated check. Visual estimates of injury to WideStrike cotton increased with each increase in glufosinate application rate. However, the injury was transient, and by 28 d after the eight-leaf application, no differences in injury were observed. WideStrike cotton growth was adversely affected during the growing season following glufosinate application at rates of 1.2 kg ha−1 and greater; however, cotton height and total nodes were unaffected by glufosinate application rate at the end of the season. WideStrike cotton maturity was delayed, and yields were reduced following glufosinate application at rates of 1.2 kg ha−1 and above. Fiber quality of LibertyLink and WideStrike cotton was unaffected by glufosinate application rate. These data indicate that glufosinate may be applied to WideStrike cotton at rates of 0.6 kg ha−1 without inhibiting cotton growth, development, or yield. Given the lack of injury or yield reduction following glufosinate application to LibertyLink cotton, these cultivars possess robust resistance to glufosinate. Growers are urged to be cautious when increasing glufosinate application rates to increase control of glyphosate-resistant Palmer amaranth in WideStrike cotton. However, glufosinate application rates may be increased to maximum labeled rates when making applications to LibertyLink cotton without fear of reducing cotton growth, development, or yield.

scholarly journals Persistence of insecticidal activity of novel bio-encapsulated formulations of Bacillus thuringiensis var. kurstaki against Choristoneura rosaceana [Lepidoptera: Tortricidae]

2005 ◽  
Vol 82 (2) ◽  
pp. 73-82 ◽  
Author(s):  
J.-C. Côté ◽  
C. Vincent ◽  
K.-H. Son ◽  
S. H. Bok
Keyword(s):  
Bacillus Thuringiensis ◽  
Insecticidal Activity ◽  
Meteorological Factors ◽  
Larval Mortality ◽  
Apple Orchard ◽  
Choristoneura Rosaceana ◽  
Obliquebanded Leafroller ◽  
Higher Doses

DiPelTM, a registered Bacillus thuringiensis var. kurstaki (Btk)-based formulation, and experimental bio-encapsulated Btk formulations were sprayed in an apple orchard. Their persistence was assessed in the laboratory against obliquebanded leafroller (Choristoneura rosaceana) larvae for three consecutive years. In 1995, DiPel and the bio-encapsulated formulation caused significantly higher larval mortality than the control at least 1 day, and up to 27 days after treatments, respectively. In 1996, although 6.4 mm of rain fell during the day of treatments, DiPel and the bio-encapsulated formulation caused respectively 21 and 33% larval mortality immediately after treatments. DiPel caused significantly higher mortality than the control for up to 3 days while the bio-encapsulated formulation caused significantly higher mortality for up to 14 days. In 1997, two Btk strains (HD-1 and BMP123) were sprayed at different concentrations in a.i. (3 and 8%) and doses (30 and 240 g 15 L-1 applied). Higher concentrations of a.i. in the Btk formulations and higher doses sprayed increased the persistence of the insecticidal activity. Among the meteorological factors that were measured (i.e. precipitations, temperature and solar radiations), precipitations reduced the persistence of the insecticidal activity. Solar radiations may have modulated the persistence of the formulations.

EFFECT OF TEMPERATURE ON TOXICITY OF BACILLUS THURINGIENSIS TO THE OBLIQUEBANDED LEAFROLLER (LEPIDOPTERA: TORTRICIDAE)

1995 ◽  
Vol 127 (2) ◽  
pp. 271-273 ◽  
Author(s):  
S.Y. Li ◽  
S.M. Fitzpatrick ◽  
M.B. Isman
Keyword(s):  
British Columbia ◽  
Bacillus Thuringiensis ◽  
First Generation ◽  
Effect Of Temperature ◽  
Choristoneura Rosaceana ◽  
Harvesting Time ◽  
Obliquebanded Leafroller ◽  
Major Pest ◽  
Fraser Valley ◽  
Heavy Infestation

In recent years, the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), has become a major pest of raspberries in the Fraser Valley, British Columbia (Anonymous 1994). Overwintering C. rosaceana larvae begin feeding on raspberry leaf buds in early April. Heavy infestation causes serious damage to raspberry plants. Larvae of the first generation hatch in late June to early July, and feed on growth terminals and berries. The occurrence of this generation usually coincides with berry harvesting time. Because the larvae are shaken from the plants by the harvesting machine, C. rosaceana can be a major contaminant of machine-harvested berries.

Response of Sweetpotato Cultivars to Linuron Rate and Application Time

2018 ◽  
Vol 32 (6) ◽  
pp. 665-670 ◽  
Author(s):  
Shawn C. Beam ◽  
Katherine M. Jennings ◽  
Sushila Chaudhari ◽  
David W. Monks ◽  
Jonathan R. Schultheis ◽  
...  
Keyword(s):  
North Carolina ◽  
Field Studies ◽  
Application Rate ◽  
Application Time ◽  
Herbicide Application ◽  
Application Rates

AbstractField studies were conducted in 2015 and 2016 in North Carolina to determine the response of ‘Covington’ and ‘Murasaki-29’ sweetpotato cultivars to four rates of linuron (420, 560, 840, and 1,120 g ai ha–1) alone or withS-metolachlor (803 g ai ha–1) applied 7 or 14 d after transplanting (DAP). Injury (chlorosis/necrosis and stunting) to both cultivars was greater when linuron was applied withS-metolachlor as compared to linuron applied alone. Herbicide application at 14 DAP caused greater injury (chlorosis/necrosis and stunting) to both cultivars than when applied at 7 DAP. At 4 wk after treatment (WAT), stunting of Covington and Murasaki-29 (hereafter Murasaki) from linuron at 420 to 1,120 g ha–1increased from 27% to 50% and 25% to 53%, respectively. At 7 or 8 WAT, crop stunting of 8% or less and 0% was observed in Covington and Murasaki, respectively, regardless of application rate and timing. Murasaki root yields were similar in the linuron alone or withS-metolachlor treatments, and were lower than the nontreated check. In 2016, no. 1 and marketable sweetpotato yields of Covington were similar for the nontreated check, linuron alone, or linuron plusS-metolachlor treatments, but not in 2015. Decreases in no. 1 and marketable root yields were observed when herbicides were applied 14 DAP compared to 7 DAP for Covington in 2015 and for Murasaki in both years. No. 1 and marketable yields of Covington were similar for 420 to 1,120 g ha–1linuron and nontreated check except marketable root yields in 2015. No. 1 and marketable sweetpotato yields of Murasaki decreased as application rates increased.

scholarly journals Influence of Spray Volume on Spray Deposition and Coverage within Nursery Trees

2008 ◽  
Vol 26 (1) ◽  
pp. 51-57 ◽  
Author(s):  
H. Zhu ◽  
R.H. Zondag ◽  
R.C. Derksen ◽  
M. Reding ◽  
C.R. Krause
Keyword(s):  
Spray Deposition ◽  
Foliar Spray ◽  
Tree Height ◽  
Application Rate ◽  
Spray Application ◽  
Application Rates ◽  
Tree Canopies ◽  
Nursery Trees ◽  
Spray Volume ◽  
Volume Method

Abstract Information on better utilizing airblast sprayers to achieve high pesticide spray application efficiency in nursery tree production is needed. Foliar spray deposition and coverage at different heights inside crabapple tree canopies were investigated for a conventional airblast sprayer operating at four different application rates ranging from 230 to 900 liters/ha [24 to 94 gallons per acre (GPA)]. Deposition on the ground at various distances from the sprayer was also measured at the 700 liters/ha (73 GPA) application rate. Foliar deposition and coverage on targets below 2.6 m (8.5 ft) inside tree canopies increased as the application rate increased, but the increase in the coverage was much lower than the deposition. For trees taller than 2.6 m (8.5 ft), the sprayer could not deliver uniform spray deposition and coverage across the tree height. The portion of trees below 2.1 m (6.9 ft) was well covered by the spray deposits with 230 liters/ha (24 GPA) application rate while higher application rates resulted in over spray application. Less than 30% of total spray volume was deposited on target trees while over 34% of the total spray volume was lost on the ground. The tree-row volume method should include foliage density and tree-row gaps to avoid excessive estimation of spray application rates for nursery tree crops.

Plant mortality and seedling recruitment responses to flupropanate in grassland populations of Nassella trichotoma

2017 ◽  
Vol 70 ◽  
pp. 160-164 ◽  
Author(s):  
G.W. Bourdôt ◽  
S. Jackman ◽  
D.J. Saville
Keyword(s):  
New Zealand ◽  
Dose Response ◽  
Sodium Salt ◽  
Seedling Recruitment ◽  
Residual Activity ◽  
Application Rate ◽  
Plant Mortality ◽  
Complete Control ◽  
Bio Synthesis

Flupropanate (sodium 2,2,3,3 tetrafluoropropanate), a slow-acting lipid bio- synthesis-inhibiting herbicide, was recently registered in New Zealand as Taskforce (745 g/L flupropanate as the sodium salt) for the selective and long-term control of Nassella trichotoma (nassella tussock) in pastures. In five dose-response experiments in permanent hill pastures in Canterbury, conducted between 2012 and 2016, we measured the efficacy of the herbicide against established plants of N. trichotoma and its residual activity against recruiting seedlings. Mortality, as an average across the five sites, was 93% 1.5 years after applying 1.49 kg flupropanate/ha (the label-recommended rate), and 100% at 2.98 kg/ha. This indicates that an application rate higher than the label rate will be necessary for complete control of a N. trichotoma infestation. The presence of 1,000 and 6,250 visible seedlings of N. trichotoma/ha in the autumn 3.2 and 2.1 years after applying 1.49 kg flupropanate/ha (at a Greta Valley and Scargill site respectively) indicates that the herbicide’s soil residues had decayed within 12 months to a concentration lower than necessary to kill the germinating seedlings of N. trichotoma.

scholarly journals Effect of different soil and weather conditions on efficacy, selectivity and dissipation of herbicides in sunflower

2020 ◽  
Vol 66 (No. 9) ◽  
pp. 468-476
Author(s):  
Miroslav Jursík ◽  
Martin Kočárek ◽  
Michaela Kolářová ◽  
Lukáš Tichý
Keyword(s):  
Cation Exchange Capacity ◽  
Chenopodium Album ◽  
Soil Layer ◽  
Weather Conditions ◽  
Growing Season ◽  
Application Rate ◽  
Exchange Capacity ◽  
Vertical Transport ◽  
Application Rates ◽  
High Precipitation

Six sunflower herbicides were tested at two application rates (1N and 2N) on three locations (with different soil types) within three years (2015–2017). Efficacy of the tested herbicides on Chenopodium album increased with an increasing cation exchange capacity (CEC) of the soil. Efficacy of pendimethalin was 95%, flurochloridone and aclonifen 94%, dimethenamid-P 72%, pethoxamid 49% and S-metolachlor 47%. All tested herbicides injured sunflower on sandy soil (Regosol) which had the lowest CEC, especially in wet conditions (phytotoxicity 27% after 1N application rate). The highest phytotoxicity was recorded after the application of dimethenamid-P (19% at 1N and 45% at 2N application rate). Main symptoms of phytotoxicity were leaf deformations and necroses and the damage of growing tips, which led to destruction of some plants. Aclonifen, pethoxamid and S-metolachlor at 1N did not injure sunflower on the soil with the highest CEC (Chernozem) in any of the experimental years. Persistence of tested herbicides was significantly longer in Fluvisol (medium CEC) compared to Regosol and Chernozem. Dimethenamid-P showed the shortest persistence in Regosol and Chernozem. The majority of herbicides was detected in the soil layer 0–5 cm in all tested soils. Vertical transport of herbicides in soil was affected by the herbicide used, soil type and weather conditions. The highest vertical transport was recorded for dimethenamid-P and pethoxamid (4, resp. 6% of applied rate) in Regosol in the growing season with high precipitation.  

scholarly journals Reproduction and biomarker responses of Eisenia fetida after exposure to imidacloprid in biochar-amended soil

Biochar ◽  
2021 ◽  
Author(s):  
Ngitheni Winnie-Kate Nyoka ◽  
Ozekeke Ogbeide ◽  
Patricks Voua Otomo
Keyword(s):  
Eisenia Fetida ◽  
Field Studies ◽  
Application Rate ◽  
Land Application ◽  
Acetylcholinesterase Inhibition ◽  
Beneficial Effects ◽  
Pesticide Pollution ◽  
The One ◽  
The Impact ◽  
Amended Soil

AbstractTerrestrial and aquatic ecosystems are increasingly threatened by pesticide pollution resulting from extensive use of pesticides, and due to the lack of regulatory measures in the developing world, there is a need for affordable means to lessen environmental effects. This study aimed to investigate the impact of biochar amendment on the toxicity of imidacloprid to life-cycle parameters and biomarker responses of the earthworm Eisenia fetida. E. fetida was exposed to 10% biochar-amended and non-amended OECD artificial soils spiked with 0, 0.75, 1.5, 2.25 and 3 mg imidacloprid/kg for 28 days. An LC50 of 2.7 mg/kg was only computed in the non-amended soil but not in the biochar-amended soil due to insignificant mortality. The EC50 calculated in the non-amended soil (0.92 mg/kg) for reproduction (fertility) was lower than the one computed in the biochar amended (0.98 mg/kg), indicating a decrease in toxicity in the biochar-amended substrate. Significant weight loss was observed at the two highest imidacloprid treatments in the non-amended soil and only at the highest treatment in the biochar-amended substrate, further highlighting the beneficial effects of biochar. Catalase activity decreased significantly at the two highest concentrations of non-amended soil. Yet, in the amended soil, the activity remained high, especially in the highest concentration, where it was significantly higher than the controls. This indicated more severe oxidative stress in the absence of biochar. In all non-amended treatments, there was a significant acetylcholinesterase inhibition, while lower inhibition percentages were observed in the biochar-amended soil. In most endpoints, the addition of biochar alleviated the toxic effects of imidacloprid, which shows that biochar has the potential to be useful in soil remediation. However, there is still a need for field studies to identify the most effective application rate of biochar for land application.

scholarly journals Effects of two wood-based biochars on the fate of added fertilizer nitrogen—a 15N tracing study

2021 ◽  
Author(s):  
Subin Kalu ◽  
Gboyega Nathaniel Oyekoya ◽  
Per Ambus ◽  
Priit Tammeorg ◽  
Asko Simojoki ◽  
...  
Keyword(s):  
Plant Uptake ◽  
Plant Biomass ◽  
Application Rate ◽  
Control Treatment ◽  
Organic N ◽  
N Leaching ◽  
Soil N ◽  
Mineral N ◽  
Total N ◽  
Application Rates

AbstractA 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.

scholarly journals Evaluation of the Regional-Scale Optimal K Rate Based on Sustainable Apple Yield and High-Efficiency K Use in Loess Plateau and Bohai Bay of China: A Meta-Analysis

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1368
Author(s):  
Wenzheng Tang ◽  
Wene Wang ◽  
Dianyu Chen ◽  
Ningbo Cui ◽  
Haosheng Yang ◽  
...  
Keyword(s):  
Loess Plateau ◽  
High Efficiency ◽  
Meta Analysis ◽  
Regional Scale ◽  
Fertilizer Application ◽  
Application Rate ◽  
Bohai Bay ◽  
The Loess Plateau ◽  
Application Rates ◽  
Relationship Model

In order to meet the growing food demand of the global population and maintain sustainable soil fertility, there is an urgent need to optimize fertilizer application amount in agricultural production practices. Most of the existing studies on the optimal K rates for apple orchards were based on case studies and lack information on optimizing K-fertilizer management on a regional scale. Here, we used the method of combining meta-analysis with the K application rate-yield relationship model to quantify and summarize the optimal K rates of the Loess Plateau and Bohai Bay regions in China. We built a dataset based on 159 observations obtained from 18 peer-reviewed literature studies distributed in 15 different research sites and evaluated the regional-scale optimal K rates for apple production. The results showed that the linear plus platform model was more suitable for estimating the regional-scale optimal K rates, which were 208.33 and 176.61 kg K ha−1 for the Loess Plateau and Bohai Bay regions of China, respectively. Compared with high K application rates, the optimal K rates increased K use efficiency by 45.88–68.57%, with almost no yield losses. The optimal K rates also enhanced the yield by 6.30% compared with the low K application rates.

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