Effect of Mesotrione and Nicosulfuron Mixtures With or Without Adjuvants

ABSTRACT: In Field experiments, a logarithmic sprayer was used to screen the efficacy of 28.5% mixture of nicosulfuron and mesotrione, and the herbicides applied separately. Three adjuvants were also used to assess how they affected the potency of the mixture. The objectives were to test whether a mixture was enhancing or detracting the effect relative to ADM (Additive Dose Model). The test plants were canola and barley. The 28.5% nicosulfuron mixture was acting antagonistic, irrespective of plant species. The antagonistic effect of the nicosulfuron mixture decreased the more developed the plants became; for barley, it almost disappeared 40 days after treatment. For both canola and barley, one adjuvant stood out as being highly effective in decreasing ED50 of the mixture. Antagonism was not alarmingly high, which is found for many herbicides. Results are discussed in relation to the practice of testing mixtures in the literature and the requirements for getting mixture patents

Spray deposition and drift during postemergence herbicide applications to turfgrass and annual flowers

Many lawn care operators use the lawn spray gun spraying system to alleviate potential non-target injury from postemergence broadleaf herbicide spray drift. This system was designed to apply dilute fertilizer and pesticide solutions at high spray volumes and low nozzle pressure. The lawn spray gun application at a mean volume rate of 1122 L ha[superscript]-1 in comparison to flat fan nozzles at 187 L ha[superscript]-1 or Raindrop nozzles at 374 L ha[superscript]-1 significantly reduced the injury potential to non-target plants 90 cm or more from the spray swath edge. The direct deposition of spray at the 30 cm downwind location suggests that a small unsprayed buffer area next to non-target plants should be left in order to avoid direct spray contact to non-target plants for all nozzle types tested. The percentage of spray recovered indicates that large differences do occur within the spray swath. The corresponding coefficient of variation (CV) values for the nozzle types were above the recommended CV value of 15%; however, other research has shown that applications with a CV range of 14% to 28% provided satisfactory uniformity for droplet deposition. The low percent spray recovery with RA-6 nozzles and the spray gun on turfgrass suggests that droplets produced by flat fan nozzles may have greater collection efficiencies than those by RA-6 nozzles or the spray gun. Simulated spray drift on annual flowers indicates that petunia (Petunia x hybrida) is extremely sensitive to the triethylamine salt of triclopyr ((3,5,6-trichloro-2-pyridinyl)oxy) acetic acid or the dimethylamine salt of 2,4-D (2,4-dichlorophenoxy)acetic acid, while impatiens (Impatiens wallerana) is one of the least sensitive species tested. Triclopyr tended to be more injurious than 2,4-D even though species sensitivity to each herbicide varied

Variable rate dosing in precision viticulture: Use of electronic devices to improve application efficiency

Two different spray application methods were compared in three vine varieties at different crop stages. A conventional spray application with a constant volume rate per unit ground area (1 ha(-1)) was compared with a variable rate application method designed to compensate electronically for measured variations in canopy dimensions. An air-blast sprayer with individual multi-nozzle spouts was fitted with three Ultrasonic sensors and three electro valves on one side, in order to modify the emitted flow rate of the nozzles according to the variability of canopy dimensions in real time. The Purpose of this prototype was to precisely apply the required amount of spray liquid and avoid over dosing. On average, a 58% saving in application volume was achieved with the variable rate method, obtaining similar or even better leaf deposits.This work was funded by the Spanish Ministry of Education and Science, and was part of research project AGL2007-66093-C04-02/AGR. We are grateful to Professor Jordi Valero from Universitat Politècnica de Catalunya for his help in the statistical analysis and Xavier Vidal director of the School of Viticulture “Mercè Rosell” at Espiells (Barcelona) for his help during the field experiments

Advanced technologies for the improvement of spray application techniques in spanish viticulture: an overview

Spraying techniques have been undergoing continuous evolution in recent decades. This paper presents part of the research work carried out in Spain in the field of sensors for characterizing vineyard canopies and monitoring spray drift in order to improve vineyard spraying and make it more sustainable. Some methods and geostatistical procedures for mapping vineyard parameters are proposed, and the development of a variable rate sprayer is described. All these technologies are interesting in terms of adjusting the amount of pesticides applied to the target canopy.Postprint (published version

Development of the TOXSWA model for predicting the behaviour of pesticides in surface water; proceedings of a workshop, held on November 8, 1994 at Wageningen, The Netherlands

In an international workshop the state of the art of the aquatic fate model TOXSWA was presented. This report gives an account of the presentations and discussions of the workshop. Model concepts of TOXSWA are explained and preliminary results of the sensitivity analysis are given. Next, the TOXSWA model is compared with the existing SLOOT.BOX model. The leaching model TRANSOL and the spray drift model IDEFICS are presented. They describe two possible entry routes and can be used to generate input data for TOXSWA. Finally, future applications of the TOXSWA model are discussed

A herbicide sprayer for tropical small-holder farmers

Imperial Users onl

Effect of the spray volume adjustment model on the efficiency of fungicides and residues in processing tomato

This study compared the effects of a proportionate spray volume (PSV) adjustment model and a fixed model (300 L/ha) on the infestation of processing tomato with potato late blight (Phytophthora infestans (Mont.) de Bary) (PLB) and azoxystrobin and chlorothalonil residues in fruits in three consecutive seasons. The fungicides were applied in alternating system with or without two spreader adjuvants. The proportionate spray volume adjustment model was based on the number of leaves on plants and spray volume index. The modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was optimized and validated for extraction of azoxystrobin and chlorothalonil residue. Gas chromatography with a nitrogen and phosphorus detector and an electron capture detector were used for the analysis of fungicides. The results showed that higher fungicidal residues were connected with lower infestation of tomato with PLB. PSV adjustment model resulted in lower infestation of tomato than the fixed model (300 L/ha) when fungicides were applied at half the dose without adjuvants. Higher expected spray interception into the tomato canopy with the PSV system was recognized as the reasons of better control of PLB. The spreader adjuvants did not have positive effect on the biological efficacy of spray volume application systems. The results suggest that PSV adjustment model can be used to determine the spray volume for fungicide application for processing tomato crop

Intranasal Opioid Compositions

The present invention relates to pharmaceutical compositions for intranasal administration to a mammal that contain an effective amount of an opioid, a liquid nasal carrier for the opioid, and optionally a sweetener, flavoring agent or masking agent. In some embodiments of the present invention, the pharmaceutical compositions have improved bioavailability. In other embodiments of the present invention, the opioid compositions improve patient compliance

Impact of glyphosate drift on non-target field margin invertebrates

Grassy arable field margins provide important permanent habitats for arthropods in agroecosystems and due to their proximity to high input areas, are exposed to pesticide drift. The aims of this thesis are to determine the likely effects of glyphosate drift in arable field margins by examining patterns of a medium quality spray drift intercepted by plant species in buffer strips and the effects of glyphosate on non-target field margin arthropods. Levels of mediumquality spray drift, analogous to herbicide drift, intercepted by field margin plant species in field boundaries were significantly reduced by inclusions of 2m and 6m wide buffer strips. Levels of spray drift interception varied between plant species and were related to plant height and leaf area. Dose-response testing of glyphosate against field margin plant species was done to establish inherent susceptibilities to the herbicide. Many species appeared to be unaffected by high levels of glyphosate (1800g ha-1), while others had relatively high ED50s that were unlikely to be exceeded by UK recommended rates of glyphosate. It was noted that lack of exposure to interspecific competition may have enhanced the plant species tolerance to high levels of glyphosate. Different rates of glyphosate were screened against the non-target arthropods Lepthyphantes tenuis (Araneae) and Leptopterna dolabrata (Heteroptera) to assess toxicity. Glyphosate was found to be non-toxic, however, applications of glyphosate to food plants increased mortality in L. dolahrata. In a field experiment, glyphosate applications of more than 360g ha-1 to a grassy arable field margin reduced Araneae, Heteroptera and Carabidae abundance. Community analyses (DCA) indicated that communities in the field margins exposed to more than 360g ha-1 glyphosate were distinct from unsprayed field margins. It is predicted that drift of field applied glyphosate at rates greater than 1440g ha-1 would reduce phytophagous Heteroptera and Gonalium rubens (Araneae) abundance

Development of bioassay techniques/ field persistence of trifluralin, simazine and diuron. Calotropis procers and Parkinsonia aculeata.

1. Development of bioassay techniques for trifluralin, simazine and diuron. 2. Field persistence of trifluralin, simazine and diuron in Wongan Hills soils. 3. Taxonomic studies of Calotropis procera, a declared weed of the North-West of Western Australia. 4. Germination studies of calotropis procera and Parkinsonia aculeata