Thirty-eight aircraft setups were submitted in order to have droplet size and drift analyses performed. Four of the eleven insecticides predicted D(v0.5)s were in the 351-400 mu m range. Seven of the herbicide setups had predicted D(v0.5)s in the 205-250 mu m range, while ten D(v0.5)s were > 351 mu m. Five of the ten predicted D(v0.5)s were between 386 and 413 mu m. Twelve different herbicides were reported as having been applied with aircraft setups that had predicted D(v0.5)s between 386 and 413 mu m. A summary of the prior swath deposit data indicated that the percent recovery generally increased as the D-v0.5 increased. The magnitudes of the deposits on inert targets and cotton leaves appeared to be about equal for a given D-v0.5. The correlation coefficient between the "percent of the spray volume in droplets : 100 mu m and <= 200 mu m in diarneter" was 0.983. This result is consistent with prior results and indicates that either 100 or 200 mu m can be effectively used as the upper limit when studying the "small droplet" component in sprays. We found several similarities or differences in the "small droplet" components based on data from different atomization tests. According to one set of atomization models, agricultural aircraft will be limited to about 225 km/h (i.e., 140 mph) in order to produce a 400 mu m D-v0.5 spray when using currently available nozzles and water plus one or more pesticides. The extremes of the predicted drift deposits for 38 agricultural aircraft setups were over 30-fold apart.

A small plot pesticide evaluation system is described that includes a computer-controlled tractor-mounted spray system, an automatic pipetter for filling bottles used on the spray tractor, and a computer program for computation of amounts of adjuvants and pesticides to be added to a pre-set volume of carrier to result in a specific mixture concentration. Benefits of the system include fast, accurate mixing of chemicals in replicate, precise spraying of pesticide, computer-controlled rinsing of the system, and reduced operator fatigue.

A field study was conducted in 1992 and 1993 to identify the spray volume and droplet size combinations to optimize control of common cocklebur (Xanthium strumarium) from acifluorfen by maximizing target deposition. In many instances, acifluorfen controlled common cocklebur better using either small (250 mum) or large (450 mum) spray droplets when applied at the lower carrier volumes of either 56 or 112 L/ha, When sprays were applied at 169 L/ha, there was little difference in control between droplet sizes. Deposition of acifluorfen was determined in 1993, Stepwise regression indicated that acifluorfen deposition amount is less important than environmental conditions for common cocklebur control. Relative humidity was the most significant variable for determining common cocklebur control with acifluorfen.

Studies were conducted to determine the effects of droplet size, leaf morphology, and a spray thickener on pesticide spray deposition using chlorpyrifos as the indicator compound. The predicted deposition efficiencies for 140 mu m droplets were 99, 77, 65, and 55%, respectively, for cocklebur; entireleaf morninglory, velvetleaf; and coffee senna leaves. Predicted deposition efficiencies decreased as droplet size increased for all four leaf types. The slopes of the linear regression equations indicated that deposition efficiency would decrease by 16, 10, 8, and 6%, respectively, with each 100 mu m increase in droplet diameter. Addition of a viscosity modifying adjuvant did not improve the deposition efficiency on coffee senna leaves.

Multiple regression procedures were used to develop models to predict spray drift from ground, boom sprayers. These models were developed to study the effect of independent variables on drift deposits. The Missouri model was developed from single nozzle tests and contained six significant variables. Spray drift deposits were most strongly related to three variables (i.e., common lograrithm of corrected downwind distance, wind speed, and nozzle height; in that order). Neither volume median diameter or the '% of the spray, volume less than or equal to 105 mu m' were significantly related to drift deposits. The Illinois model (i.e., developed from six nozzle spray boom tests) included four significant variables. The most important var0iable for this model was the 'common logarithm of the corrected downwind distance'. The common logarithm of the corrected downwind distance, nozzle pressure, and dry bulb temperature were included in both of the models. The common logarithm of the corrected downwind distance was clearly the most import variable in both models as indicated by sensitivity analyses, The results from the model verifications indicated that the predicted and measured deposits, were in very good agreement.

Effects of adjuvants on chlorpyrifos for suppression of cotton aphid, Aphis gossypii (Glover), in cotton, Gossypium hirsutum (L.), were evaluated using four parameters: percentage cotton aphid mortality, spray droplet coverage (percentage area covered) on water-sensitive cards, spray droplet penetration (average spot diameter frequency distributions) into the cotton canopy, and the rate of disappearance (decay) of chlorpyrifos residues from cotton leaf surfaces. All factors were measured on cotton averaging 171.4 cm in height at three canopy levels (from terminal): upper, 0 cm; middle, 45.7 cm; lower, 76.2 cm. Mortality of aphids in the upper canopy level (89%) was higher than middle (66%) and lower (57%) levels. Spray coverage, measured as mean percentage area of water-sensitive cards covered by spots, decreased at each lower canopy level as did mean total number of spots per square centimeter. Chlorpyrifos alone generally had a higher proportion of spots per square centimeter in the middle and lower canopy levels relative to the upper level, compared with the adjuvant combinations. No differences in spot diameter frequency distributions were detected among treatments within a canopy level or within a treatment among canopy levels. Initial mean chlorpyrifos deposits on cotton leaf surfaces were highest at the upper canopy level (678 ng/cm2) and decreased by approximately 50% at each descending canopy level. Rate of disappearance of chlorpyrifos from cotton leaf surfaces was significantly reduced at the middle and lower canopy levels compared with the upper level. Adjuvants did not significantly affect chlorpyrifos efficacy, deposition characteristics, or rate of disappearance of chlorpyrifos. Canopy level was important for all three measured criteria.

Spray deposit data from both laboratory and field studies for the same treatments were used to determine if the laboratory data could be used to eliminate some treatments prior to evaluating future field tests. Two criteria were selected and both produced consistent results for the data sets from 55-60 treatments. The first laboratory based criteria is: treatments producing spray deposit coefficients of variation (CV) greater-than-or-equal-to 13% should be eliminated. The second criteria involves single nozzle tests both with and without an airstream at a velocity of 2.3 m/s at 45.7 cm above the spray table. This criteria indicates that if the difference in the distances where the two cumulative volumetric distributions reach 50% of the spray deposited is greater-than-or-equal-to 26.7 cm, then the treatment should be eliminated. These two criteria are based on a targeted field CV of less-than-or-equal-to 15%. Use of the two criteria reduced the number of treatments (i.e., and thus time and costs) which would need to be evaluated in the field by about 30%. The proposed criteria are offered as guidelines for researchers who are interested in conducting field, uniformity spray tests and spray nozzle manufacturers.

Expert system for aerial spray drift , Expert system for aerial spray drift , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Journal Article Performance Specifications for Tobacco Budworm (Lepidoptera: Noctuidae) Larvae Treated with Vegetable Oil and Water Sprays Containing Fluvalinate Get access D. B. Smith, D. B. Smith Departments of Agricultural and Biological Engineering and Entomology, Mississippi Agricultural and Forestry Experiment Station, Mississippi State, Mississippi 39762 Search for other works by this author on: Oxford Academic PubMed Google Scholar R. G. Luttrell R. G. Luttrell Departments of Agricultural and Biological Engineering and Entomology, Mississippi Agricultural and Forestry Experiment Station, Mississippi State, Mississippi 39762 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 80, Issue 6, 1 December 1987, Pages 1314–1318, https://doi.org/10.1093/jee/80.6.1314 Published: 01 December 1987 Article history Received: 10 March 1987 Accepted: 24 July 1987 Published: 01 December 1987

Journal Article Relative Effect of Dosage, Droplet Size, Deposit Density, and Droplet Concentration on Mortality of Heliothis virescens (Lepidoptera: Noctuidae) Larvae Treated with Vegetable-oil and Water Sprays Containing Permethrin Get access J. T. Wofford, J. T. Wofford Departments of Entomology and Agricultural and Biological Engineering, Mississippi Agricultural and Forestry Experiment Station, Mississippi State University, Mississippi State, Mississippi 39762 Search for other works by this author on: Oxford Academic PubMed Google Scholar R. G. Luttrell, R. G. Luttrell Departments of Entomology and Agricultural and Biological Engineering, Mississippi Agricultural and Forestry Experiment Station, Mississippi State University, Mississippi State, Mississippi 39762 Search for other works by this author on: Oxford Academic PubMed Google Scholar D. B. Smith D. B. Smith Departments of Entomology and Agricultural and Biological Engineering, Mississippi Agricultural and Forestry Experiment Station, Mississippi State University, Mississippi State, Mississippi 39762 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 80, Issue 2, 1 April 1987, Pages 460–464, https://doi.org/10.1093/jee/80.2.460 Published: 01 April 1987 Article history Received: 19 June 1986 Accepted: 27 October 1986 Published: 01 April 1987

A small plot field study was conducted on the Plant Science Research Farm of the Mississippi Agriculture and Forestry Experiment Station, Mississippi State, MS, to determine if insecticide carriers (vegetable oil and water) and droplet characteristics (droplet size and droplet concentration) influence control of Heliothis spp. in cotton. Four-row plots (3.87 m × 15.24 m) with 10-row buffers were planted to ‘Stoneville 825’ on 15 May and 1 Jun (2 replications required replanting) in a randomized complete block design. Vegetable oil treatments were varied by manipulating droplet size with Micro Max rotary atomizers set at 1600, 3500 and 5000 RPM and by using 3 different application rates (0.25, 0.5 and 1.0 gpa) attained by varying the ground speed. Water treatments were similarly varied by using 3 different droplet sizes, attained with TX-6, TX-4 and TX-1 hollow cone nozzles, and 3 volumetric application rates (3.0, 6.0 and 12.0 gpa) attained by varying the number of nozzles per row and the ground speed. Permethrin (Pounce 3.2 EC) was used at 0.1 lb (AI)/acre for all droplet size-carrier-volumetric application rate combinations. The controls consisted of a water-only treatment, an oil only treatment and an untreated. Treatments were applied on 15, 20 and 27 Aug. Plots were evaluated 17 Aug by randomly pulling 25 squares from plants in each plot and observing the number of squares damaged by Heliothis spp. larvae. On 25 Aug whole-plant observations were made on 5 row feet to observe Heliothis spp. damage and numbers of fruiting structures present. On 5 Oct open bolls, unopened bolls and total bolls were counted on 5 row feet in each plot. Yield data were obtained by mechanically harvesting the 2 center rows of each plot on 21 Nov.

Elcar® and Coax® suspensions were manually painted on soybean leaves or stems, pods and flowers in the field. Suspension deposits on stems, pods and flowers caused ca 7 × more mortality than deposits on leaves. In a second study, a 1 × suspension deposit on stems, pods and flowers caused approximately the same bioassay mortality (i.e. 58 vs 52%) as a 2 × deposit on soybean leaves. Data from equipment evaluations in the field indicated that a deflector shield mounted immediately in front of the spray boom and positioned to contact the upper 16 – 20 cm of the soybean plants caused higher Heliothis zea (Boddie) mortalities than other treatments evaluated.

Journal Article Natural Mortality of Lepidopteran Eggs and Larvae in Missouri Soybeans Get access N. L. Marston, N. L. Marston 1Biological Control of Insects Research Laboratory, USDA-ARS, P.O. Box A, Columbia, MO 65205 Search for other works by this author on: Oxford Academic Google Scholar D. L. Hostetter, D. L. Hostetter 1Biological Control of Insects Research Laboratory, USDA-ARS, P.O. Box A, Columbia, MO 65205 Search for other works by this author on: Oxford Academic Google Scholar R. E. Pinnell, R. E. Pinnell 1Biological Control of Insects Research Laboratory, USDA-ARS, P.O. Box A, Columbia, MO 65205 Search for other works by this author on: Oxford Academic Google Scholar W. A. Dickerson, W. A. Dickerson 2Boll Weevil Eradication Research, USDA-ARS, 4120 Reedy Creek Road, Raleigh, NC 27607 Search for other works by this author on: Oxford Academic Google Scholar D. B. Smith D. B. Smith 3Bioengineering Research Unit, USDA-ARS, Building T-12, University of Missouri, Columbia, MO 65201 Search for other works by this author on: Oxford Academic Google Scholar Annals of the Entomological Society of America, Volume 77, Issue 1, 1 January 1984, Pages 21–28, https://doi.org/10.1093/aesa/77.1.21 Published: 01 January 1984 Article history Received: 03 March 1983 Accepted: 06 September 1983 Published: 01 January 1984

ABSTRACT A spray table-wind tunnel combination was used to evaluate the uniformity of spray deposits for two types of fan nozzles operated in three wind velocity regimes. Field tests were used to evaluate the uniformity and recovery of spray deposits from flooding, fan and raindrop nozzles. The flooding nozzles were evaluated for several operating conditions. The results indicate that it is difficult to consistently obtain **uniform swath deposits for spray applied under field conditions. Even under near ideal conditions, most of the treatments caused coefficients of variation for swath deposits of ^ 15%.

Journal Article Laboratory and Field Evaluations of Pathogen-Adjuvant Treatments Get access D. B. Smith, D. B. Smith Search for other works by this author on: Oxford Academic PubMed Google Scholar D. L. Hostetter D. L. Hostetter Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 75, Issue 3, 1 June 1982, Pages 472–476, https://doi.org/10.1093/jee/75.3.472 Published: 01 June 1982 Article history Received: 26 May 1981 Published: 01 June 1982

Formulations of Elcar (Baculovirus heliothis) consisting of potential adjuvants were evaluated in standardized laboratory bioassay tests against 24-h-old Heliothis zea (Boddie) larvae. A cottonseed flour adjuvant consisting of 62.5% cottonseed flour, 12.5% cottonseed oil, 25% sucrose, and 0.004% Tween 80 caused significantly higher bioassay mortality rates than the other adjuvants evaluated or than a standard Elcar-water formulation. Evaluation of the individual constituents of this adjuvant indicated that the cottonseed flour or those combinations including cottonseed flour caused significantly higher mortality rates than did either the individual or combinations of cottonseed oil, sucrose, or Tween 80. The compatibility and potential of selected gustatory, thixotrophic, protective, and surfactant agents indicated that these agents may cause slight inhibition of the insecticidal activity of the formulations. The amount of cottonseed flour in the test formulations was directly related to insecticidal activity; activity decreased as flour content was reduced from 15% (highest) to 0.5% (lowest). Formulations containing 7.5% cottonseed or soybean flour provided the most consistent mortality rates and represented the upper limit of mixability. No differences in mortality rates occurred among a 7.5% cottonseed flour, a 7.5% cottonseed flour hydrolyzate, and a 5% cottonseed flour formulation, indicating that the active factor (s) is water soluble and is not related to particulate size or content. The addition of various adjuvants to formulations containing Elcar increased bollworm bioassay mortality rates 8- to 10-fold in laboratory tests.