The effect of emulsifier volume on emulsion system stability of plant origin being the basis of diet supplements for animals in winter season was analyzed. For this purpose, measurements of the backscattered light intensity as the function of the measuring cell height were conducted with a Turbiscan LAB optical analyzer. System stability was analyzed on the basis of Turbiscan Stability Index values. A Helos laser analyzer and a Nikon Eclipse E400 POL optical microscope were used to investigate drop size distribution and analyze microscopic pictures. It was shown that emulsion with 10% (w/w) of the emulsifier was the most stable one.

In agriculture, the mixing of pesticides in tanks is a common practice. However, it is necessary to previse possible physical-chemical implications of this practice, which may affect the efficiency of the treatments performed. Therefore, the objective of this study was to evaluate the effects of the addition of acaricide to insecticidal spray mixtures on the formation of spray droplets and the interaction with citrus leaves. The experimental design was totally randomized, in a (2 × 3 + 1) factorial scheme for seven treatments. Factor A corresponded to the spray mixture used (isolate or in the mixture). Factor B corresponded to the insecticides tested (lambda-cyhalothrin + thiamethoxam, phosmet, and imidacloprid) and the control consisted of a spray mixture with spirodiclofen only. Nine replications were performed for characterization of the spray droplet size spectrum and four replications for the analysis of the surface tension and the contact angle. The mixture of pesticides showed positive results in terms of application safety. The addition of acaricide to insecticide spray mixtures reduced the surface tension and contact angle of droplets on the adaxial surface of orange leaves. There was an increment in volume median diameter (VMD), a significant reduction in the volume of droplets with drift-sensitive size and improvement in the uniformity of droplet size. Therefore, the addition of acaricide to an insecticide spray mixture positively influenced spray droplet formation and the interaction with citrus leaves providing better coverage and droplet size fractions with an appropriate size for safe and efficient application.

It is challenging to obtain proper leaf wetting. An angled spray could overcome this impediment, but which spray angle is best suited to droplet size is still unknown. In an outdoor pot experiment, seven doses of cycloxydim and sethoxydim were sprayed with single-orifice standard, anti-drift, and air induction (having a fine, medium, and extremely coarse spray quality, respectively) flat fan nozzles, using spray angles of 10°, 20° backward, 0° (vertical), 10°, 20°, 30°, 40°, 50°, and 60° forward relative to the direction of nozzle trajectory on wild barley at the three-leaf stage. Generally, the forward angled spray was better than the backward angled spray. With a standard flat fan nozzle, the forward angling of spray from 0° to 20° reduced the ED50 from 60.24 to 39.85 g a.i. ⋅ ha−1 for cycloxydim and from 150.51 to 81.13 g a.i. ⋅ ha−1 for sethoxydim. With an anti-drift flat fan nozzle, the forward angling of spray from 0° to 30° reduced the ED50 from 72.57 to 50.20 g a.i. ⋅ ha−1 for cycloxydim and from 181.94 to 104.51 g a.i. ⋅ ha−1 for sethoxydim. With an air induction flat fan nozzle, the forward angling of spray from 0° to 40° reduced the ED50 from 102.96 to 45.52 g a.i. ⋅ ha−1 for cycloxydim and from 209.91 to 92.80 g a.i. ⋅ ha−1 for sethoxydim. More angling did not improve the efficacy of these herbicides. Our results revealed that larger spray droplets needed more spray angle than smaller spray droplets to achieve an equal control.

The study was conducted at the University of Nebraska Pesticide Application and Technology Laboratory in North Platte, Nebraska in July 2015. Two application volume rates (100 and 200 l · ha−1) and three nozzle types (XR, AIXR, TTI) were selected at two flow rates (0.8 and 1.6 l · min−1) and at a single application speed of 7.7 km · h−1. Each collector type [Mylar washed (MW), Mylar image analysis (MIA), water-sensitive paper (WSP), and Kromekote (KK)] was arranged in a randomized complete block design. Each nozzle treatment was replicated twice, providing six cards of each collector type for each nozzle treatment. A water + 0.4% v/v Rhodamine WT spray solution was applied, given the fluorescent and visible qualities of Rhodamine, which allows it to be applied over all the collector types. MW had the highest coverage at 18.3% across nozzle type, followed by WSP at 18%, KK at 12% and lastly by MIA at 4%. MW resulted in a 58% increase in coverage, WSP in a 56% increase, and KK only an increase of 39% when the volume rate was doubled from 100 l · ha−1 to 200 l · ha−1 across nozzle type. MW coverage was similar to KK for half of the nozzles (XR 11002, XR 11004, AIXR 11002). Droplet number density fixed effects were all significant for nozzle type and collector type (p < 0.001) as was the interaction of nozzle type and collector type (p < 0.001). Results from this study suggest a strong correlation to data produced with WSP and MW collectors, as there was full agreement between both types except for the TTI 11004. Using both collector types in the same study would allow for a visual understanding of the distribution of the spray, while also giving an idea of the concentration of that distribution.

Nozzle type and herbicide application timing can affect herbicide efficacy. Prickly sida ( Sida spinosa) and barnyardgrass ( Echinochloa crus-galli) are problematic weeds in eastern Mississippi cotton production and have reduced yield in recent years. Field studies were conducted at two locations – Brooksville, MS (2018, 2019) and Starkville, MS (2019) to understand the nozzle type and herbicide application timing effects on prickly sida and barnyardgrass control in cotton. Studies also compared applications made by an eight-nozzle tractor-mounted sprayer with a four-nozzle backpack sprayer. Herbicide applications were made at four timings: preemergence (PRE), early-postemergence (EPOST), mid-postemergence (MPOST), and late-postemergence (LPOST) corresponding to the preemergence (immediately after planting), two-to-three leaf, four-to-six leaf, and early-bloom stages, respectively. Treatments were made at 140 l · ha−1 applied at each growth stage, with nozzle type and sprayer as variables by each timing. Results showed no differences in treatments applied with backpack and tractor-mounted sprayers. Control of barnyardgrass was significantly affected by nozzle type, but control of prickly sida was not significantly influenced by nozzle type. In all three site-years, plots receiving a MPOST only herbicide application resulted in less weed control than areas receiving a two-pass POST herbicide program. Cotton yield was significantly affected by the herbicide program at one site-year, but was not significantly affected by the herbicide program except where cotton injury exceeded 15%. A two- or three-pass herbicide program was most effective in controlling prickly sida and barnyardgrass in Mississippi cotton.