Weed Control with Single and Split Herbicide Applications in Corn

The objective of the study was to compare season-long weed control from single and sequential herbicide applications in corn. Kochia control was 90% or more late in the season, and did not differ among herbicides. All herbicides except Lumax EZ provided 90% or more Russian thistle control by the season’s end. Palmer amaranth control was lowest when Bicep II Magnum was applied preemergence (PRE) and followed by Lexar EZ postemergence (POST), and when Acuron was applied PRE and again POST. Compared to the untreated control, corn receiving herbicide treatments yielded more than three times as much grain, but yields did not differ among herbicides

A Locally Adaptable Iterative RX Detector

We present an unsupervised anomaly detection method for hyperspectral imagery (HSI) based on data characteristics inherit in HSI. A locally adaptive technique of iteratively refining the well-known RX detector (LAIRX) is developed. The technique is motivated by the need for better first- and second-order statistic estimation via avoidance of anomaly presence. Overall, experiments show favorable Receiver Operating Characteristic (ROC) curves when compared to a global anomaly detector based upon the Support Vector Data Description (SVDD) algorithm, the conventional RX detector, and decomposed versions of the LAIRX detector. Furthermore, the utilization of parallel and distributed processing allows fast processing time making LAIRX applicable in an operational setting

Active Brownian particles with velocity-alignment and active fluctuations

We consider a model of active Brownian particles with velocity-alignment in two spatial dimensions with passive and active fluctuations. Hereby, active fluctuations refers to purely non-equilibrium stochastic forces correlated with the heading of an individual active particle. In the simplest case studied here, they are assumed as independent stochastic forces parallel (speed noise) and perpendicular (angular noise) to the velocity of the particle. On the other hand, passive fluctuations are defined by a noise vector independent of the direction of motion of a particle, and may account for example for thermal fluctuations. We derive a macroscopic description of the active Brownian particle gas with velocity-alignment interaction. Hereby, we start from the individual based description in terms of stochastic differential equations (Langevin equations) and derive equations of motion for the coarse grained kinetic variables (density, velocity and temperature) via a moment expansion of the corresponding probability density function. We focus here in particular on the different impact of active and passive fluctuations on the onset of collective motion and show how active fluctuations in the active Brownian dynamics can change the phase-transition behaviour of the system. In particular, we show that active angular fluctuation lead to an earlier breakdown of collective motion and to emergence of a new bistable regime in the mean-field case.Comment: 5 figures, 22 pages, submitted to New Journal of Physic

On the attractors of two-dimensional Rayleigh oscillators including noise

We study sustained oscillations in two-dimensional oscillator systems driven by Rayleigh-type negative friction. In particular we investigate the influence of mismatch of the two frequencies. Further we study the influence of external noise and nonlinearity of the conservative forces. Our consideration is restricted to the case that the driving is rather weak and that the forces show only weak deviations from radial symmetry. For this case we provide results for the attractors and the bifurcations of the system. We show that for rational relations of the frequencies the system develops several rotational excitations with right/left symmetry, corresponding to limit cycles in the four-dimensional phase space. The corresponding noisy distributions have the form of hoops or tires in the four-dimensional space. For irrational frequency relations, as well as for increasing strength of driving or noise the periodic excitations are replaced by chaotic oscillations.Comment: 9 pages, 5 figure

Early Postemergence and Sequential Herbicides for Weed Control in Corn

In this study, herbicides were tested to compare sequential and split rates for weed control in corn. Control of green foxtail, Russian thistle, and quinoa was excellent regardless of herbicide treatment, and most herbicides provided good kochia and Palmer amaranth control. Minor corn injury occurred with some herbicides applied early postemergence or postemergence, but did not persist. All herbicide treatments increased grain yield 56 to 78% compared to the weedy control, but yields did not differ between herbicide treatments

Katagon at Two Timings Compared to Standards in Corn

The objective of this trial was to compare Katagon (tolpyralate/nicosulfuron) to standard treatments for weed control in corn. Katagon plus atrazine applied early postemergence was as effective as any herbicide tested on the weeds present. When application timing was delayed to late postemergence, most herbicides were less effective. Early season corn injury was minor and did not persist. Although most herbicide treatments increased yields relative to the non-treated control, yields were generally best when any treatment was applied early postemergence

Liberty Rates and Tank Mixes with Balance Flexx, Capreno, Diflexx, Halex GT, and Laudis for Weed Control in Irrigated Liberty-Resistant Corn

Control of common sunflower, quinoa, green foxtail, and kochia was excellent regardless of herbicide treatment or evaluation date. Palmer amaranth and crabgrass control was 95% or more regardless of herbicide treatment at 7 days after postemergence application (DAPT). Postemergence applications of Liberty (glufosinate) at any rate alone controlled Palmer amaranth greater than 85% 72 DAPT, whereas tank mixing any herbicide with Liberty increased control 7 to 15%. Crabgrass control was greater than 89% at 72 DAPT with all treatments except when Liberty at 22 oz/a was applied with Diflexx (dicamba). Corn yields did not differ among herbicide-treated plots, but all herbicide treatments increased yield 118 to 149 bu/a relative to the untreated controls

Split Applications of Coyote and Lumax for Efficacy in Grain Sorghum

In an effort to determine the efficacy of herbicide application timing in sorghum, full herbicide rates were applied 14 days preplant, and compared with split applications of half rates applied at two timings. Generally, weed control was best when half of the labeled rates were applied 14 days preplant followed by the other half preemergence, compared to full rates applied 14 days preplant. However, control of velvetleaf and common sunflower was excellent (95% or more) regardless of when the treatments were applied. Grain sorghum yields were similar among all herbicide treatments, and each treatment increased yield from 2 to 2.5-fold relative to the nontreated controls

Anthem Maxx Tank Mixture Comparisons in Irrigated Corn

The use of multiple herbicide modes of action in single versus sequential applications was examined for efficacy in corn. Common sunflower control was complete with all early postemergence and postemergence herbicides late in the season. Control of Russian thistle, Palmer amaranth, and green foxtail were 95% or more with all early postemergence and postemergence herbicides except Halex GT. All herbicide treatments increased grain yield 15–33% compared to the nontreated controls except Halex GT applied early postemergence

Fallow Weed Control with Vida Tank Mixtures

The objective of the study was to compare Vida (pyraflufen) with various tank mix partners for glyphosate-resistant kochia control. Flixweed control was complete in fallow with all herbicides by 28 days after treatment. Kochia control was best when Vida was applied with glyphosate and Spartan. However, due in part to the extremely dry conditions, no treatment controlled kochia by more than 83% at 28 days after treatment, and kochia control began to decline after this 28 DAT