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Several diseases have threatened tomato production in Florida, resulting in large losses, especially in fresh markets. In this study, a high-resolution portable spectral sensor was used to investigate the feasibility of detecting multi-diseased tomato leaves in different stages, including early or asymptomatic stages. One healthy leaf and three diseased tomato leaves (late blight, target and bacterial spots) were defined into four stages (healthy, asymptomatic, early stage and late stage) and collected from a field. Fifty-seven spectral vegetation indices (SVIs) were calculated in accordance with methods published in previous studies and established in this study. Principal component analysis was conducted to evaluate SVIs. Results revealed six principal components (PCs) whose eigenvalues were greater than 1. SVIs with weight coefficients ranking from 1 to 30 in each selected PC were applied to a K-nearest neighbour for classification. Amongst the examined leaves, the healthy ones had the highest accuracy (100%) and the lowest error rate (0) because of their uniform tissues. Late stage leaves could be distinguished more easily than the two other disease categories caused by similar symptoms on the multi-diseased leaves. Further work may incorporate the proposed technique into an image system that can be operated to monitor multi-diseased tomato plants in fields.

Nebraska is the number‐one producer of food‐grade white corn (Zea mays L.) in the United States. Food‐grade white corn has not been genetically engineered; therefore, non‐selective herbicides such as glyphosate or glufosinate cannot be used. Multiple herbicide‐resistant (MHR) Palmer amaranth (Amaranthus palmeri S. Watson) populations have been reported in multiple counties in Nebraska, and their management is a challenge, particularly for white corn producers. The objectives of this study were to evaluate the residual activity of pre‐emergence (PRE) herbicides for acetolactate synthase inhibitor (halosulfuron‐methyl)/atrazine/glyphosate‐resistant Palmer amaranth control, density, biomass, seed production, and grain yield in food‐grade white corn. Field experiments were conducted during summer 2020 and 2021 in a grower's field infested with MHR Palmer amaranth near Carleton, NE. All the PRE herbicides resulted in similar control (>90%) 30 days after PRE application (DAPRE) apart from atrazine (64%). At 45 DAPRE, acetochlor/mesotrione, atrazine/bicyclopyrone/mesotrione/S‐metolachlor, and acetochlor/clopyralid/mesotrione controlled 90%–95% Palmer amaranth. Acetochlor/clopyralid/mesotrione and atrazine/bicyclopyrone/mesotrione/S‐metolachlor provided 96%–99% MHR Palmer amaranth control and reduced Palmer amaranth density and biomass to 2–4 plants m−2 and 5–12 g m−2 60 DAPRE. The highest corn yields of 12,139 kg ha−1 and 12,093 kg ha−1 in 2020 and 2021, respectively, were obtained with acetochlor/clopyralid/mesotrione. Palmer amaranth seed production was least with acetochlor/clopyralid/mesotrione (32,894 seeds m−2). Tested residual PRE herbicides did not show corn injury and were safe to use in food‐grade white corn. It is concluded that acetochlor/clopyralid/mesotrione and atrazine/bicyclopyone/mesotrione/S‐metolachlor are the best options for early season control of MHR Palmer amaranth in food‐grade white corn.Core Ideas: Acetochlor/clopyralid/mesotrione and atrazine/bicyclopyone/mesotrione/S‐metolachlor provided >90% control of Palmer amaranth at 45 and 60 days after application.Acetochlor/clopyralid/mesotrione and atrazine/bicyclopyone/mesotrione/S‐metolachlor reduced Palmer amaranth density, biomass, and seed production and resulted in higher white corn yield.No corn injury was noticed in any of the pre‐emergence (PRE) herbicides tested in this study. [ABSTRACT FROM AUTHOR]

Multiple herbicide-resistant (MHR) Palmer amaranth is a troublesome weed in several crops across the USA, including corn. Due to unavoidable weather conditions, it is sometimes not possible for growers to apply pre-emergence herbicide; therefore, post-emergence (POST) herbicide is needed for effective control of MHR Palmer amaranth. The objectives of this study were to evaluate the effect of POST herbicides applied at two heights (10-15 cm and 20-30 cm) for MHR Palmer amaranth control and their effect on Palmer amaranth biomass, density, and seed production as well as yield of glufosinate/glyphosate-resistant corn. Field experiments were conducted at a grower’s field near Carleton, Nebraska, USA in 2020 and 2021. Control of MHR Palmer amaranth was affected by the plant height when herbicides were applied. Glufosinate, dicamba, dicamba/diflufenzopyr, and dicamba/tembotrione applied to 10-15 cm tall Palmer amaranth provided ≥ 94% control 30 d after EPOST (DAEPOST), whereas atrazine/bicyclopyone/mesotrione/S-metolachlor applied to 20-30 cm tall MHR Palmer amaranth provided 85% control in 2021. Glufosinate provided 85% to 90% control when applied to 20-30 cm tall Palmer amaranth in both years. At 90 DALPOST, dicamba, dicamba/diflufenzopyr, and dicamba/ tembotrione applied to 10-15 cm tall Palmer amaranth provided ≥ 88% control. Dicamba/tembotrione, atrazine/bicyclopyone/mesotrione/S– metolachlor, and dicamba applied to 20-30 cm tall Palmer amaranth provided 85% to 92% control. Glufosinate, dicamba, and atrazine/bicyclopyone/ mesotrione/S–metolachlor were the most effective for reducing Palmer amaranth density 2 to 19 plants m−2 when applied to 10-15 cm Palmer amaranth 30 DAEPOST compared with the nontreated control (137 plants m−2 ) in 2021; however, when applied to 20-30 cm Palmer amaranth, glufosinate, and atrazine/bicyclopyone/mesotrione/S–metolachlor reduced density 5 to 19 plants m−2 . At 30 DAEPOST, glufosinate and atrazine/bicyclopyone/ mesotrione/S–metolachlor had the lowest Palmer amaranth biomass (3-17 g m−2 ). Corn yield in 2020 was higher than 2021 due to more rain in 2020. All herbicides resulted in a similar yield in 2020. Lower seed production of 6,269 and 1,953 seeds plant-1 for 10-15 cm and 20-30 cm MHR Palmer amaranth were recorded with dicamba and atrazine/bicyclopyone/mesotrione/S–metolachlor. [ABSTRACT FROM AUTHOR]

High preweaning mortality (PWM) rates for piglets are a significant concern for the worldwide pork industries, causing economic loss and well-being issues. This study focused on identifying the factors affecting PWM, overlays, and predicting PWM using historical production data with statistical and machine learning models. Data were collected from 1,982 litters from the U.S. Meat Animal Research Center, Nebraska, over the years 2016 to 2021. Sows were housed in a farrowing building with three rooms, each with 20 farrowing crates, and taken care of by well-trained animal caretakers. A generalized linear model was used to analyze the various sow, litter, environment, and piglet parameters on PWM. Then, different models (beta-regression and machine learning model: a random forest [RF]) were evaluated. Finally, the RF model was used to predict PWM and overlays for all listed contributing factors. On average, the mean birth weight was 1.44 kg, and the mean mortality was 16.1% where 5.55% was for stillbirths and 6.20% was contributed by overlays. No significant effect was found for seasonal and location variations on PWM. Significant differences were observed in the effects of litter lines on PWM (P  < 0.05). Landrace-sired litters had a PWM of 16.26% (±0.13), whereas Yorkshire-sired litters had 15.91% (±0.13). PWM increased with higher parity orders (P  < 0.05) due to larger litter sizes. The RF model provided the best fit for PWM prediction with a root mean squared errors of 2.28 and a correlation coefficient (r) of 0.89 between observed and predicted values. Features' importance from the RF model indicated that, PWM increased with the increase of litter size (mean decrease accuracy (MDA) = 93.17), decrease in mean birth weight (MDA = 22.72), increase in health diagnosis (MDA = 15.34), longer gestation length (MDA = 11.77), and at older parity (MDA = 10.86). However, in this study, the location of the farrowing crate, seasonal differences, and litter line turned out to be the least important predictors for PWM. For overlays, parity order was the highest importance predictor (MDA = 7.68) followed by litter size and mean birth weight. Considering the challenges to reducing the PWM in the larger litters produced in modern swine industry and the limited studies exploring multiple major contributing factors, this study provides valuable insights for breeding and production management, as well as further investigations on postural transitions and behavior analysis of sows during the lactation period. [ABSTRACT FROM AUTHOR]

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