In this study, we present a non-destructive technique for estimating the Leaf Area Index (LAI) of potato crops. The mobile LAI system consists of a PAR sensor (400–700 nm) and an NIR sensor (700–1000 nm), both attached to an aluminium frame extending from the front of a tractor, thus enabling LAI estimation along the potato ridges. An RTK-GNSS module attached to the sensors provides precise geo-location information alongside the estimated LAI values, thus creating a detailed map of the measured area. A comparison with a standard PAR sensor (a photon meter) showed a high correlation with a linear coefficient of determination (R² = 0.88). Furthermore, UAV estimated crop canopy traits of height, coverage and volume were also compared.

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This study examined the effects of three pretreatments (parboiling [PB], microwave [MW], and vacuum microwave [VMW]) on stress crack reduction and the microstructure of dried corn grains, using scanning electron microscopy (SEM) and X-ray computed tomography (CT) images. Changes in microstructure and porosity were evaluated through image analysis. The results revealed that MW treatment caused swelling and reduced starch cracks, while PB treatment led to the collapse of starch structure. In contrast, VMW treatment resulted in minimal observable internal structural changes. These differences in microstructure and porosity may be attributed to the varying distributions of hard and soft starch within the corn kernels.

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Working (tillage and sowing) depth is critical for crop growth, and a simple yet highly accurate technique for measuring in-field working depth is necessary to achieve uniform growth and increased yield. Therefore, we devised a depth estimation and control system based on tractor controller area network (CAN) data, validated the CAN data accuracy, and built depth estimation models. The relative error between the CAN-derived forward speed and the measured speed was low at −1.21–2.21 %. Additionally, we built a model to estimate the measured value of the power take off speed from the CAN value with R² = 0.99. The depth estimation model showed a strong correlation between hitch height and tillage/sowing depth (R = 0.99 and 0.86, respectively).

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To clarify the growth differences between diploid and tetraploid Anthurium andraeanum ‘Pink Champion’ seedlings, their leaves, stomata, petioles, roots, root hairs, and anatomy were compared. The results showed that tetraploids had reduced leaf length, petiole length, and plant height but increased leaf width, petiole width, and stomatal length, with thicker leaf structures respectively. Tetraploid petioles, leaves, and roots had larger cross-sections and cell volumes. Root traits varied; tetraploids had decreased root number, total root length, and root hair growth rate, but increased root diameter, root area, root hair diameter, and root activity, along with higher root fresh weight and root-shoot ratio. Diploids were slender and tall, tetraploids robust and short. These indicators aided preliminary screening and cultivar selection.

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Developing a unified calibration model to assess pol content in sugarcane juice extracted using different methods can substantially reduce the costs of developing individual models and improve operational efficiency. A benchtop spectrophotometer (400–2,500 nm) was used to acquire transflectance spectra of sugarcane juice extracted using the direct extraction method (DEM) and the shredded extraction method (SEM). DEM yielded a higher pol content of 0.67 % compared with that of SEM. The unified partial least squares (PLS) calibration model accurately predicted the pol content in the DEM and SEM samples, as well as that of mixed samples, with root mean square error of prediction (RMSEP) values of 0.23 %, 0.21 %, and 0.23 %, respectively.

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Existing techniques for evaluating the sugar content in sugar beet have considerable drawbacks, underscoring the need for more efficient methods. Here, we introduce a fast and minimally invasive method for measuring Brix in sugar beet with surface impurities using cost-effective handheld NIR spectrometers. Applicable in laboratories and potentially on-site, the method shows that spectral variations due to measurement locations minimally affect accuracy. The LinkSquare NIR spectrometer performed best with PLS regression on averaged intact spectra using smoothing and standard normal variate pre-treatment. The S-G1 spectrometer achieved superior results with PLS regression on the averaged peeled spectra without pre-treatment. These findings demonstrate the efficacy of handheld NIR spectrometers for sugar beet analysis and offer strategies for optimizing their accuracy and practicality.

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The aim of this study was to investigate the effects of temperature and input condition on methane yield from the unheated anaerobic digestion of crop residues in temperate regions. We conducted two tests: batch tests at three different temperatures (17, 25, and 37 °C) and a pilot-scale continuous unheated AD test in Fukushima, Japan. In unheated AD, the material input management based on the organic loading rate (OLR) was more important than hydraulic retention time. The highest methane gas yield in continuous test was 453 L kg-VS⁻¹ d⁻¹ when the OLR was 0.42 g-VS L⁻¹ d⁻¹ at a digestion temperature of approximately 27 °C and that was 83.9 % of the total methane yield obtained in the batch test.

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An agricultural electric vehicle platform (EVP) equipped with a weed mower was developed to address agricultural issues, such as labor shortages and environmental impact. This paper describes the development of a vision-based parking control system for docking to recharge an EVP, including an active parking control feature and a passive compliant mechanism for the connectors between the vehicle and charging station. The EVP could estimate and control its position and orientation by detecting an augmented reality marker indicating the position of the charging station. The proposed parking methods were tested in outdoor environments. In addition to a 65 % increase in docking success, the two-step parking control method exhibited superior alignment accuracy for docking connectors.

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