- ItemEmbargoEnhanced detoxification via Cyt-P450 governs cross-tolerance to ALS-inhibiting herbicides in weed species of Centaurea(Elsevier, 2023) Palma-Bautista, Candelario; Vázquez-García, José G.; Portugal, Joao de; Bastida, Fernando; Alcántara-de la Cruz, Ricardo; Osuna-Ruiz, Maria D.; Torra Farré, Joel; Prado, RafaelCentaurea is a genus of winter weeds with a similar life cycle and competitive traits, which occurs in small-grains production fields in the central-southern of the Iberian Peninsula. However, most of herbicides recommended for weed management in wheat show poor control of Centaurea species. This study summarizes the biology, herbicide tolerance to acetolactate synthase (ALS) inhibitors, and recommended chemical alternatives for the control of Centaurea species. Four species (C. cyanus L., C. diluta Aiton, C. melitensis L. and C. pullata L. subsp. baetica Talavera), taxonomically characterized, were found as the main important broadleaf weeds in small-grains production fields of the Iberian Peninsula. These species showed innate tolerance to tribenuron-methyl (TM), showing LD50 values (mortality of 50% of a population) higher than the field dose of TM (20 g ai ha−1). The order of tolerance was C. diluta (LD50 = 702 g ha−1) ≫ C. pullata (LD50 = 180 g ha−1) ≫ C. cyanus (LD50 = 65 g ha−1) > C. melitensis (LD50 = 32 g ha−1). Centaurea cyanus and C. melitensis presented higher foliar retention (150–180 μL herbicide solution), absorption (14–28%) and subsequent translocation (7–12%) of TM with respect to the other two species. Centaurea spp. plants were able to metabolize 14C-TM into non-toxic forms (hydroxylated OH-metsulfuron-methyl and conjugated-metsulfuron-methyl), with cytochrome P450 (Cyt-P450) monooxygenases being responsible for herbicide detoxification. Centaurea cyanus and C. mellitensis metabolized up to 25% of TM, while C. diluta and C. pullata metabolized more than 50% of the herbicide. Centaurea species showed 80–100% survival when treated with of florasulam, imazamox and/or metsulfuron-methyl, i.e., these weeds present cross-tolerance to ALS inhibitors. In contrast, auxin mimics herbicides (2,4-D, clopyralid, dicamba, fluroxypir and MCPA) efficiently controlled the four Centaurea species. In addition, the mixture of ALS-inhibitors and auxin mimics also proved to be an interesting alternative for the control of Centaurea. These results show that plants of the genus Centaurea found in the winter cereal fields of the Iberian Peninsula have an innate tolerance to TM and cross-resistance to other ALS-inhibiting herbicides, governed by reduced absorption and translocation, but mainly by the metabolization of the herbicide via Cyt-P450.
- ItemOpen AccessLow-cost terrestrial photogrammetry for orchard sidewards 3D reconstruction(2023) Martínez Casasnovas, José Antonio; Rosell Tarragó, Miquel; Rosell Polo, Joan Ramon; Sanz Cortiella, Ricardo; Gregorio López, Eduard; Gené Mola, Jordi; Arnó Satorra, Jaume; Plata Moreno, José Manuel; Escolà i Agustí, Alexandre
- ItemOpen AccessAmodal segmentation for on-tree apple fruit size es timation with RGB-D images(2023) Gené Mola, Jordi; Gregorio López, Eduard; Ferrer Ferrer , Mar; Blok, Pieter M.; Hemming, Jochen; Morros Rubió, Josep Ramon; Rosell Polo, Joan Ramon; Vilaplana Besler, Verónica; Ruiz Hidalgo, JavierThe detection and sizing of fruits with computer vision methods is of interest because it provides relevant information to improve the management of orchard farming. However, the presence of partially occluded fruits limits the performance of existing methods, making reliable fruit sizing a challenging task. While previous fruit segmentation works limit segmentation to the visible region of fruits (known as modal segmentation), in this work we propose an amodal segmentation algorithm to predict the complete shape, which includes its visible and occluded regions. CONCLUSIONS The main advantages of the present methodology are its robustness for measuring partially occluded fruits and the capability to determine the visibility percentage. Future works should evaluate the performance of the method with commercial RGB-D sensors, which would facilitate data collection.
- ItemOpen AccessUncertainty analysis of a LiDAR-based MTLS point cloud using a high-resolution ground-truth(2023) Lavaquiol Colell, Bernat; Llorens Calveras, Jordi; Sanz Cortiella, Ricardo; Arnó Satorra, Jaume; Escolà i Agustí, AlexandreThe study of plant geometry is crucial to design specific management by providing the optimal quantities of nutrients, fertilizers, pesticides and irrigation rates. Before the advent of the first 3D characterization systems, it was very laborious to obtain accurate commercial scale 3D crop data. Nowadays, there are sensing systems which allow 3D canopy characterization to be performed in a relatively simple and fast way. LiDAR (light detection and ranging) sensors have been widely used in agriculture. When 3D scanning techniques are used, it is essential to be aware of the total measurement error. One of the limitations when using real data is the absence of ground-truth (GT) to compare the obtained measurements . In a previous research , validated a high-resolution 3D point cloud on an actual defoliated tree obtained from RGB images and stereo-photogrammetry techniques. This accurate 3D point cloud can be used as digital ground-truth (DGT) to validate 3D LiDAR point. The accuracy of the scanning system includes the errors committed by the sensor, the positioning system (GNSS), the data acquisition set up, the point cloud generation algorithms and the georeferentiation of the DGT.
- ItemOpen AccessA new Leafiness-LiDAR index to estimate light interception in intensive olive orchards(2023-07) Sandonís Pozo, Leire; Martínez Casasnovas, José Antonio; Escolà i Agustí, Alexandre; Rosell Polo, Joan Ramon; Rufat i Lamarca, Josep; Pascual Roca, MiquelCanopy light interception constitutes an important yield limiting factor in high density olive orchards. However, its characterisation still implies laborious measurements. A new index, the Leafiness-LiDAR index (LLI), is presented as a LAI estimator. LLI combines LiDAR-derived parameters: Cross-Section and Leafiness from 3D point clouds. To validate the results, photosynthetically active radiation (PAR) measurements, canopy volume, yield and quality parameters were collected and analysed. LLI showed significant correlations both with PAR and canopy volume (r = 0.8) and quality parameters (r = -0.6). LLI may be useful as an early decision canopy monitoring tool in the framework of Precision Fructiculture.