Many plants can modify their leaf profile rapidly in response to environmental stress. Image-based data are increasingly used to retrieve reliable information on plant water status in a non-contact manner that has the potential to be scaled to high-throughput and repeated through time. This paper examined the variation of leaf angle as measured by both 3D images and goniometer in progressively drought stressed grapevine. Grapevines, grown in pots, were subjected to a 21-day period of drought stress receiving 100% (CTRL), 60% (IRR 60%) and 30% (IRR 30%) of maximum soil available water capacity. Leaf angle was (i) measured manually (goniometer) and (ii) computed by a 3D reconstruction method (multi-view stereo and structure from motion). Stomatal conductance, leaf water potential, fluorescence (F v /F m), leaf area and 2D RGB data were simultaneously collected during drought imposition. Throughout the experiment, values of leaf water potential ranged from −0.4 (CTRL) to −1.1 MPa (IRR 30%) and it linearly influenced the leaf angle when measured manually (R 2 = 0.86) and with 3D image (R 2 = 0.73). Drought was negatively related to stomatal conductance and leaf area growth particularly in IRR 30% while photosynthetic parameters (i.e., F v /F m) were not impaired by water restriction. A model for leaf area estimation based on the number of pixels of 2D RGB images developed at a different phenotyping robotized platform in a closely related experiment was successfully employed (R 2 = 0.78). At the end of the experiment, top view 2D RGB images showed a ∼50% reduction of greener fraction (GGF) in CTRL and IRR 60% vines compared to initial values, while GGF in IRR 30% increased by approximately 20%.

Carbon (C) budget at cropping systems has not only agronomic but also environmental relevance because of their contribution to both emissions and removals of greenhouse gases (GHGs). Ideally, sustainable orchards are expected to remove atmospheric CO2 at a rate greater than that of the emissions because of (i) optimized biology of the system and (ii) reduced on-site/offsite inputs sourced by the technosphere. However, such a computation might produce inconsistent results and in turn biased communication on sustainability of the cropping systems because C accounting framework(s) are used under unclear context. This study examined the sustainability of orchards in terms of impact on GHGs focusing its significance at the field, ecosystem and global dimension analyzing some operational aspects and limitations of existing frameworks (e.g., net ecosystem carbon balance (NECB), life cycle assessment (LCA)). Global relevance of sustainable orchard was also discussed considering the C sequestration at cropland as instructed by Intergovernmental Panel on Climate Change (IPCC). The uniqueness of olive tree lifespan duration and C sequestration is discussed within the Product Environmental Footprint of agrifood product. The paper also highlighted overlapping components among the NECB, LCA and IPCC frameworks and the need for an integrated C accounting scheme for a more comprehensive and detailed mapping of sustainability in agriculture.

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Aim: This study examined whether the application of calcite-silicon mediated particle film (CaPF) at veraison can mitigate a drought-induced increase in leaf temperature on grapevine, thus contributing to improved leaf functionality, yield and grape composition traits.Methods and results: A total of 48 five-year-old Merlot (Vitis vinifera L.) vines grafted onto SO4 were grown (in 20 L PVC pots) under Mediterranean conditions (Southern Italy). The vines were pruned to a single spur with 3 winter buds irrigated daily to 100 % field capacity, and fertilised weekly.At veraison and using a 2×2 factorial experimental design, the two main factors, thermoregulation and water, were imposed at two levels: spraying with a thermoregulation compound (CaPF) and no spraying (NS); irrigation (WW) and drought stress (D)). A group of 24 vines was subjected to a 15-day drought period by receiving, every day, 25 % (D) of the daily water consumption of WW vines. The other 24 vines continued to be fully irrigated on a daily basis (WW). Twelve vines per group were sprayed (WW+CaPF, D+CaPF) with calcite-silicon mediate (3 % V/V) at the beginning of drought imposition, the remaining 24 vines were not sprayed (WW-NS, D-NS). Soil water moisture and stem water potential values were monitored from 11.30 to 13:30 nearly every week, and other vegetative and reproductive parameters were also measured.During the experiment, air temperature peaked at ≈35°C at midday, VPD at about 3.7 kPa and PAR reached ≈2000 µmol m-2 s–1. Results show that in CaPF sprayed vines, leaf-air temperature differences  were lower than in unsprayed vines in both irrigated and drought stressed groups. WW+CaPF vines retained significantly more leaf area and showed the highest value of accumulated vine transpiration.Conclusion: Calcite-silicon mediated particle film could enhance the resilience of grapevine to adverse environmental conditions and may contribute to preserve terroir elements in highly reputed wine grape growing areas.Significance of the study: The study showed that foliar application of calcite silicon-mediated processed particles films can be used in arid regions to mitigate leaf temperatures in grapevines.

Research on organic electrochemical transistor (OECT) based sensors to monitor in vivo plant traits such as xylem sap concentration is attracting attention for their potential application in precision agriculture. Fabrication and electronic aspects of OECT have been the subject of extensive research while its characterization within the plant water relation context deserves further efforts. This study tested the hypothesis that the response (R) of an OECT (bioristor) implanted in the trunk of olive trees is inversely proportional to the water flux density flowing through the plant (Jw). This study also examined the influence on R of vapor pressure deficit (VPD) as coupled/uncoupled with light. R was hourly recorded in potted olive trees for a 10-day period concomitantly with Jw (weight loss method). A subgroup of trees was bagged in order to reduce VPD and in turn Jw, and other trees were located in a walk-in chamber where VPD and light were independently managed. R was tightly sensitive to diurnal oscillation of Jw and at negligible values of Jw (late afternoon and night) R increased. The bioristor was not sensitive to the VPD per se unless a light source was coupled to trigger Jw. This study preliminarily examined the suitability of bioristor to estimate the mean daily nutrients accumulation rate (Ca, K) in leaves comparing chemical and sensor-based procedures showing a good agreement between them opening new perspective towards the application of OECT sensor in precision agricultural cropping systems.