Assessment of the seasonal pattern of burr and nut growth in a chestnut ‘Marrone-type’ cultivar

Seasonal patterns of burr and nut growth were measured in sweet chestnut trees (C. sativa Mill.) of the cultivar ‘Marrone di Castel del Rio’. Burr and nut growth expressed as diameter, fresh and dry weight, and dry matter were assessed from mid of June to mid of October. Results evidenced that burr mainly grows in the initial period of the season, while the nut had a rapid growth in the last part of the season (i.e., beginning of September). Dry matter of burrs started decreasing when its accumulation in the nuts was increasing. Burrs with the highest number of nuts (three), experienced a limited nut growth compared to burrs with two or one nuts per burr, but only at the beginning of nut filling phase. Lateral nut evidenced a higher growth in weight (fresh and dry) in the first part of the season with occasionally reduced dry matter compared to central nuts. The burr diameter had a strong positive relationship with the internal nut diameter and with the total nut weight

Apoplasmic and simplasmic phloem unloading mechanisms: Do they co-exist in Angeleno plums under demanding environmental conditions?

Biophysical fruit growth depends on a balance among the vascular and transpiration flows entering/exiting the fruit via phloem, xylem and through the epidermis. There is no information on vascular flows of Japanese plums, a species characterized by high-sugar content of its fruit at harvest. Vascular flows of Angeleno plums were monitored by fruit gauges during late fruit development, under the dry environment of the Goulburn Valley, Victoria, Australia. Phloem, xylem flows and skin transpiratory losses were determined, as well as diurnal leaf, stem and fruit pressure potentials. Fruit seasonal development, skin conductance and dry matter accumulation were also monitored. Fruit grew following a double-sigmoid pattern, but fruit size increased only 3.1 g over the last 3 weeks of development. Fruit grew very little in the morning, primarily due to phloem inflows (0.05 g fruit 121 hr 121 ), while water left the fruit via the xylem. Negligible skin transpiration was recorded for vapour pressure deficit (VPD) values below 3 kPa. This growth pattern, in the absence of skin transpiration, suggests apoplastic phloem unloading. However, at VPD values over 3 kPa (e.g. from early afternoon to a peak around 18:00 h), transpiratory losses through the skin (up to 0.25 g fruit 121 hr 121 ) caused fruit to shrink, leading to enhanced phloem and xylem inflows (ca. 0.15 g fruit 121 hr 121 ), a scenario that would correspond to symplastic phloem unloading. Over 24 h the fruit showed a slightly negative total growth, consistent with fruit growth measured in situ during the season at weekly intervals. A few fruit species are known to alter their phloem unloading mechanism, switching from symplastic to apoplastic during the season. Our data support the coexistence in Japanese plum of different phloem unloading strategies within the same day

IL PECCATO ORIGINALE COME FIGURA DEL CONOSCERE. STUDIO A PARTIRE DAL MANUSKRIPT DER PHILOSOPHIE DER RELIGION DI HEGEL

A research about the role of original sin and the interpretation of Genesis 3 in the Hegels thought

Precision Management of Fruit Trees

The aim of the Special Issue “Precision Management of Fruit Trees” was to collect new insights to support the adoption of advanced, efficient, and sustainable management techniques in the fruit production sector. Indeed, this is an opportunity offered by the technological innovations adopted using new-generation sensors and implemented through precise management operations. This Special Issue contains 11 scientific articles contributing to our knowledge on the precision management of fruit trees, indicating the high activity of this sector and possibly leading to the application of new techniques/protocols to overcome global and rapidly changing environmental issues. Scalisi et al. [1], in their study, aimed to (i) determine the reliability of a portable Bluetooth colour meter for fruit colour measurements; (ii) characterise the changes in quantitative skin colour attributes in a nectarine cultivar in response to time from harvest; and (iii) determine the influence of row orientation and training system on nectarine skin colour. Overall, the device proved reliable for fruit colour detection. The results of this study highlight the potential of one of the measured parameters as a quantitative index to monitor ripening prior to harvest in nectarines. Remote sensing techniques based on images acquired from unmanned aerial vehicles (UAVs) could represent an effective tool to speed up the data acquisition process in phenotyping trials and, consequently, to reduce the time and cost of the field work. Caruso et al. [2] confirmed the ability of a UAV equipped with RGB-NIR cameras to highlight differences in geometrical and spectral canopy characteristics between eight olive cultivars planted at different planting distances in a hedgerow olive orchard. Tree densities have increased greatly in olive orchards over the last few decades. Ladux et al. [3], in their study, found that the leaf area index (LAI) of neighbouring trees modifies the light quality environment prior to a tree being directly shaded, as well as the morphological responses of olive cultivars to changes in light quality. The results suggested that cultivar differences in response to light quality may be relevant for understanding adaptation to dense orchards and identifying cultivars best suited to them. Saha et al. [4] found that monitoring plant vegetative growth can provide the basis for precise crop management. In this study, a 2D light detection and ranging (LiDAR) laser scanner, mounted on a linear conveyor, was used to acquire multi-temporal, three-dimensional (3D) data from strawberry plants. The results contributed to building up an approach for estimating plant geometrical features, particularly strawberry canopy volume profile based on LiDAR point cloud for tracking plant growth. Carella et al. [5] studied the physiological and productive behaviour of different olive cultivars grown under a high-density hedgerow system and compared their fruiting and branch architecture features to determine the possibility to use ‘Calatina’ olive trees for intensive plantings, as a local alternative to the international reference ‘Arbequina’. The study indicated that ‘Calatina’ is more efficient in terms of yield and harvesting than ‘Arbequina’. This qualifies ‘Calatina’ as a superior, yield-efficient olive cultivar suitable for intensive hedgerow plantings to be harvested with straddle or side-by-side trunk shaker machines. Sirgedaitė-Šėžienė et al. [6] used ‘Rubin’ apple trees grafted on dwarfing P60 rootstocks to determine the impact of canopy training treatments as a stress factor on metabolic response to obtain key information on how to improve physiological behaviour and the management of growth and development of apple trees. The results indicated that all applied canopy training treatments significantly increased the total phenol and total starch contents in apple tree leaves. Scalisi et al. [7] in their work aimed to derive a new fruit skin colour attribute—namely, a Colour Development Index (CDI), ranging from 0 to 1, that intuitively increases as fruit becomes redder—to assess colour development in peach and nectarine fruit skin. The study found that the CDI can serve as a standardised and objective skin colour index for peaches and nectarines. Čirjak et al. [8] summarize the automatic methods (image analysis systems, smart traps, sensors, decision support systems, etc.) used to monitor the major pest in apple production (Cydia pomonella L.) and other important apple pests and fruit flies to improve sustainable pest management under frequently changing climatic conditions. Pisciotta et al. [9] released a review underlying the opportunities offered by the recently developed table-grape soil-less cultivation systems; this is an up-to-date examination of the latest experimental and applied findings of the sector’s research activities. A special emphasis is given to the evolution of the applied technical solutions, varietal choice, and environmental conditions for the aims of table-grape soil-less cultivation. Borgogno-Mondino et al. [10] evaluated a promising alternative offered by Copernicus Sentinel 2 data (S2) to midday stem water potential for monitoring the water status of pomegranate plants and for addressing irrigation management. Despite limited ground observations, the results showed the promising capability of spectral indices (NDVI, NDRE, and NDWI) and S2 bands in estimating Ψstem readings. Boini et al. [11], in their study, used shading nets to lower irrigation requirements and make apple growing more sustainable. The encouraging results showed a comparable yield and fruit quality saving 50% of irrigation water under a classic anti-hail system compared to the control treatment

L'idea assoluta come metodologia della vita

L\u2019\uabidea assoluta\ubb, definita all\u2019esordio di questo ultimo capitolo della Wissenschaft der Logik del 1816 come \uabunico oggetto e contenuto della filosofia\ubb, \ue8 da Hegel presentata, dal punto di vista del contenuto, come \uabessere, vita che non passa, verit\ue0 di s\ue9 conscia, [\u2026] tutta la verit\ue0\ubb, e dal punto di vista della forma, come \uabritorno alla vita\ubb che \uabha in s\ue9 la suprema opposizione\ubb. Come \ue8 da intendere dunque, alla fine del percorso della logica, l\u2019idea assoluta come vita? La risposta che lo sviluppo della logica stessa suggerisce \ue8 considerarla precipuamente nella guisa del metodo, \uabl\u2019universale della forma del contenuto\ubb che rappresenta il movimento di ritorno alla vita su accennato. Seguendo quest\u2019indicazione hegeliana si cercher\ue0 di mostrare, in primo luogo, in che termini questo ultimo capitolo della logica pu\uf2 essere letto come una metodologia della vita in cui si vengono a focalizzare molti fili del filosofare hegeliano sin dai suoi albori (in particolare verranno citate formulazioni giovanili e proposto un paragone con alcuni luoghi della Vorrede della Ph\ue4nomenologie des Geistes), e in che termini, in secondo luogo, l\u2019idea assoluta sia da considerarsi come la coincidenza tra contenuto e metodo, prodromo alla esposizione di questa stessa vita come sistema. Con metodologia della vita si vuole indicare uno stile di pensiero in fieri che \u2013 contro la vulgata che vede nel sistema hegeliano un pensiero monolitico dove conclusivit\ue0 \ue8 sinonimo di chiusura \u2013 non solo ha come oggetto la vita dell\u2019assoluto, ma che sia esso stesso vita, \uabattivit\ue0 assoluta universale, il movimento che determina e realizza se stesso\ubb immanente alle cose stesse. Per svolgere quest\u2019ipotesi \u2013 con aderenza al testo \u2013 si cercher\ue0 di definire il metodo e la sua costituzione in quelle che Hegel chiama \uabdeterminazioni del concetto\ubb e loro \uabrelazioni\ubb e si proceder\ue0 ad una loro analisi. Esse sono principalmente due: il \uabcominciamento\ubb e il \uabcominciamento dell\u2019andar oltre\ubb, ovvero lo \uabsviluppo\ubb, in cui verr\ue0 descritto il momento propriamente \uabdialettico\ubb del metodo assoluto, che verr\ue0 seguito nei suoi momenti: si disegner\ue0 quella struttura sillogistica che rispecchia il procedere della ragione come vita. Si noter\ue0 infine una discrepanza di formulazione riguardo all\u2019esposizione del metodo nella Wissenschaft der Logik del 1816 e nella compendiosa Logik dell\u2019Enzyklop\ue4die e la si presenter\ue0 alla discussione

Orchard floor management affects tree functionality, productivity and water consumption of a late ripening peach orchard under semi-arid conditions

Semi-arid conditions are favorable for the cultivation of late ripening peach cultivars; however, seasonal water scarcity and reduction in soil biological fertility, heightened by improper soil management, are jeopardizing this important sector. In the present two-year study, four soil managements were compared on a late ripening peach orchard: (i) completely tilled (control); (ii) mulched with reusable reflective plastic film; (iii) mulching with a Leguminosae cover-crop flattened after peach fruit set; (iv) completely tilled, supplying the water volumes of the plastic mulched treatment, supposed to be lower than the control. Comparison was performed for soil features, water use, tree functionality, fruit growth, fruit quality, yield and water productivity. Even receiving about 50% of the regular irrigation, reusable reflective mulching reduced water loss and soil carbon over mineralization, not affecting (sometimes increasing) net carbon assimilation, yield, and fruit size and increasing water productivity. The flattening technique should be refined in the last part of the season as in hot and dry areas with clay soils and low organic matter, soil cracking increased water evaporation predisposing the orchard at water stress. The development and implementation of appropriate soil management strategies could be pivotal for making peach production economically and environmentally sustainable

Fruit transpiration drives interspecific variability in fruit growth strategies

Fruit growth is a complex mechanism resulting from biochemical and biophysical events leading water and dry matter to accumulate in the fruit tissues. Understanding how fruits choose their growth strategies can help growers optimizing their resource management for a more sustainable production and a higher fruit quality. This paper compares the growth strategies adopted by different fruit crops, at different times during the season and relates their fruit surface conductance to key physiological parameters for fruit growth such as phloem and xylem inflows as well transpiration losses. Our results show how fruits capacity to transpire (determined by their surface conductance) is a key driver in determining the growth strategy adopted by a species and explains the inter-species variability existing among different crops. Indeed, fruits change their surface conductance depending on the species and the phenological stage. This has an impact on the fruit's ability to lose water due to transpiration, affecting fruit pressure potential and increasing the force with which the fruit is able to attract xylem and phloem flows, with a considerable impact on fruit growth rate

Irrigation improves tree physiological performances and nut quality in sweet chestnut

Italy is one of the most important world chestnut producers. The majority of traditional sweet chestnut orchards are still non-irrigated since they are typically located in mountain-hill areas usually characterized by environmental conditions that are not limiting for the vegetative and reproductive growth of this fruit tree crop. Nowadays, the increase of summer temperatures and the decrease of rainfall are affecting negatively chestnut physiological performances and productivity. The adoption of scheduled irrigation practices, in light also of the limited water availability/possibility of storage (e.g., artificial lakes, reservoirs) of these areas, should become part of chestnut orchard management. The aim of the present study was to evaluate the effect of irrigation on sweet chestnut physiology, nut quality and yield. The study was carried out in 2020 in a traditional chestnut orchard of the “Marron Buono di Marradi” ecotype, located in the Tuscan-Emilian Apennines (Marradi, Italy). The experimental design compared trees irrigated between August and September with a non-irrigated control. Leaf gas exchange and plant water status were monitored during the growing season and, nut quality and yield were assessed at harvest. Results showed that irrigated trees exhibited, in middle September, higher photosynthesis, transpiration, stomatal conductance and stem water potentials compared to the non-irrigated control trees. Nut size was significantly smaller in non-irrigated trees than in irrigated ones while the yield was not statistically affected by the irrigation treatment. Despite the favourable mild and rainy weather conditions occurred in 2020, the application of irrigation during the nut filling phase (e.g., late summer) was beneficial for enhancing sweet chestnut physiological performances and for improving nut quality

Agility of vortex-based nanocontact spin torque oscillators

We study the agility of current-tunable oscillators based on a magnetic vortex orbiting around a point contact in spin-valves. Theory predicts frequency-tuning by currents occurs at constant orbital radius, so an exceptional agility is anticipated. To test this, we have inserted an oscillator in a microwave interferometer to apply abrupt current variations while time resolving its emission. Using frequency shift keying, we show that the oscillator can switch between two stabilized frequencies differing by 25% in less than ten periods. With a wide frequency tunability and a good agility, such oscillators possess desirable figures of merit for modulation-based rf applications.Comment: 3 pages, 3 figure