Fruit maturity and antioxidant activity affecting superficial scald development in ‘Abate Fétel’ pears

Superficial scald (SS) is one of the main physiological disorders affecting postharvest of pears. Its onset is linked to oxidative processes. Antioxidant compounds such as ascorbic acid and phenolics could play a key role in preventing SS. Growing environment and fruit quality also have an influence on SS symptoms occurrence. The aim of this project is to understand the relationship between antioxidant activity, phenolic content, and development of SS in ‘Abate Fétel’ pear. Moreover, the effect on SS of fruit maturity at harvest was assessed using multivariate statistical approach. Data were collected in thirty orchards in the EmiliaRomagna region (Italy) in three seasons (2018, 2019 and 2020), and the fruit were stored in a regular atmosphere for 120 days. Antioxidant capacity was determined by 2,2diphenyl1picrylhydrazy (DPPH) method and total phenol content by FolinCiocalteau colorimetric protocol. The results showed that 340 mg of ascorbate/100 g of FW and 300 mg of gallic ac./100 g of FW at least provide good protection against SS. Multivariate analysis indicated that pulp firmness and index of absorbance difference (IAD) seem to keep low the SS occurrence, when at harvest are higher than 6.3 kg and 1.9, respectively. In conclusion, it would be possible to build a forecasting model to control SS that considers preharvest data and content of antioxidants in different orchards, to improve the postharvest management of ‘Abate Fétel’

The effects of chestnut orchard microclimate on burr development

Chestnut crop is regaining its fame worldwide with powerful investment perspectives. Unluckily the climate change effects are posing high threat to its cultivation with less available resources and increased production cost both in traditional and specialized orchards. Additionally, the chestnut physiological knowledge is still limited, especially as concern the burr development (i.e., the economical production target) and its relationship with the environmental parameters. The aim of the present study was to evaluate the seasonal, daily, and hourly burr growth pattern associated to environmental parameters for improving physiological knowledge on this species. The study was carried out in a traditional rainfed sweet chestnut orchard located in the Tuscan-Emilian Apennines (Monterenzio, Italy). The chestnut burr growth was measured, along the entire season, both with a digital calliper and through the use of plant-based sensors (fruit-gauges) that permitted to measure, in real-time, the burr growth pattern. Environmental data were recorded by a weather station placed in the middle of the orchard. Results evidenced a higher burr growth rate, in the last part of the season (from middle-end of August to full fall) while the daily growing pattern was characterized by increased oscillation, along the season, of night-swelling and daily-shrinkage. The night-swelling was found to be influenced by high nocturnal air relative humidity while the daily-shrinkage was influenced by the higher wind speed, solar radiation and vapour pressure deficit. Thus, the burr daily net growth can be associated, depending on the phenological stages, to environmental parameters. Precipitation but especially the atmosphere humidity, in September and October, were the main external drivers of burr daily net growth. These results could be promising for the adoption of sustainable (e.g., late season grass mowing, sprinkler irrigation) and smart practices for improving chestnut management in both traditional and specialized orchards

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

Single-shot convolution neural networks for real-time fruit detection within the tree

Image/video processing for fruit detection in the tree using hard-coded feature extraction algorithms has shown high accuracy on fruit detection during recent years. While accurate, these approaches even with high-end hardware are still computationally intensive and too slow for real-time systems. This paper details the use of deep convolution neural networks architecture based on single-stage detectors. Using deep-learning techniques eliminates the need for hard-code specific features for specific fruit shapes, color and/or other attributes. This architecture takes the input image and divides into AxA grid, where A is a configurable hyper-parameter that defines the fineness of the grid. To each grid cell an image detection and localization algorithm is applied. Each of those cells is responsible to predict bounding boxes and confidence score for fruit (apple and pear in the case of this study) detected in that cell. We want this confidence score to be high if a fruit exists in a cell, otherwise to be zero, if no fruit is in the cell. More than 100 images of apple and pear trees were taken. Each tree image with approximately 50 fruits, that at the end resulted on more than 5000 images of apple and pear fruits each. Labeling images for training consisted on manually specifying the bounding boxes for fruits, where (x, y) are the center coordinates of the box and (w, h) are width and height. This architecture showed an accuracy of more than 90% fruit detection. Based on correlation between number of visible fruits, detected fruits on one frame and the real number of fruits on one tree, a model was created to accommodate this error rate. Processing speed is higher than 20 FPS which is fast enough for any grasping/harvesting robotic arm or other real-time applications. HIGHLIGHTS: Using new convolutional deep learning techniques based on single-shot detectors to detect and count fruits (apple and pear) within the tree canopy

High levels of shading as a sustainable application for mitigating drought, in modern apple production

The sustainability of reducing light in apple orchards under well-watered (ww) and water stress (ws) conditions was evaluated for water relations, plant gas exchanges, fruit growth, yield determinants, and fruit quality over three years. A black (B) 28% shading net was compared with two different 50% shading nets: red (R) and white (W). Each net was combined with two irrigation regimes (ww and ws) based on plant water status. Under ww and ws conditions, increasing shade from 28% to 50% was not detrimental for plant gas exchanges, yield, or quality over three years. Higher shade improved plant water status regardless of irrigation regime. Higher shading could be considered sustainable in apple orchards over several seasons. Fruit quality was more sensitive to plant water status than to light reduction. ws increased fruit soluble solid content and relative dry matter, regardless of shading, and this was positively reflected in consumer’s preference. When water availability is limited, increasing shading to 50% can help save water and maintain high-quality yields associated with water stress. Given the likely reductions of water availability in agriculture, growers and consultants may consider shading apple orchards as a sustainable and safe horticultural technique to save water

Protection of podocytes from hyperhomocysteinemia-induced injury by deletion of the gp91 phox gene

In this study, mice lacking the gp91 phox gene were used to address the role of NADPH oxidase in hyperhomocysteinemia-induced podocyte injury. It was found that a folate-free diet increased plasma homocysteine levels, but failed to increase O 2 •− production in the glomeruli from gp91 phox gene knockout (gp91 These results suggest that the functional integrity of NADPH oxidase is essential for hyperhomocysteinemiainduced podocyte injury and glomerulosclerosis

Possible mechanisms of hypotension produced 70% alcoholic extract of Terminalia arjuna (L.) in anaesthetized dogs

BACKGROUND: The bark of Terminalia arjuna L. (Combretaceae) is used in Ayurveda since ancient times for the treatment of cardiac disorders. Previous laboratory investigations have demonstrated the use of the bark in cardiovascular complications. The present study was aimed to find the effect of 70% alcoholic extract of Terminalia arjuna on anaesthetized dog blood pressure and probable site of action. METHODS: Six dogs were anaesthetized with intraperitoneal injection of thiopental sodium and the blood pressure of each dog (n = 6) was measured from the left common carotid artery connected to a mercury manometer on kymograph. The femoral vein was cannulated for administration of drug solutions. The extract of T. arjuna (dissolved in propylene glycol) in the dose range of 5 to 15 mg/kg were administered intravenously in a pilot study and the dose (6 mg/kg) which produced appreciable hypotension was selected for further studies. RESULTS: Intravenous administration of T. arjuna produced dose-dependent hypotension in anaesthetized dogs. The hypotension produced by 6 mg/kg dose of the extract was blocked by propranolol but not by atropine or mepyramine maleate. This indicates that muscarinic or histaminergic mechanisms are not likely to be involved in the hypotension produced by the extract. The blockade by propranolol of the hypotension produced by T. arjuna indicates that the extract might contain active compound(s) possessing adrenergic ß(2)-receptor agonist action and/or that act directly on the heart muscle. CONCLUSION: The results indicated the likely involvement of peripheral mechanism for hypotension produced by the 70% alcoholic extract of Terminalia arjuna and lends support for the claims of its traditional usage in cardiovascular disorders

Antihypertensive Treatment Differentially Affects Vascular Sphingolipid Biology in Spontaneously Hypertensive Rats

We have previously shown that essential hypertension in humans and spontaneously hypertensive rats (SHR), is associated with increased levels of ceramide and marked alterations in sphingolipid biology. Pharmacological elevation of ceramide in isolated carotid arteries of SHR leads to vasoconstriction via a calcium-independent phospholipase A2, cyclooxygenase-1 and thromboxane synthase-dependent release of thromboxane A2. This phenomenon is almost absent in vessels from normotensive Wistar Kyoto (WKY) rats. Here we investigated whether lowering of blood pressure can reverse elevated ceramide levels and reduce ceramide-mediated contractions in SHR. Methods and Findings For this purpose SHR were treated for 4 weeks with the angiotensin II type 1 receptor antagonist losartan or the vasodilator hydralazine. Both drugs decreased blood pressure equally (SBP untreated SHR: 191±7 mmHg, losartan: 125±5 mmHg and hydralazine: 113±14 mmHg). The blood pressure lowering was associated with a 20–25% reduction in vascular ceramide levels and improved endothelial function of isolated carotid arteries in both groups. Interestingly, losartan, but not hydralazine treatment, markedly reduced sphingomyelinase-induced contractions. While both drugs lowered cyclooxygenase-1 expression, only losartan and not hydralazine, reduced the endothelial expression of calcium-independent phospholipase A2. The latter finding may explain the effect of losartan treatment on sphingomyelinase-induced vascular contraction. Conclusion In summary, this study corroborates the importance of sphingolipid biology in blood pressure control and specifically shows that blood pressure lowering reduces vascular ceramide levels in SHR and that losartan treatment, but not blood pressure lowering per se, reduces ceramide-mediated arterial contractions