Search results for "Arboricoltura"
showing 10 items of 857 documents
Millerandage and flower abscission in ‘Grillo’, ‘Frappato’ and ‘Nero d’Avola’ grapevines: Some probable causes
2018
Some Sicilian cultivars, in particular vintage, showed a high percentage of flower abscissions and shot berries. In this paper, to understand these phenomena, some aspects of the flower morphology of three Sicilian cultivars (two black: ‘Nero d’Avola’ and ‘Frappato’; and one white: ‘Grillo’) was studied. The number of stamens, ovule adherence to the ovary wall and pollen germination were evaluated using standard light microscopy. At harvest, seed number was counted on 30 berries per cultivar. The percentage of six stamens was lowest in ‘Frappato’ and highest in ‘Grillo’. The ovule adherence to the ovary wall was highest in ‘Frappato’ and lowest in ‘Nero d’Avola’. The percentage of pollen ge…
Predicting olive flowering phenology with phenoclimatic models
2018
In plants, day length and temperature are the major climatic factors that affect the transition from a phenological phase to the next one. Non-linear models, such as growing degree hours (GDH), have been successfully used to calculate thermal time required for spring bud burst in deciduous fruit trees. In this experiment, temperature records and blooming dates of olive trees in different years and for 10 different sites in the Italian territory were recorded. Olive booming time was correlated to the amount of (GDH) accumulated from the date of bud rest onset, calculated as the day when the maximum negative chilling units accumulation was reached (UTAH Model), to full bloom. The GDH model wa…
Fruit quality evaluation of affirmed and local loquat (Eriobotrya japonicaLindl) cultivars using instrumental and sensory analyses
2016
Introduction. Fruit quality can be evaluated by combining instrumental and sensory analyses. These methodologies have been affirmed and tested on different fruit tree species, but loquat is still little known from this point of view. Materials and methods. In this trial, conducted in Palermo and Catania (Sicily, Italy), both instrumental and sensory analyses were carried out on fruit of 8 loquat affirmed cultivars (‘Golden Nugget’, ‘Peluche’) and local cultivars (‘Marceno’, ‘Sanfilippara’, ‘Nespolone di Trabia’, ‘Virticchiara’, ‘Bianco Dolce’ and ‘BRT20’) with the aim of assessing their quality traits. Results and discussion. The sensory results agreed quite well with the physicochemical da…
Seasonal dynamics of photosynthesis and total carbon gain in bearing and nonbearing pistachio (Pistacia vera L.) shoots
2018
Seasonal changes in leaf gas exchange, assimilation response to light and leaf area were monitored in bearing and nonbearing pistachio shoots. Shoot bearing status did not directly affect leaf photosynthetic rate. However, photosynthetic light-response curves strongly varied during the season demonstrating the dominant effect of the treeâs seasonal phenology on assimilation. Early in the season low photosynthetic rates were associated with high rates of dark respiration indicating limited photosynthesis in the young leaves. As leaves matured, dark respiration decreased and assimilation reached maximum values. Photosynthetic efficiency was strongly reduced late in the season due to leaf ag…
Urban landscape evolution as a consequence of an invasive pest: The case of a small sicilian town
2017
The Red Palm Weevil (RPW), after its accidental introduction in Italy in 2005, determined a progressive disruption of Canary palms mostly in the central and southern regions. As it is difficult to undertake the management of this pest, the possibility of substituting the killed/symptomatic palms with other ornamental trees has been recently discussed. In this context, understanding the citizens' needs about green areas can improve the management of public parks and urban greening. Involving citizens on the natural resource management using public participation processes is crucial. The case study of a small town of Sicily (Italy) was treated and the spread of this pest was monitored. Moreov…
Root growth and soil carbon turnover in Opuntia ficus-indica as affected by soil volume availability
2019
Abstract The aim of this study was to investigate the effect of soil volume restriction, i.e. root confinement, on below-and-above ground growth of cactus pear (Opuntia ficus-indica (L.) Mill) as well as the effect on root architecture and turnover, and soil carbon turnover. In May 2014, 1- year-old cladodes were planted in five different pots size (50, 33, 18, 9 and 5 L). Soil samples were collected from each pot and dried before SOC and δ13C determination. Roots of each plant were divided visually into three groups depending on their diameter, and then measured and weighed. Results indicated a significant effect of soil volume and sampling dates on total root length, root dry mass and δ13…
Growth and water relations of field-grown ‘Valencia’ orange trees under long-term partial rootzone drying
2017
Climate, soil water potential (SWP), leaf relative water content (RWC), stem water potential (WPstem), stomatal conductance (g s), trunk, shoot and fruit growth of ‘Valencia’ orange trees were monitored during five consecutive seasons (2007–2012) to study water status and growth responses to irrigation placement or volume. 48 adult trees were exposed to conventional irrigation (CI, 100% of crop evapotranspiration on both sides of the rootzone), partial rootzone drying (PRD, 50% of CI water only on one alternated side of the rootzone) and continuous deficit irrigation (DI, 50% of CI water on both sides of the rootzone). Reducing irrigation volumes by 55% (DI) over CI increased leaf water def…
Gas Exchanges and Stem Water Potential Define Stress Thresholds for Efficient Irrigation Management in Olive (Olea europea L.)
2018
With climate change and decreased water supplies, interest in irrigation scheduling based on plant water status is increasing. Stem water potential (ΨSWP) thresholds for irrigation scheduling in olive have been proposed, however, a physiologically-based evaluation of their reliability is needed. A large dataset collected at variable environmental conditions, growing systems, and genotypes was used to characterize the relation between ΨSWP and gas exchanges for olive. Based on the effect of drought stress on the ecophysiological parameters monitored, we described three levels of stress: no stress (ΨSWP above about −2 MPa), where the high variability of stomatal conductance (gs) suggests a ti…
Water relations and carbohydrate partitioning of four greenhouse-grown olive genotypes under long-term drought
2016
The four olive genotypes exhibited different responses to drought involving leaf drop and g s reductions (broad-leaved genotypes, good leaf hydration); or growth reductions (narrow-leaved genotypes, dehydration tolerance). There was minor effect on carbohydrate levels. Olive plants of broad-leaved ‘Minuta’ (MN) and ‘Nocellara del Belice’ (NB) and narrow-leaved ‘Passulunara’ (PA) and ‘Biancolilla Siracusana’ (BS) were studied to evaluate their responses to drought. In a greenhouse, 2-year-old rooted cuttings were irrigated to field capacity (WW) or with 20% of WW evapotranspiration (DS) for over 3 months. Subsequently, all pots were rewatered to field capacity for 20 days. Gravimetric soil w…
Cladode growth dynamics in Opuntia ficus-indica under drought
2016
Abstract Cactus pear (Opuntia ficus-indica L. Miller) is a CAM plant with an extraordinary capacity to store water in its succulent stems (cladodes). However, the daily variations of cladode thickness is unknown. Studying cladode thickness fluctuations may be useful for the early prediction of plant dehydration stress. The objective of this study was to determine if age, water availability and temperature influence diel cladode shrinkage and enlargement dynamics in cactus pear. The experiment was conducted in a greenhouse from April to July 2014, using cactus pear plants, equally split into irrigated and unirrigated treatments, and unrooted cladodes detached from mother plants. Soil moistur…