Search results for "YIELD"
showing 10 items of 1338 documents
Grapevine row orientation mediated temporal and cumulative microclimatic effects on grape berry temperature and composition
2021
Abstract Ambient radiation and temperature are global drivers of grapevine growth, grape yield and composition, and wine quality. Knowledge of the implications of vineyard row orientation/microclimate is required for decision-making in current and future macro- and mesoclimates. Temporal and cumulative microclimatic changes, induced by vine row orientation (NS; EW; NE-SW; NW-SE) of vertically trellised Shiraz grapevines, on berry pulp temperature and composition at different ripeness levels were investigated. Berries dynamically gained heat energy relative to: ambient climate/weather; direct canopy wall/bunch irradiance; and berry skin colour development. Berries exposed to direct solar rad…
Evaluation of Small Vase and Y-trellis Orchard Systems for Peach and Nectarine Production in Mediterranean Regions
2015
Two peach planting systems, Small Vase (SV) and Y-trellis (Y), were evaluated and compared in the Mediterranean settings of Southern Italy. The two orchards were located next to each other on relatively uniform soil and terrain, and the observations included two peach (âRich Mayâ and âSummer Richâ) and two nectarine (âBig Bangâ and âNectarossâ) cultivars. In the SV system, trees were spaced at 4.5 A 2.5 m (888 trees/ha), whereas in the Y system, trees were spaced at 5.5 A 2 m (909 trees/ha) and no canopy gap was left between rows. Yield per tree; fruit size grade; unit price of sold peaches for each size grade; materials, labor and associated costs for cultural management;…
Bidirectional sun-induced chlorophyll fluorescence emission is influenced by leaf structure and light scattering properties : a bottom-up approach
2015
Abstract Sun-induced chlorophyll fluorescence (SIF) at leaf level is emitted in both upward and downward directions in the red and far-red part of the spectrum (650–850 nm) when a leaf is illuminated from the upper leaf surface. Hence, total SIF is represented by the sum of the upward and downward emission components. Nevertheless, the downward component of leaf SIF is often not considered despite that downward fluorescence yield (↓FY) can amount up to 40% of the total fluorescence yield (FYtot). Downward SIF is mainly emitted in the far-red, since this part of fluoresced light is highly scattered within leaves, unlike red Chl fluorescence, which is mostly reabsorbed. While total FY can be …
High-resolution UAV imagery for field olive (Olea europaea L.) phenotyping
2021
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. In this study, we assessed the ability of a UAV equipped with RGB-NIR cameras in highlighting differences in geometrical and spectral canopy characteristics between eight olive cultivars planted at different planting distances in a hedgerow olive orchard. The relationships between measured and estimated canopy height, projected canopy area and canopy volume were linear regardless of the different cultivars and planting distances (RMSE of 0.12 m…
L-band vegetation optical depth seasonal metrics for crop yield assessment
2018
Attenuation of surface microwave emission due to the overlying vegetation is proportional to the density of the canopy and to its water content. The vegetation optical depth (VOD) parameter measures this attenuation. VOD could be a valuable source of information on agroecosystems, especially at lower frequencies for which greater portion of the vegetation canopy contributes to the observed brightness temperature. In the past, visible-infrared indices have been used to provide yield estimates based on measuring the photosynthetic activity from the surface canopy layer. These indices are affected by clouds and apply only in the presence of solar illumination. In this study we instead use the …
Effect of summer pruning on some fruit quality traits in Hayward kiwifruit
2013
Introduction . The aim of our study was to analyze the effect of various levels of light availability in the fruit microenvironment (induced by summer pruning) on some fruit quality traits. Materials and methods . Two levels of summer pruning were set: removal of either 30% or 60% of the canopy leaf area. These treatments were compared with the control (unpruned vines). Two canopy layers (upper and lower) were identified in each treatment and in the control vines. At harvest, yield per cane and per shoot was recorded in the two canopy layers; fruit fresh weight, flesh firmness, total soluble solid content and total titratable acidity were measured. Fruit Total Antioxidant Capacity (TAC) and…
EFFECT OF CANOPY MANAGEMENT TECHNIQUES ON THE NUTRITIONAL QUALITY OF MONTEPULCIANO GRAPEVINE IN PUGLIA (SOUTHERN ITALY)
2012
<p style="text-align: justify;"><strong>Aims</strong>: Tests were carried out to assess the effects of early defoliation, cluster thinning and cluster cutting on the basic and nutritional composition of musts and wines of <em>Vitis vinifera</em> L. cv. Montepulciano.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Both production and quality variables of the musts were evaluated. Antioxidant activity was determined on berries and on wines, as were the phenol and anthocyanin concentrations. The wines were compared by sensory evaluation. The results attested to a positive effect of the treatments on grape compositi…
Synthesis and Characterization of Carbazole-Linked Porphyrin Tweezers
2015
Herein the synthesis, spectroscopic characterization, two-photon absorption and electrochemical properties of 3,6-disubstituted carbazole tweezers is reported. A dimer resulting from a Glaser homocoupling was isolated during a Sonogashira coupling reaction between a diethynyl-carbazole spacer and a 5-bromo-triarylporphyrin and the properties of this original compound were compared with the 3,6-disubstituted carbazole bisporphyrin tweezers. The dyads reported herein present a two-photon absorption maximum at 920 nm with two-photon absorption cross-section in the 1200 GM range. Despite a strong linear absorption in the Soret region and moderate fluorescence quantum yield, they both lead to a …
Rootstock influences seasonal dry matter and carbohydrate content and partitioning in aboveground components of 'Flordaprince' peach trees
1997
Seasonal development of leaf area, leaf area index (LAI), dry matter, and carbohydrate content were measured from harvest 1992 to harvest 1993 in above-ground components of `Flordaprince' peach [Prunus persica (L.) Batsch] trees grafted on GF 677 (Prunus persica × Prunus amygdalus) and MrS 2/5 (Prunus cerasifera free pollinated) rootstocks, which widely differ in vigor. Whole trees were separated into fruit, leaves, shoots, 1-year-old wood and >1-year-old wood. Sampling dates were coincident with key fruit and tree developmental stages: dormancy, fruit set, pit hardening, and fruit harvest. Rootstock modified the vegetative vigor of the tree, the seasonal partitioning of dry matter, and …
Highly Fluorescent and Water-Soluble Diketopyrrolopyrrole Dyes for Bioconjugation
2015
International audience; The preparation of highly water-soluble and strongly fluorescent diketopyrrolopyrrole (DPP) dyes using an unusual taurine-like sulfonated linker has been achieved. Exchanging a phenyl for a thienyl substituent shifts the emission wavelength to near λ=600 nm. The free carboxylic acid group present in these new derivatives was readily activated and the dyes were subsequently covalently linked to a model protein (bovine serum albumin; BSA). The bioconjugates were characterized by electronic absorption, fluorescence spectroscopy and MALDI-TOF mass spectrometry, thus enabling precise determination of the labeling density (ratio DPP/BSA about 3 to 8). Outstanding values of…