Search results for "rowing"
showing 10 items of 286 documents
Productivity and canopy modification of Medicago arborea as affected by defoliation management and genotype in a Mediterranean environment
2004
Medicago arborea is one of the most potentially valuable fodder shrubs in a Mediterranean environment because of its high preference by small ruminants and its nutritive value. Edible biomass production is affected by agronomic and environmental factors. A study, carried out in an inland area of Sicily in the growing seasons of 1994/95, 1995/96 and 1996/97, evaluated the forage production and canopy modification in a M. arborea plantation after (i) commencing defoliation 1 or 2 years after transplanting and (ii) defoliating only in autumn (A), only in early summer (S) or in both seasons (A and S). Six clones derived from five different Mediterranean populations were used. Plant age at the f…
Crop Load and Rootstock Influence on Dry Matter Partitioning in Trees of Early and Late Ripening Peach Cultivars
2002
ADDITIONAL INDEX WORDS. vigor, starch, fruit size, Prunus persica ABSTRACT. Effect of crop load on dry matter partitioning was studied on 3-year-old peach ((Prunus persica (L.) Batsch (Peach Group)) trees of the early ripening 'Early May Crest' (EMC) grafted on 'GF677' and Penta (Prunus domestica L.) rootstock and the late ripening 'Flaminia' grafted on 'GF677' rootstock ((Prunus persica x Prunus dulcis (Mill.) D. A. Webb) and grown outdoors in 230-L containers, for 2 years. Fruit thinning was carried out 10 days after fruit set to produce different crop loads. Trees were sampled destructively throughout two growing seasons and divided into above- ground and root components, for dry matter …
Comparison of Crop Trait Retrieval Strategies Using UAV-Based VNIR Hyperspectral Imaging.
2021
Hyperspectral cameras onboard unmanned aerial vehicles (UAVs) have recently emerged for monitoring crop traits at the sub-field scale. Different physical, statistical, and hybrid methods for crop trait retrieval have been developed. However, spectra collected from UAVs can be confounded by various issues, including illumination variation throughout the crop growing season, the effect of which on the retrieval performance is not well understood at present. In this study, four retrieval methods are compared, in terms of retrieving the leaf area index (LAI), fractional vegetation cover (fCover), and canopy chlorophyll content (CCC) of potato plants over an agricultural field for six dates duri…
Comparative responses of ‘Gala’ and ‘Fuji’ apple trees to deficit irrigation: Placement versus volume effects
2012
Aims: Climate, soil water potential (SWP), leaf relative water content (RWC), stomatal conductance (gs), fruit and shoot growth, and carbohydrate levels were monitored during the 2008 and 2009 growing seasons to study the responses of 'Gala' and 'Fuji' apple trees to irrigation placement or volume. Methods: Three irrigation treatments were imposed, conventional irrigation (CI), partial root-zone drying (PRD, 50% of CI water on one side of the root-zone, which was alternated periodically), and continuous deficit irrigation (DI, 50% of CI water on both sides of the root-zone). Results: After each irrigation season, DI generated twice the soil water deficit (SWDint) than PRD (average of dry an…
Exposure to moderate concentrations of tropospheric ozone impairs tree stomatal response to carbon dioxide.
2011
With rising concentrations of both atmospheric carbon dioxide (CO(2)) and tropospheric ozone (O(3)), it is important to better understand the interacting effects of these two trace gases on plant physiology affecting land-atmosphere gas exchange. We investigated the effect of growth under elevated CO(2) and O(3), singly and in combination, on the primary short-term stomatal response to CO(2) concentration in paper birch at the Aspen FACE experiment. Leaves from trees grown in elevated CO(2) and/or O(3) exhibited weaker short-term responses of stomatal conductance to both an increase and a decrease in CO(2) concentration from current ambient level. The impairement of the stomatal CO(2) respo…
EEG Spectral Generators Involved in Motor Imagery: A swLORETA Study
2017
In order to characterize the neural generators of the brain oscillations related to motor imagery (MI), we investigated the cortical, subcortical, and cerebellar localizations of their respective electroencephalogram (EEG) spectral power and phase locking modulations. The MI task consisted in throwing a ball with the dominant upper limb while in a standing posture, within an ecological virtual reality (VR) environment (tennis court). The MI was triggered by the visual cues common to the control condition, during which the participant remained mentally passive. As previously developed, our paradigm considers the confounding problem that the reference condition allows two complementary analys…
Strategies to decrease water drainage and nitrate emission from soilless cultures of greenhouse tomato
2010
In the spring-summer season of 2005 and 2006, we explored the influence of three fertigation strategies (A–C) on the water and nitrogen use efficiency of semi-closed rockwool culture of greenhouse tomato conducted using saline water (NaCl concentration of 9.5 mol m−3). The strategies under comparison were the following: (A) crop water uptake was compensated by refilling the mixing tank with nutrient solution at full strength (with the concentrations of macronutrients equal or close to the corresponding mean uptake concentrations as determined in previous studies) and the recirculating nutrient solution was flushed out whenever its electrical conductivity (EC) surpassed 4.5 dS m−1 due to the…
Plant chlorophyll fluorescence: active and passive measurements at canopy and leaf scales with different nitrogen treatments
2015
Highlight We studied for the first time the temporal and spatial limits within which active and passive chlorophyll fluorescence measurements are comparable.
Contact-induced phenomena in the Alps
2019
The main question underlying this chapter is to what extent language contact can affect syntactic structure. To tackle this issue we examine two relevant phenomena found in two minority languages spoken in the region Trentino-Alto Adige/South Tyrol: clitic climbing in Dolomitic Ladin and the use of the Romance complementizer ke in Cimbrian. Both phenomena are usually considered as the result of a contact-induced change influenced by the neighbouring Italo-Romance varieties. However, it is shown that the rising of clitic climbing is a language-internal process which is only accelerated by the contact with Italian. Similarly, the lexical borrowing of the complementizer ke in Cimbrian does not…
A neural network based automatic road signs recognizer
2003
Automatic road sign recognition systems are aimed at detection and recognition of one or more road signs from real-world color images. In this research, road signs are detected and extracted from real world scenes on the basis of their color and shape features. A dynamic region growing technique is adopted to enhance color segmentation results obtained in the HSV color space. The technique is based on a dynamic threshold that reduces the effect of hue instability in real scenes due to external brightness variation. Classification is then performed on extracted candidate regions using multilayer perceptron neural networks. The obtained results show good detection and recognition rates of the…