117,293 research outputs found
Effect of rootstock vigor and in-row spacing on stem and root growth, conformation, and dry-matter distribution of young apple trees
No full textThe effects of M.9 and MM.106 rootstocks and in-row spacing (0.4, 0.7, and 1 m) on the vegetative behavior of three-year-old apple (Malus domestica Borkh) trees were studied. Analysis of digital images was used to estimate canopy and root growth and conformation (shape and size), whereas dry matter distribution was used to determine partitioning to various plant parts. Trees on less vigorous M.9 rootstocks showed reduced stem and root growth as they produced less and/or shorter shoots and less and/or shorter and thinner roots. Canopy spread area (CSA) and volume were similar for trees on both rootstocks and differences in stem length density (stem length per unit canopy volume; SLD) compensated for the difference in stem growth. For M.9 roots, the decrease in growth was reflected in the reduction in root spread area (RSA), which was not compensated for by the increase in root length density (root length per unit RSA; RLD). Trees on M.9 allocated more dry matter to above-ground structures, whereas trees on MM.106 partitioned more to roots. Leaf to root surface area ratio (L:R) was also greater for trees on M.9. Stems of trees grown 0.4 m apart weighed less because they were thinner, whereas the same trees produced less and/or shorter, but thicker roots, which resulted in similar root dry weights for trees at all spacings. Canopy height increased with spacing for trees on M.9, whereas it was negatively related to spacing for MM.106. CSA was rounder at the wider spacings and exceeded the allotted soil surface at the closest one. For three-year-old apple trees, optimal in-row spacing (no shoot overlap and full coverage of allotted space) was about 0.7 m for M.9 and 0.8 m for MM.106. RSA was also rounder at the larger spacings, but never filled the allotted space. Dry matter distribution was significantly influenced by spacing, and root to shoot ratio (R:S) was highest at the widest spacing. The vegetative behavior of young apple trees was influenced by both rootstock vigor and tree spacing. Also, trees on the M.9 rootstock reflected greater ability to compete for available resources and adapt to space confinement and, therefore, may represent a better option for cultivation of apple in the settings and at the planting densities considered
Dynamics of dry matter partitioning in young ‘Nocellara del Belice’ olive trees
No full textDry matter partitioning of ‘Nocellara del Belice’ olive (Olea europaea L.) trees was assessed during one growing season. Four three-year-old potted trees from rooted cuttings trained to single-trunk free-canopy were destructively harvested at 30-day intervals during the growing season. The average dry matter increase was about 2 kg · year-1 per tree. Total plant dry weight increased linearly over the year, whereas root to shoot ratio followed a quadratic trend with its peak during winter. Dry matter of all canopy parts (trunk, branches, 1-year-old shoots, and leaves) increased linearly and leaves exhibited the fastest growth. Also fine roots accumulated dry matter over the year in a linear fashion, whereas dry matter of coarse roots increased until the end of January and then leveled off. On the average, 31% of the total dry mass was partitioned to the roots (20% coarse and 11% fine), 28% to the leaves, 14% to shoot axes, 7% to two-years-old wood, and 14% to main trunk. Trunk cross-sectional area was positively related to both root and shoot dry weight, and proves to be a good indicator of above- and below-ground vegetative growth in young olive trees
Vegetative and Reproductive Behavior of 'Conference' and 'Williams' Pear Trees Trained to V-Shape System
No full textV-shape systems represent an efficient and popular option to increase yields and fruit quality. Here we present a detailed study on canopy and root system growth and conformation, yields, fruit quality and dry matter partitioning of 'Conference' (C) and 'Williams' (W) pear trees trained to V-shape system. Digital images were used to determine total stem and root length, mean diameter and surface area; canopy and root system spread area, shape index and volume, canopy height and root depth. Dry weights were used to calculate dry matter partitioning. Stems of W trees were longer and thinner than those of C, which resulted in similar stem dry weights for the two cultivars, whereas root dry weight of W was greater than C due to greater diameter. W canopies were also taller, wider, and occupied a larger volume than C canopies, but similar for length density (length/volume) and roundness of spread area. C root systems were shallower, wider, and similar to W root systems for volume, length density and roundness of spread area. W trees also had larger leaf area and leaf/root surface ratio than C trees. W trees produced higher yields than C trees, but exhibited the same fruit weight per unit leaf area. C fruit flesh was firmer than W fruit flesh, suggesting a different degree of ripeness between the two cultivars. Despite adjustment for the degree of ripeness, W fruit was bigger, but less sweet and more acidic than C fruit. C trees partitioned a greater proportion of dry matter to stems, a similar proportion to roots, and a smaller proportion to leaves and fruit than W trees. In the early stages of orchard life, W trees represent a generally more efficient option for pear cultivation using V-shape systems
Definizione dell'epoca ottimale di raccolta meccanica nella cultivar di olivo Biancolilla in relazione alla qualità del prodotto
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Effect of a new formulated diet based on terrestrial vegetables on roe yield and quality in the sea urchin Paracentrotus lividus (L. 1816)
No full textFormulazione di un mangime altamente performante per l’acquacoltura di specie erbivore ed onnivore
No full textEfficienza fogliare nell’assorbimento azotato nell’olivo in relazione alla forma somministrata
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Efficienza fogliare nell'assorbimento azotato nell'olivo in relazione alla forma somministrata
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