Search results for "Seedling"
showing 10 items of 110 documents
Bird assemblages in isolated Ficus trees in Kenyan farmland
2006
Over the last few decades a rapid and extensive conversion of tropical forests to agricultural land has taken place resulting in mosaics of fragmented forest patches, pastures and farmland. While the effects of forest fragmentation on biodiversity have been intensively studied within the remaining forests, relatively little is known about the biodiversity in tropical farmland (Daily et al. 2001, Pimentel et al. 1992). Frugivorous birds are an important group of species in tropical farmland ecosystems. Frugivorous birds are significant seed dispersers and can play a prominent role in transporting seeds into disturbed areas and setting the stage for the regeneration of these systems. Isolated…
Phytotoxic effects of Lantana camara, Eucalyptus camaldulensis and Eriocephalus africanus essential oils in weeds of Mediterranean summer crops
2009
Abstract The essential oil composition of Lantana camara , Eucalyptus camaldulensis and Eriocephalus africanus was analyzed by means of GC and GC–MS and bioassayed in order to determine their activity against Amaranthus hybridus and Portulaca oleracea . E. camaldulensis essential oil, with spathulenol as the main compound, was the most effective, completely inhibiting germination and seedling growth on both weeds. The essential oil of E. africanus , rich in artemisia ketone, showed activity similar to that of E. camaldulensis on A. hybridus , but it was not so effective against P. oleracea , and L. camara essential oil, with high percentages in sesquiterpene hydrocarbons, also showed higher…
Powdery mildew resistance genes in Latvian barley varieties
2004
Thirty-three Latvian spring barley varieties and breeding lines and 90individual progenies from these were tested at the seedling stage for their reaction to a maximum 37 isolates of Blumeria graminis f. sp. hordei. Eighteen varieties were composed of two or three lines with different resistance. TwelveMl powdery mildew resistance genes(a1, a6, a7, a8, a9, a12, a13, at, g, k1, (Kr) and La) and four Ml genes closely linked to the Mla locus [a(Al2), a(No3), a(Em2) and a(Ru3)] were found. Mla8, Mlg and Mlk1 were the most frequent genes that occurred among the tested genotypes. The results confirm the pedigrees of all genotypes apart from cv. Agra and the breeding line L-215.
Morphogenic responsein vitroof epicotyl segments ofCitrus macrophylla
2008
Abstract The influence of explant orientation, contact of the cut surface with the medium, type of growth regulators and distance of epicotyl cuttings from the cotyledonary node (the part of the seedling where the cotyledons are attached) on in vitro morphogenesis of Citrus macrophylla (alemow) was evaluated. Maximum number of shoots was induced from epicotyl segments placed horizontally.
Improvement of the nitrogen uptake induced by titanium (iv) leaf supply in nitrogen‐stressed pepper seedlings
1996
Abstract The beneficial effect of titanium (Ti) on plant metabolism can result in more profitable use of fertilizer applied to a crop. A crop chamber experiment with paprika pepper (Capsicum annuum L., cv. Bunejo) seedlings under differential nitrogen (N) concentration levels in a nutrient solution (100% N, 75% N, 50% N, and 25% N) was performed. A third of the seedlings growing under each N support level remained Ti‐untreated and were used as the reference. Another third of the seedling received one and two 0.042 mM Ti(TV) ascorbate, pH 6.0, leaf spray treatments, respectively. The biomass production of the Ti‐untreated plants was only affected by the N supply of 50% or less. The Ti(IV) le…
Morpho-physiological variations in response to NaCl stress during vegetative and reproductive development of rice
2012
The complex nature of plant resistance to adverse environmental conditions, such as salinity and drought requires a better understanding of the stress-induced changes that may be involved in tolerance mechanisms. Here we investigate stress-related morpho-physiological effects during vegetative and reproductive growth in two Japonica rice cultivars (Bomba and Bahia) exposed to a range of NaCl concentrations from the seedling stage. The stress-related detrimental effects were observed either earlier or to a higher extent in cv. Bomba than in Bahia. Damages to the photosynthetic apparatus were related to loss of chlorophyll (Chl) and to a decrease of the maximum potential efficiency of PSII (F…
Effect of rootstock on trunk growth and foliar mineral content in cv. Bianca pistachio (Pistacia vera L.) trees
1998
Trunk cross-sectional area (TCSA) and mineral content were recorded for 4 years in the major Sicilian pistachio cultivar, Bianca, budded in 1991 onto eight in v/fro-propagated clonal rootstocks (Pistacia atlantica and P. integerrima) and one seedling rootstock (P. terebinthus). The trees were grown using standard cultural practices for Sicilian dry-land farming in a fine sandy soil, located inland in Sicily (20 km SW of Palermo, 350 m a.s.l.). From nine trees per rootstock, samples of 10 leaflets from the mid-section of current year shoots were taken yearly in August and analyzed for the main plant mineral elements (N, P, K, Ca, Mg, Fe, Mn, Zn, Cu and B). The TCSA was measured at the end of…
Does stump removal affect early growth and mycorrhizal infection of spruce (Picea abies) seedlings in clear-cuts?
2012
Abstract Stump removal procedure increases the extent of exposed mineral soil in the clear felled areas. In this study, our aim was to find out whether the early growth and mycorrhization of Norway spruce (Picea abies (L.) Karst.) seedlings differ between stump removal and mounding sites. Stumps were harvested from five one-hectare study sites and other five sites were mounded after clear felling. Twenty seedlings were planted on mounds at each study site. Although the height of spruce seedlings did not differ between the treatments after three growing periods, their mean growth was ca. 10% higher at the stump removal sites. The community of ectomycorrhizal (ECM) in the seedling roots did n…
New low-vigour apricot rootstocks compared
2010
About ten years ago nurseries began to test several novel apricot stocks developed either to reduce plant vigour and boost early as well as high cropping or as a more suitable replacement for Myrabolan (Prunus cerasifera) and Apricot seedling in water-logged or chlorotic soils. These stocks were the Italian bred selections of Prunus domestica Penta and Tetra, the P. cerasifera Adara and the Prunus insititia Adesoto® 101, both Spanish-bred seedlings, and Plumina@, a Prunus bessey × P. cerasifera hybrid developed in France. Performance testing was carried out under a national project. The trials were set up in 2001 in plots of pilot orchards at Imola in Bologna Province, Ancona, Caserta, Pale…
Growth increase of birch seedlings under the influence of earthworms—a laboratory study
1992
The effects of the earthworm Lumbricus rubellus (Hoffm.) on net production and nitrogen content of birch seedlings were studied in laboratory microcosms. Coniferous forest floors with litter, humus and mineral horizons were simulated in transparent plastic cylinders. The materials were partially sterilized by microwaving, and re-inoculated with microflora and -fauna. A young (9 cm) birch seedling (Betula pendula Roth) was planted in each container. Earthworms were added to half of the replicates. The microcosms, through which a constant air flow was maintained, were incubated in a climate chamber. After two growth periods, leaf and stem biomasses of birch in treatments with earthworms incre…