Mesocotyl elongation in Digitaria sanguinalis during seedling development

The mesocotyl is an embryonic organ present in Poaceae that plays an important role in seedling emergence. The elongation of this first internode contributes decisively to the coleoptile reaching the soil surface. This study examines the process of mesocotyl elongation under controlled conditions in three caryopsis collection sites of Digitaria sanguinalis (L.) Scop. originating from Spain (Barcelona and Girona) and Argentina that may have two patterns of germination: radicular or coleoptilar. The frequencies of the two germination patterns varied significantly depending on the origin. Light inhibited the elongation of the mesocotyl drastically, resulting in maximum lengths of 3.5mm, while in darkness the maximum length was 57mm. The time-course evolution displayed under dark conditions was quite similar for all sites of origin and both germination patterns; the growth rate ranged from 0.23 to 0.30mmh21. Within localities, caryopses with a coleoptilar pattern of germination showed a lower growth rate than those with a radicular one.Postprint (author's final draft

Soil spatial distribution in a smut fungus-annual grass interaction: exploring patterns to understand disease dynamics at plot scale

Infection of large crabgrass by loose smut occurs in the first centimetres of the soil profile. To understand the spatial-temporal disease dynamics, we try to find out the importance of the spatial distribution of spores and seeds in a field. Two soil sampling strategies were carried out after doing soil tillage, and propagules were counted; in the following season the level of disease was assessed. There was spatial autocorrelation in the case of the spores, but not in that of the seedsPostprint (updated version

Mulching as an alternative technique for weed management in mandarine orchard tree rows

Peer Reviewe

A note on prediction of maize stover qualityby near-infrared reflectance spectroscopy (NIRS)technique

Near-infrared reflectance spectroscopy (NIRS) technique was investigated as a means of predicting quality parameters in semi-exotic maize stover. These parameters included neutral detergent fibre (NDF) and in vitro dry matter (DM) digestibility. Samples of semi-exotic maize stover were formed by crossing the exotic material Across 8443 La Posta with inbred Mo 17.Postprint (published version

Hydrological soil behavior in areas with semi-arid vegetation (Beni Chougrane Mountains, Algeria)

Postprint (author's final draft

Seedling emergence through soil surface seals under laboratory conditions: effect of mechanical impedance and seal moisture

It is well known that soil sealing strongly affects seedling emergence. The effect of soil sealing on the emergence of flax and turnip seedlings was studied in the laboratory. Seeds were sown in pots, watered, then covered with loamy soil and water was added. Three different doses of water were tested. Soil sealing was obtained with a paste of soil mixed with distilled water, added to each pot as a thick homogeneous, continuous and isotropic layer. The initial water content of the seal was measured. When seedling emergence was observed (or at the end of the experiment in the case of event failure), seal strength was measured in situ by a firmness pressure tester (used as a penetrometer). Relationships between water loss and initial moisture of the seal versus mechanical impedance were obtained. Differences in emergence success between species depended on the initial soil water content as well as on the initial seal moisture. A model of seedling emergence success of the two species, flax and turnip, as a function of the initial seal moisture content was obtained using a binary logistic regression model.Postprint (author's final draft

Search for medicinal plants with pharmaceutical use by integration of the physical and biotic informations in a geographic information system: The interface steppe region - Saharan region (Algeria)

Algeria is a large, rich country in flora and fauna. The objective of this study was the integration of biological and physical data in a GIS for research of medicinal plants.Postprint (published version