Potiskujuće delovanje nekih vrsta krmnog bilja na rast Ambrosia artemisiifolia i Iva xanthiifolia

A pot trial in greenhouse conditions has been carried out to investigate the role of some plant species in suppression of Ambrosia artemisiifolia and Iva xanthiifolia growth. Screening of several plant species (Medicago sativa L., Lolium perenne L., Dactylis glomerata L. and Elymus repens (L.) Gould – all from both turf and seeds) was conducted. The results of the experiment showed that some perennial plants, especially L. perenne, D. glomerata and M. sativa, can be a reliable means of suppression of the growth and seed production of A. artemisiifolia and I. xanthiifolia. Moreover, simple greenhouse screening turned to be a reliable method for predicting this potential suppressive role under certain conditions.Uloga nekih biljnih vrsta u potiskivanju rasta Ambrosia artemisiifolia i Iva xanthiifolia ispitivana je u ogledu u posudama pod uslovima staklenika. Ispitivano je nekoliko biljnih vrsta (Medicago sativa L., Lolium perenne L., Dactylis glomerata L. i Elymus repens (L.) Gould – svaka kao busen i seme). Rezultati eksperimenta su pokazali da neke višegodišnje biljke, naročito L. perenne, D. glomerata i M. sativa, mogu predstavljati pouzdan način potiskivanja rasta i produkcije semena vrsta A. artemisiifolia i I. xanthiifolia. Pored toga, jednostavan postupak skrininga u stakleniku pokazao se kao pouzdan metod za predikciju ove potencijalno potiskujuće uloge pod određenim uslovima

Effect of Different Growing Systems of Apple on Trunk and Branch Diseases and Pests

The presented study aimed to determine apples trunk and branch diseases and pests in three growing systems conventional, integrated and biological (organic). The investigations were made on an experimental apple orchard (1 ha) of the Institute of Agriculture at Kyustendil, Southwest Bulgaria in four consecutive years from 2007 to 2010. Three scab resistant cultivars Prima, Florina and Erwin Baur grafted on rootstocks MM106 were planted in 1996. The orchard was divided into four plots. One plot was treated conventionally with a normal pesticide programme, two plots were treated integrated according to the general principles, rules and standards of integrated apple production and one plot for biological (organic). The monitoring of pests and diseases and assessment of their density were done every two weeks. It was established that during the experimental period important disease and pests on apple trees in different growing systems were black rot Botryosphaeria obtusa, apple clearwig moth Synanthedon myopaeformis and shorthole borer Scolytus rugulosus. The damages by trunk and branch diseases and pests on apple were considerable higher in biological growing system. The mean rate of attack of cultivar Erwin Baur by Botryosphaeria obtusa in biological and conventional growing systems was 52.35% and 4.65%, respectively. The percentage of damaged by Scolytus rugulosus trunk and branch area per tree reach to 58.74 in biological and 0.23 in conventional system. Reduced vitality of apple trees growing with out pesticides and mineral fertilizers in biological growing system was the reason for strong infection of Botryosphaeria obtusa and attack of Synanthedon myopaeformis and Scolytus rugulosus.</span

Effect of Different Growing Systems of Apple on Trunk and Branch Diseases and Pests

The presented study aimed to determine apples trunk and branch diseases and pests in three growing systems conventional, integrated and biological (organic). The investigations were made on an experimental apple orchard (1 ha) of the Institute of Agriculture at Kyustendil, Southwest Bulgaria in four consecutive years from 2007 to 2010. Three scab resistant cultivars Prima, Florina and Erwin Baur grafted on rootstocks MM106 were planted in 1996. The orchard was divided into four plots. One plot was treated conventionally with a normal pesticide programme, two plots were treated integrated according to the general principles, rules and standards of integrated apple production and one plot for biological (organic). The monitoring of pests and diseases and assessment of their density were done every two weeks. It was established that during the experimental period important disease and pests on apple trees in different growing systems were black rot Botryosphaeria obtusa, apple clearwig moth Synanthedon myopaeformis and shorthole borer Scolytus rugulosus. The damages by trunk and branch diseases and pests on apple were considerable higher in biological growing system. The mean rate of attack of cultivar Erwin Baur by Botryosphaeria obtusa in biological and conventional growing systems was 52.35% and 4.65%, respectively. The percentage of damaged by Scolytus rugulosus trunk and branch area per tree reach to 58.74 in biological and 0.23 in conventional system. Reduced vitality of apple trees growing with out pesticides and mineral fertilizers in biological growing system was the reason for strong infection of Botryosphaeria obtusa and attack of Synanthedon myopaeformis and Scolytus rugulosus.</span

Suppressive Effect of Some Forage Plants on the Growth of Ambrosia artemisiifolia and Iva xanthiifolia

A pot trial in greenhouse conditions has been carried out to investigate the role ofsome plant species in suppression of Ambrosia artemisiifolia and Iva xanthiifolia growth.Screening of several plant species (Medicago sativa L., Lolium perenne L., Dactylis glomerataL. and Elymus repens (L.) Gould – all from both turf and seeds) was conducted. Theresults of the experiment showed that some perennial plants, especially L. perenne, D.glomerata and M. sativa, can be a reliable means of suppression of the growth and seedproduction of A. artemisiifolia and I. xanthiifolia. Moreover, simple greenhouse screeningturned to be a reliable method for predicting this potential suppressive role under certainconditions

Application of remote sensing techniques for the identification of biotic stress in plum trees caused by the Plum pox virus

Two hyperspectral remote sensing techniques, spectral reflectance and chlorophyll fluorescence, were used for the identification of biotic stress (sharka disease) in plum trees at an early stage without visible symptoms on the leaves. The research was focused on cultivars that are widely spread in Bulgaria: ‘Angelina’, ‘Black Diamond’ and ‘Mirabelle’. Hyperspectral reflectance and fluorescence data were collected by means of a portable multichannel fibre-optics spectrometer in the visible and near infrared spectral ranges (400-1000 nm). Statistical and deterministic analyses were applied for assessing the significance of the differences between the spectral data of healthy (control) and infected plum leaves. Comparative analyses were performed with complementary serological test DAS-ELISA, broadly implemented in plant virology. The strong relationship that was found between the results from the two remote sensing techniques and serological analysis indicates the applicability of hyperspectral reflectance and fluorescence techniques for conducting health condition assessments of vegetation easily and without damage before the appearance of visible symptoms