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Leaf number and plant height of three Canna x generalis cultivars
22-24.Views:244The aim of this three-year study was to evaluate the effect of three treatments (thiophanate methyl, charcoal dust, and control) on leaf number and plant height on three Canna x generalis cultivars (City of Portland, Richard Wallace and Robert Kemp). Results showed that the 3-year means of leaf number ranged from 13.9 to 23.1 for the three cultivars. The largest leaf numbers were for cultivar Robert Camp (23.1 in 2010) and the lowest for cultivar City of Portland (13.9 in 2011). Thiophanate methyl treatment produced the highest number of leaves and the values were significantly different at P< 0.05 from the control for all years and for all cultivars. Numbers of leaves in charcoal dust treatments were larger than the control treatments but it was not significantly different. Results on plant height ranged from 69.2 to 160.5 cm for the three cultivars. The largest plant height was for cultivar Robert Kemp (160.5 cm in 2011) and the lowest for cultivar City of Portland (69.2 cm in 2011). Thiophanate methyl treatment produced the highest plant height and the values were significantly different at P< 0.05 from the control for all years and for all cultivars. Plant heights in charcoal dust treatments were larger than the control treatments but it was not significantly different.
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Some aspects of reduced disease management against Blumeriella jaapii in sour cherry production
49-51.Views:201The aim of this study was to evaluate the effectiveness of reduced spray programmes against cherry leaf spot in integrated and organic sour cherry orchards. Altogether four spray programmes were performed i) standard integrated: sprays followed by forecasting systems during the season, ii) reduced integrated: sprays followed by forecasting systems but only 75% of the spray numbers used during the season-long spray programme, iii) standard oragnic: sprays applied every 7–14 days during the season and iv) reduced organic: 60 % of the spray numbers used during the season-long spray programme. Our study showed that cherry leaf spot did not increase above 3.1, 7.4, and 8.9% in 2008, 2009, and 2010, respectively, in the integrated orchards. However, leaf spot incidence was above 20% in all years in the organic field. Reduced spray programme did not increase significantly cherry leaf spot incidence in the integrated field in either years. However, leaf spot incidence increased significanly (above 20%) in the reduced spray programme for the organic orchard.
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Anatomical relations of the leaves in strawberry
81-84.Views:163In the present study histology of the leaves of strawberry (Fragaria ananassa Duch.) variety Elsanta was the objective, which has been performed with the beginning of seedling stage, cotyledons, primary leaves and later true leaves, first cataphyll of the runner shoot as well as the bracteoles of the inflorescence. Structures of the leaf blade, the upper and lower epidermis, the petiole have been also observed. The leaf blade of cotyledons already contains a typical palisade as well as spongy parenchyma tissues, i.e. being bifacial showing a structure similar to that of the true leaf. However, the petiole displays differences from the true leaf. There are a narrow (4-5 layer) primary cortex and a tiny central cylinder. Primary leaves bear already hairs on the adaxial surface and the transporting tissue-bundles are recognised in cross sections having a "V" shape. The first true leaf composed by three leaflets is of a simple structure showing characters reminding of cotyledons and primary leaves. Leaves of intermediate size continue to grow, whereas their inner anatomy changes dramatically. In the central region of the leaflets, near to the main vein, a second palisade parenchyma appears, further on, transporting tissue bundles are branching in the petiole. Collenchyma tissues enhance the stiffness and elasticity of the petiole. Older true leaves develop thick collenchyma tissues around the transporting bundles being represented by increasing numbers. The doubled palisade parenchyma layers of the leaf blades are generally observed. The cataphylls of the runners have a more simple structure, their mesophyll is homogenous, no palisade parenchyma appears. It is evident that leaves grown at successive developmental stages are different not only in their morphological but also anatomical structure. There is a gradual change according to the developmental stage of the leaves.