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  • Hydroponic pepper growing on baked clay pellets
    37-40.
    Views:
    187

    Nowadays one of the most important issues of greenhouse vegetable production in soilless media is the protection of the environment, in particular, the selection of the root medium to be applied. The objective of the trial was to test the applicability of baked (expanded) clay granules in hydroponic pepper growing with special respect to the growing pot (plastic tubes and buckets with bottom and lateral holes). From the result of the experiment it can be concluded that baked clay pellets, similarly to rockwool, are a suitable medium for providing root anchorage for pepper, however, it is necessary to examine some technological issues (e.g. fertilization, irrigation) prior to starting a large scale commercial cultivation. Relative to the three growing containers tested, it can be concluded that with the 4-8 mm crushed clay pebbles cultivation can be carried out successfully both in the white plastic tube and in the bucket, with the latter it is recommended to locate the drainage holes on the side of the growing container (at 6 cm from the bottom of the bucket).

  • The hydroculture of calla
    90-92.
    Views:
    95

    Hydroculture was established in the early 40's. This technology became wide-spread in 60's. Because of economic considerations it played little role in Hungarian ornamental plant growing. The forthcoming joining of the EEC as well as the strict enviroment protection regulations, this technology is likely to spread in our country and like in most of the West European countries, cut flowers will be grown in hydroculture. Closed systems match the most strict environmental regulations. Calla can be well adopted to this technology because of its origin and water demand.

    We have studied three growing methods: PUR-agrofoam, container and soil-heated, of which soil-heated proved to be the best significantly.

  • Evaluation of fruit tree waterstress condition and transpiration with heat fl ux sensors
    leaf area index, evapotranspiration, water stress
    Views:
    190

    In this study the transpiration properties and response to heat stress of Granny Smith and Jonagold apple species were measured. The examinations were set at an orchard near to Debrecen. The chosen trees were two years old, without fruits, in 20l container, placed in the mixture of mulch matrix, wood chips and sawdust and grown at the same climatic conditions. One of the most important goals was to determine the leaf area of the trees which is a basic data for transpiration modeling. Leaf area was larger (signifi cance level p<0.05) in the upper part of the canopy to achieve larger photosynthetic surface. Jonagold species with less leaf number (–18% compared to Granny Smith) reached almost the same canopy area, than Granny Smith, due to larger leaf area of Jonagold. Another aim was to measure the transpiration rate of the apple trees. The transpiration measurements were carried out by sap fl ow meter. Only a small transpiration difference can be found between species. During the investigation time there were wet and cool as well as dry and extremely hot periods. In the case of dry and extreme hot periods the transpiration is decreased, which causes decrease in transpiration and enhanced the water stress of trees.

  • Studies on the effects of growing substrates and physical factors in sweet pepper forcing in context with the generation of calcium deficiency symptoms
    61-65.
    Views:
    182

    In the publications available for us, exact levels of physical factors and those of the growing technology determining Ca2+ deficiency are rarely detailed. Although the influencing role of the various environmental factors (humidity, light, temperature) is known, we had only little information about their exact values which could be presented for the growing practice. Sweet pepper varieties of the same type grown in various substrates responded to the environmental factors in different ways. Our results revealed that increasing temperature of the root zone had the most significant effect on the incidence of Ca2+ -deficient fruits. Their amount, however, gave different results depending on the growing substrate. In forced sweet pepper grown in soil the proportion of Ca2+ - deficient fruits were significantly lower compared to the plants grown on rockwool. Fruits derived from forcing on perlite, in container were damaged the least by the blossom end rot deficiency symptoms. Our experimental results and technological suggestions are based on measurement results of three years.

  • The effect of Regalis® (prohexadione calcium) on the reduction of fire blight (Erwinia amylovora) severity in apple trees
    61-66.
    Views:
    162

    Due to the lack of effective and non-phytotoxic materials for control of the blossom and shoot blight phase of fire blight in pome fruit trees, two novel control strategies have emerged: shoot growth retardation by bioregulators and applying resistance inducer compounds. Prohexadione calcium (ProCa) is the active ingredient of the bioregulator Regalis® registered in several European countries. The reduction of shoot growth elongation is the most obvious effect of ProCa. Furthermore, it causes significant changes in the spectrum of flavonoids and their phenolic precursors, leading to the considerable reduction of susceptibility to fire blight.

    In Poland, potted one-year-old apple trees of cvs. Gala Must grafted on M.26 and Sampion on M.9 (in 2001) as well as Gala Must on P.60 (in 2002) were treated with Regalis® at a range of concentration of 250, 150 or 150 + 100 ppm, respectively. The inoculation of shoots was made with the strain No.691 of E. amylovora (107 cfu/ml), on the 7th and 21st'day after treatments with Regalis. In Hungary, during the years of 2002 and 2003 one-year-old container grown apple trees of the cvs. Idared/M.9 and Freedom/M.9 were treated with the prohexadione-Ca, the active ingredient of Regalis® 100, 150 or 200 ppm, two weeks before inoculation with the Ea 1 strain of E. amylovora (107 cfu/m1).

    In Poland, the suppression of fire blight in shoots reached up to 80%, depending on concentration and application time of Regalis®. In Hungary, the effect of prohexadione-Ca treatments, determined by the length of necrotic lesion developed, proved to be better than that of streptomycin used for comparison.