Horticultural Science, 2008 (vol. 35), issue 2
Relationships between humification and productivity in peat-based and peat-free growing media
Sz. Jakusné Sári, E. Forró
Hort. Sci. (Prague), 2008, 35(2):45-49 | DOI: 10.17221/638-HORTSCI 
Peat-based and peat-free (compost) materials were tested in a vegetable forcing experiment with Danubia green pepper (Capsicum annuum L.). Stability and quality of humic substances and the turnover of different nitrogen forms was determined in the studied media during the vegetation period. The main objective was to find how the degree of humification might influence the productivity of a crop under greenhouse conditions. The highest humus stability and humus stability coefficient values were detected in the green waste compost. Among different peat media, the low-moor peat was more humificated than the mixture of low-moor and high-moor peat....
The phenotypically quantitative nature of hypersensitivity of European plum (Prunus domestica L.) against the Plum pox virus and its description using the hypersensitivity index
M. Neumüller, W. Hartmann
Hort. Sci. (Prague), 2008, 35(2):50-64 | DOI: 10.17221/639-HORTSCI
More than 1,300 seedlings of European plum originating from crossing combinations with at least one parent showing hypersensitivity resistance against PPV were analyzed for their reaction to artificial inoculation with PPV using the double grafting method with virus infected interstem. It was shown that the hypersensitivity resistance against the virus is a phenotypically quantitative trait. The different kinds of symptoms observed in the test system, which contribute to the hypersensitivity resistance, range from weak necrosis on the leaf blade and on the stem to the death of the whole young shoots. A hypersensitivity index was developed which helps...
Predicting individual phenological phases in peaches using meteorological data
T. Litschmann, I. Oukropec, B. Křižan
Hort. Sci. (Prague), 2008, 35(2):65-71 | DOI: 10.17221/640-HORTSCI
The submitted work deals with the relation between the sum of active temperatures above 7°C and important phenological phases in peach tree cultivation. The aim of the paper is to provide information for growers, especially regarding anticipated harvest dates, which is important for marketing. Data has been compiled for the period 1998-2007 for the variety Catherine, grown in the locality of Velké Bílovice in the Czech Republic. A relationship between the sum of active temperatures above 7°C from the beginning of the year up to the start of blossoming has been identified, and a model determining the harvest date on the basis of the sum of active temperatures...
Cultivar and rootstock response to drip irrigation in sweet cherry tree vigour and start of bearing during the first three years after planting
J. Blažková, I. Hlušičková
Hort. Sci. (Prague), 2008, 35(2):72-82 | DOI: 10.17221/641-HORTSCI
Fifteen sweet cherry cultivars and three rootstocks were evaluated within three years in two experimental orchards established in the same location in the autumn 2004. In one of them drip irrigation was applied in the periods of insufficient rainfall, i.e. from mid-April to mid-August. This irrigation distinctly increased the vigour of trees that was jointly expressed by trunk-cross-section area, total length of shoots and canopy volume. An increase of tree vigour was the greatest in trees on Mazzard, medium on P-HL-C and the lowest on Gisela 5 rootstocks. The trees on P-HL-C that grew without irrigation similarly as the trees on Gisela 5 grew significantly...
Impacts of the substrate medium on tomato yield and fruit quality in soilless cultivation
N. G. Tzortzakis, C. D. Economakis
Hort. Sci. (Prague), 2008, 35(2):83-89 | DOI: 10.17221/642-HORTSCI
The performance and suitability of different substrates for the soilless culture of tomato plants (Lycopersicum esculentum Mill., cv. Belladona) were studied over a 5-month period in a closed soilless culture system employing five different substrates (perlite, pumice or maize and their mixtures with 50% shredded maize stems in an unheated glasshouse). Plants grown in a maize stem-containing medium produced earlier fruits, followed by pumice. Plants grown in pumice and perlite substrates obtained lower total yield; a higher yield was associated with the addition of maize shredded stems. Pumice + 50% maize and 100% maize produced higher total...
Growth regulator effect on in vitro regeneration of rhododendron cultivars
H. Vejsadová
Hort. Sci. (Prague), 2008, 35(2):90-94 | DOI: 10.17221/643-HORTSCI
In Rhododendron L. cv. Azuro, Bohumil Kavka, Catharine van Toll, Grandiflorum, Mars, Nova Zembla, Ortrud, Ovation, Prof. Scholz, Purple Splendour, Rebe and Van Werden Poelman, the effect of growth regulators on organogenesis induction of shoot-tip meristems was tested. All cultivars significantly showed the highest shoot regeneration on MS medium containing 6 mg/dm3 isopentenyladenine (2iP). For most rhododendrons, the highest shoot multiplication was found on a medium with 8-10 mg/dm3 2iP in combination with 1 mg/dm3 indoleacetic acid (IAA). Shoots rooted successfully in the substrate with high level of peat...