The effectiveness of 25 fungicides in the control of Sphaerotheca pannosa var. rosae were tested on 10 cultivars of roses. Also their influence on plant growth and eventual phytotoxiciry were assessed. The treatments were performed 4 times at weekly intervals. Shrubs treated with Folicur BT 225 EC, Spartak Alpha 380 EC, Sys thane MZ 61 WP, Systhane 125 EC, Tango 500 SC and To pas MZ 61 WP did not show disease symptoms. Bravo 500 SC, Folpan 80 WG, Funaben 50 WP, Penncozeb 80 WG and Saprol 190 EC were slightly less effective than the other tested fungicides. The influence of chemicals on plant growth was closely correlated with cultivar - showing stimulatory. inhibitory or neutral effects. Out of tested preparations Afugan 30 EC, Opus 125 SC and Tango 500 SC were strongly phytotoxic at used doses toward all rose cultivars. The intensity of damage depended on cultivar.

Efficacy of azoxystrobin, dichlofluanid, imazalil, kresoxim-methyl, propiconazole and triforine (standard) in the control ofDiplocarpon rosae was evaluated in the years 1997-1999. The compounds were applied as a plant spray. First treatment of plants was performed when first disease symptoms occurred on leaves and spraying was repeated 9 times at weekly intervals. In the autumn of 1999 plants not previously treated with fungicides and showing visible disease symptoms were spraye and after one, 7 and 14 days diseased leaves were sampled. Spores from leaves were transferred onto Petri dishes with potato-dextrose agar. Number of germinating spores was counted after 24 h incubation (4 Petri dishes for each compounds). After 9-weeks protection of rose shrubs with the tested compounds the spread of mycelium on new leaves was strongly inhibited. Only bupirimate at concentration 0,05% gave very poor control of D. rosae. All other tested compounds were better or as good as triforine. Reduction of concentrations used resulted in lower effectiveness. After I, 7 or 14 days from the last spraying of plants with dichlofluanid, kresoxim-methyl and triforine germination of fungus spores was below 9% except kresoxim-methyl at concentration O.Ol% after 14 days (12.5%).

The shipment of cut flowers from Colombia and Ecuador to the United States, the biggest importer of this product in the world, has doubled in the last 20 years. One of the main constraints in cut roses production is the gray mold disease caused by the fungus Botrytis cinerea, which can destroy the flowers, in the crop, during storage and/or shipping. Since the resistance of the fungus to conventional fungicides has been increasing, as well as the health effects in rose growers, alternative approaches for controlling the disease are needed. The effect of UV-C light on the gray mold development in cut roses was studied. Irradiation with 2,160; 1,080 and 540 J ⋅ m–2 UV-C, every 24 h for 5 days in a humid chamber, did not harm the roses. Instead, as seen by image analysis, a highly significant reduction of the area of the lesions by the disease and of the fungus germination was obtained at 1,080 J ⋅ m–2. The addition of a 4-h dark period to the irradiation did not improve the effect of UV-C on the disease. The results of this work potentiate the use of UV-C light in the agro-industry as a low-cost and non-invasive alternative method to control diseases. They also reflect the application of optical approaches as image analysis in the evaluation of important agricultural features.

Interest in growing roses in Poland is related to the production of cut flowers as ornamentals and of petals and hips for cosmetics or food products. However, recently there has been an increasing number of reports of pest damage on rose plantations. In the case of fruits the damage has been attributed to flies (Rhagoletis alternata) or moths (Cydia tenebrosana), while nematodes have been implicated for growth reduction even on plantations grown under soil-less conditions. Field trials and laboratory experiments to test the possibility of controlling R. alternata larvae or pupae with entomopathogenic fungi and nematodes resulted in a lack of parasitism. On the other hand, the use of Bacillus thuringiensis subsp. kurstaki or Cydia pomonella granulovirus effectively controlled C. tenebrosana. Meloidogyne incognita infestation of roses growing on rock wool substrate was drastically reduced by Arthrobothrys oligospora or abamectin. Factors such as the method of product application or pest susceptibility to the used microbial-based products accounted for the observed differences in efficacy.