Features of phytosanitary condition of rose cultivars of miniature garden group of the collection of the Nikitsky Botanical Gardens

Abstract

The objective of the research is the identification of dominant species of phytophagans and the determination of species composition of causative agents of phytopathogenic diseases of garden group of miniature rose cultivars. Methods of research . Species composition of pests was studied by visual inspection of generative and vegetative organs 1 time in 7-10 days. Samples of affections were analyzed under a binocular microscope in the laboratory. The frequency of pests’ occurrence was determined on a 3-point scale. The assessment of garden roses infestation with fungal diseases was carried out on a natural infectious background on a 5-point scale. Results and discussions. The study was performed on 49 cultivars, of which 46 were introduced species, 3 cultivars were of breeding of the Nikitsky Gardens. As a result of the research, three species of phytophagans belonging to three orders of the class Insecta - Homoptera , Lepidoptera Acarina were revealed. Green rose aphid (Macrosiphum rosae L.), rose moth (Archips rosana L.), twospotted spider mite (Tetranychus urticae Koch) were most commonly observed during the growing season. In 2016, the focus of reproduction of an invasive species - cattony cushion scale (Icerya purchasi Maskell) was found for the first time on the cultivar of the miniature group Rouletii. The species composition of pathogens of phytopathogenic diseases was identified, the most harmful of which are: powdery mildew (Sphaerotheca pannosa (Wallr)). Lev.), black spot (Marsonina rosae (Lib.) Died, rust (Phragmidium tuberculosis J.). Conclusion. The cultivars that are resistant to fungal diseases mainly dominated in the garden group of miniature roses. For the stable expression of this feature, it is necessary to create optimal conditions for cultivation: the use of preventive sprays with biological preparations or low-risk pesticides and compliance with the regime of agricultural activities. On the base of complex cultivar study, cultivar evaluation and phytosanitary evaluation of roses of the miniature garden group of the Nikitsky Botanical Gardens’ collection, an assortment for flower decoration was developed, including 46 cultivars for group planting, which can be recommended for landscaping parks, squares, streets in the populated areas of the Crimea.