The research material consisted of tulip plants of ‘Leen van der Mark’ cv. The effect of two preparations was evaluated: Sunspray 850 EC and Sunspray Ultra-Fine, in which the active substance is refined paraffin-based mineral oil. Preparations were applied at three concentrations: 1, 1.5, and 2%. Research plots were sprayed three times every 7 days. The first treatment was performed at the turn of the second and third decade of April. Starting from the beginning of May, observations of plant colonization by aphids were conducted every 14 days. The observations were terminated at the end of June. It was found that spraying using mineral oils Sunspray 850 EC and Sunspray Ultra-Fine of tulip ‘Leen van der Mark’ significantly affect the degree of virus infection and infection due to disease-causing pathogens in relation to the untreated plants. Plants sprayed with mineral oil at the lowest concentration (1%) were in better health condition and were less attractive to aphids. Increasing the concentration of oil and the number of treatments intensified the phytotoxic reaction of tulips manifested as chlorosis with varying intensity. They were not, however, apparent effect on plant growth and development. The chlorophyll content (expressed as greenness index) in the tulip leaves treated with mineral oil was lower as compared to untreated leaves, when plants were sprayed three times using Sunspray Ultra-Fine oil at a concentration of 2%.

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