Sport turfgrasses are the most demanding to maintain because they are often exposed to fungal diseases and weeds. In recent years, there are fewer and fewer registered phytopharmaceuticals for their treatment. Between 2019 and 2020 we carried out a field experiment at the Laboratory field of the Biotechnical Faculty in Ljubljana composed of two parts, studying the response of five different sport grass mixtures to three different fertilization schemes (A – inorganic fertilizer with two soil improvers, B – organic fertilizer with two soil improvers and C – inorganic fertilizer) on herbage mass, colour and health, also on salicylic acid and total phenolic contents. Herbage mass is largely dependent on soil temperature, precipitation and soil water content. The occurrence of the fungus Laetisaria fuciformis was influenced by the fertilization scheme, as the % infection with the fungus was highest when organic fertilizers with low % nitrogen were used. Researching the effect of salicylic acid and total polyphenols on the natural resistance of sports turfgrasses to diseases is a relatively new area of sports turf maintenance. The average content of salicylic acid was significantly lowest under fertilization scheme C, but total polyphenols were higher under fertilization schemes B and C. We conclude that the method of fertilization has a certain effect on the salicylic acid and total polyphenols content in turfgrass mixtures, which also depends on environmental factors. In 2020 was conducted a greenhouse experiment to investigate the suppression of annual bluegrass (Poa annua L.), which is one of the main weeds of sport turfgrasses. We studied the efficacy of prohexadione calcium, ethephon and Pseudomonas fluorescens against P. Annua L., Lolium perenne L. and Poa pratensis L. Mesotrione was used as a positive control and nontreated grass was used as a negative control. We established that the efficacy of the tested products is connected to grass species and whether the grass was mowed/cut before spraying. The results of this study have indicated that the application of prohexadione calcium and P. fluorescens can inhibit the spread of annual bluegrass on football pitches.
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