Effect of sowing substrate on coverage and rate of weeding of directly sown annual flower beds

Abstract

The method of establishing directly sown annual flower beds has its benefits as well as problems. One of them is particularly surface weeding before sowing. The aim of the experiment was to find a solution to this problem, i.e. whether covering sowing substrates can suppress the germination and growth of weeds and improve growth parameters of annuals. The certified seed mixture of annuals and three variants of substrates that differed in ability to retain water were chosen for the experiment. Substrate A contained 70% vol. of sand and 30% vol. of peat; substrate B 50% vol. of sand, 20% vol. of siliceous marlite, 30% vol. of peat; and substrate C 30% vol. of sand, 40% vol. of siliceous marlite, 30% vol. of peat. In the control variant annuals were sown directly into the soil. The experiment was established in two different sites. Development of the mixture was monitored and evaluated all the season; the coverage with annuals and weed, the height of annuals and flowering time were evaluated. According to the results the use of sowing substrates ensured the successful development of mixtures of annuals, particularly in the initial stand development.