Wpływ stosowania krzemianu potasu na wzrost, plonowanie i zdrowotność roślin pomidora ‘Growdena F1’ uprawianego na uprzednio użytkowanym substracie

The aim of the study was to examine reproductive and vegetative responses of ‘Growdena F1’ tomatoes (Solanum lycopersicum L.) to use of potassium silicate fertilizer (as Silvit 15.0% SiO3) into reused peat substrate. Investigations were carried out at a greenhouse in 2013 and 2014. Tomatoes were treated with potassium silicate 2 times: immediately after tomato planting and a month later, at a rate of 0.11 g silicon (Si) per plant per year. Potassium silicate was applied as 1% water solution during plant irrigation. In each term, 200 ml Silvit of Si-containing solution per plant was applied. Plants unsupplied with potassium silicate serves as the control. The results showed that application of potassium silicate was able to improve tomato root healthiness, but only in the second year of the study, when the presence of pathogens in the tested substrate was high. The increases in marketable and total fruit yields as a result of use of potassium silicate was found only in 2014. It is concluded that at high multiplication of root pathogens in the substrate, the application of Sicontaining fertilizers do not protect sufficiently roots against infection.