Contamination of explants of Coffea arabica L. as depending on the disinfection used

A trial was conducted to study the danger of contamination of the explants of Coffea arabica L. by solutions used for disinfection. Six combinations of disinfectant solutions were tested at different exposure times in meristem culture on three modifications of the LS 65 medium. The lowest average contamination, 20.59 percent, was recorded in group 4, with 10 percent Savo (sodium hypochlorite) + 0.2 ml Tween 20, on the LS 65 medium + supplements after Staritsky. At exposure time of 25 min, contamination with this disinfectant combination was as low as 3.26 percent, but at longer exposures the contamination percentages were higher: 18.52 percent at 30 min and as much as 40 percent at 35 min. Disinfection with 2 percent Savo + 0.2 ml Tween 20, left to act for 1080 min, also produced a low contamination: 22.2 percent, 5 percent chloramine + 0.2 ml Tween was the least suitable disinfectant combination. It produced an average contamination of 80 percent