THE PHYTOTOXICITY OF DISINFECTANTS AND THEIR EFFECT AT DIFFERENT TEMPERATURES

When disinfecting plastic growth containers, only sodium hypochloride (NaClO) caused damage both to cucumber and lettuce seedlings grown on peat if the containers had not been washed with water after disinfecti on. Also the seedlings grown on rockwool cubes were susceptible to Men no-Ter-forte when the growth containers were not properly rinsed after disinfection. All tested disinfectants caused damage to cucumber, let tuce and cauliflower seedlings when mixed in the peat substrate. The e fficiency of disinfectants was higher at +20-degrees-C than at +5-degr ees-C, especially against Fusarium culmorum, F. oxysporum and Rhizocto nia solani. A decrease in temperature affected least the efficacy of N aOCl and Menno-Ter-forte and most that of Virkon S.