Abstract
Investigated was the efficacy of 4 ice nucleation‐inactive (ice‐) bacterial strains (A506, GSPB 1147, 1181, 2357) at 4 ice nucleation active (ice+) strains (553, 554, GSPB 1139, 2035) on the surface of 4 culture crops (corn, tomato, bush‐ and field bean). Examinated was the reduction of frost damage at the used culture crops by inoculation with ice+ and ice‐ strains at 4 different variants (A‐D) under laboratory conditions. The ice nucleation activity was determined by the tube‐freezing‐assay. An effective reduction of ice+ bacteria was possible, when plant surfaces were preinoculated (3days) with ice‐bacteria before ice+ bacterial strains colonized the surfaces of plants. A statistical comparison of mean values of obtained results showed, the ice crystallization (INT) by inoculation started at ‐3°C and in mean (MNT) below ‐5°C independent of the used ice+ and ice‐ strains. Obtained differences were not significant. As untreated as colonized plants with antagonists started to freeze at ‐5 and ‐6°C and in average at ‐7°C. However, the preinoculation resulted in 1.38 K differences for the temperatures, at which 50% of leaves were frozen (PROZ 50) in favour of preinoculated plants. This difference in freeze temperatures by preinoculation with ice‐ bacteria was discussed as a possible method of frost protection.
Notes
Address for correspondence: Binsenhof 35 14478 Potsdam, Axel Schranz Robert‐Baberske‐Str. 03 14480 Potsdam, Germany, e‐mail: axel‐[email protected]