Delaying Flowering of Tobacco Variety K326 by Supplemental Lighting,Night Interruption Lighting and Detopping

Early flowering is undesirable in tobacco (Nicotiana tabacumL.) production because it reduces yield and quality of raw materials. This study was carried out to determine the possibility of delaying floral induction and flowering without causing undesirable side-effects to the plants. Flue-cured tobacco plants of cultivar K326 were treated with various combinations day length and night break lighting under nethouse conditions. Four hours supplemental lighting (prolong day length duration, equivalent to 16hours/8hours day/night) and one-hour middle-of-night interruption were able to delay flower induction/flowering of the short - day tobacco plants cv. K326. Detopping of plants under field conditions to induce new branch also prolonged days to flowering. If night interruption or supplemental lighting was implemented continuously for 10 or more cycles, flowering could be delayed by 28 to 30days. Detopping to promote branching at 5th and 10thleaf position delayed flowering by 8 days and yielded in increased leaf number and size in comparison with the control.