Optimization of stage of harvest of cut spike in single petalled tuberose (Polianthes tuberosa) cultivars for ornamental postharvest quality attributes

An investigation was carried out at ICAR-Indian Agricultural Research Institute, New Delhi, India with an objective to optimize the response of different four stages of harvesting of tuberose (Polianthes tuberos Linn.) spikes i.e., Stage 1, when 1-2 floral, developed colour, stage 2, when 1-2 florets fully matured, stage 3, when 1-2 florets open and stage 4, when 3-4 florets open, on six commonly grown cultivars of Single petalled tuberose namely, Arka Shringar, Alka Nirantara, Phule Rajani, Alka Prajwal, Mexican Single. and Sikkim selection, so that flowers could be kept longer under home condition and interior decoration. The results revealed that the highest initial weight (54.0 g) and final weight (48.8 g) of spike was obtained in cultivar Arka Prajwal at 1-2 florets open stage. Whereas the lowest initial weight (29.5 g) and final weight (25.4 g) of spike was recorded in cultivar Maxican Single at 3-4 florets open stage. Physiological loss in weight (PLW) was recorded lowest (4.3%) in cultivar Arka Nirantara followed by in cultivar Arka Shringar (4.7 g) at 1-2 florets developed colour stage. Whereas the highest PLW (19.4%) was obtained in cultivar Sikkim Selection at 1-2 florets open stage. The thickest initial diameter (8.9 mm) and final diameter (8.5 mm) of spike was measured in cultivar Arka Prajwal followed by in cultivar Phule Rajani (8.7 mm and 8.4 mm, respectively) at 1-2 florets open stage. Whereas, the thinnest initial diameter (6.8 mm) and final diameter (6-4 mm) of spike was measured in cultivar Mexican Single at 1-2 florets fully matured stage. The highest percentage of florets opening (44.9) was calculated in cultivar Sikkim Selection at 1-2 florets open stage, whereas, the lowest in cultivar Arka Prajwal at 1-2 florets open stage. The widest floret diameter (4.0 cm) was measured in cultivar Arka Prajwal at 1-2 florets open stage, whereas the smallest floret diameter (2.4 cm) was measured in cultivar Phule Rajani at 1-2 florets open stage. Relative water content (RWC) remained the highest (97.7%) in cultivar Mexican Single at 1-2 florets open stage, whereas the lowest (75.9%) RWC was recorded in cultivar Phule Rajani at 1-2 florets open stage. Membrane Stability Index (MSI) recorded the highest (84.2%) in cultivar Sikkim Selection at 1-2 florets developed colour stage, whereas, the lowest (27.5%) MSI was recorded in cultivar Arka Nirantara at 1-2 florets developed colour stage. The longest vase life (6.8 d) of spike was recorded in cultivar Arka Prajwal at 1-2 florets open stage, whereas, the shortest vase life (4.5 d) was observed in cultivar Sikkim Selection at 1-2 florets stage. In general, better vase life and postharvest quality attributes in Single petalled tuberose cultivars cut spike ware found to be at 1-2 florects open stage.