Response of spike lengths on postharvest quality attributes in single petalled tuberose (Polianthes tuberosa) cultivars

Tuberose (Polianthes tuberosa Linn.) is an important herbaceous perennial flowering plant belonging to the family Agavaceae. It is being cultivated for utilization in various forms of loose flowers, cut flowers, extraction of essential oils and landscaping. A study was carried out at ICAR-Indian Agricultural Research Institute, New Delhi, India, with an objective to clarify the response of five spike lengths, viz., 40, 50, 60, 70 and 80 cm on six commonly grown cultivars of single petalled tuberose namely, Arka Shringar, Arka Nirantara, Phule Rajani, Arka Prajwal, Mexican Single and Sikkim Selection, on vase life and postharvest display quality attributes of spikes, so that cut flowers could be kept for longer duration. The results revealed that the highest initial weight (69.69g) and final weight (52.4g) of spikes was recorded in cv. Arka Prajwal with 80 cm stalk length followed by 70 cm stalk length (69.4 and 51.9 g, respectively). Whereas the lowest initial weight (19.3 g) and final weight (16.9 g) of spikes was recorded in cv. Sikkim Selection followed by cv. Arka Shringar (22.1 and 17.7g, respectively) with 40 cm stalk length. Physiological loss in weight (PLW) was recored the lowest (10.4 g) in cv. Mexican Single of 80 cm stalk length, whereas the highest PLW was measured in cv. Arka Prajwal (66.6 g) followed by in cv. Phule Rajani (56.1 g) in 40 cm spike length The thickest initial diameter (10.5 mm) and final diameter (9.7 mm) of spikes was measured in cv. Arka Nirantara followed by in cv. Arka Shringar (6.0 mm and 5.2 mm, respectively) with 40 cm stalk length. The maximum percentage of florets opening (36.2%) was calculated in cv. Arka Shringar with 50 cm spike length followed by 60 cm spike length (33.3%). The widest floret diameter (3.7 cm) was measured in cv. Phule Rajani with 40 cm spike length. Relative water content remained the highest (92.5 %) in cv. Mexican Single with 60 cm stalk length, whereas the lowest relative water content (63.2%) was recorded in cv. Arka Shringar with 50 cm stalk length. Membrane stability index (MSI) recorded the highest (83.9 %) in cv. Sikkim Selection with 40 cm stalk length, whereas the lowest MSI (65.8%) was recorded in cv. Arka Nirantara with 60 cm stalk length. Cultivar Arka Prajwal with 80 cm spike length consumed the highest uptake of solution (33.3 ml), whereas the lowest solution uptake (27.2 ml) was consumed in cv. Mexican Single with 40 cm spike length. The longest vase life of spike (5.8 d) was observed in cv. Arka Nirantara with 80 cm spike length, whereas the shortest vase life of spikes (3.2 d) was recorded in cv. Sikkim Selection with 40 cm spike length. In conclusion, better vase life and postharvest quality attributes can be achieved by selecting longer spikes in tuberose cultivars.