Efeito do pulsing em hastes cortadas de girassol ornamental ‘Sunbright Supreme’ em diferentes estádios de desenvolvimento

Abstract

The use of ornamental sunflower as a cut flower has been increasing due to the advent of new cultivars and the demand of the flowergrowing market for new products. However, there are few studies related to postharvest of this species. The objective of this research was to evaluate the water balance and durability of ‘Sunbright Supreme’ sunflower collected at three different harvest stages and submitted or not to a pulsing with sucrose. The flower stalks were collected fully open, at an intermediate opening stage and also closed; they were then standardized at 50 cm and stored in water or 4% sucrose solution during 24 hours. After this period, stalks were maintained in sealed bottles containing 500 mL of water. Fresh matter, water consumption, flower opening, complete durability and visual quality of stems were evaluated every three days, considering a rating scale of color, turgescence and stalk bending. Rates of absorption and transpiration were calculated considering the fresh matter and variation in water volume. There was an increase in fresh matter and high water consumption in inflorescences until the seventh day; after this period, there was a reduction in weight and increased transpiration rates. Stems collected closed, closed with pulsing and at an intermediate stage treated with pulsing were maintained in commercial quality about four days longer than the open harvested (with and without pulsing) and intermediate without pulsing. Sucrose pulsing leads to flower opening of stalks collected at all harvest stages. The positive water balance was observed until the seventh day and contributes to the maintenance of commercial quality in ornamental sunflower. The early harvest of ornamental sunflower ‘Sunbright Supreme’ is recommended, besides the application of 4% sucrose pulsing.

Extension of the vase life of Lilium pumilum cut flowers by pulsing solution containing sucrose, citric acid and silver thiosulfate

“…According to Dias-Tagliacozzo et al (2005), the loss of fresh weight happens because of transpiration processes and the reduction of water conductivity during the senescence of cut flowers. The presence of sucrose in the pulsing solution causes this variation in flower weight loss (Nascimento et al, 2019), probably because sugar is an osmotically active solute, which reduces the osmotic potential, maintaining cell turgor (Van Doorn, 2001). On the other hand, the control flowers lost water at the same time they absorbed it.…”

Water relations in cut calla lily flowers maintained under different postharvest solutions

“…The durability of cut flowers is influenced by the absorption, retention capacity, transport and loss of water in the tissues (Gupta and Dubey, 2018), and these parameters are directly related to the durability. The turgescence of flower stems is caused by the balance between absorption and transpiration rates (Elhindi, 2012), and it is related to the visual quality of the flowers (Nascimento et al, 2019). At the 1/3 open harvest stage, the stems kept in NaClO and 8-HQ had a negative water balance from the 3rd day after harvest.…”

“…Calla lilies are usually harvested when they show extended spathes (Almeida et al, 2009); however, different harvest stages have been recently accepted for use in decoration. Harvesting at earlier stages (closed or partial opening) can provide inflorescences with better quality and longevity (Carneiro et al, 2014;Sales et al, 2015;Mattos et al, 2017, Sanches et al, 2017, Sales et al, 2018, Nascimento et al, 2019. However, limited information is available on the influence of chemicals in the storage solution on the longevity and water relations of early harvested floral stems.…”

“…The addition of antimicrobial agents (HQS and AgNO 3 ), ethylene inhibitor (AgNO 3 ) and sucrose to conservation solutions results in better flower quality and longevity. These products increase the carbohydrate contents and water uptake, delay senescence, maintain flower turgidity, reduce bacterial proliferation and prevent xylem blockages in gladiolus (Mishra and Khanal, 2019).…”