Effect of Time of Harvest on Postharvest Leaf Abscission in Lantana (Lantana camara L. ‘Dallas Red’) Unrooted Cuttings

Abstract

<jats:p>This study investigated the preharvest carbohydrate status and postharvest ethylene action of unrooted shoot-tip cuttings of lantana ‘Dallas Red’ harvested at three times during the day (0800, 1200, and 1600 <jats:sc>hr</jats:sc>) in relation to subsequent leaf abscission, shoot apices blackening, and adventitious root formation. The cuttings harvested at various times during the day were stored in darkness at 20 ± 1 °C for 4 days in sealed polyethylene bags. The cuttings harvested at 0800 <jats:sc>hr</jats:sc> had lowest total nonstructural carbohydrate concentrations; however, the amount of ethylene production during postharvest storage was similar among harvest times and increased during the storage period. After 4 days of storage, 69% of the leaves of cuttings harvested at 0800 <jats:sc>hr</jats:sc> abscised, but only 22% and 8% of the leaves abscised in cuttings harvested at 1200 and 1600 <jats:sc>hr</jats:sc>, respectively. Application of 1-methylcyclopropene (1-MCP) increased ethylene production and suppressed leaf abscission regardless of the harvest time, but cuttings harvested at 0800 <jats:sc>hr</jats:sc> developed blackened shoot apices. Leaf abscission was negatively correlated with total nonstructural carbohydrate concentration in the leaves, but no relationship was found with ethylene production. These results indicate that a high endogenous carbohydrate status decreases the postharvest ethylene sensitivity in unrooted shoot-tip cuttings of lantana. Time of harvest influenced subsequent rooting response; however, 1-MCP application did not inhibit rooting. Among various storage treatments, the best rooting response was observed in cuttings harvested at 1600 <jats:sc>hr</jats:sc> and treated with 1-MCP. Therefore, significant improvement of postharvest storage quality in vegetative lantana cuttings could be achieved by harvesting cuttings late in the day and treating with 1-MCP.</jats:p>

Effects of Daily Harvest Time on Postharvest Longevity, Water Relations, and Carbohydrate Status of Selected Specialty Cut Flowers

“…Sucrose levels increased from morning to noon in leaves of all tested species but then decreased for afternoon-harvested stems. A similar response has also been reported by Rapaka et al (2007) for shoot-tip cuttings of lantana and leaves of sugar beet (Beta vulgaris L.) by Fondy and Geiger (1982). Fructose levels of all three species were higher in morningharvested stem tissues and noon-or afternoonharvested leaves and petals immediately after harvest, which was mobilized to petals during storage.…”

“…These findings can assist cut flower growers to extend vase life by rescheduling the time stems are harvested during the day. Similar improvements in shelf life of sweet basil (Lange and Cameron, 1994), baby salad (Clarkson et al, 2005), broccoli (Hasperué et al, 2011), and unrooted shoot-tip cuttings of lantana (Rapaka et al, 2007) were observed when harvested later in the day.…”

“…factors (Halevy and Mayak, 1981;Marissen and Benninga, 2001;van Doorn, 2012). In addition to the aforementioned factors, the time of the day when stems are harvested may be a potentially important consideration (Clarkson et al, 2005;Hasperué et al, 2011;Rapaka et al, 2007).…”

“…Thell. (Clarkson et al, 2005), and unrooted shoot-tip cuttings of lantana (Lantana comara L.) (Rapaka et al, 2007). These variations in shelf life were attributed to varying carbohydrate levels and diurnal changes in plant metabolic processes.…”

1-Methylcyclopropene Improves Ethylene Tolerance of Unrooted Herbaceous Cuttings but Delays Adventitious Root Development in Angelonia, Calibrachoa, Impatiens, Portulaca, Sutera, and Verbena Cultivars

“…(croton), Pelargonium •hortorum Bailey (pro sp.) [inquinans • zonale] (zonal geranium), and Lantana camara L. (lantana) as reported by M€ uller et al (1998), Kadner et al (2000), and Rapaka et al (2007), respectively.…”