Cultivar, Flower Stage, Silver Thiosulfate, and BA Interactions Affect Performance of Potted Miniature Roses

Abstract

<jats:p>Experiments were conducted to study the interaction of cultivar, flower stage, silver thiosulfate (STS), and BA on flower senescence and leaf abscission in greenhouse-grown potted miniature roses. Plants of <jats:italic>Rosa</jats:italic> L. `Meijikatar' (Orange Sunblaze) and `Meirutral' (Red Sunblaze) were sprayed with several concentrations of STS and BA in factorial combination. In winter, plants were sprayed with STS at 0 or 2 m<jats:sc>m</jats:sc> and BA at 0, 0.02,0.04,0.11,0.22, or 0.44 m<jats:sc>m</jats:sc> In spring, flowers at three stages of development were sprayed with STS at 0,2, or 3 m<jats:sc>m</jats:sc>, and BA at 0, 0.02, 0.04, 0.22, or 0.44 m<jats:sc>m</jats:sc> One day after treatment in both experiments, plants were placed in darkness at 16C for 4 days to simulate shipping, and then they were evaluated in a controlled environment at 21C. Poststorage floral longevity (PSFL) was longer for `Meirutral' than for `Meijikatar' plants, regardless of chemical treatment or flower stage. Flowers that were in the bud stage (stage 1) before simulated shipping lasted longer than flowers showing color (stages 2 and 3), regardless of cultivar or chemical treatment. Combinations of STS and BA did not increase PSFL compared to STS alone. Plants treated with 2 or 3 m<jats:sc>m</jats:sc> STS exhibited longer PSFL than nontreated plants; however, 2 and 3 m<jats:sc>m</jats:sc> were about equally effective. STS at 4 m<jats:sc>m</jats:sc> was phytotoxic in a preliminary experiment. Applying BA alone did not affect PSFL, but did improve postharvest flower opening on `Meijikatar' plants about the same as STS applied alone. The large flowering cultivars represented by `Meijikatar' and `Meirutral' appear to be nonresponsive to BA. A star-shaped malformation was induced on `Meijikatar' and `Meirutral' plants by simulated shipping and was not prevented by STS or BA. Chemical name used: N-(phenylmethyl) -1H-purin-6-amine (BA).</jats:p>

Seasonal Growing Environment Affects Quality Characteristics and Postproduction Longevity of Potted Miniature Roses

“…Before simulated shipping (storage treatment), four flowers each at stages 1 (tight bud, calyx not reflexing), 2 (showing color, calyx reflexing, no petals reflexed), and 3 (full color, petals beginning to reflex, traditional bud stage) were randomly tagged for each treatment (Cushman et al, 1994). Half of the plants then were watered and allowed to drain, placed in paper sleeves, and put into ventilated shipping boxes.…”

“…Morphological quality characteristics measured before postproduction treatments included plant height, flower diameter, number of breaks produced after pruning, number of shoots terminating in one or more flowers (flowering shoots), and total number of flowers (open and buds). The number of shoots with an aborted growing terminal (blind shoots) was calculated by subtracting the number of flowering shoots from the number of breaks produced after pruning.Before simulated shipping (storage treatment), four flowers each at stages 1 (tight bud, calyx not reflexing), 2 (showing color, calyx reflexing, no petals reflexed), and 3 (full color, petals beginning to reflex, traditional bud stage) were randomly tagged for each treatment (Cushman et al, 1994). Half of the plants then were watered and allowed to drain, placed in paper sleeves, and put into ventilated shipping boxes.…”

Influence of Cultivar and Seasonal Growing Environment on Growth and Postharvest Characteristics of Single-shoot Pot Rose Plants

“…'Meijikatar' and 'Confection' had more leaf abscission and/or yellowing than 'Meirutral', 'Meilarco', 'Shy Girl', and 'Ruired' after 4 d of simulated shipping at 8 °C and 7 d in a simulated interior environment (Clark et al, 1991). Flower longevity after simulated shipping (4 d at 16 °C) of 'Meirutral' plants was longer in an interior environment than 'Meijikatar' regardless of chemical treatments (Cushman et al, 1994). Müller et al (1998) reported that, for the shortlived cultivars Parade Bronze, Parade Bianca, and Kordana Ice, >50% of the fl owers faded after 10 d in a controlled interior environment.…”

“…This was accomplished by removing all but the strongest of the shoots that began growing after the pinch as they arose. When the fl ower on each plant reached developmental stage 2 [ (Cushman et al, 1994) showing color, calyx refl exing, no petals refl exed], the plant was placed in a continuously lighted simulated interior evaluation room at 21 ± 1 °C under 15 µmol•m -2 •s -1 PPF from cool-white fl uorescent lamps.…”

“…During the interior evaluation, fl ower diameter was measured at fl ower developmental stage 5 [ (Cushman et al, 1994), full open]. Postproduction fl ower longevity was defi ned as the period from fl ower developmental stage 2 to the fi rst day of fl ower developmental stage 6.…”