@article{jahnke_kalinowski_dole_2022, title={Postharvest Handling Techniques for Long-term Storage of Cut Tulip and Dutch Iris}, volume={32}, ISSN={["1943-7714"]}, DOI={10.21273/HORTTECH05010-21}, abstractNote={S UMMARY . Postharvest handling is a multifaceted stage of the cut ﬂ ower supply chain intended to maintain or improve the quality of perishable cut ﬂ ower material. During this stage, cold storage is used to maintain quality and extend availability. Three experiments were conducted over the course of 2 years using cut tulip ( Tulipa hybrids) and dutch iris ( Iris × hollandica ) cultivars to evaluate the impacts of dry storage with the bulb attached to the stem, sub-zero temperatures, and pre-storage and post-storage ﬂ oral pulses on vase life. In the ﬁ rst experiment, six tulip and two dutch iris cultivars were stored for up to 6 or 8 weeks, respectively. The longest vase life at 6 weeks of storage was achieved for all tulip cultivars when stems were stored with the bulb still attached at 2 0.6 (cid:1) C. Storing cut stems at 0.7 (cid:1) C for 6 weeks resulted in the shortest vase life. The vase life of ‘ Telstar ’ and ‘ River King ’ dutch iris was longest at 4 and 2 weeks of storage, respectively, when stored at 2 0.6 (cid:1) C with the bulb attached. Additionally, 75% to 100% of ﬂ owers fully opened when stems were stored with the bulb still attached and 42% of ﬂ owers were able to at least partially open. In the second experiment, cut stored tulip stems maintained a vase life similar to that of nonstored, pulsed stems at 6 weeks of storage when pulsed with ﬂ oral solutions containing benzyladenine and gibberellic acid phytohormones for 8 hours before storage. Similarly, dutch iris maintained signi ﬁ cantly longer vase life and were able to fully expand ﬂ owers more often (60% to 80%) when prepulsed with the ﬂ oral solutions compared with stems prepulsed with tap water after 6 weeks of storage at 2 0.6 (cid:1) C. Extending the length of pulsing time from 8 hours to 24 hours was not a signi ﬁ cant factor in vase life and post-storage evaluations of ﬂ ower opening. However, dutch iris ﬂ owers with an emerged secondary bud maintained an extended vase life up to 5 days post-storage. In the ﬁ nal experiment, the longest tulip vase life was achieved by combining a sub-zero storage temperature of 2 0.6 (cid:1) C, storing stems with the bulb attached, and pulsing stems with ﬂ oral solutions after storage. Vase life did not signi ﬁ cantly decrease over the course of the 6-week storage duration. Dutch iris stems pulsed with ﬂ oral solutions after sub-zero storage with the bulb attached were able to more fully open after 8 weeks of storage compared to stems held dry or pulsed with tap water. These three experiments over the course of 2 growing years demonstrate various strategies for successfully storing cut tulips and dutch iris for an unprecedented duration while still maintaining vase life.}, number={3}, journal={HORTTECHNOLOGY}, author={Jahnke, Nathan J. and Kalinowski, Jennifer and Dole, John M.}, year={2022}, month={Jun}, pages={263–274} } @article{jahnke_dole_bergmann_ma_perkins-veazie_2020, title={Extending Cut Paeonia Lactiflora Pall. Storage Duration Using Sub-Zero Storage Temperatures}, volume={10}, ISSN={["2073-4395"]}, DOI={10.3390/agronomy10111694}, abstractNote={Cut peonies (Paeonia lactiflora Pall.) have a relatively short vase life and limited availability due to seasonal production. Cultivars Festiva Maxima (FM), Monsieur Jules Elie (MJE), and Sarah Bernhardt (SB) stored at 0.7 °C had a longer flower open time at 12 weeks of storage compared to those held at −3.1 or 3.5 °C, while the flower bud time was unaffected. The flower open time of FM and MJE was no different for stems stored at a sub-zero temperature of −0.6 °C for 16 weeks compared to non-stored stems. Flower quality, opening, and lack of deformity was reduced at 16 weeks of storage in comparison to non-stored flowers, but higher for stems stored at −0.6 °C compared to 0.7 °C. Pre-treating stems before storage with pulses of a commercial hydrator solution or a 200 g·L−1 sucrose solution for 2 h at 4 °C had little commercial significance compared to non-pulsed control stems. The total phenolic content, malondialdehyde, and superoxide dismutase were not effective indicators of open time or quality loss. This study is the first to demonstrate the successful use of a non-freezing, sub-zero storage temperature for peony, and the first to store cut peonies for 16 weeks, despite an increased risk of reduced flower quality.}, number={11}, journal={AGRONOMY-BASEL}, author={Jahnke, Nathan J. and Dole, John M. and Bergmann, Ben A. and Ma, Guoying and Perkins-Veazie, Penelope}, year={2020}, month={Nov} } @article{jahnke_dole_livingston_bergmann_2020, title={Impacts of carbohydrate pulses and short-term sub-zero temperatures on vase life and quality of cut Paeonia lactiflora Pall. hybrids}, volume={161}, ISSN={["1873-2356"]}, DOI={10.1016/j.postharvbio.2019.111083}, abstractNote={Abstract Flower quality of cut Paeonia lactiflora (peony) Pall. hybrids is best preserved between 0 and 1 °C. However, cut flower traits such as vase life and flower size often decline following 4 or more weeks of storage. While the use of sub-zero temperatures is avoided in the cut flower industry due to fears of freeze injury, sub-zero temperatures may allow extended storage of cut flowers. Peonies are a candidate for sub-zero storage due to their natural cold tolerance, exposure to spring freezes before harvest, and limited seasonal availability. Three cultivars: Karl Rosenfield, Monsieur Jules Elie, and Sarah Bernhardt were used to evaluate freeze tolerance of cut peonies by holding cut stems at three temperatures: 0, −2, −4 °C for 5 h. Pre-cold treatment pulses consisting of 24 h in either 100 g·L−1 sucrose, 100 g·L−1 fructose, or tap water did not improve total vase life, summation of the time spent as a bud and time open. Total vase life was 10.5, 7.1, and 9.3 d for ‘Karl Rosenfield’, ‘Monsieur Jules Elie’, and ‘Sarah Bernhardt’, respectively. Sucrose-pulsed stems of ‘Karl Rosenfield’ and ‘Sarah Bernhardt’ had the lowest total vase life. Pulses and cold-treatments decreased bud time for ‘Karl Rosenfield’ and ‘Monsieur Jules Elie’ by 2–3 d and 0.5–1 d, respectively. Petals were the only tissue to develop water-soaked spotting (freeze injury) following 5 h at -4 °C. Stems kept dry (not pulsed) prior to cold treatment were uninjured. Fructose-pulsed stems of ‘Karl Rosenfield’ and ‘Monsieur Jules Elie’ had the highest injury ratings when held at -4 °C. Carbohydrate-pulsing did not influence injury ratings on ‘Sarah Bernhardt’. Supercooling and multiple freeze events were observed with infrared video in all tissues when held at -4 °C. Typically, ice nucleation started at the base of the cut stems and propagated throughout the stem, leaves, and bud within 3–5 min of initiation. Stems that were not pulsed remained in a supercooled state longer than those that were pulsed. These findings indicate that storage temperatures between 0 and -2 °C may be a good option for longer periods of dry storage for peonies and other cold tolerant cut flower species.}, journal={POSTHARVEST BIOLOGY AND TECHNOLOGY}, author={Jahnke, Nathan J. and Dole, John M. and Livingston, David P., III and Bergmann, Ben A.}, year={2020}, month={Mar} } @article{jahnke_dole_ashrafi_2020, title={Simulated storage causes carbohydrate loss and rooting differences in two poinsettia cultivars}, volume={100}, ISSN={["1918-1833"]}, DOI={10.1139/cjps-2019-0232}, abstractNote={ Unrooted cuttings of ‘Prestige Red’ and ‘White Star’ poinsettias (Euphorbia pulcherrima Willd. ex Klotzsch) were stored in a box at 10 °C for 0, 2, 4, 6 or 8 d to simulate shipping and holding. Visual root ratings decreased following ≥4 d of storage but did not differ from the non-stored cuttings. Root rating of ‘White Star’ was 0.5 higher and cuttings maintained higher fructose and glucose concentrations compared to ‘Prestige Red’. Glucose (r2 = 0.4824) followed by fructose plus glucose (r2 = 0.4222) were the best predictors of rooting. Carbohydrate maintenance may be an indicator of storage tolerant and better-rooting cultivars. }, number={4}, journal={CANADIAN JOURNAL OF PLANT SCIENCE}, author={Jahnke, Nathan J. and Dole, John M. and Ashrafi, Hamid}, year={2020}, month={Aug}, pages={459–462} } @article{dole_jahnke_mccall_loyola_bergmann_2020, title={Vase life of 58 new cut flowers}, volume={1288}, ISSN={["2406-6168"]}, DOI={10.17660/ActaHortic.2020.1288.31}, journal={IX INTERNATIONAL SYMPOSIUM ON NEW ORNAMENTAL CROPS}, author={Dole, J. M. and Jahnke, N. and McCall, I. F. and Loyola, C. and Bergmann, B.}, year={2020}, pages={207–213} } @article{jahnke_dole_shew_2018, title={Prolonged Shipping and Fluctuating Temperatures Promote Gray Mold Development and Leaf Yellowing on Geranium Liners}, volume={28}, ISSN={["1943-7714"]}, DOI={10.21273/HORTTECH04149-18}, abstractNote={Postharvest environments during storage and shipping are often conducive to plant stress and disease development. Liners of four cultivars of geraniums (Pelargonium ×hortorum) were evaluated every 2 days for their susceptibility to gray mold (Botrytis cinerea) and leaf yellowing over an 8-day simulated shipping period at either constant air temperature of 15 °C or variable air temperatures cycling every 24 hours between 10 and 30 °C. The latter treatment was created using air temperature logs of commercial liner shipments sent to five locations during Spring 2016 and Fall 2016. We sprayed a spore suspension of 2 × 104 or 2 × 106 to inoculate liners before they were subjected to the two temperature treatments. Disease ratings did not reach significant levels for the dry control until day 6 of storage. Regardless of the spore concentration, ratings were similar for inoculated cuttings. Independent of the storage temperature and spore concentration, liners developed minor lesions by day 2 of storage. Cultivars varied slightly in disease ratings, with Tango Dark Red being the most susceptible, followed by Patriot Bright Red, Patriot Rose Pink, and Americana Red. During the 8-day incubation period, ‘Patriot Rose Pink’ developed the most leaf yellowing compared with the other three cultivars. Liners that experienced variable air temperatures had marginal leaf yellowing by day 2, and this yellowing increased throughout the experiment. Liners placed at 15 °C had ≈50% less leaf yellowing compared with liners exposed to variable air temperatures until day 8, when leaf yellowing was similar between the two air temperature treatments. Disease caused by B. cinerea was avoided when simulated shipping was 2 days or fewer, and a stable air temperature of 15 °C reduced leaf yellowing on geranium liners compared with variable air temperatures.}, number={6}, journal={HORTTECHNOLOGY}, author={Jahnke, Nathan J. and Dole, John M. and Shew, H. David}, year={2018}, month={Dec}, pages={711–718} }