The greenhouse environment, including light and temperature,

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1 Editos Note: This is the second in a seven-pat seies on Extension, teaching and eseach pogams being pefomed at Pudue Univesity in West Lafayette, Ind. The Geenhouse Envionment: Boilemaking Solutions ecent eseach at pudue aims to Impove enegy use and copping efficiency. By Chistophe J. Cuey and Robeto G. Lopez The geenhouse envionment, including light and tempeatue, has a lage impact on ou ability to gow and schedule high-quality geenhouse cops. Additionally, enegy costs ae second only to labo fo many in today s geenhouse industy. As a esult, gowes want to make sue that heating and lighting ae used efficiently and pofitably. Whethe identifying how to schedule and poduce new floweing cops o educe enegy inputs fo old standbys, eseach at Pudue aims to incease the effectiveness and efficiency of envionmental inputs. This aticle is the second in a seies of aticles highlighting the Floicultue team in the Depatment of Hoticultue and Landscape Achitectue (HLA) at Pudue Univesity. The fist aticle focused on floicultue and onamental hoticultue at Pudue and summaized ou teaching and Extension outeach pogams, while subsequent aticles will focus on geenhouse cultual, sustainability and consume pefeence, and onamental pest and pathogen eseach, sevices povided by the Pudue Plant and Pest Diagnostic Lab, and the Hoticultue Gadens, geenhouses and Maste Gadene pogams. This aticle will highlight some of the ecent eseach conducted at Pudue that aims to impove enegy use and copping efficiency with the geenhouse envionment. Figue 1 (top ight). Gaphical tacking of eight poinsettia cultivas that wee planted on Aug. 13 (week 33) and cold finished at 68/56 F day/night (aveage daily tempeatue of 62 F). Figue 2 (bottom ight). Wink Coal diascia gown unde daily light integals (DLI) anging fom 1.4 to 12.3 mol m-2 d-1 fo two weeks afte a week of callusing (photo taken 21 days afte sticking cuttings). 36 gpn MAY

2 Poinsettia Cold Finishing While the holiday poinsettia ecently took second fiddle to ochids on a pe-pot-value, it is still the numbe one potted plant poduced in the United States in tems of units sold. With inceasing enegy pices, poinsettia poduces ae looking fo ways to incease pofitability fo a cop with azo-thin magins. One stategy to save money is to educe the geenhouse ai tempeatue. Howeve, the impact of lowe ai tempeatues stating in mid-octobe on poinsettia gowth, development, and quality was not clea. As a esult, eseaches at Pudue teamed up with D. Bian Kug (Univesity of New Hampshie) to assess cold-finishing poinsettias in nothen locations using cultivas that ae maketable ealy in the season (sixto eight-week esponse time), modeate- to high-vigo, and with natually lage bacts. Eight cultivas wee selected fom each of the majo beedes, including Dümmen, Selecta Fist Class, Syngenta Flowes, and the Ecke Ranch. Rooted cuttings of each cultiva wee planted on weeks 31, 32 and 33 and plants of each cultiva fom each planting date wee tansfeed to geenhouses with day/night tempeatue (12 hou/12 hou) set points of 68/56 F, 70/62 F, and 75/67 F on Oct. 15 at Pudue and the Univesity of New Hampshie. Fo all the poinsettia cultivas tested, cold finishing did not advesely affect bact size, time to maketability, o plant height as it was within the commecially acceptable ange (Figue 1). Gowes utilizing cold finishing may be able to educe heating costs by 20 to 55 pecent, depending on thei geenhouse location, stuctue, fuel souce, etc. Lighting Duing Popagation Young plants, including plugs and lines, ae poduced in late winte and ealy sping. Popagation of young plants occus when outdoo light is at seasonally low levels, while futhe eductions of up to 50 pecent can occu due to geenhouse glazing mateial, supestuctue, and hanging baskets. Reseach at Pudue is shedding some light on the benefits of poviding supplemental light duing popagation and exploing new altenatives fo poviding supplemental light. We have popagated a numbe of species of specialty annuals, fom agyanthemum to vebena, unde a ange of daily light integals (DLIs) duing ooting. As DLI duing popagation Wite in 773

3 inceased, oot gowth inceased fo all species (Figue 2). In addition to inceasing oot gowth and ooted line quality, the DLI duing popagation can also influence gowth and floweing afte tansplant. Fo example, floweing can be hastened by seveal days to weeks by inceasing DLI duing popagation. Ou eseach indicates that by inceasing the DLI duing popagation gowes may be able to educe time until ooted cuttings ae consideed salable o tansplantable, as well as finishing time afte tansplant. How can we incease the DLI duing popagation? Although supplemental light is taditionally povided by high-pessue sodium (HPS) lamps, light-emitting diodes (LEDs) ae a technology with potential as a supplemental light souce. Howeve, thee is little known about how effective LEDs ae when used in a geenhouse duing the poduction of plugs and lines. We ae cuently evaluating how effective and efficient LED light, composed of vaying amounts of ed and blue light, pefoms as a supplemental light souce compaed to HPS lamps duing seed and cutting popagation. Additionally, we ae evaluating the use of end of day ed- and fa-ed light to suppess stem elongation to poduce compact plugs. high tunnels ae not designed to eplace geenhouses fo yea-ound poduction. Howeve, we thought the seasonal natue of high tunnels may be used to poduce bedding plants finished fo the sping without using any heat. We teamed up with D. Neil Mattson (Conell Univesity) to gow common bedding plants such as pansy, petunia, osteospemum and pefect Intoduction A ll Int en High Tunnel Bedding Plants No Heat, No Poblem While bedding plant poduction is the most valuable secto of the U.S. floicultue cop maket, it is also a highly seasonal business. Theefoe, many gowes ae looking to expand poduction without investing in infastuctue that may not be suppoted with yea-ound demand fo poduction. The ecent inteest and subsequent expansion in local and sustainable agicultue has seen an incease in the constuction and use of high tunnels. While high tunnels ae commonly used fo season extension fo field-gown cops in the sping, 38 gpn MAY sity in ink an P eyes on le! p d Pu s! i ou c a Goodness G Ce Luxe Looks! Viva la Diva! ate Happiness!

4 snapdagons in an unheated high tunnel and a taditional geenhouse stating at the beginning of Apil. While cold-sensitive species such as vinca didn t finish so well in the high tunnel, cold-toleant cops gown in the high tunnel wee moe compact with lage and moe numeous flowes compaed to plants gown in the geenhouse, with minimal delay in time to flowe (Figue 3). This yea we will be looking at ways to educe the isks associated with no heat tunnel poduction. Hot New Cops fo Cool Climates Please be sue to visit us at OFA Booth 921 e! c pa Flo s we Powe om oute f This ye t a s dh colo an l tia n se s-es! nd e is co lo t h e can t-mis t! ea The Th e big ge, be se Potunia POP! New floicultue cops ae intoduced by beeding companies evey yea. While the availability of new and novel plant mateial is attactive to gowes, it can be difficult to identify successful stategies to poduce a high-quality cop on-time and efficiently. Pudue has teamed up with supplies of new genetics to geneate geenhouse lighting and heating stategies to povide gowes with the esouces to successfully popagate and finish new floicultue cops. Tecoma (Tecoma stans) is a floweing topical woody plant fom Cental and South Ameica and Ball has ecently developed a seed-popagated vaiety called Mayan Gold. Ou eseach indicates that inceasing the DLI duing popagation inceases seedling oot and shoot gowth and quality. Many topical plants ae photopeiodic and flowe in esponse to a cetain day length and Mayan Gold tecoma is no exception. Afte gowing Mayan Gold tecoma unde day lengths anging 9 to 16 hous long, it appeas to be a facultative long day plant and days 14 hous o longe induces a stong floweing esponse. To poduce highquality plants, wam tempeatues above 68 F and high DLI ae equied duing finishing (Figue 4). The Futue s! i en tte Impat RED FOX 2013 intoductions Lage flowes High heat toleance Excellent pefomance Dümmen USA, Inc Phone sales@dummenusa.com Wite in 774 With enegy pices on the ise, gowes want to ensue evey penny spent makes cents (pun intended!). Ou goal is to incease the efficiency and pofitability of geenhouse poduces, and the Floicultue and Onamentals goup at Pudue Univesity is committed to conducting eseach that povide gowes with eseach-based solutions that addess today s challenges within the geenhouse envionment. Whethe at Pudue o anothe land gant univesity, 39

5 The Insights. The Info. The Ideas. Get them all on the NEW Figue 3 (top). Single Deams Midnight petunia gown in unheated high tunnels can be of simila quality compaed to plants gown in a taditional heated geenhouse with minimal delay in time to floweing. Figue 4 (bottom). Mayan Gold tecoma (Tecoma stans) gown unde (A) 9-, 12, 14-, o 16-hou day lengths o (B) finished at 64, 68 and 72 ºF (photos taken 50 days afte tansplant). the impotance of industy, association and gowe suppot of floicultue eseach pogams is moe impotant than eve and no donation is too small. g Chistophe J. Cuey is a gaduate eseach assistant and Robeto G. Lopez is an assistant pofeso and floicultue extension specialist at Pudue Univesity. They can be eached at ccuey@pudue.edu and glopez@pudue.edu, espectively. 40 gpn MAY