Bulb Circumference Influences Growth and and moved to a glass greenhouse heated to 17 C. Measured air tem- Crop Quality in Lily peratures (Onset Computer Corp., Bourne, MA) during the experiment were 21 ± 5 C daytime maxima and Shawn D. Lyons, William B. Miller1, H. Christian Wien, and 17 ± 2 C nighttime minima. Pots Neil S. Mattson were randomized (completely random- ized design was employed) within re- spective . Pots were spaced at ADDITIONAL INDEX WORDS. blindness, bulb circumference, cut flowers, 25 cm on center. Once aboveground geophyte, specialty crops growth was observed, a commercial 20N–2.2P–16.6K fertilizer (JR Peters, SUMMARY. The objective of this study was to determine effects of bulb size on production time and factors influencing crop quality in pineapple lily (Eucomis sp.) Allentown, PA) was applied via fer- Á –1 cultivars developed originally for cut flower production. The percentage of tigation at a rate of 150 mg L producing an inflorescence increased as bulb size increased. One hundred percent of nitrogem 5 d per week. Scape length bulbs >18 cm circumference flowered in three of the four cultivars whereas ‘Tugela and leaf length (measured from the Jade’ exhibited 88% flowering. The number of flowers per inflorescence increased rim of the pot to the terminus of the as bulb size increased. Scape length increased as bulb size increased in ‘Reuben’. inflorescence or tallest leaf) was Inflorescence length increased as bulb size increased in ‘Reuben’, ‘Tugela Jade’, and recorded for each at the onset ‘Tugela Gem’. Days to anthesis from planting decreased as bulb size increased in of anthesis. Days to anthesis were ‘Reuben’ and ‘Tugela Jade’. For all cultivars, the largest bulbs produced the greatest calculated from planting date to an- number of leaves per plant and the highest quality inflorescences, largely thesis. Once all had flowered, attributable to the larger number of flowers produced per inflorescence compared with smaller bulbs. stem (pot rim lowest flower in the inflorescence) and inflorescence length (distance from lowest flower ineapple lilies are summer- inflorescence size and number of to inflorescence apex) and the num- flowering bulbs known for flowers produced per plant (De Hertogh ber of flowers per inflorescence and P their showy, long-lasting inflo- and Le Nard, 1993), but the optimum number of leaves produced by each rescences with a distinct tropical appear- bulb size for these cultivars has not plant were recorded. The percentage ance. They are a recent introduction been determined. The objective of this of plants flowering was calculated for to greenhouse floriculture and, like research was to determine the optimal each and bulb size group. many other bulbous specialty orna- bulb size for four pineapple lily culti- Analysis of variance was performed mentals, are currently underused by vars [originally bred in New Zealand with JMP statistical software (SAS the industry (Carlson, 2010). A large and derived from tall pineapple lily Institute, Cary, NC) to determine Eucomis comosa proportion of the pineapple lily culti- ( )] when grown as a significant effects. Where significant vars currently available were originally potted plants. differences were found, mean separa- bred for cut flower production (J. De Materials and methods tion comparison was conducted using Goede, personal communication). Tukey’s honestly significant differ- Several factors that made these culti- YEAR 1. Bulbs of cultivars Meg- ence at a = 0.05. vars attractive candidates for specialty aru, Reuben, and Tugela Gem were YEAR 2. Bulbs of ‘Megaru’, cut flower production, such as the received from De Goede Bulb Farm ‘Reuben’, and ‘Tugela Jade’ were production of large, showy inflores- (Mossyrock, WA) on 20 Mar. The received from De Goede Bulb Farm cences in a wide range of colors, bulbs had been lifted from fields in on 20 Apr. with size groups as in year excellent postharvest longevity, and Washington State in late November 1. Bulbs were planted immediately unique appearance are also desirable and stored in open ventilated crates and moved to greenhouse condi- for potted plant production. Although at 10 C before shipment. They were tions as described previously. Plant interest in the crop has increased in sorted into four size groups (12–14, care, data collection, and statistical recent years, many commercial green- 14–16, 16–18, and >18 cm circum- analysis were performed as described house growers are hesitant to produce ference) with 25 bulbs in each group. previously. them because of a lack of production On arrival, bulbs were kept at 9 C Results information and other grower re- before planting. On 14 Apr., bulbs sources (Carlson, 2010). were planted in 15-cm-diameter con- YEAR 1. With ‘Megaru’, the In many geophytes, bulb size tainers using a commercial peat-based greatest percent flowering was ob- plays a major role in determining substrate (LM-111; Lambert Peat served in the >18-cm bulbs (100%), competency to flower and may affect Moss Co., Riviere-Ouelle, QC, Canada) whereas the lowest percent flowering factors related to crop quality, such as

Horticulture Section, School of Integrated Plant Sciences, Cornell University, 134 Plant Sciences Units Building, Ithaca, NY 14853 To convert U.S. to SI, To convert SI to U.S., We are grateful to Jack De Goede for supplying plant multiply by U.S. unit SI unit multiply by material. 2.54 inch(es) cm 0.3937 1 Corresponding author. E-mail: [email protected]. 1 ppm mgÁL–1 1 https://doi.org/10.21273/HORTTECH04053-18 (F – 32) O 1.8 F C(C · 1.8) + 32

450 • August 2018 28(4) was seen in the 12–14-cm bulbs (4%) In ‘Tugela Gem’, the greatest stem length, or inflorescence length (Table 1). Percent flowering in- percent flowering was observed in but the number of flowers per in- creased as bulb size increased. Bulb the largest bulbs (100%), whereas florescence and number of leaves per size had no effect on scape length, the lowest percent flowering was ob- plant increased as bulb size increased stem length, or inflorescence length served in the smallest (Table 1). Per- (Table 3). (Table 2). The number of flowers per cent flowering increased as bulb size With ‘Reuben’, the greatest per- inflorescence increased from 78 to 100 increased. Bulb size did not signifi- centage of flowering was observed in as size increased from 14–16 to >18 cm cantly affect scape length or stem the >18-cm bulbs (100%), whereas (Table 2). length but inflorescence length and the lowest was observed in the 14–16- With ‘Reuben’, the greatest the number of flowers per inflores- cm bulbs (Table 1). Percent flowering percent flowering was observed in cence increased as bulb size increased generally increased as bulb size in- the >18-cm bulbs (100%), whereas (Table 2). creased. Bulb size had no significant the lowest percent flowering was YEAR 2. With ‘Megaru’, the effect on stem length. Days to anthe- observed with the smallest bulbs greatest percent flowering was ob- sis generally decreased as bulb size (Table 1). Bulb size significantly served in the 16–18- and >18-cm increased and scape length, inflores- affected scape length, stem length, bulbs (100%), whereas the lowest cence length, number of flowers per inflorescence length, and number of percent flowering was observed in inflorescence, and number of leaves flowers produced per inflorescence the smallest group (Table 1). Bulb per bulb all increased as bulb size andeachincreasedasbulbsize size did not significantly affect num- increased (Table 3). increased. ber of days to anthesis, scape length, In ‘Tugela Jade’, the greatest percent flowering was observed in the >18-cm bulbs (88%), whereas Table 1. Bulb size effects on percentage of flowering in pineapple lily cultivars Megaru, Reuben, Tugela Gem, and Tugela Jade. Values are percentages of the lowest percent flowering was ob- a single group of 25 bulbs per size class. served in the 14–16-cm bulb size group (Table 1). Bulb size did not z Bulb circumference (cm) significantly affect scape length or Yr Cultivar 12–14 14–16 16–18 >18 stem length but the inflorescence 1 Megaru 4 32 96 100 length, number of flowers per inflo- Reuben 64 96 96 100 rescence, and number of leaves per Tugela Gem 48 80 84 100 plant all increased as bulb size in- 2 Megaru 33 67 100 100 creased. Time to anthesis for the Reuben 88 79 96 100 >18-cm group was significantly less Tugela Jade 57 36 52 88 than for the 14–16- and 12–14-cm z1 cm = 0.3937 inch. groups (Table 3).

Table 2. Effect of bulb circumference on factors related to crop quality in Discussion pineapple lily cultivars Megaru, Reuben, and Tugela Gem (year 1). In many ornamental crops, the Bulb circumference Scape Stem length Inflorescence Flowers (no. per number of flowers produced per plant (cm)z length (cm) (cm) length (cm) inflorescence) or inflorescence strongly influences crop quality and marketability. In ‘Megaru’ geophytes, the size of the storage 12–14 — — — — organ frequently plays a key role in 14–16 47.0 26.8 22.3 78 cy controlling many quantitative aspects 16–18 52.5 30.1 21.0 90 b of flowering and final plant quality. >18 51.4 28.6 22.6 100 a For new cultivars and emerging orna- Significancex NS NS NS <0.0001 mental geophyte crops, trials evaluat- ‘Reuben’ ing effects of storage organ size on 12–14 39.3 c 26.6 c 12.6 b 55 d crop quality and marketability are 14–16 43.3 c 29.6 b 13.7 b 65 c crucial to identifying the optimal 16–18 47.2 b 30.7 ab 16.8 a 77 b storage bulb size for forcing. Luria >18 51.7 a 32.7 a 18.6 a 102 a et al. (1992) found monkshood (Aco- Significance <0.0001 <0.0001 <0.0001 <0.0001 nitum napellus) marketability was ‘Tugela Gem’ heavily influenced by tuber size. The 12–14 35.2 29.3 5.9 b 62 c number of flowers per inflorescence 14–16 36.5 27.9 8.5 ab 70 c increased more than 4-fold from the 16–18 36.6 28.4 8.2 ab 87 b smallest to the largest tubers evalu- >18 37.6 27.6 10.4 a 100 a ated. Larger bulbs of cape cowslip Significance NS NS 0.0309 <0.0001 (Lachenalia) produced larger plants z1 cm = 0.3937 inch. with thicker stems and more numer- yMeans followed by the same letter are not significantly different according to Tukey’s honestly significant ous florets (Kapczynska, 2014). Sim- difference procedure at a = 0.05. xIndicates significance of analysis of variance. ilar effects were expected in the NSNonsignificant at P £ 0.05. present work.

• August 2018 28(4) 451 RESEARCH REPORTS

Table 3. Effect of bulb circumference on factors related to crop quality in pineapple lily cultivars Megaru, Reuben, and Tugela Jade (year 2). Time to Scape length Stem length Inflorescence Flowers (no. per Leaves Bulb circumference (cm)z anthesis (d) (cm) (cm) length (cm) inflorescence) (no.) ‘Megaru’ 12–14 99 40.1 18.1 21.9 66 c 5.0 b 14–16 99 40.7 18.4 22.3 72 c 5.7 b 16–18 98 40.6 18.4 22.2 84 b 6.8 a >18 97 38.0 17.0 21.0 98 a 7.3 a Significancey NSx NS NS NS <0.0001 <0.0001 ‘Reuben’ 12–14 99 a 35.8 b 21.1 14.7 b 69 c 5.1 c 14–16 96 b 38.6 ab 21.7 16.9 ab 85 b 6.2 b 16–18 95 b 39.1 ab 21.9 17.3 a 89 ab 6.6 ab >18 95 b 39.7 a 21.7 18.8 a 96 a 6.8 a Significance <0.0001 <0.0001 NS <0.0001 <0.0001 <0.0001 ‘Tugela Jade’ 12–14 98 a 36.6 21.7 14.7 b 87 c 5.7 b 14–16 95 ab 40.0 22.1 17.9 a 115 b 6.4 ab 16–18 93 bc 38.5 20.8 17.8 a 117 b 7.0 a >18 91 c 39.3 20.8 18.5 a 142 a 7.0 a Significance <0.0001 NS NS 0.0306 <0.0001 <0.0001 z1 cm = 0.3937 inch. yIndicates significance of analysis of variance. xMeans followed by the same letter are not significantly different according to Tukey’s honestly significant difference procedure at a = 0.05. NSNonsignificant at P £ 0.05.

In the pineapple lily cultivars which was interesting given the larger from tall pineapple lily and that using evaluated, percent flowering and bulbs also had one to two more leaves smaller bulbs may result in unaccept- overall crop quality was greatly influ- than smaller bulbs. Future work able crop losses due to bulb blindness enced by bulb size. In both years, could more fully address this point or poor crop quality. Because ‘Meg- percent flowering exhibited a general and evaluate any deeper relationship, aru’ and ‘Reuben’ bulbs exhibited increase as bulb size increased. With if any, of the number of leaves and minimal bulb blindness in our trials, the exception of ‘Tugela Jade’, >18-cm forcing speed. A modest increase in 16–18-cm bulbs may be preferable bulbs of all cultivars exhibited 100% stem length (year 1) and scape length to >18-cm bulbs if they can be obtained inflorescence production. Bulb blind- (years 1 and 2) in ‘Reuben’ was at lower cost. ‘Tugela Jade’ exhibited ness (seemingly healthy plants not observed as bulb size increased. Bulb a high rate (12%) of blindness even in producing a viable inflorescence) was size had no effect on scape length in the largest bulbs and may be less suit- highly prevalent among 12–14- and the other cultivars evaluated. Inflo- able for potted plant production. 14–16-cm bulbs of all cultivars. rescence length increased as bulb size Bulb size had similar effects on increased in all cultivars with the Literature cited the number of flowers produced per exception of Megaru. Although little inflorescence, with the largest bulbs variation in scape length was observed Carlson, A. 2010. Developing water yielding the greatest number of between bulb size groups, scapes pro- quality standards and production and flowers per inflorescence. The num- duced by smaller bulbs were of poor postharvest protocols for specialty cut ber of flowers produced per inflores- quality because of their sparse, spindly flowers. North Carolina State Univ., cence strongly affected crop quality. appearance. Losses due to scapes top- Raleigh, Master’s Thesis. Inflorescences of larger sized bulbs, pling or excessive leaning were more De Hertogh, A. and M. Le Nard. 1993. bearing more flowers per inflores- common in the smaller bulb sizes The physiology of flower bulbs. Elsevier, cence than their smaller counterparts, (12–14 and 14–16 cm) than larger Amsterdam, The Netherlands. > appeared fuller and more regularly ones (16–18 and 18 cm), potentially Kapczynska, A. 2014. Effect of bulb size shaped. Inflorescences produced by because of smaller stem caliper (not on growth, flowering and bulb formation smaller bulbs, particularly those in the measured). In ‘Reuben’ and ‘Tugela in Lachenalia cultivars. Hort. Sci. (Pra- 12–14- and 14–16-cm bulb size Jade’, larger bulbs flowered some- gue) 41:89–94. groups, exhibited noticeable gaps be- what faster. Luria, G., A. Borochov, and A.A. Watad. tween individual flowers and often The data from these trials sug- 1992. Aconitum: Effect of tuber size, appeared less vividly colored due to gest that crop quality is uniformly day length, and GA3 on growth, flow- a lack of overlapping petals. Larger highest when >18-cm bulbs are used ering, and tuber production. Acta Hort. bulbs flowered faster for cultivars in the greenhouse production of pot- 325:113–117. Reuben and Tegula Jade (Table 3), ted pineapple lily cultivars derived

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