@article{niedziela_kim_nelson_de hertogh_2008, title={Effects of N-P-K deficiency and temperature regime on the growth and development of Lilium longiflorum 'Nellie White' during bulb production under phytotron conditions}, volume={116}, DOI={10.1016/j.scienta.2008.02.01}, number={4}, journal={Scientia Horticulturae}, author={Niedziela, C. E. and Kim, S. H. and Nelson, P. V. and De Hertogh, A. A.}, year={2008}, pages={430–436} }
 @article{kim_niedziela_nelson_de hertogh_swallow_mingis_2007, title={Growth and development of Lilium longiflorum 'Nellie White' during bulb production under controlled environments - I. Effects of constant, variable and greenhouse day/night temperature regimes on scale and stem bulblets}, volume={112}, ISSN={["0304-4238"]}, DOI={10.1016/j.scienta.2006.11.015}, abstractNote={One-year-old scale and stem bulblets of Lilium longiflorum Thunb. ‘Nellie White’ (Easter lily) were grown under constant and variable growth chamber conditions and greenhouse conditions to compare growth and development and bulb production. Eight temperatures regimes were established using the following: six growth chambers set to provide day/night temperature regimes of 30/26, 26/22, 22/18, 18/14, 14/10 and 10/6 °C; a seventh growth chamber (VAR) programmed to begin at 22/18 °C, then decline in three 4–5 week steps to 10/6 °C, and subsequently increase in three 4–5 week steps to 22/18 °C to simulate seasonal field temperatures in the coastal bulb production area of northern California and southern Oregon; and a double layer polyethylene greenhouse (GH) set to begin cooling at 22 °C and heating at 18 °C. Ten percent of the scale bulblets and 35% of the stem bulblets failed to develop shoots (“no-shows”). “No-shows” increased with increasing temperature with a significant number starting at 18/14 °C. The moderately high GH temperature also induced “no-shows”. Maximum basal bulb (the main planted bulb) weight occurred at 26/22 °C for both bulblet types. Scale bulblets not only produced heavier basal bulbs with a larger circumference than stem bulblets, but also produced heavier stem bulbs. Stem bulb formation and production was maximized in the range of 18/14–26/22 °C and in the GH for scale bulblets. Stem bulb production from stem bulblets did not differ from zero. Scale bulblets produced more basal and stem roots than the stem bulblets at the end of the early growth period, but there was no significant difference at the end of the study. Root fresh weight was greatest in the range of 14/10–18/14 °C and declined at higher or lower temperatures. The VAR and GH treatments had similar root weights to those at 18/14 °C. Shoot length was maximized at 22/18 °C for stem bulblets and in the GH and at 22/18 °C for scale bulblets. Stem plus leaf (shoot) fresh weight was not statistically different between bulblet types with the exception of an increased weight for stem bulblets grown at 22/18 °C. Scale bulblets in the GH had greater stem plus leaf weights than scale bulblets in the other temperature regimes. Shoot leaf number was highest in stem bulblets at 22/18 °C and in the GH. In these two temperature treatments, more leaves were produced by stem bulblets than scale bulblets. In all other treatments, there was no significant difference in leaf number. Bulblet type had no effect on number of flowers produced. Flower number was maximum in the range 10/6–22/18 °C, decreased at 26/22 °C and in the GH, and was absent at 30/26 °C. For bulb production, reduced flowering is desired since flowers are generally removed during the outdoor bulb production period. Meristem abortion, which also causes a desirable reduction in flowers, was greater in scale bulblets. It occurred at 26/22 °C and was greater at 30/26 °C. Scale bulbs produced the largest main bulbs, with a maximum yield at 26/22 °C.}, number={1}, journal={SCIENTIA HORTICULTURAE}, author={Kim, S. H. and Niedziela, C. E., Jr. and Nelson, P. V. and De Hertogh, A. A. and Swallow, W. H. and Mingis, N. C.}, year={2007}, month={Mar}, pages={89–94} }
 @article{kim_niedziela_nelson_de hertogh_swallow_mingis_2007, title={Growth and development of Lilium longiflorum 'Nellie White' during bulb production under controlled environments - II. Effects of shifting day/night temperature regimes on scale bulblets}, volume={112}, ISSN={["0304-4238"]}, DOI={10.1016/j.scienta.2006.11.012}, abstractNote={One-year old scale bulblets of Lilium longiflorum Thunb. ‘Nellie White’ (Easter lily) were grown for 107 days during growth period 1 (GP-1) in six growth chambers under constant day/night temperature regimes of 30/26, 26/22, 22/18, 18/14, 14/10 and 10/6 °C. Subsequently, half of the plants in each temperature regime were transferred to 18/14 °C and the other half continued at the six constant temperature regimes. Both groups of plants were grown for an additional 89 days in growth period 2 (GP-2). Continuous temperatures of 26/22, 26/22–22/18 and 26/22–18/14 °C produced the greatest increase in basal bulb fresh weight (the main planted bulb), basal bulb circumference and stem bulb fresh weight, respectively. However, shifting these optimal temperatures to 18/14 °C during GP-2 resulted in a lower increase in basal bulb fresh weight and circumference. The optimum range for stem bulb production was expanded to 30/26–14/10 °C by shifting to 18/14 °C. The greatest increase for basal root growth occurred at 14/10–10/6 °C and for stem root growth at 14/10 °C. The temperature shift did not affect either root type. Maximum increase for stem length was at 26/22 and 22/18 °C and for stem plus leaf weight at 14/10 °C under constant temperature regimes. Transferring the plants from 10/6 to 18/14 °C resulted in the greatest increase in stem length and from 10/6 and 14/10 to 18/14 °C in the greatest increase in stem plus leaf weight. The greatest increase in the number of leaves occurred at 26/22 and 10/6 °C, but this growth parameter was unaffected by shifting to 18/14 °C, indicating that leaf number was determined in GP-1. Bulbils developed only when bulbs at high GP-1 temperature regimes (30/26 and 26/22 °C) were transferred to 18/14 °C during GP-2. Lower temperatures tended to favor an increase in flower bud production under continuous temperature regimes, while shifting to 18/14 °C increased flower bud production after initially high and low temperatures. Meristem abortion was greatest at 30/26 °C followed by 26/22 °C, but was not affected by temperature shifts in GP- 2. Thus, it is concluded that the abortion was induced or initiated during GP-1.}, number={1}, journal={SCIENTIA HORTICULTURAE}, author={Kim, S. H. and Niedziela, C. E., Jr. and Nelson, P. V. and De Hertogh, A. A. and Swallow, W. H. and Mingis, N. C.}, year={2007}, month={Mar}, pages={95–98} }
 @article{fanelli_hertogh_2002, title={The effects of precooling temperatures and durations on forcing of Lilium longiflorum, 'Nellie White'}, ISBN={9066058056}, journal={Proceedings of the Eighth International Symposium on Flowerbulbs}, publisher={Leuven, Belgium : International Society for Horticultural Science}, author={Fanelli, F. L. and Hertogh, A. A. de}, editor={G. Littlejohn, R. Venter and Lombard, C.Editors}, year={2002} }
 @article{de hertogh_gallitano_2000, title={Influence of photoperiod and day/night temperatures on flowering of Amaryllis (Hippeastrum) cv. apple blossom}, ISBN={["90-6605-793-9"]}, ISSN={["0567-7572"]}, DOI={10.17660/actahortic.2000.515.15}, abstractNote={ISHS XXV International Horticultural Congress, Part 5: Culture Techniques with Special Emphasis on Environmental Implications Chemical, Physical and Biological Means of Regulating Crop Growth in Ornamentals and Other Crops INFLUENCE OF PHOTOPERIOD AND DAY/NIGHT TEMPERATURES ON FLOWERING OF AMARYLLIS (HIPPEASTRUM) CV. APPLE BLOSSOM}, number={515}, journal={XXV INTERNATIONAL HORTICULTURAL CONGRESS, PROCEEDINGS - PT 5}, author={De Hertogh, AA and Gallitano, L}, year={2000}, pages={129–134} }
 @article{de hertogh_gallitano_1998, title={Influence of bulb packing systems on forcing of Dutch-grown Hippeastrum (Amaryllis) as flowering potted plants in North America}, volume={8}, DOI={10.21273/horttech.8.2.175}, abstractNote={Dutch-grown Hippeastrum bulbs (`Apple Blossom' and `Red Lion') were packed in five readily available and economical packing systems and after transport and storage were evaluated as flowering potted plants. After being harvested and graded, bulbs were specially packed and placed in perforated cardboard boxes, shipped by boat to Raleigh, N.C., and stored in the original packing materials for 84 days at 48 °F (9 °C). At planting time, the best old basal root system and lowest disease incidence for both cultivars was obtained when bulbs were packed with hout-wol, a type of excelsior, in perforated polyethylene bags and placed in perforated cardboard boxes. Plants from bulbs with this system and those packed loose in polyethylene bags flowered the earliest. At full flower, the longest leaves were obtained with the hout-wol, box only, and wood chip systems. There were no significant effects of the five packing systems on floral stalk length, number of flowers produced per stalk, flower diameter, strength of the first floral stalk or leaves, or overall plant quality. After flowering, the root systems were harvested. The hout-wol packing system significantly increased the fresh weights of the old basal roots retained, secondary roots produced, and total weights of the root system. there were significant differences between cultivars. `Apple Blossom' produced fewer roots and lower quality plants (shorter leaves and taller floral stalks) than `Red Lion'. Other significant cultivar differences, e.g., days to flower, were attributed to genetic variation. Based on the most desirable forcing characteristics, the superior packing system for shipping and storing Dutch-grown Hippeastrum bulbus was hout-wol combined with perforated polyethylene bags.}, number={2}, journal={HortTechnology}, author={De Hertogh, A. A. and Gallitano, L. B.}, year={1998}, pages={175–179} }
 @article{de hertogh_gallitano_1997, title={Basic forcing requirements for Israeli-grown Ornithogalum dubium}, ISBN={["90-6605-819-6"]}, ISSN={["0567-7572"]}, DOI={10.17660/actahortic.1997.430.34}, number={430}, journal={FLOWER BULBS - SEVENTH INTERNATIONAL SYMPOSIUM, VOLS 1 AND 2}, author={De Hertogh, AA and Gallitano, L}, year={1997}, pages={227–232} }
 @article{hertogh_gallitano_1997, title={Basic forcing requirements for Israeli-grown Ornithogalum dubium}, ISBN={9066058196}, number={430}, journal={Acta Horticulturae}, author={Hertogh, A. A. de and Gallitano, L.}, year={1997}, pages={227} }
 @inbook{de hertogh_1997, title={Technologies for forcing flower bulbs}, booktitle={Seventh International Symposium on Flower Bulbs: March 10-16, 1996, Herzliya, Israel  (Acta horticulturae;  no. 430)}, publisher={Wageningen, Netherlands: ISHS Ornamental Plant Section, International Working Group on Flower Bulbs}, author={De Hertogh, A. A.}, editor={H. Lilien-Kipnis, A. H. Halevy and Borochov, A.Editors}, year={1997}, pages={175–182} }
 @article{hertogh_1997, title={Technologies for forcing flower bulbs}, ISBN={9066058196}, number={430}, journal={Acta Horticulturae}, author={Hertogh, A. A. de}, year={1997}, pages={175} }
 @article{hertogh_1996, title={Marketing and research requirements for Lilium in North America}, ISBN={906605977X}, number={414}, journal={Acta Horticulturae}, author={Hertogh, A. A. de}, year={1996}, pages={17} }
 @article{hertogh_nell_nard_1992, title={Marketing opportunities for ornamental geophytes}, ISBN={906605235X}, number={325}, journal={Acta Horticulturae}, author={Hertogh, A. A. de and Nell, T. A. and Nard, M. le}, year={1992}, pages={319} }
 @article{hertogh_tilley_1991, title={Planting medium effects on forced Swaziland- and Dutch-grown Hippeastrum hybrids}, volume={26}, number={9}, journal={HortScience}, author={Hertogh, A. A. de and Tilley, M.}, year={1991}, pages={1168} }
 @article{hertogh_milks_1990, title={Forcing Dutch-grown freesias as potted plants in the U.S. and Canada}, number={266}, journal={Acta Horticulturae}, author={Hertogh, A. A. de and Milks, R.}, year={1990}, pages={115} }
 @article{hertogh_1990, title={Perspectives on future marketing, research and educational programs for flower bulbs}, ISBN={9066051442}, number={266}, journal={Acta Horticulturae}, author={Hertogh, A. A. de}, year={1990}, pages={43} }
 @article{hertogh_1987, title={Forcing of selected ornamental Oxalis spp. as potted plants}, number={205}, journal={Acta Horticulturae}, author={Hertogh, A. A. de}, year={1987}, pages={213} }
 @article{hertogh_kamp_1986, title={Commercial forcing and marketing requirements for flower-bulbs in the U.S. and Canada}, number={177}, journal={Acta Horticulturae}, author={Hertogh, A. A. de and Kamp, M.}, year={1986}, pages={267} }
 @article{hertogh_aung_benschop_1983, title={The tulip: Botany, usage, growth and development}, volume={5}, journal={Horticultural Reviews}, author={Hertogh, A. A. De and Aung, L. H. and Benschop, M.}, year={1983}, pages={45} }
 @inbook{hertogh_1980, title={Bulbous plants}, ISBN={9780124376502}, booktitle={Introduction to floriculture}, publisher={New York: Academic Press}, author={Hertogh, A. De}, year={1980}, pages={215} }
 @article{hertogh_breg_1980, title={Internodal growth of the tulip during the greenhouse phase of standard forcing}, journal={Acta Horticulturae}, author={Hertogh, A. A. De and Breg, T.}, year={1980}, pages={157} }
 @article{hertogh_dilley_blakely_1980, title={Response variation of tulip cultivars to exogenous ethylene}, journal={Acta Horticulturae}, author={Hertogh, A. A. De and Dilley, D. R. and Blakely, N.}, year={1980}, pages={205} }