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- Author or Editor: A.A. De Hertogh x
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.
Abstract
Using gas-liquid chromatography (GLC) and GLC-mass spectrometry (MS) the main sterols of sprout tissue from Iris hollandica Hoog cv. Wedgwood were identified as β-sitosterol, stigmasterol and campesterol. A 4th substance which co-chromatographed with cholesterol was shown by MS to be octacosanol, a saturated C28 primary alcohol.
Abstract
Ethylene was detected in the internal atmosphere of 5 bulb species. Some, if not all, of the determined ethylene concn are of physiological significance. Experiments using methyl l-(butylcarbamoyl)-2-benzimi-dazole carbamate, a protective fungicide, indicate that fungi normally associated with tulip bulbs are at least partially responsible for the gas.
Abstract
Flowering of ‘Kees Nelis’ (Tulipa gesneriana L.) tulip bulbs was not impaired after 4 weeks of storage at 17°C in either 3 or 5% oxygen. ‘Kees Nelis’ bulbs stored in air or 1% O2 for 4 or 6 weeks and ‘Prominence’ bulbs stored at any reduced O2 level for 4 or 6 weeks flowered unsatisfactorily. Bulbs specially precooled later in the forcing season yielded unsatisfactory flowering after storage at 17°C regardless of cultivar. Low O2 levels (1 to 5%) reduced the respiration rate of bulbs stored at 17°C for 6 weeks compared to bulbs stored in air. Storage of ‘Kees Nelis’ bulbs for 3 weeks in air with 5 ppm ethylene caused flower abortion upon forcing. Three or 5% O2 reduced ethylene-induced flower abortion during storage.
Abstract
Determination of carbohydrates in different organs of 3 tulip cultivars stored at 4°C showed that sucrose and starch constituted 95% of the bulb carbohydrates with reducing sugars constituting 5%. Dry storage at 4° in the dark for 7 or 14 weeks resulted in an increase in total carbohydrates in all cultivars. Starch content of ‘Edith Eddy’, ‘Bellona’ and ‘Schoon-oord’ was increased 28%, 116%, and 270% respectively following 14 weeks of 4°C storage. Changes in sucrose and reducing sugars varied with cultivar and duration of 4° treatment. On a μg/mg dry weight basis, carbohydrate concentrations were generally higher in the shoot, developing bulblets and basalplate than in the storage scales. Dry matter loss was higher in ‘Edith Eddy’ than in ‘Schoonoord’ and ‘Bellona’. The loss of dry matter during 4° storage was reflected by cumulative losses in each of the organs.
Abstract
Conflicting opinions have been expressed for a number of years about the use, effectiveness, and cost of HortScience and the Journal. Because of the importance of these publications, the Publications Committee decided to conduct a survey of the membership to get a more complete picture of member views and to obtain some solid facts regarding the publishing behavior of different classes of members.
Abstract
The effects of a 63° period of development prior to cooling on the forcing of Lilium longiflorum were compared with precooling treatments. Different bulb sizes of ‘Ace’ and ‘Nellie White’ lilies were used. It was found that a growing period at 63° prior to cooling significantly increased the number of leaves and floral buds. It had no consistent effect on the number of days to flower or final plant height.
With the ‘Ace’ lily, the greatest number of floral buds was observed with a treatment of 3 weeks at 63° followed by 5 weeks at 38°. Within a single bulb size, the ‘Ace’ lily produced more floral buds, was a taller plant, and had more leaves than ‘Nellie White’. The number of leaves and floral buds increased with an increase in bulb size regardless of the type of low temperature treatment or cultivar used.
Abstract
Procedures are described for critical point drying the shoot apical meristems of Easter lilies for viewing in the scanning electron microscope. This preparatory technique was superior to either freeze-drying or the use of freshly isolated meristems. Photomicrographs of the morphological development of the entire shoot apex from the vegetative through several reproductive stages are presented. The morphology of a single flower is also illustrated.
Meristem diameter measurements revealed seasonal and bulb source variations. Diameter increased with increasing bulb size. When compared to non-cooled bulbs, low temperature treatments reduced meristem diameter prior to flower initiation. The average date of flower initiation of controlled temperature forced ‘Ace’ lilies over a 5-year period was January 21; whereas precooled lilies initiated about 1 week earlier. Greenhouse temperatures of 17−25°C accelerated the date of flower initiation when compared to 13°. A simplified technique for measuring the meristem diameter and observing the stage of development was developed.
The Easter lily forms 2 classes of primary flowers, initial and raised. They can also form secondary flowers. The number of initial primary flowers was correlated with meristem diameter. Larger bulb sizes resulted in a greater number of raised primary flowers. In general, only large bulbs formed secondary flowers. A greenhouse temperature of 13°C promoted the formation of raised primary flowers, while 21° promoted the formation of secondary flowers.
A measurement of the sprouting index showed seasonal and bulb source differences.
Abstract
Potted ‘Ace’ lily bulbs were treated with gibberellic acid (GA3) as a soil drench using varying concentrations, numbers of applications and at different stages of development. There was no consistent effect on the forcing days to flower, plant height or the number of leaves, however, specific treatments with 1000 ppm significantly reduced the number of floral buds initiated. It appears that the most sensitive stage of application is that period just prior to flower initiation and that the GA3 must be applied at this time in order to reduce the number of floral buds initiated. A preliminary experiment indicated that GA4+7 was more effective than GA3. GA4+7 influenced plant height and leaf length as well as the number of floral buds but had no effect on the forcing days to flower.
Abstract
Factors affecting floral stalk elongation of tulips during the period from floral bud coloring (budded flower) to the senescence of the perianth were studied. All internodes elongated, however, the greatest elongation occurred in the internode directly beneath the flower and most of the elongation occurred in the upper two-thirds of the internode. Cut tulips elongated less than plants left in the forcing flats. Removal of the budded flower inhibited elongation of the last internode while removal of the leaves was stimulatory with some cultivars. With cut tulips, the perianth appeared to be the primary organ controlling floral stalk elongation followed by the gynoecium and androecium. When the flowers were left intact on the plant the gynoecium exerted the greatest control followed by the perianth and androecium. When the complete flower was removed and IAA or NAA was applied as a lanolin paste to replace the flower, the last internode elongated in a manner similar to the intact flower. Similar applications of kinetin and GA3 were ineffective.