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- Author or Editor: A. A. De Hertogh x
Abstract
At the University level, horticulture is one of the most dynamic fields in Agriculture. Undergraduate student enrollments, both for majors and nonmajors, have never been higher. The number of requests for graduate student assistantships are increasing. Extension personnel are under constant pressure from their clientele for more and more programs and information. The requirements for research have never been greater. In addition, with the democratic system which has been developed, scientists are spending more time on administrative matters than ever before. All of these points have their advantages and disadvantages but the time is past due for a detailed analysis of their impact on our programs by the individuals who are directly involved in carrying out the research, teaching, and extension functions. This is particularly true for those of us in the field of floriculture and ornamental horticulture.
Abstract
Exercises are described to familiarize horticultural students with the ‘Standard Forcing’ of potted tulips, hyacinths, daffodils, Iris reticulata, Crocus and grape hyacinths as well as cut tulips and daffodils. Procedures are outlined for ‘Special Precooling’ of tulips and Dutch iris as cut flowers. In addition, a simplified list of readily available cultivars of the spring-flowering bulbs covered is provided. The exercises utilize Valentine’s Day as the marketing holiday.
Over 3 years, greenhouse and phytotron trials were conducted using Israeli-grown Leucojum aestivum. The objective was to evaluate the potential of this bulb as a potted plant for North American forcing. It was found that bulb sizes of 12/14, 14/16, and 16/up cm (in circumference) produced quality plants. Bulbs of 10/12 cm had reduced number of florets per floral stalk. The optimal cold requirement was 15-19 weeks. The major physiological disorder associated with forcing was flower abortion. Phytotron studies showed that this occurred readily at 30/26 C (Day/Night temperatures) and was minimal at 18/14 C. When > 12 cm bulbs were properly programmed and forced in the greenhouse, they produced plants that were 25-35 cm tall at flowering, with 1-2 floral stalks and 4-6 florets per stalk. No plant growth retardants are required for forcing this bulb as a 15 cm diameter potted plant.
Abstract
This column has had articles on many subjects that need to be addressed, e.g., funding research (4), horticultural education (2), professions in horticulture (5), and interdisciplinary research (3). After reading these articles, and I encourage all members to do so, I came to the conclusion that they tend to concentrate on only one point. The question remains: what is the primary mission of horticultural science? I believe that the answer is simple and straightforward: to service production horticulture. This was the original purpose of establishing the land-grant university system and the USDA-Agricultural Research Service. It remains our primary mission and horticultural scientists must not lose sight of it.
The Swaziland-grown Hippeastrum bulbs `Summertime' and `Sun Dance' reached the market and flowering stages of development in fewer days than the Dutch-grown bulbs `Apple Blossom' and `Red Lion'. `Sun Dance' was the quickest flower and `Red Lion' the slowest. The effects of the planting medium on days to market and flowering were variable and no medium appeared to be the best for this criterion. `Summertime' and `Red Lion' produced longer leaves at flowering than `Apple Blossom' and `Sun Dance'. Three media that led to the production of the longest leaves, a desirable trait, were: Sunshine no. 4, Fafard 3-B, and Sunshine Post-Harvest. `Apple Blossom' was the tallest cultivar followed by `Sun Dance', `Red Lion', and `Summertime'. Effects of the planting medium on total plant height were variable. The overall plant quality ratings for use as potted plants ranged from 3.4 to 3.8 out of 4 for `Summertime', `Sun Dance', and `Red Lion'. `Apple Blossom' was rated 3.0 because it was tall and had short leaves. It would be suitable as a cut flower. Regardless of the planting medium used, `Apple Blossom' lost the greatest amount of old basal roots. Consequently, it produced many new basal roots. The planting medium had variable effects on old and new basal roots and secondary root growth, depending on the cultivar. Based on all the flowering criteria and the rooting responses, the best media for all cultivars as potted plants were Fafard 3-B and Sunshine Mix no. 4. Fafard no. 2 was best for cut-flower usage since it produced taller plants with a good root system.
Abstract
Floral stalk topple, a disorder of greenhouse-forced hyacinths was investigated using ‘Pink Pearl’, a non-topple type, and ‘Blue Giant’, topple-prone type. The total floral stalk of ‘Blue Giant’ was longer than ‘Pink Pearl’. The ratio of the scape to inflorescence of ‘Pink Pearl’ was 1.0 while that of ‘Blue Giant’ was 1.8. Anatomical sections revealed that ‘Pink Pearl’ had shorter and narrower pith cells in the scape than ‘Blue Giant’. The cellular arrangement of the pith and cortex showed that, in contrast to ‘Blue Giant’, those of ‘Pink Pearl’ were tightly interwoven with very few intercellular spaces. Soil drenches of ancymidol at 2 or 4 mg/15 cm pot reduced the incidence of stem topple in ‘Blue Giant’. Ancymidol modified cell sizes and shapes and reduced the floral stalk length and scape to inflorescence ratio. It appears that floral stalk topple is related both to the anatomical structure of the cultivar and its floral stalk characteristics.
Almost all Amaryllis (Hippeastrum) forced in the U.S. and Canada by either homeowners or commercial forcers are grown overseas. In order to comply with USDA/APHIS plant quarantine regulations, all bulbs must be free of soil. Thus, they are washed once or twice prior to packing and shipping. As a result of this treatment, the bulbs arrive with only basal roots and no secondary roots. Therefore, over the past year, 2 hand made mixes and 7 commercially prepared mixes were evaluated using 2 cultivars each of Swaziland- and Dutch-grown bulbs. The effects of these media on forcing characteristics, e.g. total plant height, leaf length, flower number, etc. were examined. Also, the influence of the various media on basal root growth and formation of new secondary roots was measured. The results of these 2 studies will be presented.