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- Author or Editor: Harold F. Wilkins x
Abstract
In the May 1971 issue of Smithsonian I read that Neanderthal man evidently used flowers in some manner to honor his dead, since pollen counts were higher than average in the soil near the burial place, particularly around the head. One wonders whether these men were first to place a flower stem into water, some 60,000 years ago, in order to prevent wilting. Indeed, have we progressed enough in all these years in developing and disseminating information on the proper care of harvested flowers? I fear the answer is, “No!” I would venture to say that in this very metropolitan area that not more than 30% of the flowers locally grown or shipped ever see an ounce or even 1 ppm of a floral preservative, much less a clean sterile water bucket in the wholesaler's or retailer's refrigerators on their long tortuous journey to the consumer.
Abstract
The uncertainty of continuous supplies and the rapid increase in fossil fuel costs in recent years are serious threats to the nation’s greenhouse industry, especially in northern climates. Temporary fuel shortages for only a few hours during cold weather will destroy many greenhouse crops and bring immediate economic disaster to the individual independent operator. Costs have skyrocketed, and even in the relatively warm state of Florida, greenhouse operators using oil have experienced over 500% cost increases in the past 5 years and are spending as much as $25,000 per ha ($10,000 per acre) for fuel. Continued cost increases could bring about a major shift in the geographical location of greenhouse and related horticulutral industries from northern locations to the southern latitudes of the U.S., or even into the subtropical and tropical regions of the Caribbean area and Central and South America.
Easter lily (Lilium longiflorum Thunb. `Nellie White') bulbs were exposed to 1, 2, 3, 4, 5, or 6 weeks of cold before shoot emergence; 0, 1, 2, 3, 4, 5, or 6 weeks of long days (LD) upon shoot emergence; or a combination of cold followed by LD: 1/5 (weeks cold/weeks LD), 2/4,3/3,4/2, or 5/1. Experiments were repeated for three consecutive years. LD did not substitute equally for cold; at least 3 weeks of cold were required before LD treatments resulted in anthesis. Depending on the year, 100% of the plants flowered when treated with 3 to 6 weeks of cold alone or in combination with LD. Days to first flower anthesis from planting increased with decreasing weeks of cold in years 1 and 3, but was similar for all treatments in year 2. Decreasing weeks of cold in combination with LD, however, decreased days to anthesis in years 1 and 2, but had no effect in year 3. Regardless of LD, days from emergence to visible bud increased with decreasing weeks of cold in all years, and days to emergence from placement in the greenhouse increased with decreasing cold in years 1 and 3, but not in year 2. Increasing weeks of cold, regardless of LD, decreased leaf count, but had no effect on plant height. Flower count was unaffected by cold when combined with LD, but was significantly reduced by increasing weeks of cold.
Easter lily bulbs (Lilium longiflorum `Nellie White') were given 6 weeks of cold, placed in the greenhouse and subsequently divided into groups based on emergence date after placement in the greenhouse: 0-6, 7-13, 14-20 and 21-27 days. At emergence bulbs received 0, 1, 2 or 3 weeks of long days (LD). Late-emerging plants had fewer days to visible bud and anthesis from emergence than early-emerging plants; consequently, late-emerging plants flowered within 3-10 days of early emerging plants despite 14-21 days difference in emergence time. Late emerging plants were tallest and middle emerging plants had the highest leaf number. Increasing LD tended to decrease numbers of days from emergence to visible bud and anthesis and increase plant height. LD did not effect leaf or flower number. Interactions between LD and emergence date will be discussed. Experiment was repeated for three consecutive years.
Vegetative, single-stem poinsettia plants (Euphorbia pulcherrima Willd. `Gutbier V-14 Glory') were allowed to develop 10, 15, or 20 nodes (nodal groups). Within each nodal group, blades from the same node position were removed, combined into one sample per node, and analyzed for nutrient content. Nutrient concentrations were found to be distributed within the plant in one of three patterns: 1) N, P, and K concentrations were higher in upper than in lower leaves; 2) Ca, Mg, Fe, Mn, and B concentrations were higher in lower than in upper leaves; and 3) Cu and Zn concentrations were higher in upper and lower leaves than in middle leaves. When 10, 15, and 20 noded groups were compared, the distributional patterns were similar, but actual nutrient concentrations between groups differed. Leaf P, Ca, Mg, Fe, Mn, Zn, and B concentrations increased over time. However, concentrations of N, K, and Cu were highest in 43-day-old leaves and lowest in 19-day-old leaves for N and Cu and lowest in 67-day-old leaves for K.
Poinsettia (Euphorbia pulcherrima Wind. ex. Klotzsch) cultivars were divided into free-branching and restricted-branching groups. Auto and reciprocal grafts were made among three free-branching cultivars, Annette Hegg Brilliant Diamond (BD), Annette Hegg Topwhite (TW), and Annette Hegg Hot Pink (HP), and two restricted-branching cultivars, Eckespoint C-1 Red (CR) and Eckespoint C-1 White (CW). when CR scions were grafted onto BD stocks, vegetative characteristics of branching pattern and leaf morphology of CR plants were altered when compared to the control graft combination CR/CR (scion/stock). Branching pattern was determined by pinching the scion above the 12th node and measuring axillary shoot length, diameter, and node number 30 days later. CR scions grafted onto BD stocks produced a plant very similar to BD plants when axillary shoot length and node number were compared. However, axillary shoot diameter and leaf morphology were intermediate between CR and BD plants. Changes were retained after two generations of serial vegetative propagation and are considered permanent. The reproductive characteristics of anthesis date, bract color, and cyathia cluster diameter were not influenced by the stock. CR/BD plants produced twice as many axillary inflorescences as BD/BD or BD/CR plants, while CR/CR plants did not produce any. All of the free-branching cultivars were able to alter the vegetative characteristics of all of the restricted-branching cultivars.
The free-branching poinsettia (Euphorbia pulcherrima Willd. ex. Klotzsch) cultivar Annette Hegg Brilliant Diamond (BD) contained a free-branching agent that was graft-transmissible to the restricted-branching cultivar Eckespoint C-1 Red (CR). CR plants were transformed by the agent regardless of whether BD plants were used as scion or stock, indicating that the agent moved basipetally and acropetally through the graft union. The agent was repeatedly transmitted to a CR plant by serial grafting with a free-branching poinsettia plant. A minimum of 10 days contact through grafting was required for BD plants to transmit the agent to CR plants. Percentage of CR plants exhibiting the free-branching characteristic increased from 0% for < 10 days of graft contact with BD plants to 100% after 30 days.
Abstract
Early winter flowering of Alstroemeria ‘Regina’ plants was accomplished by a long-day, high-pressure sodium vapor lamp (HPS) treatment before the low 5°C temperature induction treatment. This HPS treatment predisposed the plants to respond to a subsequent long photoperiod treatment during winter. Winter generative shoot yield was increased by 35% through the use of HPS pretreatment. Stem length increased as the duration of the HPS treatment prior to cold induction increased.
Abstract
Phytochrome decay and reversion were measured in excised inner scales of Lilium longiflorum. Total phytochrome decreased by 25% in 4 hours after the initial 10 minute red light treatment. There was dark reversion of the phytochrome pigment from the far-red absorbing form to the red absorbing form.
Abstract
Treatment of inner daughter scales of lily bulbs with red or far-red light significantly accelerated shoot emergence. A red or far-red treatment from 2200-0200 accelerated emergence after a red or dark treatment from 0800-1600. A red or far-red treatment from 2200-0200 after a far-red treatment from 0800-1600 delayed emergence when compared to a far-red, dark treatment sequence.