Poinsettias

On ornamental plants CCC is appHed to a2aleas, geraniums, and hibiscus (Hibiscus sp] to make compact plants, and to poinsettias to reduce stem height and increase the red color of the bracts. A considerable amount of work has been carried out on cereals with CCC to reduce stem length and inhibit lodging. In Europe, the effect of CCC on shortening the culms of cereals is dependent upon the genotype. It has been demonstrated that the effect is as follows wheat > triticale > durum wheat > rye > oats > barley > corn = millet = rice (37). In barley, culms are initially inhibited but later the plant overcomes the inhibition (37). This has been attributed to poor assimilation, translocation, and rapid breakdown in wheat (38). 

Amaranthus Palmeri S. Wats., Palmer amaranth, is a coarse, weedy, drought-resistant, dioecious member of the Amaranthaceae and is related to A. retroflexus L., redroot pigweed, and the ornamentals k. tricolor L., sumner poinsettia, and /. caudatus L., love-lies-bleeding. Palmer amaranth was used by natives of the North American desert as a protein source and cereal to supplement maize and beans. Another member of the same family, A. spinosus L., spiny amaranth, has been reported to exhibit allelopathic activity toward coffee... 

Craker reported a reduction in petunia flower weight after a 53-day exposure to ozone at 0.05-0.07 ppm, but an increase in petunia flower weight was found in a 7-day exposure to three different concentrations. Carnations continuously exposed to 0.07-0.08 ppm produced a single deformed flower, but the controls had 24 normal flowers. Poinsettia bract area was decreased by 39% after a 50-day exposure (6 h/day) to ozone at 0.10-0.12 ppm. 

Poinsettia 0.10-0.12 6/day, 5 days/week, 10 weeks 39, bract size 80... 

There are several reports of the use of ozone with biotic pathogens, and the responses noted were independent of each other. These reports include Lophodermium pinastri infection of white pine, Fusarium. infection of cabbage, Botrytis infection of poinsettia bracts, rust on bean, and brown root rot of tomato. These results could reflect the conditions used. 

Poinsettia Ozone Ancymidol (100-ppm spray) (jrowth retardant 100 58... 

POINSETTIA (Poinsettia pulcherrima Willd.) Polygonum aviculare L. 

Craker, L. E., and W. A. Feder. Development of the inflorescence in petunia, geranium, and poinsettia under ozone stress. HortScience 7 59-60, 1972. 

Tetraterp. linear lycopene (Lycopersicon esculentum Mill., Ang., also cultivated and genetically engineered MI) Cp473 (Curtobacteriumflaccumfaciens pvar. poinsettiae pathogen Bact. ofPoimettia spp., Euphorbiaceae, Ang Haberli 2000). 

Poinsettias grown to maturity in air mixed with 10 ppm of ozone have smaller colored bracts and take 2 weeks longer to mature (49). Carnations and geraniums reflect the same kind of patterns. Poinsettias, chrysanthemums, carnations, and duckweed show no visible injury symptoms even though they suffer depressed growth and productivity. Corn,... 

Work with duckweed and poinsettias indicates that as long as these plants are growing in the presence of low ozone levels, growth rates, etc. are reduced. As soon as the plants are removed to clean, ozone-free air, growth resumes at a normal rate, and the plant rapidly reaches its normal size and habit. Thus duckweed exposed to 10 ppm of ozone for 14 days and then removed to fresh air exhibits a spurt in frond and flower production which quickly brings the population up to the normal level (44) (Table II). 

Geranium, and Poinsettia under Ozone Stress, HortSci. (1972) 7, 59. 

Ricin was found by Stillmark in 1889 as the first plant lectin derived from the seeds of the castor plant, Ricinus communis L., a member of the Euphorbiaceae or spurge family. Other members of this family include the popular houseplants poinsettia E. pulcherrima), and the croton species. The term castor bean is used commonly to refer to both the plant and seed of R. communis. Ricinus communis commonly grows along streams and riverbeds in addition to subtropical locations high in nutrients. Ricinus communis is a coarse perennial, 10-13 m tall in the tropics, with a stem 7.5-15 cm... 

Haberh A., Bircher C., and Pfander H. (2000) Isolation of a new carotenoid and two new carotenoid glycosides from Curtobacterium flaccumfaciens pvar poinsettiae. Helvetica ChimicaActa 83, 328—335. 

The genera in the family of Euphorbiaceae (Table 1) include various spurges, such as poinsettia and croton. 

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