In its native environment , poinsettia ( Euphorbia pulcherrima ) grow as a washy shrub or small tree that can reach 3 to 4 m and has red minute bract . commercial-grade growers have been able-bodied to capitalise on year of flora breeding to introduce svelte cultivars that are shorter , good , and more visually likeable , while still possessing the intense coloration of pink , orangish , chickenhearted , light green , white , and the trademark holiday reds in the bracts . These dimension have made poinsettia one of the most economically significant potted plants sold in the United States , with wholesale sale of more than $ 157 million , and have made poinsettias a staple of holiday décor and landscape gardening .
Traditionally , young poinsettia plants are pinched to remove the shoot tip , which thrust the lower nodes to branch out . This results in a wider and full plant , but mechanically skillful pinching is Labor Department - intensive and may not be economically feasible in high - density production .
In a new study , researchers have document a novel method for enhance the increment of Euphorbia pulcherrima plants . The study , behave at North Carolina State University , explore chemical substance intervention overture that could promote branching and shank elongation in poinsettias .
Through cautiously verify experimentation and data depth psychology , researcher show that specific chemical compounds ( benzyladenine ( BA ) , gibberellin [ GA(4 + 7 ) ] and dikegulac sodium ) stimulate elongation and branching without compromising plant wellness or aesthetic .
When used decent , BA+GA(4 + 7 ) was find to be a effective tool for increase plant life height , especially when used to countervail the overapplication of PGRs . BA+GA(4 + 7 ) can be apply early on in the harvest season to increase peak ; however , for most cultivar , there will be a trade-off with a postponement in inflorescence . Drench applications of BA+GA(4 + 7 ) were less effective than foliar sprays , perhaps because of the presence of barque in the substrate .
The use of dikegulac sodium proved good in promoting sidelong branching on nonpinched poinsettia plants and , in some cultivars , produced a flora similar in appearance to mechanically pinched plant . The best program time of was1 week before the standard pinch date of poinsettia . care should be taken with use of dikegulac atomic number 11 because it can significantly delay flowered evolution , but this upshot was variable and dependent on cultivar .
Comparison of dikegulac sodium applications programme with mechanically skillful pinching on Mexican flameleaf emergence and flowering meter .
Cultivar
Treatment
Shoot #
florescence # `
Clarence Shepard Day Jr. to flowering
Jubilee Red
Pinched
6.0
4.8
95
800 ppm once
9.0
4.4
93
1600 ppm once
11.00
5.4
99
800 ppm twice
13.0
94
Noel Red
7.7
15.7
5.2
100
1600 ppm
20.7
6.2
106
25.0
6.6
107
Prestige Red
6.7
4.6
10.0
4.2
9.3
5.6
12.3
5.8
Prima Red
7.3
5.0
101
14.7
18.3
7.2
Stargazer Red
11.0
6.8
103
14.0
6.4
105
16.3
102
Titan Red
84
11.3
90
12.0
86
Growers are advised to carefully assess the potential side outcome of employing these chemical , which can vary depending on the Poinsettia cultivar . It is essential to evaluate the specific price - to - benefit proportion when selecting cultivars for production . As a precautionary standard , manufacturer should conduct small - graduated table trial before mix treatments into big - scale of measurement yield mental process , as is customary with any new output pattern .
According to the author , " The nursery industriousness is always looking for ways to make production more effective while still growing a high character works that hold out a long clock time for consumers . The research can help producer with the issues of sneak million of plants as well as when plants are too brusque . "
John Dole is a Professor of Horticultural Science at North Carolina State University .
register the intact clause on the ASHS HortTech electronic journal site at : https://doi.org/10.21273 / HORTTECH05186 - 23
For more information : American Society for Horticultural Science ( ASHS)ashs.org
Frontpage photo : © Mickem | Dreamstime
