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- Author or Editor: Roy A. Larson x
- HortScience x
Abstract
Once upon a time, in a far-off land, a member of the genus Gallus was walking through a forest populated with trees of the genus Quercus. Suddenly, something fell and struck this creature on the head. The creature was quite cowardly—you might even call it “chicken”—and it began to run and cry, “The sky is falling, the sky is falling, and I must tell the king”. On the way to the palace, she encountered other feathered members, whose names are really inappropriate to use in a sophisticated presidential address—names such as Henny Penny, Cocky Locky, Goosey Loosey, and Turkey Lurkey—and she told them the news and they joined her in her rush to see the king. They then met a rather devious character, who said he would show them a short-cut to the palace, but he really intended to have a sumptuous dinner of low-cholesterol, low-protein poultry products. Chicken Little forever remained a pessimist and never again went into the oak forest without an umbrella.
Abstract
2,3-Dihydro-5-6-diphenyl-l,4-oxanthin (UNI-P293), was used to determine its effectiveness as a disbudding agent of Chrysanthemum morifolium cv. May Shoesmith. Concentrations of 0.5, 0.75 and 1.0% were applied on the 18th, 21st and 24th short day (SD). The optimum concentration on the 18th SD was 0.5% and 1.00% on the 21st SD. There was no difference among concentration levels on the 24th SD. Flower size and date of anthesis were not adversely affected when manual disbudding was used as a supplement to chemical treatment, but smaller flowers and delayed anthesis usually occurred when only the chemical was used for disbudding. All treated plants were shorter than untreated plants.
Abstract
α-Cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol) applied to inherently tall-growing chrysanthemum cultivars controlled ht at concn of 62 mg/liter (0.06 mg/15 cm pot) when applied as a foliar spray, and 0.12 mg/15 cm pot when applied as a soil drench. An thesis was delayed in plants treated with high concn of the growth retardant but flower size and no., and node no. were unaffected.
Experiments were designed to determine if the combination of 6-benzyl adenine + gibberellic acid 4+7 can promote increased lateral shoots of desirable number and length on azaleas (Rhododendron simsii Planch.). The use of dikegulac-sodium with the addition of GA4+7 was also investigated to determine if GA4+7 could overcome decreased plant height and diameter caused by dikegulac application. Treatments were applied by spraying 204 ml·m-2 to pinched plants of mean diameter and mean height of 16 and 13 cm, respectively, potted in 1.3 liter plastic containers. Shoot number, plant height and plant diameter were measured 9 weeks after application for the commercially prominent cvs. `Gloria' and `Prize'. Preliminary results indicate that 2100 mg·l-1 ai BA + 2100 mg·l-1 ai GA4+7 increases number of lateral shoots. Initial results suggest the addition of 2100 mg·l-1 ai GA4+7 to 3900 mg·l-1 ai dikegulac overcomes inhibition of internodal elongation induced by dikegulac alone. Further studies will determine the effectiveness of Promalin (N-(phenylmethyl)-1H-purine-6-amine + GA4+7, 1:1) as a pinching agent on azaleas.
Dikegulac, dikegulac + GA4+7, BA, and Promalin (GA4+7 + BA) were evaluated as lateral shoot-inducing agents on greenhouse forcing azalea, Rhododendron cultivars Gloria and Prize. The addition of GA4+7 (1000 or 2000 mg.L-1) to a commercial rate of dikegulac (3900 mg.L-1) did not effectively increase plant diameter or leaf width compared to plants sprayed with dikegulac alone. The combination of dikegulac and GA4+7 (3900 + 2000 mg.L-1, respectively) was more phytotoxic than dikegulac alone. Foliar sprays of BA and Promalin at 1000 and 2000 mg.L-1 and 1000 and 1816 mg.L-1, respectively, did not increase lateral shoot count. Neither the addition of GA4+7 to dikegulac nor the use of Promalin is a viable alternative to dikegulac application for inducing lateral branch development of dikegulac-sensitive cultivars. Chemical names used: Na 2,3:4,6-Bis-0-(l-methylethylidene)-α-L-xylo-2-hexulofuranosonic acid (dikegulac), (lα,2β,4aα,4bβ,10β)-2,4a,7-trihydroxy-l-methyl-8-methylenegibb-3-ene-l,10-dicarboxylic acid l,4a-lactone (GA4+7),N-(phenylmethyl)-lH-purin-6-amine (BA), and Promalin [1:1 (wt/wt) GA4+7 and BA].
Experiments were designed to determine if the combination of 6-benzyl adenine + gibberellic acid 4+7 can promote increased lateral shoots of desirable number and length on azaleas (Rhododendron simsii Planch.). The use of dikegulac-sodium with the addition of GA4+7 was also investigated to determine if GA4+7 could overcome decreased plant height and diameter caused by dikegulac application. Treatments were applied by spraying 204 ml·m-2 to pinched plants of mean diameter and mean height of 16 and 13 cm, respectively, potted in 1.3 liter plastic containers. Shoot number, plant height and plant diameter were measured 9 weeks after application for the commercially prominent cvs. `Gloria' and `Prize'. Preliminary results indicate that 2100 mg·l-1 ai BA + 2100 mg·l-1 ai GA4+7 increases number of lateral shoots. Initial results suggest the addition of 2100 mg·l-1 ai GA4+7 to 3900 mg·l-1 ai dikegulac overcomes inhibition of internodal elongation induced by dikegulac alone. Further studies will determine the effectiveness of Promalin (N-(phenylmethyl)-1H-purine-6-amine + GA4+7, 1:1) as a pinching agent on azaleas.
Abstract
Low light intensity caused an increase in size and a delay in flowering of gloxinias (Sinningia speciosa Benth and Hooke cv. Dwarf Delight and Royal Frosted Red). The growth regulators succinic acid-2,2-dimethyl hydrazine (SADH) and (αcyclopropyl-α-(4 methoxyphenyl)-5-prymidinemethanol (ancymidol) decreased plant size and delayed flowering. ‘Dwarf Delight’ showed damage in response to ancymidol at 250 mg/liter and higher but ‘Royal Frosted Red’ showed no damage. SADH caused a noticeable increase in anthocyanin content of the inflorescence and chlorophyll content of the leaves.
Abstract
Two poinsettia cultivars, ‘Annette Hegg’ and ‘Eckespoint C-l’ were grown at 60° and 65°F night temperatures, and subjected to growth retardant treatments. 2-ChloroethyI trimethyl ammonium chloride (CCC) soil drenches resulted in the shortest plants, but effective height control was achieved with combination spray applications of CCC and succinic acid 2,2-dimethylhydrazide (SADH), or CCC and N-pyrrolidinosuccinamic acid (F 529) applied once, or 2 foliar applications of CCC applied 3 weeks apart. Date of flowering was not appreciably affected by the growth retardants, but was affected by temperature. Flowering was accelerated at the warmer temperature, but plant heights and bract diam were similar at both temperatures.