scholarly journals Effect of Plant Growth Regulators on Growth and Flowering of Potted Red Firespike

2016 ◽  
Vol 26 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Amir Rezazadeh ◽  
Richard L. Harkess ◽  
Guihong Bi

The effect of plant growth regulators (PGRs) on growth and flowering of potted red firespike (Odontonema strictum) were examined in two experiments. In Expt. 1, foliar spray applications of daminozide, uniconazole, paclobutrazol, or flurprimidol or media drenches of paclobutrazol or flurprimidol were applied. In Expt. 2, foliar spray application of daminozide or media drenches of paclobutrazol or flurprimidol were further tested for efficacy of height control. Both studies included an untreated control. In Expt. 1, drench applications of paclobutrazol and flurprimidol resulted in plants 65% or 46% to 62% shorter than control, respectively. Paclobutrazol and flurprimidol drenches also decreased overall plant growth by 81% to 88% and 74% to 84%, respectively, compared with the control plants. PGRs did not affect number of inflorescences; however, paclobutrazol and flurprimidol delayed flowering 23 to 31 days. In Expt. 2, plants treated with flurprimidol or paclobutrazol drenches were shorter than the control. The greatest reduction in total plant growth occurred using a flurprimidol drench at 0.47 mg/pot, which resulted in plants 78% smaller than the untreated control. Paclobutrazol and flurprimidol increased the time to flowering 11 to 27 days and 10 to 26 days, respectively. The most attractive and well-shaped plants were achieved with flurprimidol applied at 0.24 mg/pot or applications of paclobutrazol at 0.35 mg/pot.

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 432b-432
Author(s):  
Anna Perkins Nina Bassuk

Budbreak inhibition and poor overwinter survival (OS) limit successful cutting propagation of Acer rubrum October Glory, A. rubrum Red Sunset, Hamamelis vernalis, H. virginiana and Stewartia pseudocamellia. Localized blanching (banding) of the cutting on the stock plant; a range of 3 IBA concentrations, and foliar spray application of: 1% silver thiosulfate(STS), STS followed ten days later by Gibberellin, GA4/7:250ppm(STS GA),50ppm thidiazuron (TDZ) and TDZ followed by GA4/7 (TDZ GA)were tested for increasing growth and overwinter survival.. Carbohydrates were analyzed in cuttings which did and didn't grow. A. rubrum October Glory*, and Hamamelis spp all had increased OS for cuttings which grew. A. rubrum Red Sunset demonstrated a similar trend. Hamamelis spp. had significant increase in carbohydrates for cuttings which grew. A. rubrum October Glory' exhibited the same trend. S. pseudocamellia did not have increased OS with growth. and showed no increases in carbohydrates with growth, but the cuttings that didn't grow had at least 93 % more carbohydrates than the other species analyzed. All species had higher OS when stored in the 3° C cooler, than in the fluctuating cold frame. Banding increased growth of A. rubrum October Glory, and H. virginiana. IBA concentration affected growth of all species. STS increased growth of H. virginiana and S. pseudocamellia. GA4/7 increased growth of all cuttings except A. rubrum October Glory.


2001 ◽  
Vol 11 (2) ◽  
pp. 226-230 ◽  
Author(s):  
James L. Gibson ◽  
Brian E. Whipker

Ornamental cabbage and kale (Brassica oleracea var. acephala) plants of cultivars Osaka White and Nagoya Red were treated with paclobutrazol and uniconazole as foliar sprays or substrate drenches. These treatments were compared to the industry standard of daminozide foliar sprays. Applying drenches of paclobutrazol (a.i.) at 4 mg/pot or uniconazole (a.i.) at 1 mg/pot (28,350 mg = 1.0 oz) resulted in 6% or 17%, respectively, shorter `Osaka White' plants while a 2 mg/pot paclobutrazol drench or a uniconazole drench at 0.25 mg/pot resulted in 25% shorter `Nagoya Red' plants. Although effective, the expense of substrate drenches for both plant growth regulators (PGRs) would not be economically feasible for growers to use. Paclobutrazol foliar sprays at concentrations of up to 80 mg·L-1 (ppm) were ineffective in controlling plant height and diameter of either `Osaka White' or `Nagoya Red'. A uniconazole foliar spray of 16 mg·L-1 resulted in 17% shorter `Nagoya Red' plants and 6% shorter `Osaka White' plants. A daminozide foliar spray of 2500 mg·L-1, sprayed twice, resulted in 21% shorter plants for both cultivars. Spraying daminozide would provide optimal height control for the retail grower. Although spraying daminozide twice controlled plant height and costs half the amount of an uniconazole spray at 16 mg·L-1, plant diameter was not affected with daminozide, therefore a wholesale grower who would desire a smaller diameter plant should use a uniconazole spray of 16 mg·L-1.


2012 ◽  
Vol 150 (5) ◽  
pp. 595-602 ◽  
Author(s):  
E. D. GONIAS ◽  
D. M. OOSTERHUIS ◽  
A. C. BIBI

SUMMARYPlant growth regulators are widely used in cotton production to improve crop management. Previous research has demonstrated changes in crop growth, dry matter (DM) partitioning and lint yield of cotton after the application of plant growth regulators. However, no reports are available demonstrating the effect of plant growth regulators on light interception and radiation use efficiency (RUE). Field studies were conducted in Fayetteville, Arkansas, USA in 2006 and 2007. RUE was estimated for the period between the pinhead square stage (PHS) of growth and 3 weeks after first flower (FF+3) from plots receiving three applications of the nitrophenolate and mepiquat chloride with Bacillus cereus plant growth regulators (Chaperone™) at 7·19 g a.i./ha and Pix Plus® at 41·94 g a.i./ha compared with an untreated control. No differences between the Chaperone treatment and the untreated control were found in the present study. However, Pix Plus significantly reduced plant height (both 2006 and 2007) and leaf area (2007 only), and altered the canopy structure of the crop as recorded by increased values of canopy extinction coefficient. Although DM accumulation was found not to be affected by plant growth regulator treatments, RUE was significantly increased after Pix Plus application, by 33·2%. RUE was increased because less light was intercepted by the Pix Plus treatment for the same biomass production, and this is probably a result of changes in photosynthetic capacity of the leaves and changes in light distribution throughout the canopy.


Author(s):  
Zahida Rashid ◽  
Tanveer Ahmad Ahngar ◽  
B. Sabiya ◽  
N. Sabina ◽  
N. S. Khuroo ◽  
...  

A field experiment was conducted at Dry land Agricultural Research Station, Rangreth, Srinagar, SKUAST-K in Kharif 2020 to study the effect of Plant Growth Regulators and micronutrients on growth, yield and quality of sorghum. The objective of the study was to assess the effect of Plant Growth Regulators and micronutrients on herbage yield and quality. The treatments included; T1: Tricontanol 10 ppm at 30 DAS (foliar spray), T2: Salicylic acid 100 ppm at 30 DAS (foliar spray), T3: 5 kg Zn/ha soil application, T4: 2 kg B/ha soil application, T5: 5 kg Zn + 2 kg B/ha soil application, T6: 5 kg Zn/ha (soil application ) + Triacontanol 10 ppm at 30 DAS (foliar spray), T7: 5 kg Zn/ha (soil application) + salicylic acid 100 ppm at 30 DAS (foliar spray), T8: 2 kg B/ha (soil application) + Triacontanol 10 ppm at 30 DAS (foliar spray), T9: 2 kg B/ha (soil application )+ salicylic acid 100 ppm at 30 DAS (foliar spray), T10: 5 kg Zn + 2 kg B/ha (soil application) + Triacontanol 10 ppm at 30 DAS (foliar spray), T11: 5 kg Zn + 2 kg B/ha (soil application) + salicylic acid 100 ppm at 30 DAS (foliar spray) and T12: Water spray at the time of PGR application. Zn and B were applied at the time of sowing in the soil. The crop was raised with recommended package of practices. In treatments, where zinc was not a treatment, an amount of sulphur through gypsum equivalent to sulphate supplied with 5 kg ZnSO4 was applied to compensate. The crop was sown in 30.0 cm apart lines. The trial was laid out in Randomized Block Design with three replications. The results indicated that all the treatments improved the green fodder yield over control. Among different treatments, T10: 5 kg Zn + 2 kg B/ha soil application + Triacontanol 10 ppm at 30 DAS foliar spray and T11: 5 kg Zn + 2 kg B/ha soil application + salicylic acid 100 ppm at 30 DAS foliar spray produced maximum GFY (493.6 and 490.5q/ha) on locational mean basis. It was significantly superior to other treatments. These treatments improved the green fodder yields by 35.0 % and 34.2 %, respectively, over control (spray of water). In terms of dry matter, similar trend was noted and the improvement with T10 and T11 was to the tune of 36.8 % and 41.0 % over control. Tricontanol 10 ppm at 30 DAS (foliar spray) (T1) improved the green fodder yield and dry fodder yield by 13.6% and 14.3 % respectively over T12Water spray at the time of Plant Growth Regulator application. Similarly spray of T2: Salicylic acid 100 ppm at 30 DAS (foliar spray) improved the green fodder yield and dry fodder yield by 14.4% and 15.4% respectively over T12Water spray at the time of Plant Growth Regulator application. Similar trend was observed with respect to quality parameters (crude protein content and crude protein yield) of sorghum.


2006 ◽  
Vol 24 (3) ◽  
pp. 165-168
Author(s):  
Stanislav V. Magnitskiy ◽  
Claudio C. Pasian ◽  
Mark A. Bennett ◽  
James D. Metzger

Abstract Soaking French marigold seeds in growth regulator solutions produced larger reductions in seedling height than foliar sprays. Seeds soaked in 1 to 5 ppm uniconazole solutions for 0.15, 5, or 45 min resulted in plants that were up to 23% shorter than controls at 30 DAS, whereas foliar applications of 10 to 20 ppm uniconazole solutions resulted in plants 18% shorter than controls at 14 DAS. French marigold seedlings from seeds soaked in 60 pm ancymidol for 5 or 45 min were 5 or 6%, respectively, shorter than controls. Foliar spray applications of 25 or 100 ppm ancymidol to French marigold seedlings resulted in plants 8% shorter than controls. Chlormequat solutions applied either as a seed soak (1000–5000 ppm) or foliar spray (500–3000 ppm) did not reduce French marigold seedling height. Emergence of French marigold seedlings from seeds soaked in uniconazole, ancymidol, or chlormequat solutions was not different from that of control seeds. No effect on seedling height or emergence was found when soaking celosia seeds in uniconazole, ancymidol, or chlormequat solutions. Spraying celosia seedlings with uniconazole, ancymidol, or chlormequat solutions did not reduce seedling height.


2015 ◽  
Vol 25 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Amir Rezazadeh ◽  
Richard L. Harkess

Purple firespike (Odontonema callistachyum), native to Central America, has potential for use as a new flowering potted plant. The effects of number of pinches (zero, one, or two) and number of cuttings (one, two, or three) per 6-inch pot were evaluated on the control of plant height. Plant height was suppressed as the pinch number increased. The greatest reduction was recorded with one cutting per pot and two pinches. The maximum number of branches per pot was recorded with two pinches and three cuttings per pot. In a second experiment, plant growth regulators (PGR) were also tested for efficacy of height control; 2 weeks after pinching, foliar sprays of paclobutrazol, flurprimidol, daminozide, chlormequat, and a tank-mix of daminozide + chlormequat or media drenches of paclobutrazol, uniconazole, or flurprimidol were applied. Plant height, leaf area, and leaf dry weight were recorded at 3, 6, and 9 weeks after PGR application. Maximum height control was obtained with uniconazole drench at 8 ppm, resulting in plants 22 cm tall, 61% shorter than the untreated control (56 cm); however, it resulted in severe leaf distortion. Plant height was 56% and 46% shorter than the control using drenches of paclobutrazol at 30 ppm and flurprimidol at 15 ppm, respectively. Daminozide spray at 2000 ppm and tank-mix of daminozide + chlormequat at 4500/1500 ppm suppressed stem elongation by 20.3% and 19%, respectively. Plants treated with paclobutrazol drench at 30 ppm reduced leaf area and leaf dry weight compared with other PGRs. Chlormequat spray at tested concentrations was ineffective for controlling firespike plant growth. The most attractive potted plants were produced using a drench application of paclobutrazol at 10 or 15 ppm.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 438D-438
Author(s):  
Brian E. Whipker ◽  
Shravan Dasoju

Plant growth retardant (PGR) foliar spray treatments (mg•liter–1) of daminozide at 1000 to 16,000; paclobutrazol from 5 to 80; and uniconazole from 2 to 32 were applied to `Pacino' pot sunflowers (Helianthus annuus) to compare their effectiveness at chemical height control. When the first inflorescence opened, the number of days from seeding until flowering, total plant height measured from the pot rim to the top of the inflorescence, inflorescence diameter, and plant diameter were recorded. Total plant height, plant diameter, inflorescence diameter, and days until flowering were significant for the PGR treatment interaction. Marketable-sized plants grown in the 1.2-liter pots were produced with uniconazole concentrations between 16 and 32 mg•liter–1 or with daminozide concentrations between 4000 and 8000 mg•liter–1. Paclobutrazol foliar sprays up to 80 mg•liter–1 had little effect and higher concentrations or medium drench treatments should be considered.


2005 ◽  
Vol 15 (2) ◽  
pp. 222-231 ◽  
Author(s):  
Martin J. Bukovac

The importance of spray application and the role of spray additives are reviewed in reference to increasing the effectiveness of plant growth regulators (PGR). The spray application process is composed of a number of interrelated components, from formulation of the active ingredient into a sprayable, bioactive solution (emulsion/suspension), to atomization, delivery, retention, and penetration into the plant tissue. Each of these events is critical to performance of the PGR. Also, each can be affected by spray additives, particularly adjuvants, which may be incorporated in the formulation of the active ingredient or added to the spray mixture. The role of the individual components and effects of spray adjuvants, particularly surfactants and fertilizer adjuvants, on the component processes are discussed.


2020 ◽  
Vol 49 (2) ◽  
pp. 223-228
Author(s):  
R Sivakumar ◽  
K Krishna Surendar

Impact of plant growth regulators viz., benzyl amino purine (BAP - 50 ppm), brassinolide (BL - 0.5 ppm), and nutrient like KCl (1%) alone and with combination on growth and growth analytical parameters, and yield of finger millet by foliar spray at panicle initiation stage under rainfed condition was studied in field experiment. The treatments including control, KCl, BAP, BL, KCl + BAP, KCl + BL, BAP + BL and KCl + BAP + BL and different growth and growth analytical parameters were estimated. Combination of KCl, BAP and BL registered highest root length (17.2 cm), leaf area (425.3 cm2), leaf area index (1.82) and leaf area duration (55.7 days) compared to other treatments. Higher specific leaf weight and crop growth rate were recorded by KCl + BAP, and BAP + BL, respectively. The highest grain yield of 22.5 Q/ha was recorded by KCl + BAP + BL.


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