scholarly journals Paclobutrazol and Uniconazole Solutions Maintain Efficacy after Multiple Lily Bulb Dip Events

2005 ◽  
Vol 15 (3) ◽  
pp. 551-553 ◽  
Author(s):  
N.K. Damayanthi Ranwala ◽  
Anil P. Ranwala ◽  
William B. Miller

One of the problems associated with preplant bulb dips into plant growth regulator (PGR) solutions is the lack of knowledge of solution efficacy as an increasing number of bulbs are treated. We evaluated the effectiveness (“longevity”) of paclobutrazol (Bonzi) and uniconazole (Sumagic) solutions repeatedly used to dip hybrid lily (Lilium sp.) bulbs. Experiments were conducted over a 2-year period, using sequential 1-minute dips into paclobutrazol (100 or 200 mg·L–1) or uniconazole (2.5 mg·L–1). No difference in plant height occurred as the number of bulbs dipped into PGR solutions increased to at least 55 bulbs per liter. This was true whether bulbs were washed (with tap water to remove soil particles attached to the bulbs) or unwashed prior to the PGR dip. These findings have an important impact on cost effectiveness of bulb dips, as the more times the solution can be used, the lower the cost. Washed bulbs were taller than unwashed bulbs due to lower PGR liquid uptake in washed bulbs (about 1 mL less per bulb) compared to the unwashed bulbs. These results indicate that the hydration condition of bulbs prior to dipping can affect the amount of PGR liquid uptake and therefore final plant height.

2005 ◽  
Vol 15 (2) ◽  
pp. 370-373 ◽  
Author(s):  
Brian A. Krug ◽  
Brian E. Whipker ◽  
Ingram McCall ◽  
John M. Dole

Preplant bulb soaks of ancymidol, flurprimidol, paclobutrazol, and uniconazole; foliar sprays of flurprimidol; and substrate drenches of flurprimidol, paclobutrazol, and uniconazole were compared for height control of `Prominence' tulips (Tulipa sp.). Height control was evaluated at anthesis in the greenhouse and 10 days later under postharvest conditions. Substrate drenches of ancymidol, flurprimidol, and paclobutrazol resulted in adequate control using concentrations of 0.5, 0.5, and 1 mg/pot a.i. (28,350 mg = 1 oz), respectively. At these concentrations, ancymidol drenches cost $0.06/pot and paclobutrazol drenches $0.03/pot. Since flurprimidol is not yet available and no price is available, growers will need to assess the cost compared to ancymidol and paclobutrazol. Flurprimidol foliar sprays at <80 mg·L–1 (ppm) were ineffective in controlling height during greenhouse forcing, but during postharvest evaluation 80 mg·L–1 resulted in 14% shorter plants than the untreated control. Preplant bulb soaks of flurprimidol, paclobutrazol, and uniconazole at concentrations of 25, 50, and 10 mg·L–1, respectively, effectively controlled plant height. Preplant plant growth regulator soaks are a cost-effective method of controlling plant height of tulips because of the limited amount of chemical required to treat a large quantity of bulbs.


1991 ◽  
Vol 116 (2) ◽  
pp. 191-200 ◽  
Author(s):  
E. M. White

SUMMARYApplications of nitrogen and a plant growth regulator (mepiquat chloride and ethephon) were used to manipulate stem structure and induce differing degrees of damage due to leaning and lodging in six cultivars of winter barley grown in Belfast, UK, in 1986/87. Weighted incidences of leaning and lodging were combined to give an index indicating damage susceptibility of the cultivars. The index was very high (70) in Pipkin and ranged between 1 and 18 in the other cultivars. Differences between cultivars in number of internodes, plant height and stem weight did not explain their differences in resistance to damage. However, dry weight per unit length ranged from 2·35 and 2·34 mg/mm in the strongest cultivars, Panda and Jennifer, respectively, to 1·75 mg/mm in the weakest cultivar, Pipkin.Nitrogen application increased plant height but did not affect dry weight/main stem, so that dry weight/unit length of stem decreased. The growth regulator treatments reduced plant height and although dry weight/stem did not decrease significantly, dry weight/unit length of stem was similar in treated and untreated plots.Dry weight/unit length has potential as an objective indicator of straw strength in winter barley cultivars and could be used in cultivar evaluation in the absence of damage in field trials.


1996 ◽  
Vol 10 (4) ◽  
pp. 851-855
Author(s):  
C. Dale Monks ◽  
Michael G. Patterson ◽  
Malcolm Pegues

Field experiments were conducted in Alabama from 1992 through 1994 to evaluate the potential of the methyl ester of bensulfuron applied at sublethal rates as a plant growth regulator for reducing plant height and boll rot in cotton. Bensulfuron at 0.017 and 0.034 g ai/ha or mepiquat chloride at 10 g ai/ha was applied POST alone at the pinhead square or early-bloom stage of cotton growth or sequentially at 0.017 followed by (fb) 0.017 g/ha, 0.034 fb 0.034 g/ha of bensulfuron and 5 fb 5, 10 fb 10, 10 fb 20, or 20 fb 20 g/ha of mepiquat chloride. Mepiquat chloride had no effect on yield in 1992 and 1994 but decreased yield when applied sequentially in 1993. Bensulfuron was generally detrimental to first position fruit retention, and it delayed maturity. Treatments that reduced plant height did not reduce boll rot. Bensulfuron treatments that reduced plant height also reduced yield; therefore, the potential for its use as a growth regulator in cotton appears limited.


2020 ◽  
Vol 100 (6) ◽  
pp. 653-665
Author(s):  
B.D. Tidemann ◽  
J.T. O’Donovan ◽  
M. Izydorczyk ◽  
T.K. Turkington ◽  
L. Oatway ◽  
...  

Malting barley is important in western Canada, yet many malting cultivars do not meet malt quality standards, in part due to lodging. Lodging can decrease barley yield and quality thereby reducing the acceptability for malting. In other countries, plant growth regulator (PGR) applications are used to mitigate lodging. Chlormequat chloride (chlormequat), trinexapac-ethyl (trinexapac), and ethephon were tested at five locations over 3 yr in western Canada for their ability to limit lodging, as well as their effects on yield, agronomic traits, and pre-malt quality characteristics. PGR applications occurred between Zadoks growth stage (GS) 30–33 for chlormequat and trinexapac and GS 37–49 for ethephon. Seeding rates of 200, 300, and 400 seeds m−2 of CDC Copeland barley were used to increase the likelihood of lodging. Increased seeding rate decreased tillers per plant, height, days to maturity, kernel protein, and kernel weight. Ethephon increased the number of tillers per plant and decreased plant height, kernel plumpness, and kernel weight. Trinexapac decreased plant height and kernel weight. Days to maturity was investigated across site-years, with ethephon increasing maturity in 60% of comparisons. Trinexapac and chlormequat had limited effects on maturity. Lodging was investigated across site-years, with trinexapac showing the largest number of lodging reductions and scale of reductions. Ethephon reduced lodging in 36% of comparisons, while chlormequat had inconsistent effects. None of the products affected yield or grain protein. The results suggest PGRs may not be the solution to lodging for CDC Copeland barley on the Canadian Prairies; however, trinexapac shows the most promise of the products tested.


1992 ◽  
Vol 72 (4) ◽  
pp. 1153-1156 ◽  
Author(s):  
K. J. Kirkland

A 3-yr field experiment was conducted at the Scott Experimental Farm to determine the effect of the growth regulator, triapenthenol, on the growth and development of Argentine canola (Brassica napus L.). Triapenthenol reduced plant height 25–45 cm under optimal growing conditions. Increases in yield, branches and total pods were observed. Application at the bud stage was more effective than earlier treatment in the rosette. It was concluded that triapenthenol application to canola could be a useful management tool, particularly under optimal growing conditions.Key words: Canola, growth regulator, RSW-0411, lodging


2018 ◽  
Vol 51 (4) ◽  
pp. 60-72
Author(s):  
E.K. Eifediyi ◽  
F.O. Ogedegbe ◽  
N.B. Izuogu ◽  
C.A. Adedokun ◽  
A. Katibi ◽  
...  

Abstract The Guinea savannah zone of Nigeria is beset by increasing population and infrastructural development, thereby putting pressure on available land with rapidly declining fertility due to low organic matter content, soil erosion, high temperature and seasonal bush burning. Sesame is cultivated in this zone and the yield has remained very low, compared to yield in other parts of the world. This could be attributed to poor nutrient status and poor cultural practices used by peasant farmers. A field experiment was conducted at the Teaching and Research Farm, University of Ilorin, Nigeria, in a southern Guinea savannah zone in 2015 and repeated in 2016 cropping season to determine the effects of 2,4-Dichlorophenoxyacetic acid (2,4-D), a plant growth regulator and NPK fertilizer on the growth and yield of sesame. The experiment was laid out as a factorial arrangement, fitted into a randomized complete block design replicated thrice. The factors imposed were 2,4-D (0, 5 and 10 ppm ha−1) and NPK 15:15:15 (0, 100, 200 and 300 kg ha−1). Data were collected on vegetative traits (plant height, number of leaves, leaf area) and yield components (number of capsules per plant; yield per plant and per hectare). The data were subjected to analysis of variance (ANOVA) using the Genstat statistical package 17th edition and significant means were separated by using the least significant difference at 5% level of probability. The result revealed that using plant growth regulator and NPK fertilizer had significant effects (p<0.05) on plant height (151 cm) and yield per hectare (530 kg/ha). The qualitative and quantitative analysis of the seeds further reaffirmed the presence of bioactive compounds, such as saponins, tannins, flavonoids and phenolic compounds, which are important health promoting food in the seeds.


2000 ◽  
Vol 10 (1) ◽  
pp. 151-153 ◽  
Author(s):  
Brian E. Whipker ◽  
Shravan K. Dasoju ◽  
Michael R. Evans

Drench applications of paclobutrazol or uniconazole were applied at doses of 0, 0.0025, 0.005, 0.01, 0.02, or 0.04 mg a.i./pot (28,350 mg = 1.0 oz) to vegetatively propagated `Aurora', `Medallion Dark Red', and `Pink Satisfaction' geranium (Pelargonium ×hortorum L.H. Bailey). Geranium total plant height, leaf canopy height, and plant diameter responded similarly to drench applications of either paclobutrazol or uniconazole. There was a significant quadratic relationship between plant growth regulator (PGR) dose and total plant height and leaf canopy height for `Aurora' and `Medallion Dark Red', with total plant height and leaf canopy height being shorter as paclobutrazol or uniconazole doses increased up to 0.02 mg. However, doses of ≥0.02 mg had little additional effect on total plant height and leaf canopy height. Most of the total height control achieved by the use of PGRs was primarily due to a reduction of leaf canopy height, rather than inflorescence height. Doses of 0.005 to 0.01 mg of either PGR produced marketable sized potted plants of `Medallion Dark Red' and `Pink Satisfaction'. `Aurora', which was the most vigorous cultivar, required doses of 0.01 or 0.02 mg of either paclobutrazol or uniconazole to produce marketable sized potted plants.


2016 ◽  
Vol 26 (3) ◽  
pp. 320-326
Author(s):  
Christopher J. Currey ◽  
Kellie J. Walters ◽  
Kenneth G. McCabe

Our objective was to quantify the efficacy of different plant growth regulator (PGR) substrate drenches on growth of lantana (Lantana camara) cultivars varying in growth habit. Rooted ‘Little Lucky Peach Glow’, ‘Lucky Peach’, and ‘Landmark Peach Sunrise’ lantana cuttings were individually planted into 4-inch-diameter containers filled with a commercial, soilless growing substrate. Fourteen days after planting, solutions containing 0 (control), 0.5, 1, 2, or 4 mg·L−1 ancymidol, flurprimidol, paclobutrazol, or uniconazole were applied to the surface of the growing substrate. Six weeks after applying PGR drenches, data were collected. The growth index (GI), an integrated measurement of plant size incorporating the height and widths of plants, was calculated. There was variation in the GI among the control plants, reflecting variation among cultivars within the species. In addition, we measured variation in activity among the different PGRs applied. Across the concentrations applied, ancymidol generally had the lowest activity across the four PGRs. For example, drenches containing 4 mg·L−1 ancymidol resulted in plants that were similar to plants treated with 0.5 to 1 mg·L−1 flurprimidol or uniconazole or 2 mg·L−1 paclobutrazol for ‘Lucky Peach’ lantana. Across all cultivars, flurprimidol and uniconazole had the greatest activity in suppressing plant height, width, and GI. Substrate drenches containing flurprimidol, paclobutrazol, or uniconazole are useful to control size of lantana produced in containers, though the recommended concentration depends on the active ingredient and the growth habit of cultivars being treated.


2007 ◽  
Vol 64 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Fábio Suano de Souza ◽  
Ciro Antonio Rosolem

In some regions where cotton is grown in Brazil rainfall amounts to about 2,000 mm per year, which imposes a great risk for Mepiquat Chloride (MP) to be washed from cotton leaves before being absorbed. The objective of this research was to evaluate the MC persistence when applied on cotton plants submitted to different rain intensities after spraying. The treatments were three MC rates: 0, 15.0 and 30.0 g a.i. ha-1 and four simulated rainfalls, applied 90 minutes after MC spraying: 5, 10, 20 and 40 mm, plus a treatment without rain. Cotton plants of the cv. Delta Opal were grown in 12 L pots filled with an Haplortox. The experimental design was consisted of complete randomized blocks, in a factorial scheme, with four replicates. The evaluated parameters were: plant height, number of reproductive branches, dry matter weight, reproductive structures, retention and leaf area. The higher the rainfall the lower the effectiveness of the plant growth regulator in controlling plant height. A simulated rainfall as low as 5 mm occurring 90 minutes after MC application was enough to wash some of the plant growth regulator from cotton leaves.


2017 ◽  
Vol 23 (3) ◽  
pp. 307 ◽  
Author(s):  
Christiane de Fátima Martins França ◽  
Lucas Cavalcante Da Costa ◽  
Wellington Souto Ribeiro ◽  
Teresa Drummond Correia Mendes ◽  
Mirelle Nayana De Sousa Santos ◽  
...  

The effects of three paclobutrazol (PBZ) application methods on ornamental characteristics of two pepper cultivars (‘Biquinho Vermelha’ and ‘Bode Amarela’) were evaluated. Plant growth regulator at 10 μM PBZ was added at transplanting by drenching 250 mL PBZ solution on the pot substrate, foliar spray of 10 mL PBZ solution or by submerging seedlings root + substrate for 10 seconds in the PBZ solution. Control plants were treated with tap water applied directly on the substrate. Plant height, canopy compactness, fruits and leaves number, and leaf chlorophyll content were evaluated when 50% of the plants had approximately 30% of mature fruits (commercial maturity). PBZ applied by drenching influenced positively the ornamental characteristics of ‘Bode Amarela’. Otherwise, the best PBZ application method for ‘Biquinho Vermelha’ was not established. The results suggest that search for suitable PBZ application method that no affects the pepper ornamental characteristics must be done specifically for each pepper cultivar.


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