Growth Response and Carbohydrate Status of Gibberellin-treated Spectral Filter-grown Chrysanthemum Plants

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 522c-522
Author(s):  
Anuradha Tatineni ◽  
Sonja L. Maki ◽  
Nihal C. Rajapakse

Interest in the use of non- (or less) chemical methods to reduce the height of ornamental crops has increased tremendously. Manipulation of greenhouse light quality is one alternative for plant growth regulation. We have shown that eliminating far-red light from the greenhouse environment with liquid CuSO4 spectral filters is effective in reducing the height of a wide range of plants though plant carbohydrate status is also altered under CuSO4 filter. In previous studies, application of GA3 reversed both the reduction of plant height and carbohydrate status of CuSO4 spectral filter grown plants. It has been proposed that GAs enhance the activity of the enzyme sucrose phosphate synthase to regulate carbohydrate levels. In the present study the role of exogenously applied GA19, GA1, and GA3 in overcoming the reduction of plant height and carbohydrate levels was investigated. Chrysanthemum plants were treated weekly for 4 weeks with saturating doses of GA19, GA1 and GA3 (25 μg) or the growth retardants paclobutrazol and prohexadione. GA1 was also applied with paclobutrazol and prohexadione to assess whether response to GAs is altered under CuSO4 filter. GA1 and GA3 promoted growth similarly under control or CuSO4 filter. GA19 was least effective in promoting growth under CuSO4 filter. In summary, these results suggest that gibberellin physiology is altered under spectral filters with the conversion of GA19 a possible point of regulation. The correlation between the carbohydrate status and the growth of the plants will be discussed.

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 745d-745
Author(s):  
Venkat K. Reddy ◽  
Nihal C. Rajapakse

The response of `Bright Golden Anne' chrysanthemum plants grown under CuSO4 spectral filters to exogenous GA3 application was evaluated to determine the relationship between gibberellins (GAs) and carbohydrate levels. The CuSO4 filters removed far red (FR) wavelengths of light and increased red: far red (R:FR), blue: far red (B:FR), blue: red (B:R) ratios, and phytochrome photoequilibrium (Ø) values of transmitted light compared to water (control) filter. Plant height, internode length, and leaf and stem dry weights were significantly reduced by light passing through CuSO4 filters in spring and summer seasons. Weekly applications of exogenous GA3 reversed the reduction in height and internode length induced by CuSO4 filters. Plants grown under CuSO4 filters responded more to exogenous GA3 application with respect to height and internode length, suggesting that the sensitivity to GA was not lowered. Light passing through CuSO4 filters reduced the carbohydrate levels, but the response varied with the season. Weekly GA3 application increased the carbohydrate levels, but did not totally reverse the reduction in carbohydrate levels under the CuSO4 filters. Although GA3 application increased the carbohydrate levels partially in CuSO4 filter-grown plants, the inhibition of GAs may not be solely responsible for reduction of carbohydrate levels under CuSO4 filters, showing that exogenous GAs and carbohydrate levels are not well correlated under CuSO4 spectral filters.


Nabatia ◽  
2016 ◽  
Vol 4 (2) ◽  
pp. 57-63
Author(s):  
M Abror ◽  
M Koko Ardiansyah

This study aims to determine the effect of trimming with a wide variety of growing media hydroponic system fertigation on growth and yield of melon. Research will be conducted in the green house (House of plastic) UMSIDA Agriculture Faculty, Campus 2, Gelam, Candi, Sidoarjo, research time between the months of March to June 2016 using analysis of variance and continued test HSD 5%. The variables measured were plant height, leaf number, level of sweetness of fruit, fruit weight, high-fruit, thickness of the flesh of the fruit, conclusion from this research is going on the effect of trimming and a wide variety of growing media hydroponic system fertigation in treatment PM5 (trimming down, kokopit). There was also a real influence on the treatment PM6 (without pruning, kokopit) .In observation of plant height, leaf number, fruit weight, and high fruit. And also happens to influence a wide range of growing media on growth and yield of melon on hydroponics fertigation system, the PM6 treatment (without pruning, kokopit) had the highest rates in the observation of plant height, weight of the fruit, and the number of leaves.


Author(s):  
Andréia de L. Moreno ◽  
Jorge F. Kusdra ◽  
Angelita A. C. Picazevicz

ABSTRACT Rhizobacteria have a wide range of plant growth-promoting mechanisms of action, making them an alternative and/or complementary biological input for chemical fertilizers. In this respect, the present study aimed to assess growth and nitrogen accumulation in maize plants as a function of Azospirillum brasilense, Bacillus subtilis, zinc and nitrogen application at sowing. The experiment with the ‘AL Bandeirante’ maize variety was conducted in a greenhouse, using a completely randomized design. The treatments were arranged in a 2 x 2 x 2 x 2 factorial scheme, with six repetitions, considering the presence and absence of Azospirillum brasilense (5 g kg-1), Bacillus subtilis (5 mL kg-1) and zinc (20 g kg-1) in the seeds and addition or not of nitrogen (30 kg ha-1) to the soil. The variables assessed were plant height, stem diameter, leaf, stem, shoot, root and total dry weight, and shoot nitrogen content. Nitrogen fertilization in the absence of zinc increased shoot and total dry weight as well as shoot nitrogen content. Zinc applied to the seeds improved the total and stem dry weight of maize plants in the absence of Bacillus subtilis. Inoculation with Azospirillum brasilense and Bacillus subtilis increased the stem diameter and shoot nitrogen content of maize plants when nitrogen fertilization was not performed at sowing. There was no isolated or interaction effect between factors for plant height and root dry weight.


Author(s):  
V. Nirubana ◽  
R. Ravikesavan ◽  
K. Ganesamurthy

Background: Kodo millet is an important drought tolerant crop and has high nutritional values, dietary fiber and antioxidant properties. It has considerable production potential in marginal and low fertility soils under diverse environmental conditions. Considering the importance of the crop, it is necessary to improve the nutritional quality along with grain yield of the crop. With this background, the investigation was aimed to study the correlation and path coefficient analysis which helps to identify the promising traits for yield and quality improvement. Methods: One hundred and three kodo millet germplasm lines were evaluated for 13 morpho-agronomic and two grain nutritional traits. The crop was raised in randomized block design to select the promising genotypes and to study the association among the traits and the magnitude of direct and indirect effects for fifteen quantitative traits. Result: Based on the overall mean performance the significant genotypes were identified and found wide range of variability for different traits. Character association studies indicated that days to first flowering, days to 50 per cent flowering, plant height, number of productive tillers, peduncle length, inflorescence length, length of the longest raceme and thumb length were significantly positive association with grain yield per plant. Path coefficient analysis revealed that inflorescence length, plant height, length of the longest raceme, flag leaf blade length and number of productive tillers exhibited high direct positive effect on grain yield. Therefore, giving importance of these traits during selections may be useful for developing nutritionally superior high yielding kodo millet genotypes.


2018 ◽  
Vol 98 (6) ◽  
pp. 1321-1330
Author(s):  
Jaimin S. Patel ◽  
Leora Radetsky ◽  
Mark S. Rea

Sweet basil (Ocimum basilicum L.) is primarily used for culinary purposes, but it is also used in the fragrance and medicinal industries. In the last few years, global sweet basil production has been significantly impacted by downy mildew caused by Peronospora belbahrii Thines. Nighttime exposure to red light has been shown to inhibit sporulation of P. belbahrii. The objective of this study was to determine if nighttime exposure to red light from light-emitting diodes (λmax = 625 nm) could increase plant growth (plant height and leaf size) and yield (number and weight of leaves) in basil plants. In two sets of greenhouse experiments, red light was applied at a photosynthetic photon flux density of 60 μmol m−2 s−1 during the otherwise dark night for 10 h (from 2000 to 0600). The results demonstrate that exposure to red light at night can increase the number of basil leaves per plant, plant height, leaf size (length and width), and leaf fresh and dry weight compared with plants in darkness at night. The addition of incremental red light at night has the potential to be cost-effective for fresh organic basil production in controlled environments.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 272 ◽  
Author(s):  
Muhammad Azhar Nadeem ◽  
Tolga Karaköy ◽  
Mehmet Zahit Yeken ◽  
Ephrem Habyarimana ◽  
Ruştu Hatipoğlu ◽  
...  

Plant landraces represent a repository of a gene pool, local adaptation of their domestic species, and thereby are considered a great source of genetic variations. Such genetic variation can be helpful to mitigate the current and future food challenges. A total of 183 common bean accessions including three commercial varieties collected from 19 Turkish provinces were grown to record their morpho-agronomic variations and to evaluate the best performing accessions under multi-environmental conditions. Plant height, days to maturity, pods weight, seed length, and 100-seed weight were used to evaluate the best performing accessions under different environmental conditions. A wide range of variations for traits like days to maturity (99–161), plant height (21–168.7 cm), seed length (7.41–16.4 mm), seeds per plant (17.8–254.4), and 100-seeds weight (24.97–73.8 g) were observed and can be useful for breeding purposes. The analytic results derived from the first three eigenvectors suggested that plant height, plant weight, 100-seed weight, and days to flowering were biologically significant bean traits. Seed yield per plant was positively and significantly correlated with plant weight and pods weight. Genotype × environment biplot discriminated the studied common bean accessions based on their plant height and growth habit. Plant height, days to maturity, seed width, and first pod height were found highly heritable traits and were least affected by environmental forces. Among 19 provinces, accessions of Bilecik showed maximum pods per plant, seed yield per plant and 100-seed weight, while Erzincan and Sivas provinces reflected the prevalence of bushy and early maturing accessions. Information provided herein comprehensively explored the occurrence of genotypic variations which can be used for the development of candidate varieties responding to breeder, farmer, and consumer preferences.


2015 ◽  
Vol 8 (1) ◽  
pp. 1-11 ◽  
Author(s):  
A.A. Eslami ◽  
S.A. Khodaparast ◽  
S. Mousanejad ◽  
F. Padasht Dehkaei

Summary Sclerotium rolfsii is a soil borne pathogen responsible for root and stem rot on a wide range of crops. This study was conducted to identify the virulence of different S. rolfsii isolates on a susceptible local peanut germplasm and determine the resistance of 20 peanut genotypes to the most virulent isolate and also the relationship between virulence and mycelial compatibility groups (MCGs). Seventy eight isolates of this fungus from 10 host plants and six known MCGs were used in the experiment. The experiment was done in greenhouse conditions (25±5°C) using a complete randomized block design with three replications. Pots containing sterile soil (pH=6.7) were inoculated with barley seeds colonized by each isolate separately before being seeded with the peanut germplasm. Disease severity was assessed by scoring the wilting, yellowing or death of plants, mycelia or sclerotia production on the soil surface or on plant stem, stem area affected (%) and stem lesion length, at the stage of plant maturity. Also, shoot wet weight and plant height were recorded at this stage. According to the results of the pathogenicity tests, all of the isolates were virulent on the susceptible peanut germplasm and the virulence diff ered signifi cantly between the isolates (P≤0.01). There was no relationship between the virulence of the five groups of isolates identified in the present study and the MCGs. The peanut genotype 140, which was better than the others based on seed size, plant height and the canopy size, was also the most resistant one


2014 ◽  
Vol 70 (4) ◽  
Author(s):  
Tanweer Hasan ◽  
Ishtiaque Ahmed ◽  
Hamid O. Al-Bar

There is an increased public concern about the role of aggressive driving and "road rage" in crashes and traffic fatalities. There is no general agreement as to what constitutes aggressive driving. Consequently, the objective of the study was to survey of the perceptions on the specific unsafe driving acts. Perceptions and beliefs of drivers about unsafe and aggressive driving actions and their countermeasures are presented in this paper. The study primarily looked at the wide range of driver attitudes about speeding and other forms of unsafe driving behavior. The study was conducted in Jeddah, the second largest city of Saudi Arabia by interviewing a sample of 300 drivers. The results indicated that the drivers, in general, prefer to drive at higher speeds and could be considered as more aggressive compared to the drivers in the United States. The most dangerous reported driving act was "drive thru red light", followed by "racing another driver". Only 23% of the drivers thought that it was dangerous to drive over 30 km of the legal speed limits. The most often seen unsafe driving action was "speeding (70%), followed by "driving too closely (57%), "failing to use turn signals (53%), "drive inattentively (50%)", and "running red lights (43%)". The main causes of unsafe driving behaviors were "being in a hurry/time pressure (66%)", "aggressive behavior of others (52%)", and "refusing traffic rules (51%)". The countermeasure that was viewed to be the most effective in reducing unsafe driving behaviors was assigning more traffic police officers (66%). The study revealed that, more than half the drivers believed that more frequent ticketing (60%), doubling or tripling fines (54%), and doubling the length of imprisonment (53%) would be effective in reducing unsafe driving behaviors.


1993 ◽  
Vol 53 (3) ◽  
pp. 249-259 ◽  
Author(s):  
Nihal C. Rajapakse ◽  
Margaret J. McMahon ◽  
John W. Kelly

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