scholarly journals Growth Control of Lisianthus by Photoselective Plastic Films

2001 ◽  
Vol 11 (4) ◽  
pp. 581-584 ◽  
Author(s):  
Sandra B. Wilson ◽  
Nihal C. Rajapakse

Plant response to photoselective plastic films with varying spectral transmission properties was tested using lisianthus (Eustoma grandiflorum) `Florida Pink', `Florida Blue', and `Florida Sky Blue'. Films were designated YXE-10 (far-red light-absorbing film) and SXE-4 (red light absorbing film). Light transmitted through YXE-10 films reduced plant height compared to control plants by 10% (`Florida Blue'), and stem dry weight by 19% to 40%, but the response varied by cultivar. Internode length was reduced by 10% to 19% when `Florida Pink' and `Florida Sky Blue' plants were grown under YXE-10 films. Leaf and root dry weights were not affected by YXE-10 films, with the exception that `Florida Sky Blue' plants had a lower leaf dry weight than the control plants. Light transmitted through SXE-4 films increased plant height of `Florida Pink' plants by 15% but not of `Florida Blue' or `Florida Sky Blue.' Regardless of cultivar, dry weight of leaf, stem and root tissue was not affected by SXE-4 films as compared to control films. The average number of days to flower and bud number were not affected by YXE-10 or SXE-4 films, regardless of cultivar. The results suggest that selective reduction of far-red wavelengths from sunlight may be an alternative technique for greenhouse production of compact plants, but the magnitude of the response is cultivar specific.

2001 ◽  
Vol 19 (2) ◽  
pp. 65-68
Author(s):  
Sandra B. Wilson ◽  
Nihal C. Rajapakse

Abstract Plant response to photoselective plastic films with varying spectral distribution properties was tested using three sub-tropical perennials: golden shrimp plant (Pachystachys lutea), Persian shield (Strobilanthes dyerianus), and cat whiskers (Orthosiphon stamineus). Films were designated YXE-10 [far-red (FR) light-absorbing film] and SXE-4 [red (R) light absorbing film]. Light transmitted through YXE-10 films reduced plant height (stem length) of golden shrimp plant and cat whiskers by 10 and 20%, respectively. Light transmitted through SXE-4 films increased plant height by 9% for golden shrimp plant but did not significantly increase stem length of Persian shield and cat whiskers species. Chlorophyll, leaf area, and mean days to flower generally were not affected by photoselective films, with the exception that cat whisker plants grown under YXE-10 films had reduced leaf area when compared to plants grown under SXE-4 or control films. As compared to the control film, light transmitted through YXE-10 films reduced leaf dry weight by 22–31% and stem dry weight by 19–28%, depending on the plant species. Root dry weight was not affected by spectral films.


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.


Pastura ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 33
Author(s):  
Roni N.G.K. ◽  
S.A. Lindawati

The productivity of forage depends on the availability of nutrients in the soil where it is grown, so fertilization to replace harvested produce is absolutely necessary. This study aims to study the response of gamal and indigofera forage on application of inorganic and organic fertilizers. Research using a completely randomized design factorial pattern of two factors, the first factor is the type of plant (G = Gamal; I = Indigofera) and the second factor is the type of fertilizer (T = without Fertilizer; A = Inorganic fertilizer NPK; K = commercial organic fertilizer; O = conventional organic fertilizer; B = bioorganic fertilizer), repeated 4 times so that it consists of 40 experimental units. The variables observed were plant height, number of leaves, stem diameter, leaf dry weight, stem dry weight, total dry weight of leaves, ratio of dry weight of leaves/stems and leaf area per pot. The results showed that there was no interaction between plant species and types of fertilizer in influencing the response of gamal and indigofera plants. Plant species have a significant effect on stem diameter, while fertilizer types have a significant effect on plant height, leaf dry weight, total dry weight of leaves and leaf area per pot. Based on the results of the study it can be concluded that the response of gamal plants is similar to indigofera, all types of fertilizers can improve the response of plants and organic fertilizers produce the same crop response with inorganic fertilizers. Keywords: gamal, indigofera, inorganic fertilizer, organic fertilizer


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 674e-674
Author(s):  
Joseph P. Albano ◽  
William B. Miller

Our objective was to assess the susceptibility of seven marigold varieties to Fe toxicity. Marigold varieties included were one hedge type, `Orange Jubilee'; five semi-dwarf types, `First Lady', `Gold Lady', `Orange Lady', `Marvel Gold', and `Yellow Galore'; and one dwarf type, `Discovery Orange'. Plants were grown in a greenhouse in a soilless medium and treatments consisted of 0.018 mm (low) and 0.36 mm (high) Fe-DTPA incorporated into a nutrient solution. Plant height was not affected by Fe treatment and ranged from 32 cm in `Orange Jubilee', 13 to 14 cm in the semi-dwarf varieties, and 7.0 cm in `Discovery Orange'. Leaf dry weight per plant was not affected by Fe treatment and ranged from 1.15 g in `Orange Jubilee', 0.68 to 0.95 g in the semi-dwarf varieties, and 0.56 g in `Discovery Orange'. Symptoms of Fe toxicity only developed in the high Fe treatment, and the percent leaf dry weight separated at harvest as symptomatic ranged from 97% in `Orange Jubilee', 55% to 85% in the semidwarf varieties, and 15% in `Discovery Orange'. The Fe concentration in leaves in the high Fe treatment was 5.7-times greater in `Orange Jubilee', 2 to 3-times greater in the semi-dwarf varieties, and 1.6-times greater in `Discovery Orange' than in the low Fe treatment. Based on these findings, `Orange Jubilee' and `Discovery Orange' were the most and least susceptible varieties, respectively, to Fe toxicity of the seven marigold varieties evaluated in this study.


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.


2016 ◽  
Vol 3 (1) ◽  
pp. 17
Author(s):  
. Djumali

<p>Hasil dan mutu tembakau temanggung merupakan hasil interaksi pengaruh genetik tanaman dan kondisi ling-kungan tumbuh. Pada tembakau virginia, peubah-peubah agronomi tanaman merupakan karakter genetik ta-naman yang mempengaruhi hasil dan mutu. Pada tembakau temanggung, hal ini belum diketahui. Penelitian yang bertujuan untuk memperoleh peubah agronomi sebagai karakter genetik tembakau temanggung dan ka-itannya dengan hasil dan mutu rajangan kering dilakukan di rumah kaca Balittas, Malang sejak Maret–Agus-tus 2008. Sembilan kultivar tembakau temanggung disusun dalam rancangan acak kelompok yang diulang ti-ga kali. Pengamatan dilakukan terhadap peubah agronomi yang dimulai pada saat pemangkasan sampai pa-nen akhir. Hasil penelitian menunjukkan bahwa peubah agronomi yang meliputi tinggi tanaman, sudut daun, luas daun, jumlah daun, bobot spesifik daun, luas daun per helai, bobot kering tanaman, bobot kering tajuk, bobot kering akar, rasio tajuk/akar, bobot kering batang, bobot kering daun, bobot kering bunga, dan bobot kering tunas samping merupakan karakter genetik tembakau temanggung. Karakter agronomi tersebut mem-pengaruhi hasil dan mutu rajangan kering dengan total pengaruh masing-masing sebesar 92,8% dan 76,7%. Lima karakter agronomi utama yang mempengaruhi hasil rajangan kering adalah luas daun per helai, jumlah daun, bobot spesifik daun, tinggi tanaman, dan bobot kering daun dengan total pengaruh sebesar 89,4%. Adapun lima karakter agronomi utama yang mempengaruhi mutu rajangan kering adalah luas daun, rasio tajuk/akar, bobot kering tanaman, bobot kering bunga, dan tinggi tanaman dengan total pengaruh sebesar 75,7%.</p><p> </p><p>The yield and quality of temanggung tobacco are influenced by plant genetic and growth environmental. In virginia tobacco, plant agronomic variables were genetical characteristics determining yield and quality. The effect of agronomical characteristic on yield and quality of temanggung tobacco is not yet well defined. The research which aim to find plant agronomical variables as genetic characters and its relationship on dry slice and quality of temanggung tobacco, was conducted in glass house of IToFCRI, Malang from March–August 2008. Nine cultivars of temanggung tobacco were arranged in randomized block design and three replica-tions. The results showed that agronomic variables i.e. plant height, leaf angle, leaf area, number of leaf, spe-cific leaf weight, leaf area per strand, plant dry weight, shoot dry weight, root dry weight, shoot/root ratio, bast dry weight, leaf dry weight, flower dry weight, and sucker dry weight were genetic characters of temang-gung tobacco, which had effect on yield and quality with total effect of them were 92.8% and 76.7% res-pectively. Leaf area per strand, number of leaf, specific leaf weight, plant height, and leaf dry weight were agronomical characteristics which had significant effect on dry slice yield of 89.4%. Leaf area, shoot/ root ra-tio, plant dry weight, flower dry weight, and plant height were agronomical characteristics which had signi-ficant effect on quality of 75.7%.</p>


2003 ◽  
Vol 60 (1) ◽  
pp. 65-69 ◽  
Author(s):  
Maria Cristina Veiga De Vincenzo ◽  
João Tessarioli Neto

Summer-planted onion (Allium cepa L.) can increase grower profits, but the production of seedlings for transplant is difficult. This experiment was carried out in Piracicaba, SP, Brazil, with the objective of studying the behavior of the short-day onion hybrid Mercedes, in its initial stage, under controlled greenhouse environment, as summer-planted onions. Four formulated substrates, two different numbers of plants per cell were tested, and 288-cell styrofoam trays used. Trials were set up in split-plot design (n=3). Substrate and number of plants per cell represented main plots, and N application (2 and 3 times a week) the subplots. The number of three plants per cell decrease the earlier onset of bulbing and increase plant height; substrates did not show differences; and the N application 3 times a week increased plant height and leaf dry weight, but did not result in earlier onset of bulbing.


HortScience ◽  
2002 ◽  
Vol 37 (2) ◽  
pp. 319-321 ◽  
Author(s):  
Amanda Miller ◽  
Allan M. Armitage

The influence of temperature, irradiance, photoperiod and growth retardants on growth and flowering of Angelonia angustifolia Angel Mist series was evaluated. When temperature was increased from 15 to 30 °C, time to visible bud and time to flower decreased in a quadratic manner but total plant height and flower stem dry weight increased linearly. As irradiance increased, time to flower, time to visible bud, and height decreased quadratically. Changes in photoperiod had no effect on growth or flowering, suggesting that A. angustifolia is a day-neutral species with regards to height and flowering time. Daminozide, ancymidol, and paclobutrazol resulted in significant reduction of plant height compared with control plants but did not influence flowering time. Chemical names used: K-cyclopropyl-K-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); butanedioic acid mono (2,2-dimethylhydrazide) (daminozide); K-[(4-chlorophenyl)methyl]-K-(1,1-dimethyethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 834F-835
Author(s):  
Venkat K. Reddy ◽  
Nihal C. Rajapakse

The influence of removal of specific wavelengths [red (R), blue (B), and farred (FR)] from sunlight on the height of chrysanthemum plants was investigated by overlaying Roscolux™ colored acetate films on 4% CuSO4 or water (control) spectral filters. CuSO4 filters removed FR wavelengths and significantly reduced plant height and internode length compared to control plants that received B, R, and FR wavelengths of light. Plants grown under Roscolux blue filters did not receive R light and were significantly taller compared to plants from any other treatments. Plants grown under Roscolux red filters did not receive B light and were significantly shorter compared to plants from other treatments. Leaf area, leaf dry weight, and stem dry weight were highest in plants grown under Roscolux red and control filter combination. The amount of leaf chlorophyll and the ratio of Chl A: Chl B was highest in plants grown under Roscolux blue filters. In general, plants that received FR light (control + film) were taller than the plants that did not receive FR light in the corresponding (CuSO4 + film) filter combination. The influence of removal of specific wavelengths on plant height control and developmental physiology will be discussed.


Pastura ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 105
Author(s):  
Roni N. G. K. ◽  
S. A. Lindawati

This study aims to obtain a study of the productivity of Gliricidia sepium and Indigofera zollingeriana plants which are given various dosage of bioorganic fertilizer. This study used a completely randomized design of factorial patterns of two factors: the first factor was the type of plant (G = Gamal; I = Indigofera) and the second factor was the dosage of bioorganic fertilizer: D0 = without fertilizer; D1 = 5 tons ha-1; D2 = 10 tons ha-1; D3 = 15 tons ha-1; D4 = 20 tons ha-1; D5 = 25 tons ha-1; and D6 = 30 tons ha-1, so there are 14 treatment combinations. Each treatment was repeated three times so that it consisted of 42 experimental units. The variables observed were plant height, leaf number, stem diameter, leaf dry weight, stem dry weight, total herbage dry weight, amount of chlorophyll, ratio of dry weight of leaf / stems, and leaf area per pot. The results showed that the productivity of Indigofera zollingeriana significant higher than Gliricidia sepium. The application of bioorganic fertilizer significantly increased plant height, leaf number, dry weight leaf, stem dry weight, total forage dry weight, amount of chlorophyll, and leaf area per pot, and the highest yield at 30 tons/ha. Based on the results of the study it can be concluded that the productivity of Indigofera zollingeriana is higher than Gliricidia sepium, bioorganic fertilizer increased plant productivity with the highest yield at 30 tons ha-1, and interaction only occurs in the leaf area per pot. Keywords: Indigofera zollingeriana, Gliricidia sepium, dosage of fertilizer, bioorganic fertilizer


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