Concentrations Of Ethephon Research Articles

On the mechanism of genotoxicity of ethephon on embryonic fibroblast cells

Ethephon is one of the most widely used plant growth regulator in agriculture that its application has been increased in recent years. Many reports have raised concern over the safety of this organophosphorus compound. The aim of the current study was to assess the potential genotoxic effect of ethephon on murine embryonic fibroblast (MEF) cell line, using two genotoxicity endpoints: γH2AX expression and comet assay. γH2AX served as an early and sensitive biomarker of genotoxic damage. Oxidative stress biomarkers, including reactive oxygen species (ROS), lipid peroxidation (LPO) and total antioxidant capacity were also examined. The results showed a significant increase in cell proliferation, 24 h post-treatment with 10, 40,160 μg/ml ethephon, while at the higher concentrations cytotoxic effect was observed. The γH2AX expression and γH2AX foci count per cell were significantly increased at non-cytotoxic concentrations of ethephon, accompanied with increased DNA damage as illustrated by comet assay. LPO and ROS levels were elevated only at 160 μg/ml and higher doses. The results interestingly showed that low non-cytotoxic doses of ethephon promoted DNA damage inducing cell proliferation, raising the possibility of ethephon mutagenicity. The genotoxic effect of ethephon at low doses might not relate to oxidative damage and that increased in the level of ROS and LPO generation at higher doses could account for the cytotoxic effect of ethephon. Taken together, our study provides strong in vitro evidence on potential genotoxicity of ethephon at low doses. More precise studies are needed to clarify the mutagenic effect of chronic exposure to ethephon.

Concentration and Timing of Ethephon Drench Applications Interact to Affect Growth and Flowering of Containerized Angelonia and Geranium

Ethephon drenches have been reported to effectively control growth of containerized bedding plants. However, previous researchers have indicated that the effects of ethephon drenches on growth and flowering may differ depending on the timing of applications. Our objectives were to quantify the effects of ethephon concentration, timing of substrate drench application, and their interaction on the growth, size, and flowering of two annual bedding plants. Angelonia (Angelonia angustifolia) and geranium (Pelargonium ×hortorum), seedlings were planted in 10.2-cm-diameter containers filled with a commercial, soilless growing substrate composed of (by vol.) 75% sphagnum peatmoss, and 25% perlite. Five, 10, 15, or 20 days after transplanting seedlings, 70-mL aliquots containing 0, 50, 100, or 200 mg·L−1 ethephon were applied as substrate drenches. Species varied in their growth and flowering responses to ethephon concentration, drench application timing, and their interaction. For angelonia, flowering was delayed most with early applications and high concentrations, and delay was diminished with later applications. Angelonia height was unaffected by late applications, though lateral growth was suppressed 20 days after transplant with 200 mg·L−1 ethephon. Flowering of geranium was only delayed when ethephon was applied 5 days after transplanting, whereas flowering, vegetative height, and shoot dry weight were affected more by earlier applications and higher concentrations. Width and root weight were only affected by ethephon concentration, with growth suppression increasing as concentrations increased. Ethephon is an effective growth regulator when applied as a substrate drench. However, the degree of activity and resulting impact on flowering, size, and growth is influenced by the interaction between ethephon concentrations and the timing of drench applications after transplanting.

Effects and Mechanism of 1-Methylcyclopropene and Ethephon on Softening in Ailsa Craig Tomato Fruit

Studies were conducted to determine the efficacy and mechanism of 1-methylcyclopropene (1-MCP) and ethephon on softening of Ailsa Craig tomato fruit. Ethylene production, reduction of fruit firmness and protopectin content were suppressed in fruit exposed to 1.0 µL/L 1-MCP. Comparing with control fruit, the climacteric ethylene peak was delayed by approximately 12 d and polygalacturonase activity was strongly inhibited in 1.0 µL/L 1-MCP treated fruit. On the other hand, ethylene production, reduction of fruit firmness, protopectin content and polygalacturonase activity of 100 µL/L ethephon treated fruit were strongly promoted compared with these indexes of untreated fruit. Moreover, electrophoretic mobility shift assay (EMSA) and Chromatin Immunoprecipitation (ChIP) assay proved that the expression of PG and tomato fruit softening was regulated by the transcription activator RIN. Practical Applications The RIN transcription factor plays an indispensable role in fruit ripening and softening. According to the physiological index of tomato fruit under varied concentrations of 1-MCP and ethephon, optimal concentrations of 1-MCP and ethephon would be used for further studies and industrial applications. Furthermore our study clearly showed RIN transcription factor directly regulated the expression of PG. Since the importance of polygalacturonase (PG) activity and indispensable role of RIN during the process of fruit softening, it suggested that RIN affects tomato fruit softening via directly acting on PG. It provides new clues to understand the molecular mechanism of fruit softening. To sum, these results will help to further clarify the mechanism of tomato fruit softening, and to maintain the quality and prolong the shelf life of tomato fruit.

Branching, flowering and fruiting of Jatropha curcas treated with ethephon or benzyladenine and gibberellins.

Jatropha curcas L. has been identified for biofuel production but it presents limited commercial yields due to limited branching and a lack of yield uniformity. The objective of this study was to evaluate the effects of single application of ethephon or a combination of 6-benzyladenine (BA) with gibberellic acid isomers A4 and A7 (GA4+7) on branch induction, flowering and fruit production in jatropha plants with and without leaves. Plants with and without leaves showed differences for growth and reproductive variables. For all variables except inflorescence set, there were no significant statistical interactions between the presence of leaves and plant growth regulators concentration. The total number of flowers per inflorescence was reduced as ethephon concentration was increased. As BA + GA4 +7 concentration increased, seed dry weight increased. Thus, ethephon and BA + GA4 +7 applications appeared to affect flowering and seed production to a greater extent than branching. The inability to discern significant treatment effects for most variables might have been due to the large variability within plant populations studied and thus resulting in an insufficient sample size. Therefore, data collected from this study were used for statistical estimations of sample sizes to provide a reference for future studies.

Role of ethylene in germination and seedling growth of littleseed canarygrass (Phalaris minor Retz.)

Littleseed canarygrass is a major weed of wheat in rice–wheat cropping system of North-West India. The present study was conducted to study the role of ethylene in germination ecology and seedling growth of littleseed canarygrass and wheat using cobalt chloride (inhibitor of ethylene synthesis) and ethephon (ethylene source). Cobalt chloride at concentrations ≥0.1 mM caused significant reduction in germination (%), germination index and increased the mean germination time of littleseed canarygrass, whereas wheat seeds exhibited significant decrease in germination (%) at cobalt chloride concentrations ≥0.5 mM. Cobalt chloride at higher concentrations significantly reduced the seedling growth of littleseed canarygrass and wheat with more pronounced effect on root length as compared to shoot length. It also significantly increased the membrane leakage and soluble sugar content of seedlings of both species with concomitant decrease in chlorophyll and protein content. Ethephon at 0.1 and 1 mM concentrations significantly increased the germination (%), speed of germination with concomitant decrease in mean germination time as compared to control. Ethephon concentrations 0.1 and 1 mM had no effect on membrane leakage, total soluble sugars and protein content but increased the chlorophyll content in seedlings of both species. Seed dormancy of littleseed canarygrass induced by higher concentrations of cobalt chloride, i.e., 2.5 and 5 mM could also be overcome by treatment with 1 mM ethephon, confirming the role of ethylene in germination of this weed.

Ethephon As a Potential Abscission Agent for Table Grapes: Effects on Pre-Harvest Abscission, Fruit Quality, and Residue.

Some plant growth regulators, including ethephon, can stimulate abscission of mature grape berries. The stimulation of grape berry abscission reduces fruit detachment force (FDF) and promotes the development of a dry stem scar, both of which could facilitate the production of high quality stemless fresh-cut table grapes. The objective of this research was to determine how two potential abscission treatments, 1445 and 2890 mg/L ethephon, affected FDF, pre-harvest abscission, fruit quality, and ethephon residue of Thompson Seedless and Crimson Seedless grapes. Both ethephon treatments strongly induced abscission of Thompson Seedless berries causing >90% pre-harvest abscission. Lower ethephon rates, a shorter post-harvest interval, or berry retention systems such as nets, would be needed to prevent excessive pre-harvest losses. The treatments also slightly affected Thompson Seedless berry skin color, with treated fruit being darker, less uniform in color, and with a more yellow hue than non-treated fruit. Ethephon residues on Thompson Seedless grapes treated with the lower concentration of ethephon were below legal limits at harvest. Ethephon treatments also promoted abscission of Crimson Seedless berries, but pre-harvest abscission was much lower (≅49%) in Crimson Seedless compared to Thompson Seedless. Treated fruits were slightly darker than non-treated fruits, but ethephon did not affect SSC, acidity, or firmness of Crimson Seedless, and ethephon residues were below legal limits.

Influence of ethephon on ripening and quality of winter tomato fruit harvested at different maturity stages

An experiment taking tomato fruits (cv. BARI Tomato-14) of three maturity stages (mature green stage, breaker stage and half ripen stage) and four ethephon levels [control (distilled water spray), 500, 750 and 1000 ppm] was carried out at the laboratory of plant physiology section of Horticulture research centre, Bangladesh Agricultural Research Institute) during February 14, 2013 to February 27, 2012 to find out the suitable stage of fruit maturity for post harvest application of ethephon (ethrel) for tomato ripening. The source of ethrel was Spectrum (ethephon 39%) manufactured in the United States of America. Treatment with 500 - 1000 ppm ethephon hastened ripening of tomato by 4 days in mature green stage but by 2 and 4 days in breaker stage tomatoes when compared with control fruits. The highest value of rotting was shown by half ripen tomatoes. The 1000 ppm ethrel gave the maximum rotting irrespective of maturity stages. However, the maximum weight loss and shelf life were found in green mature tomatoes. The shelf life of tomato fruits of green mature and breaker stage tomatoes treated with 500 and 750 ppm was also high. The percentage of rotting and weight loss was increased with gradual advancement of time. The highest value of weight loss and shelf life was recorded in green mature tomatoes without ethephon and with 500 and 750 ppm ethephon treatment. The highest value of vitamin-C, TSS and titrable acidity were shown by half ripen and pH by green mature tomatoes at different days of storage. The ethephon concentration of 750 ppm the gave maximum vitamin-C at 6 and 9 days of storage but 1000 ppm gave the maximum TSS% followed by 750 ppm ethephon. The ethephon @ 750 ppm produced the maximum TSS at 9 day of storage in mature green tomatoes but in breaker and half ripen stage tomatoes 750 ppm ethephon gave TSS identical to 1000 ppm at different days of storage. The residue level of ethrel in tomato fruits treated with all ethephon concentrations at 3 and 5 days of storage was below 2 mg/kg which is safe for human health. Therefore, treated tomatoes should be consumed after 3 days of ethephon application.Bangladesh J. Agril. Res. 40(4): 567-580, December 2015

Ethylene-Induced Vinblastine Accumulation Is Related to Activated Expression of Downstream TIA Pathway Genes in Catharanthus roseus.

We selected different concentrations of ethephon, to stress C. roseus. We used qRT-PCR and HPLC followed by PCA to obtain comprehensive profiling of the vinblastine biosynthesis in response to ethephon. Based on our findings, the results showed that the high concentration of ethephon had a positive effect at both transcriptional and metabolite level. Meanwhile, there was a remarkable decrease of hydrogen peroxide content and a promoted peroxidase activity in leaves. The loading plot combination with correlation analysis suggested that CrPrx1 could be regarded as a positive regulator and interacts with ethylene response factor (ERF) to play a key role in vinblastine content and peroxidase (POD) activity. This study provides the foundation for a better understanding of the regulation and accumulation of vinblastine in response to ethephon.

Insight into prevention of enzymatic browning and increase of antioxidant potential of crepe rubber with ethephon stimulation

The effect of different ethephon concentrations 1%-5% (w/v) on colour of crepe rubber and plasticity retention index (PRI) was studied. The study was conducted with the RRISL 121 clone using S/2, d3 harvesting system. The results revealed that ethephon stimulation affects strongly the antioxidant and polyphenol oxidase (PPO) inhibitory potential. Further, thiol content and PRI values were increased while giving low Lovibond colour index upto 3% ethephon concentration and the properties were found to be inferior above 3% concentration. A probable reaction mechanism is proposed for colour improvement with optimum concentration of ethephon.

Ethephon Foliar Sprays Prevent Premature Flowering of Tissue Culture-propagated Streptocarpus Hybrids

Our objective was to quantify foliar ethephon application effects on flowering and growth of several streptocarpus (Streptocarpus ×hybridus) cultivars. ‘Ladyslippers Blue Halo’, ‘Ladyslippers Deep Blue Vein’, and ‘Ladyslippers Red Rose’ streptocarpus were planted in 6-inch containers filled with a soilless substrate. Foliar spray applications of solutions containing 0, 125, 250, 500, or 1000 mg·L−1 ethephon were applied either 2 weeks after planting (one application) or 2 and 4 weeks after planting (two applications). After 13 weeks, the total number of inflorescences was recorded and the growth index (GI) and time to flower were calculated. The efficacy of ethephon sprays depended on the concentration, number of applications, and cultivar. A single application of 250 to 1000 mg·L−1 ethephon delayed flowering of ‘Ladyslipper Deep Blue Vein’ by 9 to 27 days, whereas one application of 1000 mg·L−1 applied to ‘Ladyslipper Red Rose’ delayed flowering by 9 days. Similarly, two applications of any ethephon concentration delayed flowering of ‘Ladyslipper Deep Blue Vein’ by up to 37 days, while flowering of ‘Ladyslipper Red Rose’ was delayed by 17 days when 1000 mg·L−1 was applied. The GI of ‘Ladyslipper Deep Blue’ and ‘Ladyslipper Red Rose’ was unaffected by ethephon and, while the GI of ‘Ladyslipper Blue Halo’ was smaller than untreated plants when one or two applications of 500 or 1000 mg·L−1 ethephon was applied; these smaller plants were still of marketable size and quality. We conclude that ethephon may be used to delay flowering and reduce the number of inflorescences formed before finishing with minimal impact on finished plant size.

A novel role of ethephon in controlling the noxious weed Ipomoea cairica (Linn.) Sweet.

Several auxin herbicides, such as 2, 4-D and dicamba, have been used to eradicate an exotic invasive weed Ipomoea cairica in subtropical China, but restraining the re-explosion of this weed is still a challenge. Since ethylene is one of the major intermediate functioning products during the eradication process, we explored the possibility, mechanism and efficiency of using ethephon which can release ethylene to control Ipomoea cairica. The results of the pot experiment showed that 7.2 g /L ethephon could totally kill Ipomoea cairica including the stems and roots. The water culture experiment indicated that ethephon released an abundance of ethylene directly in leaves and caused increases in electrolyte leakage, 1-aminocyclopropane-1-carboxylic acid (ACC), abscisic acid (ABA) and H2O2 and decreases in chlorophyll content and photosynthetic activity, finally leading to the death of Ipomoea cairica. The field experiment showed that the theoretical effective concentration of ethephon for controlling Ipomoea cairica (weed control efficacy, WCE = 98%) was 4.06 g/L and the half inhibitory concentration (I50) was 0.56 g/L. More than 50% of the accompanying species were insensitive to the phytotoxicity of ethephon. Therefore, ethephon is an excellent alternative herbicide for controlling Ipomoea cairica.

Raleio químico de frutos de ameixeira com ethephon

O raleio promove equilíbrio entre o crescimento vegetativo e produtivo, aumento no tamanho dos frutos e evita alternância da produção. O objetivo deste trabalho foi avaliar o efeito de diferentes concentrações de ethephon no raleio químico de frutos das ameixeiras cultivares 'Irati' e 'Reubennel', na região de Arapoti-PR. Os tratamentos foram cinco concentrações de ethephon (0, 60, 80, 100, 120 μL L-1) para cultivar 'Irati' e quatro concentrações (0, 60, 80, 120 μL L-1) para a cultivar 'Reubennel', aplicadas quando os frutos apresentavam 5 mm de diâmetro. Foram avaliados: produção por planta, massa dos frutos, calibre, teor de sólidos solúveis, firmeza, acidez titulável, pH e coloração dos frutos. Na concentração de 120 μL L-1 de ethephon a cultivar 'Irati' produziu 20 kg planta-1 e a cultivar 'Reubennel' 56 kg planta-1, apresentando quantidade satisfatória de frutos com calibre III e IV. Não houve diferença significativa entre os tratamentos para as variáveis firmeza, sólidos solúveis, pH, acidez e coloração, avaliadas na pós-colheita para as duas cultivares de ameixeira

Longevidade e sensibilidade de helicônias ‘Golden Torch’ ao etileno exógeno

<p> Neste trabalho, objetivou-se avaliar o efeito do etileno exógeno na longevidade e sensibilidade de helicônias ‘Golden Torch’ armazenadas em condições ambiente. As inflorescências foram colhidas com duas brácteas expandidas e uma fechada, em área de produção comercial localizada em Petrolina-PE. Os tratamentos consistiram de doses de ethephon (0; 0,1; 1; 10; 100 e 1.000 mg L-1) e datas de avaliação das hastes (0, 2, 4, 6, 8 e 10 dias, a 20,4 ± 3,7 ºC e 49 ± 11% UR). O delineamento experimental foi inteiramente casualizado, em fatorial 6 x 6, com 4 repetições de 4 hastes. Foram observadas perdas de massa fresca, aparência, luminosidade e croma das brácteas com o aumento das concentrações de ethephon e do tempo de armazenamento. O ângulo Hue das brácteas que receberam 100 e 1.000 mg L-1 de ethephon indicou coloração menos laranja. O consumo de água pelas inflorescências decresceu com o tempo de armazenamento, independente dos tratamen­tos com ethephon. A longevidade de inflorescências somente foi reduzida com as doses mais altas: 100 e 1.000 mg L-1 de ethephon, que a restringiram a dois e quatro dias, respectivamente. Por tais razões, as hastes de helicônias ‘Golden Torch’ caracterizaram-se como pouco sensíveis ao etileno exógeno.</p>

EFFECT OF ETHEPHON ON RIPENING PROCESS OF KELSEY PLUM FRUITS.

The present study was carried out during 2010and 2011seasons to evaluate the effect of dipping Kelsey plum fruits in different concentrations of ethephon (250,500,750 and 1000ppm) as post harvest treatment to hasten fruit ripening. The data showed clear that ethephon application increased both loss in fruit weight , decayed fruit and total loss in fruit weight than the control.Yet, higher concentration was superior in this respect furthermore these treatment reduced both fruit firmness and chlorophyll A,B but increased SSC, and total anthocyanin than the control. Also, that data presented that higher concentration (1000 and 750 ppm) gave a higher effect in this respect.

트리티케일 종자 안정 생산을 위한 생장억제제 및 건조제 처리 효과

Ethephon을 처리하여 트리티케일의 간장을 단축시켜 도복을 방지하는 방법을 찾기 위하여 시험한 결과 Ethephon 처리시 출수기는 수잉기에 처리했을 때는 무처리에 비해 250 ppm과 500 ppm 농도에서는 2일, 1,000 ppm 이상에서는 4일이 늦어졌으나, 개화기와 성숙기는 차이가 없었다. 간장은 Ethephon 농도가 높을수록 작아졌고, 간장 단축률은 수잉기의 1,500 ppm 처리가 37%의 단축률로 처리 효과가 가장 컸으며, 하위절보다 상위절의 단축률이 컸다. 수장, 영화수, 리터중 등에서 무처리와 큰 차이가 없었고, 천립중은 무처리에 비해 약간 무거웠다. 발아율은 차이가 없었으며, 수량은 처리 농도에 관계 없이 모두 증수하는 경향을 보였으며, 수잉기 1,000 ppm 처리에서 최고 5%까지 증수하였다. 발아에 영향을 미치지 않으면서 수확시기를 앞당길 수 있는 방법을 찾고자 실시한 건조제 처리 후 수확시기 단축효과와 종자의 품질을 보면, 건조제 처리후 수확적기 수분함량에 도달하는 일수는 출수 후 30일 처리가 15일, 출수 후 35일 처리가 10일이 걸렸고, 출수 후 40일과 45일 처리가 5일이 걸다. 건조제 처리 후 수확시기는 출수 후 30일과 35일 처리가 관행재배에 비해 8일, 출수 후 40일 처리가 5일이 빨랐다. 건조제 처리시 천립중은 출수 후 처리 일수가 늦어질수록 무거웠고, 발아율 또한 출수 후 처리 일수가 늦어질수록 높아지는 경향을 보였으나, 출수 후 35일 이후에는 통계적인 유의성은 없었다. 수량은 출수 후 30일 처리구가 관행재배의 37% 수준, 출수 후 35일 처리가 70%수준이었고 출수 후 40일 처리가 92% 수준으로 생리적 성숙기 이전에 건조제를 처리하면 품질에 큰 영향을 준다. As for Ethephon treatment, the heading stage is 2 days later at the concentration of 250 ppm and 500 ppm for the booting stage that when there is no treatment, 4 days later at the concentration of 1000 or more ppm but no difference for the blossoming and ripening stage. The culm length get shorter as the concentration of Ethephon is higher and the rate of culm length damaged is 37% for 1500 ppm of booting stage, which is the most effective processing, and the inferior culm length damage rate is bigger than the superior culm length damage rate. There is no difference between the number of glumous flower, culm and litter weight and the non-processing and as for the thousand grain weight, it is slightly bigger than when there is not any processing. The rate of germination is indifferent, the number of seeds get numerous regardless of the concentration of treatment and the number augments by 5% maximum for the booting stage. The number of days it takes from treatment of desiccant to the moisture content for harvesting time is respectively 15 days for seeds of 30 day-treatment, 10 days for seeds of 35 days-treatment and 5 days for seeds of 40 to 45 day-treatment. As for the harvest time after treatment of desiccant, the treatment at <TEX>$30^{th}$</TEX> days and <TEX>$35^{th}$</TEX> after the earing is 8 days earlier than the culture by conventional methods, 8 days earlier for the treatment at <TEX>$40^{th}$</TEX> day. When the desiccant treatment is implemented, the thousand grain weight is heavier as the number of days of treatment gets later. The rate of germination gets higher as the number of days of treatment after earing gets later but there is no statistically significant difference 35 days after the earing. Yields are 37% compared to the culture by conventional methods for the treatment of 30 days after the earing, 70% compared to the culture by conventional methods for the treatment of 35 days after the earing, and 92% compared to the culture by conventional methods for the treatment of 40 days after the earing. The treatment before the physiological maturity impacts greatly upon the quality of seeds.

Pematahan Dormansi Rimpang Kaempferia parvifloraWall. ExBaker

&lt;p&gt;&lt;em&gt;&lt;span style="text-decoration: underline;"&gt;Kaempferiaparviflora&lt;/span&gt;&lt;/em&gt;&lt;em&gt; (Zingiberaceae family) has a potency to be developed for a new medicinal plants in Indonesia. One of problems in its cultivation is the lack of planting material availability due to the long dormant period. The objectives of this research were to study the effect of various concentrations of BAP and ethephon, and also the effect of the prior growing condition to the dormancy breaking and shoot growth of &lt;span style="text-decoration: underline;"&gt;K.parviflora&lt;/span&gt; rhizome. Two separate experiments were applied for two lots of rhizomes namely Cikabayan and Pasir Sarongge lots. Each experiment was arranged in completely random design with 2 factors. Experiment-1 used 4 concentrations of BAP (0, 50, 100, and 150 ppm) as the first factor. While, experiment-2 used 5 concentrations of ethephon (0, 200, 400, 600 and 800 ppm) as the first factor. The second factor in both experiments were prior shade condition at 55% artificial shading and natural shading. A rhizome without soaked application (control) and a rhizome with soaked by aquadestilata without PGRs (0 ppm) were used as compared items. Data was analyzed with ANOVA. Combined Analysis of Variance and t-test were performed in order to compare between 2 lots. Result showed that concentration of BAP until 150 ppm and concentration of ethephon until 800 ppm were not effective to stimulate bud induction time. Meanwhile, rhizome from 55% artificial shading had a shorter periode of dormancy than the natural shading. In the addition, plants from Pasir Sarongge rhizomes lot had more plant number, plant height, leaf number, leaf length, and leaf width than Cikabayan rhizomes lot.&lt;/em&gt;&lt;/p&gt;

Effect of Different Ethephon Concentrations on Olive Fruits Harvesting at Different Orchard Locations

An experiment was conducted to determine the optimum ethephon concentration on olive fruit harvesting at different Jordan locations. The study was carried out on Nabali olive cultivar at “Irbid and Ajlon” locations. Treatments were consisted of five ethephon concentrations, which are: 0, 1000, 2000, 3000 and 4000 ppm, each concentration was repeated 4 times. 10 days after ethephon applications, data were collected and analyzed according to the randomized completely block design. Results revealed that all of the used ethephon concentrations promote leaf drop, which remains within the acceptable ranges in both locations. Although, ethephon dosage had significant effects on harvesting productivity at 0.05 levels; best results were obtained by using 3000 ppm concentration at Irbid location, while at Ajlon; best results were observed with treating the olive fruits with 4000 ppm ethephon concentration. On the other hand, positive correlation were observed between the percent of leaf drop and the total harvested fruits

Effect of Different Ethephon Concentrations on Olive Fruits Harvesting at Different Orchard Locations

An experiment was conducted to determine the optimum ethephon concentration on olive fruit harvesting at different Jordan locations. The study was carried out on Nabali olive cultivar at “Irbid and Ajlon” locations. Treatments were consisted of five ethephon concentrations, which are: 0, 1000, 2000, 3000 and 4000 ppm, each concentration was repeated 4 times. 10 days after ethephon applications, data were collected and analyzed according to the randomized completely block design. Results revealed that all of the used ethephon concentrations promote leaf drop, which remains within the acceptable ranges in both locations. Although, ethephon dosage had significant effects on harvesting productivity at 0.05 levels; best results were obtained by using 3000 ppm concentration at Irbid location, while at Ajlon; best results were observed with treating the olive fruits with 4000 ppm ethephon concentration. On the other hand, positive correlation were observed between the percent of leaf drop and the total harvested fruits

Changes in fruit colour of Dusehari mangoes during ethephon induced ripening

The effect of ethephon on colour changes of Dusehari mango (Mangifera indica) fruits during ripening was examined. Physiological mature fruits were given post harvest dip of ethephon solution @ 0, 200, 400, 600, 800 and 1000 ppm for five minutes. Treated fruits were packed in CFB boxes placed at ambient conditions for ripening. Fruit peel and pulp colour was determined after 48, 72, 96, 120 and 144 h after ripening treatments using Hunter Lab scale. Results revealed that all ethephon treatments enhanced colour development as compared to control. The luminosity of peel increased with increase in concentration of ethephon as well as with ripening period. The greenness of peel as reflected by ‘a’ values decreased with ripening treatments and period. However ‘a’ value for pulp increased with development of redness of tissue. The fruit peel developed yellowish colour with ethephon treatments as evidenced by increase in values of ‘b’. The effect of ethephon on colour changes at higher doses (800 ppm and 1000 ppm) was non-significant after 120 h of ripening period.

Influence of exogenous ethylene on cambial activity, xylogenesis and ray initiation in young shoots of Leucaena leucocephala (lam.) de Wit

The effect of exogenous ethephon on cambial activity, xylem production and ray population in young shoots of Leucaena leucocephala was investigated anatomically. The application of ethephon showed a diphasic effect on cambial activity and xylogenesis in a dose dependent manner. Lower concentration of ethephon enhanced cambial activity while high concentrations reduced cambial cell divisions and daughter-cell differentiation. High ethephon concentration also resulted in shorter vessel elements, thick walled fibers and phenolic accumulation in ray cells and vessel elements, whereas low concentration allowed elongation of fibers and vessel elements. The density of rays increased significantly with increase in ethylene concentration. The evaluation of longitudinal sections of cambial zone in ethephon treated plants showed high frequency of transformation of fusiform initials into ray initials through divisions and segmentation, resulting in high ray frequency in both xylem and phloem. The present study demonstrates that ethylene plays an important role in regulating secondary vascular tissue composition by reducing the population of fusiform initials in the cambium.