Application Of Ethrel Research Articles

Gene Expression Profiling and Qualitative Characteristics in Delaying Flesh Softening of Avocado Fruits.

In this research, qualitative characteristics were studied under different post-harvest treatments in Hass and Fuerte cultivars of avocado (Persea americana) fruits. The post-harvest treatments performed in fruits of these cultivars comprised Ethrel application and plastic film (membrane) covering. The measurements of qualitative characteristics were related to color; flesh consistency; measurements of titratable acidity, total soluble solids, percentage of total phenolic contents, and ascorbic peroxidase activity; and the real-time (quantitative) polymerase chain reaction (qPCR) of gene expression and enzyme activities of phenylalanine ammonia-lyase (PAL) and beta-galactosidase (β-gal). The experiments found that the application of plastic film has excellent results in retaining qualitative characteristics and enzyme activities via maintaining firmness in higher levels. The plastic film covering appeared to delay ripening without the use of chemicals and, therefore, it has the potential to extend the duration of the post-harvest life of the avocado fruit. Variations between the two cultivars were found in the measurements of total soluble solids (Fuerte cultivar showed an increase of 22%, whereas Hass cultivar showed an increase of 120% in Brix values) and total phenolic contents (Fuerte cultivar showed a decrease of 16% and Hass cultivar showed an increase of 29%). It is worth noting that PAL's activity increased significantly (over 44%), as compared to other treatments, and β-galactosidase's activity decreased, as compared to other treatments. In conclusion, plastic film covering results in a decrease in the activity of β-galactosidase, as shown by the reaction of hydrolysis (enzyme activity) but also from the expression of the related genes.

Application of phytohormone Ethrel using a brush and by injection into the trunk of the sapodilla tree (Manilkara zapota (L.) P. Royen) to promote the production of Latex in the Noh Bec common.

Application of phytohormone Ethrel using a brush and by injection into the trunk of the sapodilla tree (Manilkara zapota (L.) P. Royen) to promote the production of Latex in the Noh Bec common.

Effect of ethrel and gibbrellic acid on bio-chemical changes and productivity of sugarcane (Saccharum species hybrid complex)

The present study was conducted during the spring seasons of 2015–16 to 2017–18 to investigate the effects of application of ethrel and gibbrellic acid on growth, yield and sucrose content of spring planted sugarcane in order to work out its potential to be used as germination and growth enhancer in subtropical region. The treatments viz., planting of setts after overnight soaking in water, T2 ; planting of setts after overnight soaking in 50 ppm ethrel solution, T3 ; planting of setts after overnight soaking in 100 ppm ethrel solution, T4 ; T1 + GA3 spray @ 35 ppm at 90, 120 and 150 DAP, T5 ; T2 + GA3 spray @ 35 ppm at 90, 120 and 150 DAP, T6 ; T3 + GA3 spray @ 35 ppm at 90, 120 and 150 DAP, T7 and T4 + GA3 spray @ 35 ppm at 90, 120 and 150 DAP, T8 were compared with T1 (conventional planting/farmers practice treatment). Sugarcane growth, yield, and quality parameters were significantly influenced by various treatments. Owing to enhanced reducing sugars, acid invertase (AI), indole acetic acid oxidase (IAAO) and superoxide dismutase (SOD) activity in treated setts, planting of setts after overnight soaking in 50 ppm ethrel solution resulted in higher germination count at 10, 20, 30, 40 and 50 days after planting (DAP). Planting of setts after overnight soaking in 50 ppm ethrel solution + GA3 spray @ 35 ppm at 90, 120, and 150 DAP resulted in a greater plant population at all stages of growth, which was responsible for a higher number of millable canes at harvesting. Treatment planting of setts after overnight soaking in 50 ppm ethrel solution + GA3 spray @ 35 ppm at 90, 120 and 150 DAP recorded higher leaf area index at 180 and 240 DAP. Similarly, treatment (T7 ) also recorded higher shoot and root dry weight at 120, 180, 240 and 300 DAP. Net assimilation rate during 120–180 DAP (5.78 g/m2 /day) and 180–240 DAP (3.95/m2 /day) were also recorded highest in treatment T7 . Similarly, planting of setts after overnight soaking in 50 ppm ethrel solution + GA3 spray @ 35 ppm at 90, 120 and 150 DAP recorded higher cane yield (101.2 t/ha) and net returns (166.25 × 103 `/ha) with a benefit: cost ratio of 1.31 which was significantly higher than farmers practice and planting of setts after overnight soaking in water. Thus, planting of setts after overnight soaking in 50 ppm ethrel solution + GA3 spray @ 35 ppm at 90, 120 and 150 DAP should be adopted to obtain the maximum productivity and profitability by spring sugarcane.

Physio-Chemical Changes during Ethrel Treatment of Mango cv. Alphonso under Different Temperature Regimes

Aim: Mango (Mangifera indica L.) is the second most consumed fruit which belongs to the family Anacardiaceae. Ripening in mango (climacteric fruit) is hastened by application of ethrel. The experiment was conducted to study the effect of different temperatures during ethrel treatment on shelf life and quality of mango cv. Alphonso.
 Study Design: The experiment consisted of three treatments and seven replications laid out in Completely randomized design (CRD).
 Place and Duration of Study: The study was conducted at Department of Fruit Science, Horticulture College and research Institute, Tamil Nadu Agricultural University, Coimbatore during 2022-2023. 
 Methodology: Mango cv. Alphonso was subjected to ethrel treatment in three different ripening chambers having different temperatures viz., T1 – silpaulin chamber (33°C), T2 – zero energy cool chamber (26°C), T3 – cold chamber (22°C) for a period of 24 hours. After ethylene treatment, the fruits were stored at ambient temperature to study the ripening behaviour. Shelf life and quality parameters were observed and recorded. 
 Results: The days taken for ripening was lesser (6 days) and the rate of conversion of quality attributes were higher in fruits subjected to ethrel treatment in silpaulin chamber. The quality attributes like TSS (22°Brix), acidity (0.25 %), TSS : acid ratio (88) were significantly higher in fruits treated in silpaulin chamber on the day of ripening. The physiological loss in weight was found to be significantly lesser in fruits subjected to ethylene treatment in cold chamber (6.56 %) and were on par with fruits treated in zero energy cool chamber (6.71%) whereas the firmness and shelf life were found to be significantly higher in cold chamber treated fruits (2.35 N, 15 days respectively) but firmness was on par with fruits subjected to ethylene treatment in zero energy cool chamber (2.21 N) on ripening. The overall acceptability of fruits in sensory evaluations was significantly higher in fruits treated in zero energy cool chamber (8.3) which was on par with fruits treated in cold chamber (8.1).
 Conclusion: The fruits treated in silpaulin chamber had better TSS, acidity and TSS: acid blend. The fruits treated in cold chamber were superior in shelf life and sensory score which was also on par with fruits treated in zero energy cool chamber. Hence zero energy cool chamber can be used as an alternative to cold chamber for ethrel treatment which would be cost effective, environment friendly and can be used by small traders and farmers.

Effect of growth regulators and micronutrients on quality parameters in cashew (Anacardium occidentale L.)

Cashew (Anacardium occidentale L.) is an important tropical nut crop of social and economic importance worldwide. However, the crop is threatened with the low yield. In the present study, an attempt was made to test the effects of plant growth hormones as well as micronutrients on nut and apple quality of cashew var. Bhaskara. Significant differences in kernel weight, shelling percentage, carbohydrates and starch content of cashew kernel and juice content of cashew apple were observed with the foliar application of growth hormones and micronutrients. The foliar application of ethrel @ 50 ppm increased shelling percentage (35.8%), carbohydrate content (21.63%), sugar content (6.26%), protein content (32.4%), starch content (31.42%), juice content (78.3%) and total soluble solids (120 Brix). Further, the foliar spray of zinc sulphate (0.5%) + borax (0.1%) increased shelling (36.13%), protein content (32.15%), starch content (32.03%) among all the treatments tested. Furthermore, higher cashew apple juice content (78%) and total soluble solids (120Brix) was also recorded with the foliar spray of zinc sulphate (0.5%) + borax (0.1%).

Regulating Enzymatic Antioxidants, Biochemical and Physiological Properties of Tomato under Cold Stress: A Crucial Role of Ethylene

The production of tomato under low-temperature stress in the open fields is a challenge faced by many farmers. The current study compares the use of different ethylene treatments to accelerate the fruit ripening of tomato during two successive seasons under cold stress. The treatments included foliar application of ethrel (2500, 5000, and 7500 ppm) in the open field at the mature green stage, dipping collected fruits in ethrel solution (1000, 1500, and 2000 ppm) right after harvest, and application of gaseous ethylene (100, 200, and 300 ppm) to the harvested fruits. The effects were compared to untreated fruits (control). Characteristics, such as physical properties (ripening, weight loss, firmness, decay, and fruit color), chemical properties (ascorbic acid, acidity, total soluble sugars, and pigments), and enzymatic activities (polygalacturonase and pectin methylesterase), were sampled throughout the storage period. In general, the ethylene gas application was the most effective method in accelerating the fruit ripening process compared to the other methods applied. The highest vitamin C total soluble solid contents and redness parameters were found after applying the highest dose of ethylene gas (300 ppm). This indicates that the ripening of tomato fruits, which are cultivated under cold stress conditions as found during the early summer season in a Mediterranean climate, might be harvested at a mature green stage and exposed to ethylene application.

Influence of plant growth regulators on morphological and flowering behavior of bottle gourd (Lagenaria siceraria (Mol.) Standl.)

A field experiment was conducted for evaluating the influence of three plant growth regulators (PGR) viz., gibberellic acid (GA3), Naphthalene acetic acid (NAA) and Ethrel on morphological and flowering behaviour of bottle gourd. The foliar application of Ethrel @ 300 ppm was found beneficial for days taken for appearance of first female flower, number of male flowers, number of female flowers, sex ratio. Whereas, maximum length of vine at 60 and 90 DAS, minimum number of days taken from fruit set to edible maturity was obtained by the foliage application of GA3 @ 40 ppm however minimum days taken for appearance of first male flower was obtained with GA3 @ 60 ppm. Based on these observations, it could be suggested that the significant increase in flowering and growth characters would be obtained by the spraying of Ethrel @ 300 ppm at 2-4 true leaf stage.

Transcriptional and Metabolic Characterization of Feeding Ramie Growth Enhanced by a Combined Application of Gibberellin and Ethrel.

Feeding ramie cultivars (Boehmaria nivea L.) are an important feedstock for livestock. Increasing their biomass and improving their nutritional values are essential for animal feeding. Gibberellin (GA3) and ethylene (ETH) are two plant hormones that regulate the growth, development, and metabolism of plants. Herein, we report effects of the GA3 and ETH application on the growth and plant metabolism of feeding ramie in the field. A combination of GA3 and ETH was designed to spray new plants. The two hormones enhanced the growth of plants to produce more biomass. Meanwhile, the two hormones reduced the contents of lignin in leaves and stems, while increased the content of flavonoids in leaves. To understand the potential mechanisms behind these results, we used RNA-seq-based transcriptomics and UPLC-MS/MS-based metabolomics to characterize gene expression and metabolite profiles associated with the treatment of GA3 and ETH. 1562 and 2364 differentially expressed genes (DEGs) were obtained from leaves and stems (treated versus control), respectively. Meanwhile, 99 and 88 differentially accumulated metabolites (DAMs) were annotated from treated versus control leaves and treated versus control stems, respectively. Data mining revealed that both DEGs and DAMs were associated with multiple plant metabolisms, especially plant secondary metabolism. A specific focus on the plant phenylpropanoid pathway identified candidates of DEGs and DEMs that were associated with lignin and flavonoid biosynthesis. Shikimate hydroxycinnamoyl transferase (HCT) is a key enzyme that is involved in the lignin biosynthesis. The gene encoding B. nivea HCT was downregulated in the treated leaves and stems. In addition, genes encoding 4-coumaryl CoA ligase (4CL) and trans-cinnamate 4-monooxygenase (CYP73A), two lignin pathway enzymes, were downregulated in the treated stems. Meanwhile, the reduction in lignin in the treated leaves led to an increase in cinnamic acid and p-coumaryl CoA, two shared substrates of flavonoids that are enhanced in contents. Taken together, these findings indicated that an appropriate combination of GA3 and ETH is an effective strategy to enhance plant growth via altering gene expression and plant secondary metabolism for biomass-enhanced and value-improved feeding ramie.

Effect of Different Growth Regulators on Plant Growth and Yield of Bottle Gourd (Lagenaria siceraria L.) cv. Arka Bahar

An experiment was conducted during 2021 to study the effect of different growth regulators on bottle gourd cv. Arka Bahar during kharif season with three growth regulators at different concentrations: Ethrel (100ppm, 200ppm, 300ppm), NAA (150 ppm, 200ppm, 250ppm) and GA3 (50ppm, 100ppm, 150ppm).Water was used as control. The growth regulators were sprayed at two and four leaf stage. All the treatments were replicated three times in a randomized block design keeping the plot size 2m×2m. Plant growth regulators treatments rendered their significant effect on almost all the growth, flowering and yield of bottle gourd. The treatment T9 GA3 150 ppm was found maximum in increasing the vine length (9.01m) whereas T3 Ethrel 200 ppm was found most effective in terms of days to first appearance of male (40.89 days) and female flower (45.44 days), node number to first male (8.11) and female flower (10.11), number of male (16.33) and female flowers (11.33) per vine, fruit diameter (8.67 cm), fruit length (39.84 cm), fruit weight (1064.28 g), number of fruits per plant (10.11), fruit yield per plant (8.72 kg), fruit yield per hectare(29.01 t/ha) The significantly higher gross return (Rs 348120/ha), Net profit (Rs 269898/ha) and B: C ratio (4.45) was also recorded under ethrel 200 ppm (T3). Overall results revealed that application of ethrel 200 ppm proved to be better for different growth and yield traits in bottle gourd.

Effects of coffee maturation regulators

The maturation of coffee fruits is a concern of coffee growers, as it directly influences the efficiency of the harvest and can interfere with the quality of the product. Therefore, the use of maturation regulators that act by controlling the speed of maturation are being increasingly used. As such, the objective of this work was to evaluate the effects of the regulators Ethrel® and MathuryTM, in 4 treatments composed by the control, application of Ethrel®, application of MathuryTM, application of the combination of Ethrel® followed by the application of MathuryTM. Thus, the maturation stage of the fruits, the type, and the final grade regarding the quality of the drink were evaluated. After that, the data of the evaluated characteristics were submitted to statistical analysis by the Scott-Knott test at 5% probability. The maturation regulators used in this experiment did not interfere with the quality of the product and the classification of the coffee. However, treatments with application of Ethrel® alone or combined with MathuryTM provided anticipation and uniformity of coffee fruits.

Impacts of 1-Aminocyclopropane-1-Carboxylic Acid as a Late Post-Bloom Thinner on Fruit Set, Yield, and Fruit Quality in “Gala” and “Fuji” Apples

A few post-bloom thinners are available for apple (Malus domestica Borkh.) and the prospects for additional thinners appear to be limited. Application of blossom thinners may present a risk of overthining in the areas where weather is less predictable. Thus, we studied the impacts of various rates of 1-aminocyclopropane-1-carboxylic acid (ACC) in three strains of “Fuji” apple and different rates of ACC and one rate of Ethrel in “Buckeye Gala” apple, when fruitlet diameter was about 20 mm, on fruit set, yield and fruit quality attributes at harvest, and return bloom in southwest Idaho in the Intermountain West region, USA. In 2013, application of Ethrel at 300 mg·L-1 did not affect fruit set, fruit weight, diameter (D), length(L), or L/D ratio 34 days after application, or yield, fruit weight, color, russet, and starch degradation pattern (SDP) at harvest, while application of ACC at 150 mg·L-1 or higher reduced fruit set by 19% to 34% in “Buckeye Gala” apple. In this cultivar, application of ACC at 350 mg·L-1 significantly increased fruit weight, diameter and length 34 days after application, and increased fruit weight, color, and SDP at harvest time. Application of ACC at all rates reduced total yield per tree in “Buckeye Gala”. Application of ACC at 300 mg·L-1 significantly reduced fruit set but applications of 150 mg·L-1 or 300 mg·L-1 ACC did not affect yield or quality attributes of “Sun Fuji” apple in Sunny Slope area in 2013. Application of ACC reduced fruit set and slightly increased fruit size in “Top Export Fuji” in 2013. Application of ACC at 600 mg·L-1 significantly reduced fruit set in “Aztec Fuji” apple in 2014. Application of ACC in a season never reduced bloom density (return bloom) of the next season. Overall, we conclude that ACC is an excellent tool as a late-season post-bloom fruit thinner and can be effective when applied fruitlet diameter is about 20 mm.

Integrated crop management (ICM) practices to enhance watermelon yield and farm income

Field demonstrations on integrated crop management (ICM) practices on watermelon (Citrullus lanatus L) to increase the yield and farm income were conducted in Cuddalore district of Tamil Nadu by Krishi Vigyan Kendra, Tamil Nadu Agricultural University, Vridhachalam, Cuddlaore district, Tamil Nadu. In total, ten farmers were selected in three blocks viz Kattumannarkoil, Vridhachalam and Panruti of Cuddalore district. Critical inputs viz Azospirillum, phosphobacteria, Pseudomonos flurescense and ethrel were distributed to the farmers along with seeds of watermelon variety Arka Muthu. The biofertlizers and bio-inoculant were applied in the soil @ 25 g per plant. Foliar application of ethrel @ 200 ppm was done at 15 days after sowing and repeated three times at weekly interval. It was observed that ICM practices viz high yielding variety Arka Muthu, soil application of biofertilizers Azospirillum and phosphobacteria and bio-inoculant P flurescense each @ 25 g per plant and foliar application of ethrel @ 200 ppm registered higher values for number of fruits per plant (3.80), fruit weight (3.40 kg) and fruit yield (398.71 q/ha). The demonstration plots registered higher net income of Rs 1,99,104.28 compared to check which registered a net income of Rs 1,40,455.55 and higher B-C ratio of 2.55 as compared to 1.89 in local check.

Pre-harvest Application of Ethrel and Potassium Schoenite on Yield, Quality, Biochemical Changes, and Shelf-life in Crimson Seedless Grapes

Pre-harvest Application of Ethrel and Potassium Schoenite on Yield, Quality, Biochemical Changes, and Shelf-life in Crimson Seedless Grapes

Ethylene attenuates chilling injury of banana fruit via the MabHLH060/183 module in controlling phosphatidic acid formation genes

Chilling injury (CI) of banana represents a serious problem constraining postharvest preservation in the industry. Application of ethylene was found to efficiently attenuate CI of banana, however, the mechanism of which remains to be investigated. Here, we found that application of ethrel could ameliorate the CI of banana, as evidenced by lower CI index, electrolytic leakage and malondialdehyde content. Meanwhile, expression of phosphatidic acid (PA) formation genes MaPLDδ1, MaPLDδ5 and MaDGK2, as well as two transcriptional regulators MabHLH060 and MabHLH183 was significantly increased with the progression of CI, but decreased under ethrel treatment. MabHLH060 and MabHLH183 were shown to locate in nucleus and have transactivation ability. Importantly, these two transcriptional regulators MabHLH060/183 recognized the E-box elements in the promoters of MaPLDδ1, MaPLDδ5 and MaDGK2, and promoted their transcription. Together, these findings suggest that ethylene-alleviated CI of banana may involve the MabHLH060/183 module in modulating the expression of PA formation genes.

Crop Regulation in Pomegranate (Punica granatum L.) through Induced Water Stress and Ethrel Application

The present investigation was carried out at ICAR-CIAH, Bikaner, Rajasthan, India during 2017 to 2019 to regulate crop production in pomegranate at the desired period with higher number of bisexual flower for higher quality fruit yield and to minimize fruit splitting through water stress, pruning and ethrel application. Pooled data analysis revealed that horticultural interventions, chemical treatments and their interactions significantly improved plant volume, bisexual flower number, maturity index, fruit yield with significant reduction in fruit splitting, mite and fungal spot incidence. Among different treatment combinations, maximum canopy volume, number of bisexual flowers, maturity index, fruit yield and lower fruit splitting were recorded (8.56 m3, 85.11 plant-1, 47.81, 124.01 q ha-1 and 1.87 kg plant-1) in withholding irrigation during June+pruning+thinning+ethrel 2 ml l-1 as compared to absolute control (3.41 m3, 75.62 plant-1, 33.35, 85.66 q ha-1 and 2.41 kg plant-1), respectively. The mite and fungal spot incidence were recorded minimum (4.72 and 8.50%) in withholding irrigation during June+pruning+thinning+ethrel 3 ml l-1 application in comparison to maximum recorded in absolute control (29.73 and 33.68%), respectively. Therefore, it can be concluded that withholding irrigation during June+pruning+thinning with ethrel 2 ml l-1 treatment significantly improved quality fruit yield with higher number of bisexual flowers and reduced fruit splitting through induction of flowering and fruit growth during optimal climatic conditions.

Effect of Exogenous Gibberellin, Paclobutrazol, Abscisic Acid, and Ethrel Application on Bulblet Development in Lycoris radiata.

Lycoris species have great ornamental and medicinal values; however, their low regeneration efficiency significantly restricts their commercial production. Exogenous hormone application is an effective way to promote bulblet development, but their effect on Lycoris radiata has not been verified to date. In the present study, we examined the effect of different exogenous hormones on bulblet development in L. radiata, and found that gibberellic acid (GA) significantly inhibited, whereas paclobutrazol (PBZ), abscisic acid (ABA), and ethrel promoted bulblet development, especially PBZ, a GA biosynthesis inhibitor. Furthermore, GA reduced endogenous cytokinin (CK) content, as well as the activities of carbohydrate metabolism enzymes, including sucrose synthase (SUS) and glucose-1-phosphate adenylyltransferase (AGPase), by downregulating the expression levels of LrSUS1, LrSUS2, and genes encoding AGPase large and small subunits. This resulted in the decrease in carbohydrate accumulation in the bulblets, thus hindering their development. PBZ had the opposite effect to GA on carbohydrate metabolism; it decreased endogenous GA15 and GA24, thereby promoting bulblet development. ABA promoted endogenous auxin content and the activities of starch synthesis enzymes, especially soluble starch synthase (SSS) and granule-bound SS (GBSS), through the up-regulation of the expression levels of LrSS1, LrSS2, and LrGBSS1 genes, which could also result in the accumulation of carbohydrates in the bulblets and promote their development. In addition, ethrel application partly promoted bulblet development by promoting endogenous CK content. Although the accumulation of carbohydrates and the activity of starch enzymes were increased by ethrel treatment, we hypothesized that the effect of ethrel on regulating carbohydrate metabolism may be indirect. Our results could provide a basis for improving the propagation efficiency of L. radiata for production, as well as propose some directions for future research.

Integrated Application of Ethrel and Microbial Consortia: Effect on Dry Matter Accumulation, Its Partitioning, and Nutrients Uptake in Late-planted Sugarcane Under Subtropical Indian Condition

Late (summer) planting of sugarcane is very much common in subtropical India. Due to the adoption of sugarcane–ratoon–wheat cropping system in the region, sugarcane planting is delayed. Delay in planting of sugarcane reduces the period of tillering. Thus to improve tillering, growth, and yield of late-planted sugarcane, a field experiment was conducted to assess the four levels of seed cane material (S1: conventional 3 bud setts, S2: sett soaking in water for 4 h S3: sett soaking in 100 ppm ethrel solution for 4 h and S4: foliar application of 100 ppm ethrel and mixture of 1% urea on seed cane, one week before planting) and two levels of NPK fertilizers with and without microbial consortia (M1: 50% of recommended NPK with microbial consortia (Pseudomonas fluorescens (phosphate-solubilizing bacteria) + Gluconacetobacter + Trichoderma); M2: Recommended NPK (150 kg ha−1, 25 kg ha−1, 50 kg ha−1 without microbial consortia). Foliar spray of ethrel increased total N uptake by 47.27% at the harvest stage (145.9 kg ha−1). An improvement of 36.40% in P accumulation was recorded with foliar application of ethrel on seed cane as compared to control during the tillering phase. However, P improvement in stalk increased to the level of 18.71 kg ha−1 at harvest stage. Foliar spray of ethrel accumulated 33.04% higher K than control (124.4 kg a−1) at harvest. About 26.16% improvement in individual cane weight was recorded with foliar application of ethrel. Thus, foliar application of ethrel improved sugarcane (73.15 t ha−1) and sugar yield (8.55 t ha−1). Integrated use of microbial consortia and 50% of recommended NPK could bring forth 9.85% (68.48 t ha−1) and 7.86% (8.10 t ha−1) improvement in sugarcane and sugar yields over the recommended NPK in summer-planted sugarcane in subtropical India.

Effect of flower regulation on biotic and abiotic stress management in Pomegranate (Punica granatumL.) under hot arid climate

The present study was carried out for management of abiotic stresses (fruit cracking) and biotic stresses (mite and fungal spot) in pomegranate by flower regulation through water stress, pruning and ethrel application. The results revealed that horticultural interventions, chemical treatments and their interactions significantly minimized mite, fungal spot and fruit cracking incidence in pomegranate. In different combinations treatments of horticultural interventions and chemical, minimum mite incidence (4.80 and 4.65%) and fungal spot incidence (9.17 and 7.83%) were recorded in withholding irrigation during June + pruning + thinning with ethrel 2 ml/l treatment as compared to maximum mite (31.95 and 27.51%) and fungal spot (35.78 and 32.58%) recorded in control natural flowering without chemicals during the years 2017-18 and 2018-19, respectively. Lower fruit cracking incidence i.e. <2.0 kg/plant was observed in withholding of irrigation during June + pruning + thinning with ethrel applications in both years. The maximum fruit cracking (2.51 and 3.24 kg/plant) was recorded in withholding of irrigation during March without chemicals treatment during 2017-18 and 2018-19, respectively. Therefore, it can be concluded that withholding irrigation during June + pruning + thinning with ethrel 2 ml/l treatment reduced mite and fungal spot incidence and fruit cracking through induction of flowering and fruit growth during optimal climatic conditions and enhanced management.

Enhancing cane and sugar productivity applying variable modes of plant growth regulators in sugarcane (Saccharum sp. complex) cultivation under coastal climatic conditions of India

A field experiment was carried out for three crop seasons at Sugarcane Research Station, Nayagarh (Odisha) during spring seasons of 2015-16, 2016-17 and 2017-18 to assess the effect of ethrel and gibberellic acid on growth, yield attributing characters, yield and quality of sugarcane (Saccharum sp. complex). Pooled data of three years study indicated that different treatments with plant growth regulators had significant effect on growth, yield and quality parameters of sugarcane. Germination percent of cane buds was the highest in the treatment involving planting of sugarcane setts after overnight soaking in 100 ppm ethrel solution followed by foliar application of gibberellic acid @35 ppm at 90,120 and 150 days after planting (DAP). Other sugarcane growth parameters, viz. number of tillers and plant heights were significantly higher with the application of growth regulators which produced higher number of millable canes (at harvest) than that of other treatments in the test. Overnight soaking of cane setts in 100 ppm ethrel solution followed by foliar application of gibberellic acid @35 ppm at 90,120 and 150 days after planting also produced significantly higher yield parameters, viz. number of millable cane (84.26’ 000 ha-1), cane length (313.6 cm), cane girth (2.94 cm) and single cane weight (1.64 kg) as compared to conventionally planted sugarcane crop. There was no significant influence on juice quality parameters due to various treatments in this study. However, overnight soaking of setts with 100 ppm ethrel solution followed by foliar application of gibberellic acid @ 35 ppm at 90, 120 and 150 days after planting showed comparatively higher values in all the juice quality parameters. Significantly higher cane and sugar yields of 116.14 t/ha and 12.82 t/ha, respectively were obtained with planting of sugarcane after overnight soaking in 100 ppm ethrel solution followed by gibberellic acid spray @ 35 ppm at 90, 120 and 150 days after planting. The above higher yields were attributed mainly to marked improvement in growth and yield attributes in response to application of plant growth regulators. Therefore, it can be concluded that combined application of ethrel and gibberellic acid had the positive effect to improve the growth parameters, yield and quality of sugarcane.

Roles of ethylene, jasmonic acid, and salicylic acid and their interactions in frankincense resin production in Boswellia sacra Flueck. trees

The roles of ethylene, jasmonic acid, and salicylic acid and their interactions in frankincense resin production in Boswellia sacra trees growing in the drylands of Oman were studied. On March 18 (Experiment 1) and September 17 (Experiment 2), 2018, 32-year-old B. sacra trees with multiple trunks were selected at the Agricultural Experiment Station, Sultan Qaboos University, Oman. Various lanolin pastes containing Ethrel, an ethylene-releasing compound; methyl jasmonate; sodium salicylate; and combinations of these compounds were applied to debarked wounds 15 mm in diameter on the trunks. After a certain period, the frankincense resin secreted from each wound was harvested and weighed. The anatomical characteristics of the resin ducts were also studied in the bark tissue near the upper end of each wound. The combination of Ethrel and methyl jasmonate greatly enhanced frankincense resin production within 7 days in both seasons. The application of methyl jasmonate alone, sodium salicylate alone or a combination of both did not affect resin production. These findings suggest a high possibility of artificial enhancement of frankincense resin production by the combined application of Ethrel and methyl jasmonate to B. sacra trees.