Application Of Plant Growth Regulators Research Articles

Tea (Camellia sinensis L. O. Kuntze) callus development based on morphological and phytochemical traits applied by variations in plant growth regulators (PGRs)

A variation of the clonal propagation system for tea has been established through in vitro methods, utilizing shoots and leaves derived from primary explants of mature field-grown plants. The research aimed to assess the diversity of tea calluses based on morphological and phytochemical traits derived from leaf and shoot explants on MS media induced by the application of plant growth regulators, including auxin and cytokinin. The research was conducted at the Seed Technology Unit Tissue Culture Laboratory, Faculty of Agriculture, Jatinangor, from April 2022 to February 2023. The experiment employed MS-modified multiplication media and PGR, with BAP at 9 mg/L, TDZ at 1.0 mg/L, Zeatin at 0.1 mg/L, NAA at 0.01 mg/L, and 1 mg/L. Results indicated that applying PGR, auxin, and cytokinin with MS media influenced morphological and phytochemical traits of tea's callus derived from leaves and shoots. Specifically, the treatment of 1 mg/L NAA + 1 mg/L BAP showed the best performance on callus weight and total phenolic and flavonoid contents compared to other treatments., i.e. 9.038% % and 0.05% %, respectively. The success of clonal propagation in tea through in vitro methods is expected to increase by carefully selecting the appropriate source and type of explant, planting media, PGR, and addressing potential contaminants.

Enhancing growth and phytoremediation efficiency of Pennisetum purpureum cv. Mahasarakham in weathered PAH-contaminated soil through thidiazuron application

Polycyclic aromatic hydrocarbons (PAHs) are phytotoxic, which can limit their phytoremediation. When the ability of plants to phytoremediation PAHs is compromised, the application of plant growth regulators can enhance the growth of the plants. This study aimed to determine the best plant growth regulator (1-naphthalene acetic acid, 6-benzyladenine, or thidiazuron) to enhance the phytoremediation ability of sweet grass (Pennisetum purpureum cv. Mahasarakham) when grown in weather PAH-contaminated soil. In a greenhouse study, 0.01 mg/l thidiazuron resulted in the highest growth of sweet grass when compared to the other tested plant growth regulators (dry shoot weight 24.11 ± 1.28 g and dry root weight 0.70 ± 0.02 g). Sweet grass was grown in soil contaminated with PAH, which demonstrated the toxicity to sweet grass by reducing the total chlorophyll (1.01 µg/g fresh weight) and carotenoid (0.28 µg/g fresh weight) contents with proline increased (6.63 µg/g fresh weight). Meanwhile, total chlorophyll, carotenoid, and proline content in leaves of sweet grass grown in non-contaminated soil were 1.68, 0.44, and 5.23 µg/g fresh weight, respectively. When sweet grass was used to phytoremediate PAHs, there were reductions in acenaphthylene (4.69 ± 0.50%), acenaphthene (10.69 ± 1.47%), and phenanthrene (3.61 ± 0.07%), which compared to levels of over 30% in non-planted soil. For the three PAHs, the bioconcentration factors were 1.6 to 2.4, but the translocation factors were below 1, showing limited movement to the aerial parts of the plant, thereby suggesting that the main mechanism is rhizoremediation. Sweet grass is an excellent candidate for PAH remediation, especially when thidiazuron is applied to relieve plant stress.

Foliar application of plant growth regulators increases the production of biomass, content, yield and chemical constituents of Origanum vulgare L. essential oil

Foliar application of plant growth regulators increases the production of biomass, content, yield and chemical constituents of Origanum vulgare L. essential oil

Effect of foliar application of plant growth regulators on incidence of insect-pests and diseases in autumn planted seed potato (Solanum tuberosum)

A field experiment was conducted during 2019–20 and 2020–21 at Punjab Agricultural University, Ludhiana, Punjab to study the effect of foliar application of plant growth regulators on insect-pest and disease incidence in potato (Solanum tuberosum L.) under subtropical conditions. A total of 11 treatments including control were tested in a randomized complete block design (RCBD) with three replications on the potato cv. Kufri Pukhraj. The results indicated that plant growth regulators, like GA3, IBA, NAA, ethrel, jeevamrit and waste decomposer were not producing any significant effect on the incidence of aphid, jassid and whitefly population in comparison to untreated control. However, diseases such as scab and scurf did not reveal any significant differences among the plant growth regulator’s treatments except in late blight. Foliar application of gibberellic acid (200 ppm) at 45 and 60 days after sowing (DAS) significantly reduced the late blight incidence and severity in seed potato cv. Kufri Pukhraj.

Application of plant growth regulators in prevention of autumn flowering in pear

Application of plant growth regulators in prevention of autumn flowering in pear

Effect of plant growth regulators and fertilizers on the growth and yield of black gram (Vigna mungo L.)

A field experiment was carried out to assess the effect of foliar application of plant growth regulators and fertilizers on the growth, yield attributes and grain yield of black gram. The results revealed that the application of RDF + DAP 2% + NAA 60 ppm recorded significantly higher growth attributes viz., plant height (47.87 cm), number of leaves plant-1 (34.22), number of primary branches plant-1 (7.06) and number of secondary branches plant-1 (19.63), as well as yield and yield attributes including number of pods plant-1 (34.39), pod length (6.82 cm), number of grains pod-1 (6.61), test weight (38.67g), grain yield (1234.19 kg ha-1) and straw yield (3640 kg ha-1). The net returns and benefitcost ratio (Rs. 75667.66 and 2.17, respectively) were also recorded substantially higher with the application of RDF + DAP 2% + NAA 60 ppm over the rest of the treatments. Based on the present findings it was concluded that the application of RDF + DAP 2% + NAA 60 ppm in black gram crop is profitable.

Application of Plant Growth Regulators Mitigates Water Stress in Basil

Application of Plant Growth Regulators Mitigates Water Stress in Basil

Impact of Foliar Application of Plant Growth Regulators in Soybean [Glycine max (L.) Merill)] on Seed Quality and Seedling Establishment

Impact of Foliar Application of Plant Growth Regulators in Soybean [Glycine max (L.) Merill)] on Seed Quality and Seedling Establishment

Influence of plant growth regulators on fruit set, yield and quality of mango varieties under HDP

Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations. Phytohormones determine the formation of flowers, fruit set, stems, leaves, shedding of leaves, and development and ripening of fruits. They shape the plant, affecting seed growth, time of flowering, sex of flowers, senescence of leaves and fruits. Hormones are vital for plant growth and lacking them, plants would be mostly a mass of undifferentiated cells. Plant growth regulators include salicylic acid, CPPU, tricontanol and brassinosteroid. The production of poor quality fruits is a matter of common experience. It would be therefore worth while to improve the yield and quality of fruit crops by foliar application of plant growth regulators. The use of growth regulators has become an important component of agro-technical procedures for most of the cultivated plants and especially for fruit plants. In this review, we focus on the role of plant growth regulators on fruit production.

Plant Growth Regulators Enhance Maize (Zea mays L.) Yield under High Density by Optimizing Canopy Structure and Delaying Leaf Senescence

Shaping the canopy architecture and delaying leaf senescence in maize are pivotal strategies for extending the crop’s photosynthetic period and improving yield. The application of plant growth regulators (PGRs) is a critical cultivation measure, with the timing of application being of paramount importance. To explore the effects of PGR application time on maize canopy structure, leaf senescence characteristics and yield, a comparative two-year field study was undertaken during the 2019–2020 growing seasons at the Gongzhuling Experimental Station of the Jilin Academy of Agricultural Sciences, utilizing a PGR containing ethephon as the active ingredient. The experiment was structured with two plant densities of 60,000 and 90,000 plants ha−1, and three distinct PGR application protocols: T10 (application of PGR at the 10th leaf stage), T15 (application at the 15th leaf stage), and CK (control group sprayed with water). The result indicated that the yield increased by 5.62% following T15 treatment compared to the CK under high density (90,000 plants ha−1). Furthermore, the kernel per ear and the 1000-kernel weight increased by 3.93% and 5.62% respectively, while the abortion rate decreased. Correlation analysis showed that yield and yield components were correlated with plant morphology, physiology, and aging characteristics under 90,000 plants ha−1. Pollen density was also positively correlated with the top leaf area and the top leaf angle (p < 0.01). Furthermore, relative green leaf area at maturity (RGLAM) showed positive correlations with chlorophyll b, superoxide dismutase activity (SOD), peroxidase activity (POD), catalase activity (CAT), and soluble protein content (p < 0.01), while displaying a negative correlation with malondialdehyde content (MDA) (p < 0.01). Spraying plant growth regulators at the 15-leaf stage under high density can effectively enhance the top canopy structure of the maize and reduce the upper leaf area and angle, increase pollen density, and boost the number of grains. Furthermore, it delayed the senescence of leaves, prolonged the functional period of the leaves, increased kernel weight, optimized light resource utilization, and ultimately enhanced the maize yield.

Sustaining the Yield of Maize, Blackgram, Greengram, Groundnut, Cotton, Sugarcane, and Coconut through the Application of Nutrients and Plant Growth Regulator Mixture.

The foliar application of nutrients and plant growth regulators (PGRs) at critical crop growth periods can improve the yield of field crops. Hence, the present study was conducted to quantify the effects of the combined application of nutrients and PGRs (crop-specific formulation) on maize, blackgram, greengram, groundnut, cotton, sugarcane, and coconut yield. In all the crops except coconut, the treatments included (i) a foliar spray of crop-specific nutrients and PGR combinations and (ii) an unsprayed control. In coconut, the treatments included (i) the root feeding of coconut-specific nutrients and PGR combinations and (ii) an untreated control. Crop-specific nutrient and PGR formulations were sprayed, namely, Tamil Nadu Agricultural University (TNAU) maize maxim 1.5% at the tassel initiation and grain-filling stages of maize, TNAU pulse wonder 1.0% at the peak flowering stage of green gram and black gram, TNAU groundnut-rich 1.0% at the flowering and pod-filling stages of groundnut, TNAU cotton plus 1.25% at the flowering and boll development stages of cotton, and TNAU sugarcane booster 0.5% at 45 days after planting (DAP), 0.75% at 60 DAP, and 1.0% at 75 DAP of sugarcane. The results showed that the foliar application of TNAU maize maxim, TNAU pulse wonder, TNAU groundnut-rich, TNAU cotton plus and TNAU sugarcane booster and the root feeding of TNAU coconut tonic increased the yield of maize, pulses, groundnut, cotton, sugarcane, and coconut, resulting in higher economic returns.

Leader Bagging Improves Lateral Branching and Cropping Potential of ‘Gala’ and ‘WA 38’ Apple during Orchard Establishment

Inadequate lateral branch development can lead to decreased apple (Malus ×domestica Borkh.) orchard productivity and profitability in modern high-density orchard systems. Although plant growth regulator applications are used to increase lateral branching on leaders of young apple trees, inconsistent responses have been observed in the southeastern United States. In North Carolina and Washington, three experiments were conducted to identify effective leader management strategies to increase lateral branching. Effects and interactions of leader bagging, 6-benzyladenine (6-BA), and 6-BA + gibberellic acid (GA4+7) on lateral branch development of 1-year-old leaders were evaluated. Across all experiments, leader bagging was an influential factor. When compared with unbagged trees, leader bagging increased lateral branch number (20% to 48%), number of feathers (74% to 125%), average branch length (28% to 34%), and total linear bearing surface (428%) of the treated section of the leader. Blossom cluster density and final fruit set were increased in bagged trees, 65% and 36%, respectively. At the rates and timings tested, 6-BA and 6-BA + GA4+7 were generally ineffective in stimulating lateral branching and interactions among the factors evaluated were not influential. Leader bagging was an effective lateral branch induction strategy, although the mechanism of action is poorly understood. Future research to characterize the bagged environment and/or physiological responses to bagging may aid in the development of future environmentally sustainable technologies to stimulate lateral branching of apple trees.

Foliar application of Boron, Calcium, and Indole-3-butyric acid on onion plants to improve seed production

Onion is the third most important cultivated vegetable crop around the world. Two types of varieties are cultivated: Open pollinated cultivars (OP) and first generation hybrids (F1). Little is known about the effects of foliar applications on onion seed production. This study was conducted to evaluate the enhancement of onion seed yield and seed quality through foliar applications of Boron (B), Calcium (Ca), and an auxin, indole-3-butyric acid (IBA). Male-sterile lines (MSL), and OP planted in pots and open field conditions were used over four seasons. The experiments were carried out with different levels of nutrients and IBA applied to the plants. Our results showed that foliar applications of nutrients and plant growth regulators were effective methods to improve onion seed yield and the number of seed per fruit, while seed quality parameters remained stable. The seed yield was enhanced by B by up to 83 %, but with an increasingly wide variability in comparison to the control. Indole-3-butyric acid improved yields when it was applied alone and mixed with B and Ca (40–45 % for OP and MSL, respectively) compared to the control. Therefore, foliar application of IBA, B and Ca could be effective in improving onion seed yields.

Agrochemical Spray Technology Adoption and Safety Awareness Assessment in Crop Protection in Vineyard Cultivation

A study was conducted in the Jalna district of Maharashtra to assess the adoption pattern of spray technology, and safety awareness among grape growers. The respondents were selected through random sampling and data was collected through a structured interview. The study revealed that among marginal landholders (< 1 ha) back-pack type sprayer was mostly in operation with an adoption level of 75%. In small landholders (1-2 ha), horizontal triplex pump (HTP) sprayers with an adoption level of 51.85% followed by tractor-operated air-blast sprayers (40.75%) were prevalent pesticide spraying technologies. More than 2/3rd (76.00%) of medium landholders (2-4 ha) had adopted tractor-operated air blast sprayers. For the application of plant growth regulators, 62.5% of small farmers, 81.8% of medium, and 100% of farmers had adopted electrostatic sprayers. The number of chemical sprays per season varied from 25 to 100, making grapes one of the major pesticide-consuming crops. Capacity, efficiency, cost, and availability of sprayers on a custom hiring basis were the four major factors affecting the adoption of spraying technologies.

Growth, productivity and quality of colored capsicum (Capsicum annuum L.) as influenced by hybrids and plant growth regulators under controlled environment conditions

In developing countries like India, rapid urbanisation was under way and the diet habits of the people have been changing day to day. Under this transformation, a section of the population is focused on nutritional security where vegetables play a major role in daily diet. Among different vegetables coloured bell pepper which is commonly known as capsicum, has importance due to its nutritional quality and market demand. The quality and productivity of coloured capsicum can be improved by choosing the best performing hybrids and exogenous application of plant growth regulators. Considering the above, the present study was conducted from November to April of 2020-21 and 2021-22 at the Protected Cultivation Unit of Centurion University of Technology and Management, Paralakhemundi, Odisha under controlled environment conditions. The experiment was laid out in factorial randomized block design consisting of two hybrids, namely, Orobelle (yellow colored) and Bomby (red colored); and eight treatments of growth regulators which were GA3 @ 25 ppm, GA3 @ 50 ppm, GA3 @ 75 ppm, GA3 @ 100 ppm, NAA @ 20 ppm, NAA @ 40 ppm, NAA @ 60 ppm and NAA @ 80 ppm. A total of 16 treatment combinations were worked out in the experiment which were replicated thrice. The results of the experiment revealed that there was no significant variation among the hybrids cultivated with respect to yield attributes, yield, quality parameters and growth attributes excluding plant height and number of leaves per plant at 60 DAS and 90 DAS. However, there was a significant impact of plant growth regulators on growth attributes, yield attributes, yield and quality parameters. The application of NAA @ 80 ppm resulted in early flowering (43.8 days after planting). Moreover, the maximum number of flowers per plant (32.5 flowers/plant), flower to fruit ratio (52.9), fruits per plant (19.5) and weight of the fruit (133.6 g) recorded in GA3 @ 100 ppm application. There was a significant interaction effect among treatment combinations in fruit yield where the highest value was recorded in Bomby hybrid with GA3 @ 100 PPM application. From the study it may be concluded that cultivation of both the hybrids can be considered as per the fruit colour and market demand along with the application of GA3 @ 100 ppm under controlled environment conditions.

Metabolomics analysis reveals enhanced salt tolerance in maize through exogenous Valine-Threonine-Isoleucine-Aspartic acid application.

Salt stress is a well-known abiotic constraint that hampers crop productivity, affecting more than 424 million hectares of topsoil worldwide. Applying plant growth regulators externally has proven effective in enhancing crop resilience to salt stress. Previous metabolomics studies revealed an accumulation of Valine-Threonine-Isoleucine-Aspartic acid (VTID) in salt-stressed maize seedlings, suggesting its potential to assist maize adaptation to salt stress. To explore the effectiveness of VTID in enhancing salt tolerance in maize, 10 nM VTID was applied to salt-stressed maize seedlings. The results showed a remarkable 152.29% increase in plant height and a 122.40% increase in fresh weight compared to salt-stressed seedlings. Moreover, the addition of VTID enhanced the activity of antioxidant enzymes, specifically superoxide dismutase (SOD) and catalase (CAT), while reducing the level of malondialdehyde (MDA), a marker of oxidative stress. Additionally, VTID supplementation resulted in a significant increase in osmoregulatory substances such as proline. Metabolomic analysis revealed substantial changes in the metabolite profile of maize seedlings when treated with VTID during salt stress. Differential metabolites (DMs) analysis revealed that the identified DMs primarily belonged to lipids and lipid-like molecules. The receiver operating characteristic curve and linear regression analysis determined a correlation between isodolichantoside and the height of maize seedlings under salt-stress conditions. In conclusion, these findings validate that VTID effectively regulates tolerance in maize seedlings and offers valuable insights into the potential of short peptides for mitigating salt stress.

The effect of foliar application of plant growth regulators on functional and qualitative characteristics of wheat (Triticum aestivum L.) under salinity and drought stress conditions

This study aimed to investigate the effect of salinity and water stress on the physiological and functional characteristics of winter wheat (Triticum aestivum L.) under the foliar application of plant growth regulators (PGRs). The experiment was carried out as a split plot based on a randomized complete block design with three replications in two environments. In each environment, water stress at two irrigation levels (after 90 and 120 mm of pan evaporation) and with two EC of 1.5 and 10 dS/m in the main plots and spraying of PGRs including salicylic acid (SA), gibberellic acid (GA3), and cytokinins (CK) (purine) content with a concentration of 100 ppm and the control treatment (spraying solution with normal water) were placed in subplots. Results indicated that all treatments caused significant increases in functional and qualitative characteristics and yield of Triticum aestivum L. The saline environment and irrigation level after 120 mm of pan evaporation caused a reduction in grain yield in all traits except for seed proline, seed nitrogen content, and seed protein content. Also, the combined foliar application of GA3 + CK + SA increased yield in most traits. The highest RWC of flag leaves was observed in the foliar application of GA3 + SA (3.36 kg/ha) and then in the foliar application of GA3 + SA + CK (57.87 kg/ha). GA3 interacts with PGR spraying to balance another development under saline and non-saline conditions.

Effect of Foliar Application of Selected Plant Growth Regulators on Growth and Yield of Soybean [Glycine max (L.) Merrill

Background: Soybean (Glycine max), a prized oilseed crop known for its nutritional richness, is the focus of a study aiming to boost production with minimal environmental impact. The research explores the application of plant growth regulators (PGRs), specifically Gibberellic Acid (GA3), Kinetin and Salicylic Acid, in field experiments during the kharif seasons of 2022 and 2023 in Beed, India. Methods: The study applied Gibberellic Acid (GA3), Kinetin and Salicylic Acid at different concentrations in field experiments. A comprehensive analysis of growth and yield attributes, including plant height, primary branches, Leaf Area Index (LAI), root nodules and Crop Growth Rate (CGR), was conducted to assess the influence of PGR treatments on soybean growth. Yield attributes such as pod count, pod weight, seed count per pod and 100-seed weight were scrutinized to understand their effects on soybean productivity. Result: The study highlighted significant effects of PGR treatments on soybean growth and yield. Notably, Kinetin at 500 ppm promoted the tallest plants, while GA3 at 200 ppm resulted in the shortest. Kinetin at 100 ppm increased primary branches and Salicylic Acid at 50 ppm exhibited the highest LAI and abundant root nodules. Kinetin at 500 ppm and Salicylic Acid at 50 ppm showed higher CGR, indicating efficient crop growth. For yield, Kinetin at 500 ppm excelled in pod count and weight. GA3 at 100 ppm was identified as the most effective PGR for enhancing various growth parameters and soybean seed yield, suggesting the potential of PGRs in sustainable cultivation, reducing reliance on chemical inputs.

Fertiliser supplementation with a PGR complex of chlormequat chloride (CCC) and paclobutrazol (PBZ) alters Cannabis sativa growth

ABSTRACT Cannabis (Cannabis sativa) is a high-value crop, wherein growth within controlled environments is common for the purposes of maximising yield, quality, and uniformity, however, uncontrolled-growth in proximity to artificial lighting can compromise yields. Within the floricultural industry it is common practice to apply plant growth regulators (PGRs) to retard plant growth and maximise yield and quality, with two well-established PGRs being chlormequat chloride (CCC) and paclobutrazol (PBZ). Accordingly, the aim of this study was to investigate the potential of a PGR complex of CCC and PBZ for novel application to cannabis to control plant height. Treatment of cannabis with the PGR complex within an indoor hydroponic growth system resulted in a 91.1% reduction in post-treatment plant growth (p < 0.001) leading to plants with end-point height and internodal spacing (INS) 0.568-fold (p < 0.001) and 0.469-fold (p < 0.001) shorter than control plants, respectively. These results demonstrate the capacity of CCC and PBZ to beneficially halt the growth of cannabis. Accordingly, application of these PGRs in combination may be utilised to restrict cannabis height without compromising yield within commercial cultivation.

Successful shoot tip grafting of cacao (Theobroma cacao L.) due to the application of plant growth regulators on various concentrations

Cacao plays an important role in the Indonesia economy. Therefore, its production and area expansion have to increase to achieve maximum cacao productivity by the quality and superior cacao clones. Shoot tip grafting is one of the propagation methods to obtain superior cacao plants by applying Plant Growth Regulators (PGRs). Research on the effect of several PGRs with various concentrations on cacao (Theobroma cacao L.) shoot tip grafting was conducted at the Integrated Innovation Farmer Group, Belubus, Sungai Talang Village, Guguak District, Lima Puluh Kota Regency, West Sumatra from February until June 2022. This study aimed to determine the interaction between PGR type and concentration on the grafting success and growth of cacao shoot tip grafted seedling. The research was designed by a Factorial Completely Randomized Design with three replications. The first factor was the type of PGR, i.e., synthetic PGR (BAP), young corn seed extract, shallot extract, and young coconut water. The second factor was the concentration of PGR, i.e., 0%, 25%, 50%, 75% and 100%. The results showed an interaction between PGRs with some concentrations on the number of shoots, shoot length, and leaf length on the grafted cacao seedling. The natural PGR from young coconut water at a concentration of 75% gave the best effect on the number of shoots (3.33 shoots) and shoot length (24.50 cm) of cacao seedling.