Foliar Application Of Gibberellic Acid Research Articles

Exogenously applied gibberellic acid and benzylamine modulate growth and chemical constituents of dwarf schefflera: a stepwise regression analysis

Ornamental foliage plants that have a dense appearance are highly valued. One way to achieve this is by using plant growth regulators as a tool for plant growth management. In a greenhouse with a mist irrigation system, a study was conducted on dwarf schefflera, an ornamental foliage plant, which was exposed to foliar application of gibberellic acid and benzyladenine hormones. The hormones were sprayed on dwarf schefflera leaves at 0, 100, and 200 mg/l concentrations, at 15-day intervals in three stages. The experiment was conducted as a factorial based on a completely randomized design, with four replicates. The combination of gibberellic acid and benzyladenine at 200 mg/l concentration had a significant effect on leaf number, leaf area, and plant height. The treatment also resulted in the highest content of photosynthetic pigments. Furthermore, the highest soluble carbohydrate to reducing sugars ratio was observed in treatments of 100 and 200 mg/l benzyladenine, and 200 mg/l gibberellic acid + benzyladenine. Stepwise regression analysis showed that root volume was the first variable to enter the model, explaining 44% of variations. The next variable was root fresh weight, and the two-variable model explained 63% of variations in leaf number. The greatest positive effect on leaf number was related to root fresh weight (0.43), which had a positive correlation with leaf number (0.47). The results showed that 200 mg/l concentration of gibberellic acid and benzyladenine significantly improved morphological growth, chlorophyll and carotenoid synthesis, and reducing sugar and soluble carbohydrate contents in dwarf schefflera.

Influence of Zinc and Gibberellic Acid on Growth and Yield of Maize (Zea mays L.)

A field experiment was carried out during kharif season of 2022 on Maize crop at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj, (U.P.), to study the “Influence of Zinc and Gibberellic acid on growth and yield of Maize ( Zea mays L.)” The treatments consisted of 3 levels of Zinc (Soil application 20 kg/ha, Foliar application 0.5% and Soil application 10 kg/ha + Foliar 0.25%) and Foliar application of Gibberellic Acid (50, 100 and 150 ppm) and a control. The experiment was laid out in Randomized Block Design (RBD) with 10 treatments and each were replicated thrice. The results revealed that treatment 9 with Soil application of Zinc (10 kg/ha) + Foliar (0.25%) with combination of GA3 at 150 ppm produced higher plant height (187.73 cm), more dry weight (184.05 g), maximum number of cobs per plant (1.60), maximum number of rows per cob (14.67), maximum number of grains per row (26.33), test weight (215.78 g), higher grain yield (6.76 t/ha), higher stover yield (13.80) and higher harvest index (32.87%). Similarly, maximum gross return (2,18,280.00 INR/ha), net return ( 1,49,997.00 INR/ha) and highest B:C ratio (2.20) was also recorded in treatment 9 with Soil application of Zinc (10 kg/ha) + Foliar (0.25%) with combination of GA3 at 150 ppm.

Exploring the Role of Anti-Oxidant on Growth and Yield of Cotton to Mitigate the Heat Stress

Agriculture experiencing a continuous pressure of food in order to meet the necessities of rising population. The cottonseed used as oilseed as well as a major source of edible oil in Pakistan. Cotton production affected by biotic and abiotic factors. Experiment was done at Central Cotton Research Institute, Multan in 2019 to study the effect of foliar application of gibberellic acid (GA), ascorbic acid (AA), citric acid (CA) and a control group in which no antioxidant was used against heat stress. Design used for experiment was randomized complete block design (RCBD). In trial cultivar of cotton CIM-610 was used. Experiment was replicated four times. Plot size was 9m (length) x 6m (width) with net plot size of 54 m2 . Statistically significant results among the morphological plus physiological attributes were observed. Almost yield parameters as plant height, nodes per plant buds per plant and bolls per plant have maximum values every month from May to October, sympodial branches (39), boll weight (2.97g), seed cotton yield (3097 kg), ginning out turn (39.133), fiber length (27.33 mm), fiber strength (28.8g tex), 100 seed weight (8.363g), fiber brightness (68.97Rd), micronaire (5.5) and uniformity index (83.48%) were leading in exogenous application of GA then AA, thirdly application of CA. In GA treatment maximum of plant height,bolls per plant, boll weight, monopodial branches and seed cotton yield were seemed. Seed cotton and lint quality yield reduced greatly due to heat stress. Antioxidants application of exogenous can sustain cotton yield and quality against heat stress conditions. Antioxidants of plants gave best results than where no treatment was applied

Effects of Plant Growth Regulators Including Micro-nutrients on Fruit Set and Yield of Mandarin in Dhankuta District of Nepal

The study evaluated foliar applications of three plant growth regulators, viz. GA3 @ 20ppm; 2,4-D @ 15ppm; and NAA @ 50ppm; alone and their combinations including three plant micro-nutrients, viz. B @ 0.4% + Zn @ 0.2% + Ca @ 1% in order to determine the best foliar spray of growth hormones and plant nutrients for the increased fruit set and yield of mandarin. The foliar sprays were applied five times, started from full-bloom until late September (pre-harvest stage). The experiments were conducted in Dhankuta, Nepal during 2019 and 2020. The highest bloom fruit set of 6.1% was recorded at the foliar application of GA3 20ppm + NAA @ 50ppm, compared to the control treatment of 4.6%. Likewise, there were significant effects of plant growth regulations and micro-nutrients applications on the fruit drops across the fruit growing periods. The foliar application of GA3 + 2,4-D + micronutrients resulted in the lowest fruit drop during the months of June (63.9%), July (65.9%), and September (20.8%), as opposed to the control treatment's fruit drops of 77.6, 80.4, and 41.5%. In addition, the fruit drops occurred at the foliar sprays of GA3 + 2,4-D were statistically at par with the GA3 + 2,4-D + micro-nutrients. Also, the GA3 + 2,4-D + micronutrient spray treatment had the largest number of fruits (995 nos.) and total fruit weight (64.2 kg) per tree, which were considerably higher than the control by 201.5 and 175.5%, respectively. To sum up, a combined foliar application of gibberellic acid, 2,4-D and micro-nutrients is recommended for improving the fruit set, retention and yield of mandarin.

Effect on yield and qualitative characteristics of strawberry (Frageria annanasa) cv. chandler to foliar application of gibberellic acid and zinc

Effect on yield and qualitative characteristics of strawberry (Frageria annanasa) cv. chandler to foliar application of gibberellic acid and zinc

Water relations and yield characteristics of mungbean as influenced by foliar application of gibberellic acid (GA3)

Optimizing the dose and foliar application frequency of growth regulators such as gibberellic acid (GA3) may play an important role in ensuring food security under changing climate scenarios by boosting grain yield of food legumes such as mungbean. A trial was conducted to evaluate the growth promoting effect of foliage applied gibberellic acid (GA3) at various spraying frequencies for mungbean crop. The employed treatments included four gibberellic acid levels (0, 100, 200, and 300 ppm) and two application frequencies (single spray at 30 days after sowing DAS, and two sprays at 30 and 40 DAS). Water relations, yield contributing characteristics and mungbean grain yield were among the response variables investigated. The research findings revealed that GA3(200 ppm applied twice at pre-flowering and post-flowering stages) significantly improved the water relations, morphological and yield attributes of mungbean. This treatment combination remained unmatched by producing the highest relative water content in the stem (85.52), water retention capacity in the stem (17.24), and water uptake capacity in the stem and leaf (2.35). Furthermore, the same treatment combination resulted in the maximum plant height (50.04 cm), pods per plant (11.07), pod length (6.62 cm), grains number per pod (11.00), 100-grains weight (3.78 g), grain yield per plant (4.57 g), and a minimum water saturation deficit. Thus, GA3foliage application at 200 ppm at 30 and 60 DAS has the potential to stimulate growth and increase the yield attributes and grain yield of mungbean. However, additional in-depth field trials with various doses of GA3sprayed at a higher frequency may be required before recommending GA3for general adoption to mungbean growers.

Foliar application of gibberellic acid in combination with cowdung enhances growth and yield attributes of okra(Abelmoschus esculentus)

A field experiment was conducted at the Horticulture Farm of Bangladesh Agricultural University, Mymensingh during March to July 2020 to investigate the results of various amount of cowdung and gibberellic acid (GA3) on okra growth and production. The experiment comprised of Factor A: three doses of cowdung such as C0= 0 ton (Control), C1= 5 t ha-1, C2= 10 t ha-1and Factor B: four variable concentrations of GA3such as G0= Control (with no gibberellic acid), G1= 50 ppm gibberellic acid, G2= 100 ppm gibberellic acid and G3= 150 ppm gibberellic acid. Three replications ofthe experiment were set up using a Randomized Complete Block Design (RCBD). Most of the developmental and yield-contributing parameters of the okra tested significantly varied when various quantities of cowdung and varying amounts of gibberellic acid wereused. The 10 t ha-1cowdung (C2) had the maximum yield (11.34 t/ha) as well as the amount of green pods(13.77)per plant. From a 0 t ha-1cowdung (C0) treatment, the fewest green pods (14.18), and lowest green pod production (5.98 t/ha), were produced. On the other hand, gibberellic acid with 100 ppm (G2) showed the best performance on number of green pods (13.77), green pod output (10.51 t/ha) and the lowest performance on number of green pods (10.05), green pod produce (6.47 t/ha) from control (G0) treatment (without gibberellin). Okra's development and yield-contributing characteristics were greatly impacted by the interaction of cowdung and gibberellic acid. The integration of 10 t ha-1 cowdung (C2) and 100 ppm gibberellic acid performed the best on the number of green pods (15.91), green pod yield (13.47 t/ha) tremendously non-identical from the combination of treatment of 0 t ha-1(C0) with no gibberellic acid applied plants in the same parameters viz. number of green pods (7.72), green pod yield (4.13 t/ha). The finding of this study suggested that application of 10 tons cowdung per hectare combine with 100 ppm gibberellic acid to be recommended for okra cultivation.

Effect of Plant Growth Regulators on Seed Yield and Seed Quality Traits in Tomato (Solanum lycopersicum L.) cv. Kashi Adarsh

A field experiment was conducted at the College of Agriculture and Research Station, Kunkuri, Jashpur, Chhattisgarh, during rabi 2020-21 with an aim to standardize foliar spray of plant growth regulator for higher seed yield in tomato. The experiment was laid out in randomized complete block design having nine treatments and three replications. Seedling quality traits were recorded in laboratory in completely randomized design. Foliar application of Gibberellic acid (GA3), Naphthaleneacetic acid (NAA), Cycocel and Salicylic acid in various concentrations in tomato were applied as foliar spray at 30 and 45 days after transplanting of tomato seedlings of cultivar Kashi Adarsh. Results revealed that maximum plant height (121.89 cm), number of branches per plant (10.39), number of fruits per plant length of fruit (33.06), length of fruit (4.66 cm), diameter of fruit (4.52 cm), seed yield per plant (19.14 g) was recorded in treatment foliar spray of GA3 at 50 ppm. In laboratory condition seedling traits were evaluated and the highest germination (96.25 %), root length (6.78 cm), shoot length (8.76 cm), root fresh weight (0.81 g), shoot fresh weight (3.37g), root dry weight (0.061 g), shoot dry weight (0.209 g), vigour index- I (789.25) and vigour index- II (22.66) was also recorded in GA3 at 50 ppm.

Effect of Foliar Application of Gibberellic acid, Salicylic acid and Ammonium nitrate on Berry Quality of Ruby Seedless Grape Cultivar

Effect of Foliar Application of Gibberellic acid, Salicylic acid and Ammonium nitrate on Berry Quality of Ruby Seedless Grape Cultivar

Heat stress mitigation in tomato (Solanum lycopersicum L.) through foliar application of gibberellic acid

Phytohormones mediate physiological, morphological, and enzymatic responses and are important regulators of plant growth and development at different stages. Even though temperature is one of the most important abiotic stressors for plant development and production, a spike in the temperature may have disastrous repercussions for crop performance. Physiology and growth of two tomato genotypes ('Ahmar' and 'Roma') were studied in two growth chambers (25 and 45 °C) when gibberellic acid (GA3) was applied exogenously. After the 45 days of planting, tomato plants were sprayed with GA3 at concentrations of 25, 50, 75, and 100 mg L−1, whereas untreated plants were kept as control. Under both temperature conditions, shoot and root biomass was greatest in 'Roma' plants receiving 75 mg L−1 GA3, followed by 50 mg L−1 GA3. Maximum CO2 index, photosynthetic rate, transpiration rate, and greenness index were recorded in 'Roma' plants cultivated at 25 °C, demonstrating good effects of GA3 on tomato physiology. Likewise, GA3 enhanced the proline, nitrogen, phosphorus, and potassium levels in the leaves of both genotypes at both temperatures. Foliar-sprayed GA3 up to 100 mg L−1 alleviated the oxidative stress, as inferred from the lower concentrations of MDA and H2O2, and boosted the activities of superoxide dismutase, peroxidase, catalase. The difference between control and GA3-treated heat-stressed plants suggests that GA3 may have a function in mitigating heat stress. Overall, our findings indicate that 75 mg L−1 of GA3 is the optimal dosage to reduce heat stress in tomatoes and improve their morphological, physiological, and biochemical characteristics.

Effect of Row Spacing and Gibberellic Acid on Growth and Yield of Chickpea (Cicer arietinum L.) under Rainfed Conditions

A field experiment on chickpea was conducted during Rabi, 2021 at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P). INDIA. The soil of the experimental plot was sandy loam in texture, nearly neutral in soil reaction (pH 6.9), organic carbon (0.71%), available N (273.54 kg/ha), available P (31.14 kg/ha), and available K (327 kg/ha). The treatments comprised of spacing (25cm x 10cm, 35cm x 10cm, 45cm x 10cm), and foliar application of Gibberellic acid (15, 30, & 45ppm/ha). The experiment was laid out in Randomized Block Design with nine treatments each replicated three times. The results showed that viz: Plant height (68.91 cm), number of branches per plant (28.19), plant dry weight (27.48 g/plant) were recorded significantly higher with 35 x10 cm + GA3 45ppm/ha. Whereas, crop growth rate (17.68 g/m2/day), relative growth rate (0.023 g/g/day) recorded higher in 25 x 10cm + GA3 30ppm/ha. Number of pods per plant (60.04), number of seeds per pod (1.93), seed yield (246.67 kg/ha), haulm yield (5064.53 kg/ha) were recorded significantly higher.
 Higher gross returns (1,08,022.50 ₹/ha), net returns (75,676.47 ₹/ha), and benefit-cost ratio (3.33) were obtained with the application of 35 x10 cm + GA3 45ppm/ha. Thus, spacing with foliar application of Gibberellic acid (15,30 and 45ppm) could be a promising option for yield enhancement in chickpea.
 
 
 
 

Non-Structural Carbohydrates, Foliar Nutrients, Yield Components and Oxidative Metabolism in Pecan Trees in Response to Foliar Applications of Growth Regulators

Foliar sprays of growth regulators have commercial potential for improving the performance of some of the parameters associated with alternate bearing in pecan trees. The objective was to evaluate the behaviour of alternate bearing through analysis of seasonal variations in buds and leaflets of non-structural carbohydrates (glucose, fructose, sucrose, and starch), mineral nutrients (N-total, P, K+, Ca2+, Mg2+, Fe2+, Cu2+, Mn2+ and Zn2+), yield components (nut weight per kilogram and kernel percentage) and oxidative metabolism (superoxide dismutase, hydrogen peroxide, catalase, guaiacol peroxidase and antioxidant capacity) in cv. Wichita pecan trees in response to foliar applications of gibberellic acid (50 mg L−1), calcium prohexadione (500 mg L−1) or thidiazuron (10 mg L−1). The experiment was of a completely randomized experimental design with five replicates. Foliar growth regulator (GRs) sprays help maintain the concentration of non-structural carbohydrates in the leaflets and buds between the evaluation years. With the exception of K+ (12.9 and 10.9 g kg−1) and Zn2+ (45.1 and 30.5 mg kg−1), the GRs did not show any effects on the concentrations of the foliar mineral nutrients. The results suggest foliar sprays of gibberellic acid improve the performance of parameters associated with alternate bearing, including oxidative metabolism.

Effects of foliar application of gibberellic acid, boric acid and sucrose on noni (M. citrifolia L.) fruit growth and quality

Noni juice processing industry depends explicitly on the quality of noni fruits and its juice together with increased production of fruits. This study evaluated the effects of chemical treatments on noni's fruiting capacity, fruit yield and the fruit antioxidant properties. Noni plants in fruiting stage were foliar fed with boric acid (BA) at a concentration of 100 ppm or 200 ppm, gibberellic acid (GA3) at 20 ppm or 40 ppm and sucrose solution at 5 or 20% and water (control). Changes in fruiting numbers, fruit growth rates, fruit yield, total soluble solids (TSS), fruit antioxidant capacity and total phenolic content of fruits were determined after the foliar treatments. Fruiting, fruit growth rate and yield were significantly increased in BA, GA3 and sucrose treated plants when compared to the control treatment. Fruit TSS, antioxidant capacity and total phenol content were not affected. Sucrose 20% and BA treatments (100 ppm and 200 ppm) produced the highest fruit yields.

Foliar application of gibberellic acid improves yield and head phenolic compounds in globe artichoke

Applications of gibberellic acid (GA3) during the vegetative stage is used routinely in artichoke production systems in semi-arid regions to induce vernalization and improve yield. The objective of this two-year field study was to evaluate the effect of exogenous GA3 (20 mg l−1) application date (4th and 8th leaf stages) and frequency (two and three times) on morphological and physiological traits, yield and head quality of globe artichoke (Cynara cardunculus L. cv. Green Globe Improved) under a warm and semi-arid environment. Foliar application of GA3 at the 4-leaf stage increased plant height across growing seasons. However, no significant differences between application dates were noticed in plant width, gas exchange and leaf area index when measured at the harvesting period. GA3 application frequency (two or three) did not affect yield and head quality. Interestingly, foliar application of GA3 at 8-leaf stage increased yield by 13%, chlorogenic acid by 19%, cynarin by 30% and total N by 20% compared to the application at 4-leaf stage. In both years, GA3 applied at 8-leaf stage delayed the harvesting by 10 days when compared to plants that received GA3 application at 4-leaf stage. Considering the increase in yield and head quality without negative effects in canopy morphology or leaf physiology two applications of GA3 at the 8-leaf stage appears an effective crop management strategy for globe artichoke grown under warm climates.

Cadmium Toxicity Alleviation through Exogenous Application of Gibberellic Acid (GA3) in Mustard (Brassica juncea (L.) Czern.) and Rapeseed (Brassica rapa L.)

An experiment was carried out by considering adverse impact of heavy metals on human health through consumption of crops. To alleviate the adverse effects of cadmium (Cd) toxicity through foliar application of gibberellic acid (GA3), two varieties of Brassica including Indian mustard (Brassica juncea (L.) Czern.) commonly known as ‘Raya’ and rapeseed (Brassica rapaL.) as ‘Toria’ were studied. The Completely Randomized Design (CRD) was used with eight treatments including control in four replicates. Treatments were as following, T0 (control), T1 (150 μM CdCl2), T2 (50 mg/L GA3), T3 (75 mg/L GA3), T4 (100 mg/L GA3), T5 (150 μM CdCl2 + 50 mg/L GA3), T6 (150 μM CdCl2 + 75 mg/L GA3), and T7 (150 μM CdCl2 + 100 mg/L GA3). Gibberellic acid (GA3), a plant growth regulator applied exogenously. The concentration of cadmium (150 µM CdCl2) resulted in Cd toxicity affected adversely the morphological and biochemical parameters. Foliar application of GA3 (50 mg, 75 mg and 100 mg) positively influenced the various growth parameters as root length (30 cm), shoot length (129.75 cm), number of leaves (14.5), pods per plant (88) and biochemical parameters like total chlorophyll (0.19 mg/g), protein content (0.70 mg/mL), carbohydrates (0.37 mg/mL) and CAT (0.56 units/mg). Outcome indicated that GA3 reduces the harmful effects of Cd stress in both varieties. It was concluded that all growth and yield parameters of variety ‘Raya’ were better as compared to variety ‘Toria’, hence Raya recommended for large scale cultivation with GA3 under Cd stress.

Boosting antioxidant defense mechanism of mungbean with foliar application of gibberellic acid to alleviate cadmium toxicity

Boosting antioxidant defense mechanism of mungbean with foliar application of gibberellic acid to alleviate cadmium toxicity

Plant Growth Regulator Impacts on Vegetative Cutting Production of Moroccan Pincushion (Pterocephalus depressus) Plants

Abstract Moroccan pincushion (Pterocephalus depressus) is a drought-tolerant perennial that is being used in landscapes throughout arid areas of the western United States. This paper describes two experiments researching vegetative cutting production from stock plants. Moroccan pincushion stock plants received foliar applications of gibberellic acid (GA3), benzyladenine, ethephon, or auxin [indole-3-butyric acid (IBA)] plant growth regulators (PGR). Plant growth regulators were applied singularly and in combination with GA3 to determine efficacy on stock plant growth. A propagation study was conducted simultaneously to determine effects of these different PGR treatments applied to stock plants on the rooting of moroccan pincushion cuttings. The stock plant study showed GA3 + benzyladenine application increased cutting production over other PGR treatments. Fresh weight of moroccan pincushion cuttings did not differ among treatments. While cuttings did not differ in dry weight in experiment 1, statistical differences were observed in experiment 2. However, these differences in dry weight did not affect the quality of the cuttings. Cuttings from stock plants treated with GA3 + IBA treatment had the highest numerical growth index [(height + width + width)/3]. Cuttings from stock plants treated with GA3 alone or in combination with another PGR were all greater in average growth index and statistically differed from those without GA3 being applied. PGR treatments did not affect rooting percentages of the cuttings with nontreated stock plant cuttings successfully rooting at an average rate of 95%. However, GA3 + IBA was the only treatment where cuttings had 100% rooting for both experiments, indicating potential rooting benefits. Index words: Plant growth regulator, propagation, Pterocephalus depressus, vegetative cuttings. Species used in this study: Moroccan pincushion [Pterocephalus depressus Archibald]. Chemicals used in this study: gibberellic acid (GA3), benzyladenine, ethephon, indole-3-butyric acid (IBA).

Alleviation of Copper-Induced Stress in Pea (Pisum sativum L.) through Foliar Application of Gibberellic Acid.

Simple SummaryPhytohormones are key regulators of several stages of plant growth and development as well as provide the regulatory response against various heavy metals stresses by mediating physio-morphological responses and enzymatic activities. The current study evaluated the effects of gibberellic acid (GA3) foliar applications on the performance of pea grown either in Cu-contaminated (Cu+) and non-contaminated (Cu−) soil. GA3 was applied exogenously (0, 10, 50, and 100 mg·L−1) on 15-days-old plants, and the results show that the increasing concentration of GA3 buffered the phytotoxic effects of Cu, coupled with an increase in plant growth and physiological variables. The results also showed that foliar-applied GA3 up to 100 mg·L−1 alleviated the oxidative stress, as inferred from the lower concentrations of malondialdehyde (MDA) and H2O2, which mirrored the increased activity of antioxidant enzymes, i.e., superoxide dismutase, peroxidase, and catalase. In addition, enhanced growth, physiology, and enzymatic activities were also observed in pea plants sprayed with GA3 up to 100 mg·L−1 in Cu− soil. Overall, the foliar application of GA3 boosted phytoextraction of Cu from the soil and alleviated the oxidative stress in pea plants grown in Cu-polluted soil.Copper (Cu) is an essential metal for plants. However, its excess in soil can adversely affect plant metabolism. The current study evaluated the effects of gibberellic acid (GA3) foliar applications on the performance of pea plants grown either in Cu-contaminated (Cu+) and non-contaminated (Cu−) soil. GA3 was sprayed (0, 10, 50, and 100 mg·L−1) on 15-days-old plants. The results showed that the increasing concentration of GA3 buffered the phytotoxic effects of Cu and enhanced plant growth, photosynthesis, and leaf chlorophyll content. Foliar-sprayed GA3 up to 100 mg·L−1 alleviated the oxidative stress, as inferred from the lower concentrations of MDA and H2O2 (33.3 µmol·g−1 and 182 µmol·g−1, respectively), and boosted the activity of superoxide dismutase (64.4 U·g−1·FW), peroxidase (122.7 U·g−1·FW), and catalase (226.3 U·g−1·FW). Interestingly, GA3 promoted Cu accumulation in different plant parts when compared to untreated plants, likely due to increased photosynthetic and transpiration rates. Overall, foliar application of GA3 promoted phytoextraction of Cu and alleviated the oxidative stress in pea plants grown in Cu+ soil.

Does the application of growth bioregulators improve the foliar concentration of nutrients, non-structural carbohydrates and yield in pecan?

ABSTRACT Carya illinoinensis (Wangenh.) K. Koch. is a deciduous fruit species with high economic impact and nutritional value that exhibits alternate bearing behavior. In this study, the concentration of foliar nutrients, non-structural carbohydrates and yield were evaluated in cultivar Western Schley pecan in response to the foliar application of gibberellic acid (50 mg L-1 GA3), prohexadione calcium (500 mg L-1 PCa) and thidiazuron (10 mg L-1 TDZ).The statistical analysis reveals that between agricultural cycles, the treatments showed no variation in the foliar concentration of nitrogen total (N-total), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), manganese (Mn) and non-structural carbohydrates (fructose, glucose, sucrose and starch). However, the application of PCa showed no significant effect on the concentration of phosphorus (P) (1.5 and 1.9 g kg-1). On the other hand, the concentration of zinc (Zn) (27.0-60.1 mg kg-1) showed a significant difference between years, with no effect due to the application of growth bioregulators. The trees treated with GA3 minimized alternate bearing by presenting similar values (12.4 and 15.3 kg tree-1) of yield. Likewise, the applied treatments did not affect the nut weight per kilogram (kg) (5.5-6.8 g) and kernel percentage (56.5-60.8). These data provide a new perspective on the complex nature of alternate bearing production in cultivar Western Schley pecan and are interpreted to indicate that alternate production could be regulated by carbohydrate reserve, nutrient concentration, and gibberellins.

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.