Banner
Current IssueEditorial BoardOnline First ArticlesArchive
Current IssueEditorial BoardOnline First ArticlesArchive

Full Research Article

Response of Foliar Application of Plant Hormones and Nutrients to Enhance the Fruit Set in Jamun cv. Konkan Bahadoli

N
N. Bhavya1
J
J. Satisha2,*
K
K.S. Shivashankara3
V
Venkat Rao1
1Department of Fruit Science, College of Horticulture, Bengaluru, University of Horticultural Sciences, Bagalkot-587 101, Karnataka, India.
2Division of Fruit Crops, ICAR-Indian Institute of Horticultural Research, Hesaraghatta, Bengaluru-560 089, Karnataka, India.
3Division of Basic Sciences, ICAR-Indian Institute of Horticultural Research, Hesaraghatta, Bengaluru-560 089, Karnataka, India.

ABSTRACT

Background: Fruit production is primarily influenced by the percentage of flowering and fruit set; flower and fruit drop are significant factors contributing to reduced production and productivity in numerous fruit crops. Thoughjamun,till recently, was categorized as an underutilized fruit, but due to growing health concerns, jamun was drawn to the limelight because of its nutritional and economic value. Hence, to increase profitability from the cultivation of Jamun, it’s important to enhance fruit set in Jamun.

Methods: The present investigation on foliar sprays to enhance fruit set was conducted at the College of Horticulture, Bengaluru, for two consecutive years, 2022-2023 and 2023-2024. The experiment was conducted on Jamun cv. Konkan Bahadoli by spraying two plant hormones GA3 (50 and 100 ppm) and NAA (100 and 200 ppm) and three nutrients, namely KNO3 (0.5 and 1%), Urea (7.5 and 10%) and micronutrients (mango special at 0.5 per cent).

Result: The results indicated that the maximum number of flowers per panicle had been observed in treatment T3: NAA at 100 ppm (39.91), while the highest percentage of fruit set occurred in treatment T5: KNO3 at 0.5% (65.87%), which was comparable to T6 (64.33%). The control treatment T10 exhibited the lowest fruit set at 47.87%. The number of fruits per panicle (15.50) and yield per tree (8.20 kg) had been maximized in T5: KNO3 at 0.5%, comparable to T6 (KNO3 at 1%), whereas the control treatment exhibited the lowest values.

INTRODUCTION

Jamun (Syzygium cuminii Skeels) is a significant fruit crop indigenous to India, classified under the Myrtaceae family. Jamun fruit and seed have medicinal properties used to treat diabetic patients.They regulate the rapid conversion of starch into sugar and mitigate the variability of sugar levels in the body. Jamun fruit contains bioactive compounds such as anthocyanins, flavonoids, phenols, antioxidants and vitamin C. The seed contains glycoside jambolin and alkaloid jambosin. Jamun possesses numerous therapeutic properties, including anti-diabetic, anti-cancer, antimicrobial, blood purification, anti-inflammatory, antibacterial, antipyretic, antiviral, antifungal and radioprotective activities. Jamun can be well cultivated in all kinds of soils, it tolerates saline and sodic soils up to pH of 10.5 (Singh et al., 1997). It thrives well under dry climatic conditions, especially during flowering and fruit set. Fruit is a berry and polyembryony is found in seeds. Flowering occurs in February and fruits come to harvest in July. Maximum fruit set observed in jamun varied between 36% to 44% (Devi et al., 2016) when pollination occurred on the same day of anthesis. Flower drop and fruit drop lead to economic losses.An investigation to enhance fruit set in jamun is a major concern.Many proven results on effective foliar spray to enhance fruit set were studied in different crops with plant hormones and nutrients such as GA3, NAA, KNO3, Urea and micronutrient sprays.GA3 helps in reducing flower and fruit drop and thus enhances fruit set (Sharma and Tiwari, 2015). NAA is known to reduce premature dropping of flowers and fruit, reducing abscission (Nartvaranant, 2018). KNO3 acts as a nutrient source and mobilizes minerals, leading to higher fruit retention (Vijay et al., 2016). Urea contributes to ovaries development and enhances fruit set (Katiyar et al., 2010). Micronutrients (mango special) play a major role in hormone regulation and metabolic processes and enhance fruit set and fruit quality (Gurjar et al., 2015).This research investigates the application of plant hormones and nutrition sprays for the foliage to enhance fruit set and retention in the Jamun cultivar Konkan Bahadoli. In many fruit crops use of nutrients and plant hormones to enhance fruit set and productivity has been carried out and has shown positive results. Hence, to increase profitability from the cultivation of Jamun, it’s important to enhance fruit set in Jamun. Nearly 50 to 60 per cent of flower drop is seen post-pollination. Enhancing the fruit set to 50 to 60 per cent can increase the profitability. The premature fruit drop may occur due to many factors, such as problems during post-fertilization, or due to complex interactions between physiology, environment, genetic and hormonal factors. Flower drop and fruit drop lead to economic losses. To increase profitability from the cultivation of Jamun, it’s important to enhance fruit set in Jamun.

MATERIALS AND METHODS

Research site
 
The research was performed at the College of Horticulture, UHS campus, Bengaluru, located in the Eastern dry zone (Zone 5) of Karnataka’s agro-climatic zones at 12o58'  North Latitude and 77o35' East Longitude, at an elevation of 930 meters above mean sea level. The work was conducted over two consecutive years, 2022-2023 and 2023-2024, focusing on the Jamun cultivar Konkan Bahadoli. The 7-year-old Konkan Bahadoli variety was selected for investigation. Each tree was randomly tagged in a Jamun block and twelve trees for each treatment were selected. The investigation was planned with ten treatments and three replications in a randomised block design. Trees were spaced at 5 × 5 meters.
 
Treatment details
 
T1: GA3 @ 50ppm, T2: GA3 @ 100ppm, T3: NAA @100ppm, T4: NAA @ 200ppm, T5: KNO3 @ 0.5%, T6: KNO3 @ 1%, T7: Urea @7.5%, T8: Urea @10%, T9: Micronutrient’s mixture (Mango special) @ 0.5%, T10: control.
 
Treatment application
 
Spray treatments were carried out twice with a time gap of 8 to 10 days,whereinthe first spray was taken at the flower initiation stage and the second spray was taken at the full bloom stage. GA3 and NAA were first dissolved in ethanol and mixed with 15 litres of water and a spray was taken using a knapsack sprayer. Spray was taken in the early morning hours between 7 AM to 9 AM.
 
Observation recorded
 
Flower and fruit parameters
 
1.  Number of flowers per panicle.
2.  Percentage of fruit set.
3.  Fruit weight.
4.  Seed weight.
 
Yield parameters
 
1.  Number of fruits per panicle.
2.  Yield/tree.
 
Biochemical parameters
 
1.  TSS (p B).
2.  Acidity (%).
3.  Phenols (mg/100 g FW).
4.  Antioxidants (mg/100 g FW).
5.  Flavonoids (mg/100 g FW).
6.  Anthocyanins (mg/100 g FW).

Statistical analysis

The data had been presented as pooled analysis data by taking the means of two years in each replication and emphasis is given to the pooled analysis results. Each season’s data was statistically analysed using RBD design and presented. The data presented above across all parameters were organized and subjected to statistical analysis through “ANOVA (Analysis of Variance)” to compare treatment means. A significant F-test at a 5 per cent critical difference (C.D. at 5%) was utilized to compare the two treatments. Statistical analysis was conducted using R software and Microsoft Excel 2003.

RESULTS AND DISCUSSION

The fruit set percentage was significantly higher in trees treated with nutrients and hormones, whereas the biochemical composition, viz., anthocyanins, flavonoids andantioxidantcontents of fruits, was higher in the control treatment due to smaller fruit size. 
 
Flower and fruit parameters
 
Number of flowers per panicle were significantly higher (39.91) in trees which received T3 treatment (NAA @100 ppm) followed by T8 (39.66), T5(39.33), T4(38.91) and T9 (38.58) and least number of flowers per panicle (33.50) were observed in T2 GA3 @ 100ppm (Table 1). NAA is known to induce flowering and decrease flower fall by reducing abscission. Comparable results were documented in Guava by Sagar et al. (2024) and in Litchi by Anand et al., (2003), indicating that KNO3 facilitates the mobilization of essential resources, including nitrogen and potassium, while promoting starch and carbohydrate accumulation, hence triggering and sustaining flowering. Similar reports were found in mango (Afiqah et al., 2012). The percentage fruit set was significantly higher (65.87%) in treatment T5 (KNO3 @ 0.5%) which was at par with T6 (64.33%), T9 (62.09%), T2 (61.64%) and T1 (60.36%) and the lowest fruit set (47.87%) was observed in control treatment T10 (Table1). Potassium has a major role in plants’ physiological activity, such as energizing enzymes and nutrient mobilization,when foliar application is done at the time of flowering and fruit bud differentiation. Similar findings were observed in the mango cv. Alphonso, when KNO3 was applied at 2% concentration (Sudha et al., 2012).

Table 1: Effect of foliar application of plant hormones and nutrients on number of flowers per panicle, percentage of fruit set and fruit weight in Jamun cv. Konkan Bahadoli.


       
The fruit weight was highest (9.12 g) in treatment T9 (Micronutrients (Mango special) @ 0.5%),which was on par with T6 (8.81g) and T5 (8.77 g) and the lowest fruit weight wasfound in treatment T10 control treatment (Table 1). A combination of micronutrients has a significant effect on enhancing fruit weight. Copper, zinc and borax play a significant role in enhancing fruit size (Ilyas et al., 2015 and Sebastian et al., 2025) similarl study was conducted by Vijayvargiya and Singh (2024) in mango. The maximum seed weight was noted at 1.48 g in treatment T9 (Micronutrients (Mango special) @ 0.5%), which was comparable to treatment T4: NAA @ 200 ppm (1.39 g). The minimum seed weight of 1.14 g was obtained in treatments T1 and T2 (T1: GA3 @ 50 ppm, T2: GA3 @ 100 ppm) (Table 2). Iron, manganese, zinc and boronhavea greater effect on enhancing seed weight. Micronutrient sprays have a major effect on enhancing physical attributes of fruit, such as fruit length, width and weight. The augmented fruit size in trees treated with a micronutrient mixture may be ascribed to the zinc content, which could facilitate the synthesis of tryptophan, a precursor to IAA synthesis, hence increasing the cell count in early fruitlets. An increased quantity of cells directly influences the ultimate size of the fruit. Application of GA3 at the bud break and flowering stages has caused seedlessness in Jamun (Raja and Rani, 2021).

Table 2: Effect of foliar application of plant hormones and nutrients on number of seed weight, number of fruits per panicle and yield/tree in Jamun cv. Konkan Bahadoli.


 
Yield parameters
 
The largest number of fruits per panicle had been recorded in treatment T5 (KNO3 @ 0.5%) with 15.50 fruits, followed by T6 (KNO3 @ 1%), while the lowest count of 9.00 fruits per panicle was found in treatment T10 (control). The maximum yield per tree was recorded at 9.85kg in treatments T5 (KNO3 @ 0.5%) and T6 (KNO3 @ 1%), whereas the minimum yield per tree, 5.15 kg, was noted in treatment T10 control (Table 2).
       
Potassium helps in stress resistance, activation of metabolic processes and mobilization of nutrients from source to sink, enhancing yield and quality in fruits. Nitrogen in the form of nitrate helps chlorophyll and protein synthesis. Similar works were also reported in many fruit crops.In pear fruit, yield was maximum (60.1kg/tree) when KNO3 at 2% concentration was applied as a foliar spray reported by Sajid et al., (2022) and investigation done by Arora et al. (2021) on mango, foliar spray of KNO3 at 3% concentration significantly enhanced fruit yield (39.79 kg/tree). KNO3 application had increased yield in other crops as reported by Machado and Sao Jose (2000) and Debnath and Kundu (2001).
 
Biochemical parameters
 
TSS and acidity showed significant differences in the 2nd season, whereas the 1st season data and pooled data showed a non-significant difference, the highest phenolic content (1047.49 mg/100 g FW), antioxidant content (775.09 mg/ 100 g FW), flavonoids (217.56 mg/100 g FW) and anthocyanin content (360.14 mg/100 g FW) was recorded in T10 treatment (control)and lowest phenol content (501.58 mg/100 g FW) and antioxidant capacity was observed in treatment T8 (Urea @10%). The lowest flavonoid content and anthocyanin content were observed in T3 (NAA @100 ppm) (Table 3 and 4).          

Table 3: Effect of foliar application of plant hormones and nutrients on TSS, acidity and phenols in jamun cv. Konkan Bahadoli.



Table 4: Effect of foliar application of plant hormones and nutrients on antioxidants, flavonoids and anthocyanins in jamun cv. Konkan Bahadoli.

                     

The fruit weight has a negative correlation with antioxidant and total phenolic content in the fruits of black jamun land races. Based on the fruit weight, fruits were categorized with land race codes and confirmed that the fruits (BJLR-6) with the lowest fruit weight (3 g) havethe highest antioxidant activity and phenolic content. (Gajera et al., 2017). Similarly, the TSS and acidity, TSS was higher in small fruits and acidity was lower here there is a negative correlation between TSS and acidity (Table 3). The dilution effect might be the reason for the lower concentration of most of the biochemical constituents in bigger fruits, which were harvested from trees treated with hormones and nutrients, while a higher concentration may be due to a greater concentration in smaller fruits where no sprays were given to those trees (T10).

CONCLUSION

The experiment demonstrates that a 0.5 per cent concen-tration of potassium nitrate significantly enhances fruit set percentage, the quantity of fruits per panicle and yield per tree. Whereas fruit quality, such as fruit weight and seed weight, was significantly higher in the micronutrient treatment, as micronutrients enhance fruit quality. The biochemical parameters such as TSS, anthocyanin, phenols, flavonoids and antioxidant activity were high in the control treatment due to small-sized fruits.
 
Authors contribution
 
Bhavya N.: Performed experiment, data collection, analysis of data, drafted the paper and data interpretation. Dr. Satisha J.: Designed the experiment and methodology to carry out the experiments, manuscript corrections and helped in data interpretation Dr. Shivashankara K. S.: Provided access to carry out analysis and research components and helped tointerpret data. Dr. Venkat Rao: Provided access to research components (experimental site and samples) and helped in grammatical revision of manuscript.
 
Declaration
 
I confirm that all authors of the manuscript have no conflict of interest to declare and confirm that the manuscript is the author’s original work and that the manuscript has not been previously published elsewhere. All authors listed on the title page have contributed significantly to the work, have read the manuscript, attest to the validity and legitimacy of the data and its interpretation and agree to its submission. We confirm that the paper now submitted is not a copied or plagiarized version of some other published work.

CONFLICT OF INTEREST

The authors have no conflict of interest.

REFERENCES


  1. Afiqah, A.N., Jaafar, H.Z.E., Rosimah, N. and Misri, K. (2012). Flowering enhancement of Chok Anan mango through application of potassium nitrate. Trans. Malaysian Soc. PlantPhysiol. 20: 106-110.

  2. Anand, M., Kahlon, P.S. and Mahajan, B.V.C. (2003) Effect of exogenous application of growth regulators on fruit drop, cracking and quality of litchi (Litchi chinensis Sonn.) cv. Dehradun. Agric. Sci. Dig. 23(3): 191-194.

  3. Arora, R. Singh, P.N., Gill, M.S. and Kaur, S. (2021). Influence of foliar feeding of KNO3 on fruit yield and quality parameters of mango. Agric. Res. J. 58(5): 828-834.

  4. Debnath, S. and Kundu, S. (2001). Effect of bioregulators and nutrients on growth and differentiation of mango (Mangifera indica L.) shoots. Environment and Ecology. 19: 829-832.

  5. Devi, C.A., Swamy, G.S.K. and Naik, N. (2016). Studies on flowering and fruit characters of Jamun genotypes (Syzygium cuminii Skeels). Biosci. Biotech. Res. Asia. 13(4).

  6. Gajera, H.P., Gevariya, S.N., Hirpara, D.G., Patel, S.V. and Golakiya,  B.A. (2017). Antidiabetic and antioxidant functionality associated with phenolic constituents from fruit parts of indigenous black jamun (Syzygium cumini L.) landraces. J. Food Sci.Technol. 54(10): 3180-3191.

  7. Gurjar, T.D., Patel, N.L., Panchal, B. and Chaudhari, D. (2015). Effect of foliar spray of micronutrients on flowering and fruiting of Alphonso mango. The Bioscan. 10(3): 1053-1056.

  8. Ilyas, A., Ashraf, M.Y., Hussain, M., Ashraf, M., Ahmed, R. and Kamal, A. (2015). Effect ofmicronutrients (Zn, Cu and B) on photosynthetic and fruit yield attributes of Citrus reticulata Blanco var. Kinnow. Pak. J. Bot. 47(4): 1241-1247.

  9. Katiyar, P. N., Yadav, V. and Singh, J. P., 2010, Effect of preharvest spray of NAA, GA3 and Urea on fruiting, fruit quality and yield of ber (Zizyphus mauritiana Lamk.) cv. Banarasi Karaka. Annals of Horticulture. 3(1): 92-94.

  10. Machado, E.M. and Sao, J.A.R. (2000). Effect of different intervals of potassium nitrate spraying on flowering and production of mango trees (Mangifera indica L.) cv. Tommy Atkins. Acta Hortic. 509: 581-585.

  11. Nartvaranant, P. (2018). The influence of exogenously applied 2,4-D and NAA on fruit drop reduction in pummelo cv. Thong Dee. Int. J. Fruit Sci. 18(2): 215-225.

  12. Raja, K. and Rani, A.M.S. (2021). Influence of gibberellic acid on seedlessness in Jamun (Syzygium cuminii L. Skeels). Curr. Sci. 121(12): 1619-1627.

  13. Sagar, D.C., Vastrad, S.M., Saini, S., Prakash, H.T., Shilpa and Chogatapur, V. (2024). Influence of GA3 and NAA on growth, flowering, fruiting and yield of guava (Psidium guajava L.) cv Sardar under Northern Dry Zone of Karnataka. Int. J. Adv. Biochem. Res. 8(1): 505-507

  14. Sajid, M., Haq, U.S., Jan, A., Noor, F., Ali, Q.S., Alam, M., Zaman, A., Shah, A.F., Mosa,  W.F.A. and Abada, S.H. (2022). Effect of foliar application with potassium nitrate and copper sulfate on fruit yield and quality of pear (Pyrus communis L.) Trees, Int. J. Fruit Sci. 22(1): 759-768.

  15. Sebastian, K., Bindu, B., Rafeekher, M., Mini, C. and Joseph, B. (2025). Response of fertigation and foliar sprays on yield and fruit quality of papaya variety Surya. Indian J. Agric. Res. 59(2): 295-299. doi: 10.18805/IJARe.A-6022.

  16. Sharma, R. and Tiwari, R. (2015). Effect of growth regulator sprays on growth, yield and quality of guava under malwa plateau conditions. Ann. Plant Soil Res. 17(3): 287-291.

  17. Singh, G., Dagar, J.C. and Singh, N.T. (1997). Growing fruit trees in highly alkaline soils. Land Degrad. Dev. 8: 257-268.

  18. Sudha, R., Balamohan, T.N. and Soorianathasundaram, K. (2012). Effect of foliar spray ofnitrogenous chemicals on flowering, fruit set and yield in mango (Mangifera indica L.) cv. Alphonso J. Hortl. Sci. Vol. 7(2): 190-193

  19. Vijay, R.P.S., Dalal, B.S.B. and Hemant, S. (2016). Impact of foliar application of potassium and its spray schedule on yield and quality of sweet orange (Citrus sinensis) cv. Jaffa. J. Appl. Nat. Sci. 8(4): 1893-1895.

  20. Vijayvargiya, V. and Singh, G. (2024). Maximizing fruit quality and production of mango cv. Dashehari: The impact of micronutrient  treatments. Agric. Sci. Dig. doi: 10.18805/ag.D-5872.
Published In
Agricultural Science Digest
Article Metrics
Metrics Icon
0
Views
0
Citations
Reviewed By
Share Article
Download Article
In this Article
    Contact us
    Follow us

    Full Research Article

    Response of Foliar Application of Plant Hormones and Nutrients to Enhance the Fruit Set in Jamun cv. Konkan Bahadoli

    N
    N. Bhavya1
    J
    J. Satisha2,*
    K
    K.S. Shivashankara3
    V
    Venkat Rao1
    1Department of Fruit Science, College of Horticulture, Bengaluru, University of Horticultural Sciences, Bagalkot-587 101, Karnataka, India.
    2Division of Fruit Crops, ICAR-Indian Institute of Horticultural Research, Hesaraghatta, Bengaluru-560 089, Karnataka, India.
    3Division of Basic Sciences, ICAR-Indian Institute of Horticultural Research, Hesaraghatta, Bengaluru-560 089, Karnataka, India.

    ABSTRACT

    Background: Fruit production is primarily influenced by the percentage of flowering and fruit set; flower and fruit drop are significant factors contributing to reduced production and productivity in numerous fruit crops. Thoughjamun,till recently, was categorized as an underutilized fruit, but due to growing health concerns, jamun was drawn to the limelight because of its nutritional and economic value. Hence, to increase profitability from the cultivation of Jamun, it’s important to enhance fruit set in Jamun.

    Methods: The present investigation on foliar sprays to enhance fruit set was conducted at the College of Horticulture, Bengaluru, for two consecutive years, 2022-2023 and 2023-2024. The experiment was conducted on Jamun cv. Konkan Bahadoli by spraying two plant hormones GA3 (50 and 100 ppm) and NAA (100 and 200 ppm) and three nutrients, namely KNO3 (0.5 and 1%), Urea (7.5 and 10%) and micronutrients (mango special at 0.5 per cent).

    Result: The results indicated that the maximum number of flowers per panicle had been observed in treatment T3: NAA at 100 ppm (39.91), while the highest percentage of fruit set occurred in treatment T5: KNO3 at 0.5% (65.87%), which was comparable to T6 (64.33%). The control treatment T10 exhibited the lowest fruit set at 47.87%. The number of fruits per panicle (15.50) and yield per tree (8.20 kg) had been maximized in T5: KNO3 at 0.5%, comparable to T6 (KNO3 at 1%), whereas the control treatment exhibited the lowest values.

    INTRODUCTION

    Jamun (Syzygium cuminii Skeels) is a significant fruit crop indigenous to India, classified under the Myrtaceae family. Jamun fruit and seed have medicinal properties used to treat diabetic patients.They regulate the rapid conversion of starch into sugar and mitigate the variability of sugar levels in the body. Jamun fruit contains bioactive compounds such as anthocyanins, flavonoids, phenols, antioxidants and vitamin C. The seed contains glycoside jambolin and alkaloid jambosin. Jamun possesses numerous therapeutic properties, including anti-diabetic, anti-cancer, antimicrobial, blood purification, anti-inflammatory, antibacterial, antipyretic, antiviral, antifungal and radioprotective activities. Jamun can be well cultivated in all kinds of soils, it tolerates saline and sodic soils up to pH of 10.5 (Singh et al., 1997). It thrives well under dry climatic conditions, especially during flowering and fruit set. Fruit is a berry and polyembryony is found in seeds. Flowering occurs in February and fruits come to harvest in July. Maximum fruit set observed in jamun varied between 36% to 44% (Devi et al., 2016) when pollination occurred on the same day of anthesis. Flower drop and fruit drop lead to economic losses.An investigation to enhance fruit set in jamun is a major concern.Many proven results on effective foliar spray to enhance fruit set were studied in different crops with plant hormones and nutrients such as GA3, NAA, KNO3, Urea and micronutrient sprays.GA3 helps in reducing flower and fruit drop and thus enhances fruit set (Sharma and Tiwari, 2015). NAA is known to reduce premature dropping of flowers and fruit, reducing abscission (Nartvaranant, 2018). KNO3 acts as a nutrient source and mobilizes minerals, leading to higher fruit retention (Vijay et al., 2016). Urea contributes to ovaries development and enhances fruit set (Katiyar et al., 2010). Micronutrients (mango special) play a major role in hormone regulation and metabolic processes and enhance fruit set and fruit quality (Gurjar et al., 2015).This research investigates the application of plant hormones and nutrition sprays for the foliage to enhance fruit set and retention in the Jamun cultivar Konkan Bahadoli. In many fruit crops use of nutrients and plant hormones to enhance fruit set and productivity has been carried out and has shown positive results. Hence, to increase profitability from the cultivation of Jamun, it’s important to enhance fruit set in Jamun. Nearly 50 to 60 per cent of flower drop is seen post-pollination. Enhancing the fruit set to 50 to 60 per cent can increase the profitability. The premature fruit drop may occur due to many factors, such as problems during post-fertilization, or due to complex interactions between physiology, environment, genetic and hormonal factors. Flower drop and fruit drop lead to economic losses. To increase profitability from the cultivation of Jamun, it’s important to enhance fruit set in Jamun.

    MATERIALS AND METHODS

    Research site
     
    The research was performed at the College of Horticulture, UHS campus, Bengaluru, located in the Eastern dry zone (Zone 5) of Karnataka’s agro-climatic zones at 12o58'  North Latitude and 77o35' East Longitude, at an elevation of 930 meters above mean sea level. The work was conducted over two consecutive years, 2022-2023 and 2023-2024, focusing on the Jamun cultivar Konkan Bahadoli. The 7-year-old Konkan Bahadoli variety was selected for investigation. Each tree was randomly tagged in a Jamun block and twelve trees for each treatment were selected. The investigation was planned with ten treatments and three replications in a randomised block design. Trees were spaced at 5 × 5 meters.
     
    Treatment details
     
    T1: GA3 @ 50ppm, T2: GA3 @ 100ppm, T3: NAA @100ppm, T4: NAA @ 200ppm, T5: KNO3 @ 0.5%, T6: KNO3 @ 1%, T7: Urea @7.5%, T8: Urea @10%, T9: Micronutrient’s mixture (Mango special) @ 0.5%, T10: control.
     
    Treatment application
     
    Spray treatments were carried out twice with a time gap of 8 to 10 days,whereinthe first spray was taken at the flower initiation stage and the second spray was taken at the full bloom stage. GA3 and NAA were first dissolved in ethanol and mixed with 15 litres of water and a spray was taken using a knapsack sprayer. Spray was taken in the early morning hours between 7 AM to 9 AM.
     
    Observation recorded
     
    Flower and fruit parameters
     
    1.  Number of flowers per panicle.
    2.  Percentage of fruit set.
    3.  Fruit weight.
    4.  Seed weight.
     
    Yield parameters
     
    1.  Number of fruits per panicle.
    2.  Yield/tree.
     
    Biochemical parameters
     
    1.  TSS (p B).
    2.  Acidity (%).
    3.  Phenols (mg/100 g FW).
    4.  Antioxidants (mg/100 g FW).
    5.  Flavonoids (mg/100 g FW).
    6.  Anthocyanins (mg/100 g FW).

    Statistical analysis

    The data had been presented as pooled analysis data by taking the means of two years in each replication and emphasis is given to the pooled analysis results. Each season’s data was statistically analysed using RBD design and presented. The data presented above across all parameters were organized and subjected to statistical analysis through “ANOVA (Analysis of Variance)” to compare treatment means. A significant F-test at a 5 per cent critical difference (C.D. at 5%) was utilized to compare the two treatments. Statistical analysis was conducted using R software and Microsoft Excel 2003.

    RESULTS AND DISCUSSION

    The fruit set percentage was significantly higher in trees treated with nutrients and hormones, whereas the biochemical composition, viz., anthocyanins, flavonoids andantioxidantcontents of fruits, was higher in the control treatment due to smaller fruit size. 
     
    Flower and fruit parameters
     
    Number of flowers per panicle were significantly higher (39.91) in trees which received T3 treatment (NAA @100 ppm) followed by T8 (39.66), T5(39.33), T4(38.91) and T9 (38.58) and least number of flowers per panicle (33.50) were observed in T2 GA3 @ 100ppm (Table 1). NAA is known to induce flowering and decrease flower fall by reducing abscission. Comparable results were documented in Guava by Sagar et al. (2024) and in Litchi by Anand et al., (2003), indicating that KNO3 facilitates the mobilization of essential resources, including nitrogen and potassium, while promoting starch and carbohydrate accumulation, hence triggering and sustaining flowering. Similar reports were found in mango (Afiqah et al., 2012). The percentage fruit set was significantly higher (65.87%) in treatment T5 (KNO3 @ 0.5%) which was at par with T6 (64.33%), T9 (62.09%), T2 (61.64%) and T1 (60.36%) and the lowest fruit set (47.87%) was observed in control treatment T10 (Table1). Potassium has a major role in plants’ physiological activity, such as energizing enzymes and nutrient mobilization,when foliar application is done at the time of flowering and fruit bud differentiation. Similar findings were observed in the mango cv. Alphonso, when KNO3 was applied at 2% concentration (Sudha et al., 2012).

    Table 1: Effect of foliar application of plant hormones and nutrients on number of flowers per panicle, percentage of fruit set and fruit weight in Jamun cv. Konkan Bahadoli.


           
    The fruit weight was highest (9.12 g) in treatment T9 (Micronutrients (Mango special) @ 0.5%),which was on par with T6 (8.81g) and T5 (8.77 g) and the lowest fruit weight wasfound in treatment T10 control treatment (Table 1). A combination of micronutrients has a significant effect on enhancing fruit weight. Copper, zinc and borax play a significant role in enhancing fruit size (Ilyas et al., 2015 and Sebastian et al., 2025) similarl study was conducted by Vijayvargiya and Singh (2024) in mango. The maximum seed weight was noted at 1.48 g in treatment T9 (Micronutrients (Mango special) @ 0.5%), which was comparable to treatment T4: NAA @ 200 ppm (1.39 g). The minimum seed weight of 1.14 g was obtained in treatments T1 and T2 (T1: GA3 @ 50 ppm, T2: GA3 @ 100 ppm) (Table 2). Iron, manganese, zinc and boronhavea greater effect on enhancing seed weight. Micronutrient sprays have a major effect on enhancing physical attributes of fruit, such as fruit length, width and weight. The augmented fruit size in trees treated with a micronutrient mixture may be ascribed to the zinc content, which could facilitate the synthesis of tryptophan, a precursor to IAA synthesis, hence increasing the cell count in early fruitlets. An increased quantity of cells directly influences the ultimate size of the fruit. Application of GA3 at the bud break and flowering stages has caused seedlessness in Jamun (Raja and Rani, 2021).

    Table 2: Effect of foliar application of plant hormones and nutrients on number of seed weight, number of fruits per panicle and yield/tree in Jamun cv. Konkan Bahadoli.


     
    Yield parameters
     
    The largest number of fruits per panicle had been recorded in treatment T5 (KNO3 @ 0.5%) with 15.50 fruits, followed by T6 (KNO3 @ 1%), while the lowest count of 9.00 fruits per panicle was found in treatment T10 (control). The maximum yield per tree was recorded at 9.85kg in treatments T5 (KNO3 @ 0.5%) and T6 (KNO3 @ 1%), whereas the minimum yield per tree, 5.15 kg, was noted in treatment T10 control (Table 2).
           
    Potassium helps in stress resistance, activation of metabolic processes and mobilization of nutrients from source to sink, enhancing yield and quality in fruits. Nitrogen in the form of nitrate helps chlorophyll and protein synthesis. Similar works were also reported in many fruit crops.In pear fruit, yield was maximum (60.1kg/tree) when KNO3 at 2% concentration was applied as a foliar spray reported by Sajid et al., (2022) and investigation done by Arora et al. (2021) on mango, foliar spray of KNO3 at 3% concentration significantly enhanced fruit yield (39.79 kg/tree). KNO3 application had increased yield in other crops as reported by Machado and Sao Jose (2000) and Debnath and Kundu (2001).
     
    Biochemical parameters
     
    TSS and acidity showed significant differences in the 2nd season, whereas the 1st season data and pooled data showed a non-significant difference, the highest phenolic content (1047.49 mg/100 g FW), antioxidant content (775.09 mg/ 100 g FW), flavonoids (217.56 mg/100 g FW) and anthocyanin content (360.14 mg/100 g FW) was recorded in T10 treatment (control)and lowest phenol content (501.58 mg/100 g FW) and antioxidant capacity was observed in treatment T8 (Urea @10%). The lowest flavonoid content and anthocyanin content were observed in T3 (NAA @100 ppm) (Table 3 and 4).          

    Table 3: Effect of foliar application of plant hormones and nutrients on TSS, acidity and phenols in jamun cv. Konkan Bahadoli.



    Table 4: Effect of foliar application of plant hormones and nutrients on antioxidants, flavonoids and anthocyanins in jamun cv. Konkan Bahadoli.

                         

    The fruit weight has a negative correlation with antioxidant and total phenolic content in the fruits of black jamun land races. Based on the fruit weight, fruits were categorized with land race codes and confirmed that the fruits (BJLR-6) with the lowest fruit weight (3 g) havethe highest antioxidant activity and phenolic content. (Gajera et al., 2017). Similarly, the TSS and acidity, TSS was higher in small fruits and acidity was lower here there is a negative correlation between TSS and acidity (Table 3). The dilution effect might be the reason for the lower concentration of most of the biochemical constituents in bigger fruits, which were harvested from trees treated with hormones and nutrients, while a higher concentration may be due to a greater concentration in smaller fruits where no sprays were given to those trees (T10).

    CONCLUSION

    The experiment demonstrates that a 0.5 per cent concen-tration of potassium nitrate significantly enhances fruit set percentage, the quantity of fruits per panicle and yield per tree. Whereas fruit quality, such as fruit weight and seed weight, was significantly higher in the micronutrient treatment, as micronutrients enhance fruit quality. The biochemical parameters such as TSS, anthocyanin, phenols, flavonoids and antioxidant activity were high in the control treatment due to small-sized fruits.
     
    Authors contribution
     
    Bhavya N.: Performed experiment, data collection, analysis of data, drafted the paper and data interpretation. Dr. Satisha J.: Designed the experiment and methodology to carry out the experiments, manuscript corrections and helped in data interpretation Dr. Shivashankara K. S.: Provided access to carry out analysis and research components and helped tointerpret data. Dr. Venkat Rao: Provided access to research components (experimental site and samples) and helped in grammatical revision of manuscript.
     
    Declaration
     
    I confirm that all authors of the manuscript have no conflict of interest to declare and confirm that the manuscript is the author’s original work and that the manuscript has not been previously published elsewhere. All authors listed on the title page have contributed significantly to the work, have read the manuscript, attest to the validity and legitimacy of the data and its interpretation and agree to its submission. We confirm that the paper now submitted is not a copied or plagiarized version of some other published work.

    CONFLICT OF INTEREST

    The authors have no conflict of interest.

    REFERENCES


    1. Afiqah, A.N., Jaafar, H.Z.E., Rosimah, N. and Misri, K. (2012). Flowering enhancement of Chok Anan mango through application of potassium nitrate. Trans. Malaysian Soc. PlantPhysiol. 20: 106-110.

    2. Anand, M., Kahlon, P.S. and Mahajan, B.V.C. (2003) Effect of exogenous application of growth regulators on fruit drop, cracking and quality of litchi (Litchi chinensis Sonn.) cv. Dehradun. Agric. Sci. Dig. 23(3): 191-194.

    3. Arora, R. Singh, P.N., Gill, M.S. and Kaur, S. (2021). Influence of foliar feeding of KNO3 on fruit yield and quality parameters of mango. Agric. Res. J. 58(5): 828-834.

    4. Debnath, S. and Kundu, S. (2001). Effect of bioregulators and nutrients on growth and differentiation of mango (Mangifera indica L.) shoots. Environment and Ecology. 19: 829-832.

    5. Devi, C.A., Swamy, G.S.K. and Naik, N. (2016). Studies on flowering and fruit characters of Jamun genotypes (Syzygium cuminii Skeels). Biosci. Biotech. Res. Asia. 13(4).

    6. Gajera, H.P., Gevariya, S.N., Hirpara, D.G., Patel, S.V. and Golakiya,  B.A. (2017). Antidiabetic and antioxidant functionality associated with phenolic constituents from fruit parts of indigenous black jamun (Syzygium cumini L.) landraces. J. Food Sci.Technol. 54(10): 3180-3191.

    7. Gurjar, T.D., Patel, N.L., Panchal, B. and Chaudhari, D. (2015). Effect of foliar spray of micronutrients on flowering and fruiting of Alphonso mango. The Bioscan. 10(3): 1053-1056.

    8. Ilyas, A., Ashraf, M.Y., Hussain, M., Ashraf, M., Ahmed, R. and Kamal, A. (2015). Effect ofmicronutrients (Zn, Cu and B) on photosynthetic and fruit yield attributes of Citrus reticulata Blanco var. Kinnow. Pak. J. Bot. 47(4): 1241-1247.

    9. Katiyar, P. N., Yadav, V. and Singh, J. P., 2010, Effect of preharvest spray of NAA, GA3 and Urea on fruiting, fruit quality and yield of ber (Zizyphus mauritiana Lamk.) cv. Banarasi Karaka. Annals of Horticulture. 3(1): 92-94.

    10. Machado, E.M. and Sao, J.A.R. (2000). Effect of different intervals of potassium nitrate spraying on flowering and production of mango trees (Mangifera indica L.) cv. Tommy Atkins. Acta Hortic. 509: 581-585.

    11. Nartvaranant, P. (2018). The influence of exogenously applied 2,4-D and NAA on fruit drop reduction in pummelo cv. Thong Dee. Int. J. Fruit Sci. 18(2): 215-225.

    12. Raja, K. and Rani, A.M.S. (2021). Influence of gibberellic acid on seedlessness in Jamun (Syzygium cuminii L. Skeels). Curr. Sci. 121(12): 1619-1627.

    13. Sagar, D.C., Vastrad, S.M., Saini, S., Prakash, H.T., Shilpa and Chogatapur, V. (2024). Influence of GA3 and NAA on growth, flowering, fruiting and yield of guava (Psidium guajava L.) cv Sardar under Northern Dry Zone of Karnataka. Int. J. Adv. Biochem. Res. 8(1): 505-507

    14. Sajid, M., Haq, U.S., Jan, A., Noor, F., Ali, Q.S., Alam, M., Zaman, A., Shah, A.F., Mosa,  W.F.A. and Abada, S.H. (2022). Effect of foliar application with potassium nitrate and copper sulfate on fruit yield and quality of pear (Pyrus communis L.) Trees, Int. J. Fruit Sci. 22(1): 759-768.

    15. Sebastian, K., Bindu, B., Rafeekher, M., Mini, C. and Joseph, B. (2025). Response of fertigation and foliar sprays on yield and fruit quality of papaya variety Surya. Indian J. Agric. Res. 59(2): 295-299. doi: 10.18805/IJARe.A-6022.

    16. Sharma, R. and Tiwari, R. (2015). Effect of growth regulator sprays on growth, yield and quality of guava under malwa plateau conditions. Ann. Plant Soil Res. 17(3): 287-291.

    17. Singh, G., Dagar, J.C. and Singh, N.T. (1997). Growing fruit trees in highly alkaline soils. Land Degrad. Dev. 8: 257-268.

    18. Sudha, R., Balamohan, T.N. and Soorianathasundaram, K. (2012). Effect of foliar spray ofnitrogenous chemicals on flowering, fruit set and yield in mango (Mangifera indica L.) cv. Alphonso J. Hortl. Sci. Vol. 7(2): 190-193

    19. Vijay, R.P.S., Dalal, B.S.B. and Hemant, S. (2016). Impact of foliar application of potassium and its spray schedule on yield and quality of sweet orange (Citrus sinensis) cv. Jaffa. J. Appl. Nat. Sci. 8(4): 1893-1895.

    20. Vijayvargiya, V. and Singh, G. (2024). Maximizing fruit quality and production of mango cv. Dashehari: The impact of micronutrient  treatments. Agric. Sci. Dig. doi: 10.18805/ag.D-5872.
    In this Article
      Contact us
      Follow us
      Published In
      Agricultural Science Digest

      Editorial Board

      View all (0)