Effect of foliar application of new generation PGR’s on fruit yield of mango (Mangifera indica L.) cv. Amrapali

Introduction

Mango (Mangifera indica L.), belonging to the family Anacardiacea, is one of the most economically important and widely cultivated fruit crops of the tropical and subtropical regions. Mango is a nutritionally rich fruit and an excellent source of vitamins, minerals, and dietary fiber. It is particularly high in β-carotene, vitamin A, and vitamin C, along with appreciable amounts of vitamin B-complex and essential minerals. On average, 100 g of fresh mango pulp contains 81.7 g water, 16 g carbohydrates, 0.7 g protein, 0.4 g fat, and 0.1 g fiber. Among the improved mango hybrids, 'Amrapali' is a developed through hybridization between 'Dashehari' and 'Neelum' at the Indian Agricultural Research Institute (IARI), New Delhi, in 1978. Brassinosteroids, triacontanol and salicylic acid have emerged as important plant growth regulators due to their positive influence on fruit development and yield. Several studies have demonstrated their effectiveness in improving photosynthetic activity, nutrient assimilation, stress tolerance and post-harvest performance of fruit crops. The judicious use of these PGRs has shown promising results in minimizing yield losses and enhancing the economic returns from mango cultivation Patel et al., (2021) [5] . mg/L Brassinosteroid, T 4: 4.0 mg/L Brassinosteroid, T 5: 50 ml/L Triacontanol, T 6: 100 ml/L Triacontanol and T 7: Water spray. Foliar application of different new generation PGR's were given as per treatments on mango plants with the help of foot sprayer. Three sprays were given, the first spray was applied at marble stage and the second and third sprays were subsequently applied at one-month intervals following the preceding application. Existing trees of mango with equal age (22 years), canopy and growth were selected.

Results and Discussion

Effect of different new generation PGR's on fruit yield of mango cv. Amrapali Number of fruits per panicle at pea stage

The perusal of data (Table 1) shows the data collected on number of fruits per panicle at pea stage. The results were found non-significant with regards to number of fruits per panicle before spraying, which may be attributed to the absence of plant growth regulator application at this stage and the uniform cultural practices followed for all treatments.

Number of fruits per panicle at marble stage

The perusal of data (Table 1) indicated that results related to number of fruits per panicle at marble stage as influenced by various treatments. Foliar application of salicylic acid, brassinosteroid and triacontanol had a significant effect on the number of fruits per panicle at marble stage. The treatment T 6 (100 ml/L Triacontanol) had maximum number of fruits per panicle at marble stage (14.53), which was at par with treatment T 2 (13.92). Whereas, the control treatment showed minimum number of fruits per panicle at marble stage in T 7 (11.67). Among all the treatments, 100 ml/L triacontanol had higher results. This might be due to application of triacontanol reduces synthesis of ABA and abscission layer at fruit neck hence reduce fruit drop. Similar results found by Patel et al., (2021) [5] , Momin et al.

(2016) [2] , Paralkar (2018) [3] and Gaikwad (2021) [1] in mango.

Fruit drop percentage per panicle at marble stage

Fruit drop percentage per panicle at marble stage cv. Amrapali as influenced by various new generation PGR's treatments, is presented in Table 1. The results indicated statistically significant differences among treatments. The data revealed that the minimum fruit drop percentage was recorded with T 6 (100 ml/L triacontanol) i.e. (46.17%) followed by T 2 (48.26%), while maximum fruit drop percentage (53.02%) was observed in control T 7. The minimum fruit drop percentage was observed in triacontanol which enhance photosynthesis and carbohydrate availability, which strengthens fruit retention and reduces abscission.

The similar finding was reported by Momin et al. (2016) [2] , Paralkar (2018) [3] and Gaikwad (2021) [1] in mango.

Fruit drop percentage per panicle at harvest stage

The data concerning to the number of fruits per panicle at harvest stage of mango as affected by various different new generation PGR's treatments is presented in Table 1. Statistically significant differences were observed among the treatments. The maximum number of fruits per panicle at harvest stage (4.09) was recorded with T 6 (100 ml/L triacontanol) which was at par with T 2 (3.97), whereas minimum fruits (2.67) was observed in control T 7 .The highest number of fruits per panicle at harvest stage recorded with triacontanol because it enhancing photosynthetic efficiency and assimilate translocation, which improves fruit set and reduces early fruit drop, resulting in higher fruit retention. These results are consistent with findings of Patel et al., (2021) [5] , Momin et al. (2016) [2] , Paralkar (2018) [3] Gaikwad (2021) [1] and Patel et al. (2021) [5] in mango.

Number of fruits per tree

The data concerning to the number of fruits per tree of mango as affected by various different new generation PGR's treatments is presented in Table 2. Statistically significant differences were observed among the treatments. The maximum number of fruits per tree (363.67) was recorded with T 6 (100 ml/L triacontanol) followed by T 2 (345.51), whereas minimum fruits (305.66) was observed in control T 7 . The highest number of fruits per tree recorded with triacontanol because it enhancing photosynthetic efficiency and assimilate translocation, which improves fruit set and reduces early fruit drop, resulting in higher fruit retention. These results are consistent with findings of Momin et al. (2016) [2] , Paralkar (2018) [3] , Gaikwad (2021) [1] and Patel et al. (2021) [5] in mango.

The data concerning to the yield per tree (kg) of mango as affected by various different new generation PGR's treatments is presented in Table 2. Statistically significant differences were observed among the treatments. The maximum yield per tree (65.62 kg) was recorded with T 6 (100 ml/L triacontanol) followed by T 2 (59.82 kg), whereas minimum fruits (45.42 kg) was observed in control T 7 . The highest yield per tree recorded with triacontanol because it enhancing photosynthetic efficiency and assimilate translocation, which improves fruit set and reduces early fruit drop, resulting in higher fruit retention. These results are consistent with findings of Momin et al. (2016) [2] , Paralkar (2018) [3] , Gaikwad (2021) [1] and Patel et al.

The data pertaining to the fruit weight of mango as affected by various different new generation PGR's treatments is presented in Table 2. Statistically significant differences were observed among the treatments. The maximum fruit weight (180.47 g) was recorded under with T 6 (100 ml/L triacontanol) followed by T 2 (173.13 g), whereas minimum fruit weight (146.41 g) was observed in control T 7 . The increase in fruit weight in triacontanol may be attributed to enhanced cell division and cell enlargement in developing fruits due to triacontanol application. These findings are supported by work of Momin et al. (2016) [2] , Paralkar (2018) [3] , Gaikwad (2021) [1] and Patel et al. (2021) [5] in mango.

The data regarding the fruit length of mango as affected by various different new generation PGR's treatments is presented in Table 2. Statistically significant differences were observed among the treatments. The maximum fruit length (10.64 cm) was recorded under with T 6 (100 ml/L triacontanol) followed by T 2 (10.02 cm), whereas minimum fruit length (8.53 cm) was observed in control T 7 . The increase in fruit length in T 6 may be attributed to the stimulatory effect of triacontanol on physiological and metabolic activities of the plant. It enhances photosynthetic efficiency and assimilate production, resulting in greater availability of carbohydrates to developing fruits. It also promotes cell division and cell enlargement, which supports better fruit growth. These findings are supported by work of Momin et al. (2016) [2] , Paralkar (2018) [3] , Gaikwad (2021) [1] and Patel et al. (2021) [5] in mango.

The data related to the equatorial diameter of mango as affected by various different new generation PGR's treatments is presented in Table 2. Statistically significant differences were observed among the treatments. The maximum equatorial diameter (7.12 cm) was recorded under with T 6 (100 ml/L triacontanol) followed by T 2 (6.71 cm), whereas minimum equatorial diameter (5.32 cm) was observed in control T 7 . The increase in equatorial diameter in T 6 may be attributed to the stimulatory effect of triacontanol on physiological and metabolic activities of the plant. It enhances photosynthetic efficiency and assimilate production, resulting in greater availability of carbohydrates to developing fruits. It also promotes cell division and cell enlargement, which supports better fruit growth. These findings are supported by work of Momin et al. (2016) [2] , Paralkar (2018) [3] , Gaikwad (2021) [1] and Patel et al.

Fruit volume (cc)

The data regarding to the fruit volume of mango as affected by various different new generation PGR's treatments is presented in Table 2. Statistically significant differences were observed among the treatments. The maximum fruit volume (130.33 cc) was recorded under with T 6 (100 ml/L triacontanol) followed by T 2 (129.33 cc), whereas minimum fruit volume (111.33 cc) was observed in control T 7 . The increase in fruit volume in T 6 may be attributed to the stimulatory effect of triacontanol on physiological and metabolic activities of the plant. It enhances photosynthetic efficiency and assimilate production, resulting in greater availability of carbohydrates to developing fruits. It also promotes cell division and cell enlargement, which supports better fruit growth. These findings are supported by work of Momin et al. (2016) [2] , Paralkar (2018) [3] , Gaikwad (2021) [1] and Patel et al. (2021) [5] in mango.

Conclusion

Based on the findings of the present investigation, it can be concluded that foliar application of triacontanol at 100 ml/L, with the first spray applied at the marble stage followed by two subsequent sprays at one-month intervals, was the most effective treatment for improving the yield parameters of mango cv. Amrapali. Therefore, to getting higher yield of fruits of the mango cv. Amrapali should be sprayed with triacontanol at 100 ml/L with three foliar sprays applied at the marble stage followed by two subsequent sprays at onemonth intervals.

References

1. Gaikwad GB. Effect of plant growth regulators and chemicals on fruit setting, yield and quality of mango (Mangifera indica L.) var. Kesar [Master's thesis]. Badnapur: College of Agriculture, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani; 2021. Available from: https://krishikosh.egranth.ac.in/handle/1/5810187330
2. Momin SK, Gaikwad SS, Patel RJ, Amarcholi JJ, Sharma KM. Effect of foliar application of chemicals on fruiting parameters of mango (Mangifera indica L.) cv. Kesar. Research Journal of Agricultural Sciences. 2016;7(1):143-144.
3. Paralkar PD. Effect of chemicals on fruit retention and quality of mango (Mangifera indica L.) cv. Kesar [Doctoral dissertation]. Badnapur: College of Agriculture, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani; 2018. Available from: http://krishikosh.egranth.ac.in/handle/1/5810066491
4. Dashehari. International Journal of Plant & Soil Science. 2021;33(20):1-7.
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