Effect of pre-harvest treatments on various attributes of guava fruits cv. Allahabad Safeda

Introduction

Guava (Psidium guajava L.) is a common tropical fruit cultivated in many tropical and subtropical regions. This may be due to the high nutritive value of fruits, good source of vitamin C, minerals, and pleasant aroma. The common guava is a small tree in the myrtle family (Myrtaceae), native to Mexico, Central America, the Caribbean and northern South America. It is also known as 'Apple of the tropics' or 'Poor man's apple.' In India, Guava is the fourth most important fruit crop in area and production after mango, banana and citrus with production of 49.16 lakh tonnes from an area of 3.15 lakh ha. It is an important fruit crop cultivated all over India, especially in the regions of Uttar Pradesh, Madhya Pradesh, Bihar, Maharashtra, West Bengal, Punjab, Chhattisgarh, Haryana, Karnataka, and Gujarat. In Chhattisgarh, guava is grown in an area of 20.5 thousand hectares, with an annual production of 201.3 thousand MT. Guava fruits are highly perishable and have less shelf life of 5-7 days. Application of suitable chemicals as a pre-harvest spray is required to conserve and enhance the fruit yield, quality at harvest as well as post-harvest life of fruits. Pre-harvest calcium spray is one of the most important practices of new strategies applied in the integrated fruit production systems, improving fruit characteristics, and minimizing fungicides sprays towards the end of the harvest period, since they improve fruit resistance to brown rot (Conway et al., 1994) [6] . Application of Ascorbic acid had many stimulating effects on growth and physiological activities of various plants (Dewick, 2000, Ismail, 2008 and Abdou et al., 2015) [7,9,1] . Ascorbic acid is a good antioxidant that keeps fruit from darkening and improves destruction of bacteria. Antioxidants are used instead of auxins for improving fruit growth, development and fruiting of trees (Maksoud et al., 2009) [13] . Hence, present investigation was conducted to find out the effect of pre-harvest spray of Calcium chloride, Calcium nitrate and Ascorbic acid on physical attributes and post-harvest behaviour of guava cv. Allahabad Safeda.

Materials and Methods

The field experiment was carried out during the year 2023-24 in winter season at Precision Farming Development Centre (PFDC), Department of Fruit Science, College of Agriculture, IGKV, Raipur (C.G.). The experiment consists of total 7 pre-harvest treatments i.e., T 0 (control), T 1 (CaCl 2 @ 1%), T 2 (CaCl 2 @ 2%), T 3 (Ca(NO 3 ) 2 @ 1%), T 4 (Ca(NO 3 ) 2 @ 2%), T 5 (ascorbic acid @ 150 ppm) and T 6 (ascorbic acid @ 300 ppm) which were randomly assigned to different guava trees with three replications across the fertility gradient. Foliar application of these treatments was done on guava fruits selected from all four directions of each tree at 30 days before harvest of fruits. Observation for physical attributes was recorded immediately after harvest and statistically analyzed.

Result and Discussion

Fruit Weight (g) Maximum mean of fruit weight (137 g) was recorded in T 4 (Ca(NO 3 ) 2 @ 2%) followed by T 2 (CaCl 2 @ 2%) with 123 g mean fruit weight whereas minimum fruit weight (108 g) was recorded in T 0 (Control). T 5 (ascorbic acid @150 ppm) and T 6 (ascorbic acid @300 ppm) with mean values 110 g and 114 g respectively were found to be statistically at par with the control treatment. T 1 (CaCl 2 @ 1%) and T 3 (Ca(NO 3 ) 2 @ 1%) were also at par with T 2 (CaCl 2 @ 2%) having mean values of 120 g and 120 g respectively. The results obtained in present study align with the outcomes reported by Roychaudhary (1992) [14] in guava fruits, Alila and Achumi (2010) [2] in litchi, Tripathi and Shukla (2011) [16] in Aonla and Kaur et al. (2019) [10] in guava.

The highest mean fruit length (6.66 cm) was recorded under T 4 (Ca(NO 3 ) 2 @ 2%) followed by 6.39 cm length in T 2 (CaCl 2 @ 2%) which is statistically at par with T 1 (CaCl 2 @ 1%), T 3 (Ca(NO 3 ) 2 @ 1%) and T 6 (Ascorbic acid @ 300 ppm) with mean values 6.26cm, 6.21cm and 6.18cm respectively. The lowest mean fruit length (5.58cm) was observed in T 0 (control) found to be at par with T 5 (Ascorbic acid @ 150 ppm) having 6.08cm length. Similar results were reported by Roychaudhary (1992) [14] in guava fruits, Alila and Achumi (2010) [2] in litchis, Lal et al. (2015) [12] in kinnow mandarins, and Sidhu et al. (2020) [15] in strawberries.

After the statistical analysis, it is revealed that T 4 (Ca(NO 3 ) 2 @ 2%) had the highest mean fruit diameter (6.73 cm) followed by 5.53 cm diameter in T 2 (CaCl 2 @ 2%) which is found to be at par with T 1 (CaCl 2 @ 1%), T 3 (Ca(NO 3 ) 2 @ 1%) and T 6 (Ascorbic acid @ 300 ppm) with mean values 6.44cm, 6.42 cm, 6.28 cm respectively. However, T 4 showed significant difference with the lowest mean fruit diameter (5.64 cm) recorded under control (T 0 ). Similar outcomes were noted in studies conducted by Roychaudhary (1992) [14] on guava fruits, Koul and Muthoo (1999) [11] on peaches, Alila and Achumi (2010) [2] on litchis, and Sidhu et al. (2020) [15] on strawberries.

The data revealed a significant difference between treatments with maximum mean specific gravity (1.18 g/cc) observed under T 4 (Ca(NO 3 ) 2 @ 2%) followed by T 2 (CaCl 2 @ 2%) with mean value 1.11 g/cc while the minimum mean specific gravity (0.99 g/cc) was recorded in T 0 (Control). The present results agree with research conducted by Roychaudhary (1992) [14] in guava fruits, Koul and Muthoo (1999) [11] in peach, Alila and Achumi (2010) [2] in litchi, Lal et al. (2015) [12] in kinnow mandarin, and Sidhu et al. (2020) [15] in strawberry.

According to the statistical analysis of the data, T 4 (Ca(NO 3 ) 2 @ 2%) recorded the maximum mean pulp weight of 97.4 g followed by T 2 (CaCl 2 @ 2%) with 83.6 g of mean pulp weight whereas minimum (63.1 g) was recorded under control treatment(T 0 ). Moreover. T 1 (CaCl 2 @ 1%), T 3 (Ca(NO 3 ) 2 @ 1%), T 5 (Ascorbic acid @ 150 ppm) and T 6 (Ascorbic acid @ 300 ppm) with mean values 76 g, 74.1 g, 72.2 g and 69 g respectively showed no significant difference with each other. Similarly, Tripathi and Shukla (2011) [16] also concluded that higher pulp content was observed under calcium nitrate @ 1.5% in Aonla cv. Banarasi.

The outcome of statistical analysis showed that maximum mean of seed weight (45.5 g) was recorded in T 3 (Ca(NO 3 ) 2 @ 1%) followed by T 4 (Ca(NO 3 ) 2 @ 2%) with 41 g mean seed weight. On the other hand, minimum mean seed weight (33.2 g) was recorded in T 0 (Control) and T 5 (ascorbic acid @150 ppm) with mean values 35.1 g was found to be statistically at par with the control treatment. T 1 (CaCl 2 @ 1%), T 2 (CaCl 2 @ 2%) and T 6 (Ascorbic acid @ 300 ppm) with mean values 38.2 g, 38.2 g and 36.2 g respectively showed no significant difference with each other. These findings mirror those reported by Bisen et al. (2014) in guava plants.

Fruit grading

The fruits were graded as A, B and C according to the fruit size (fruit diameter) and appearance. where, 'A' -≥ 6.5cm, 'B' -6.5 -6cm, 'C' -≤ 6 cm. The data revealed that the fruits treated with high concentration of calcium shows better quality and increased fruit size hence, fruits treated with T 4 (Ca(NO 3 ) 2 @ 2%) and T 2 (CaCl 2 @ 2%) are found to be graded as 'A' while the lowest grade 'C' was given to the fruits of T 0 (control). T 1 (CaCl 2 @ 1%), T 3 (Ca(NO 3 ) 2 @ 1%), T 5 (ascorbic acid @150 ppm) and T 6 (Ascorbic acid @ 300 ppm) had no significant difference and were graded as 'B'.

Conclusion

On the basis of findings reported upon completion of the research, the effect of pre-harvest treatments had significant influence on the physical attributes of guava fruits. However, calcium sprays proved to be the most effective among all the pre-harvest treatments. Therefore, it can be concluded that treatment T 4 (Ca(NO 3 ) 2 @ 2%) followed by T 2 (CaCl 2 @ 2%) showed the best results with regard to fruits physical parameter i.e., fruit weight, fruit length, fruit diameter, specific gravity, pulp weight and fruit grading. However, T 3 (Ca(NO 3 ) 2 @ 1%) showed the best results with regard to seed weight.

References

1. Abdou MAH, Ahmed EET, Ibrahim TIE. Effect of nitrogen sources and ascorbic acid on growth and essential oil production of geranium (Pelargonium graveolens L.) plants. Sci J Flowers Ornamental Plants. 2015;2(2):157-165.
2. Alila P, Achumi I. Pre-harvest chemical treatments affect post-harvest quality of Litchi fruit. Acta Horticulturae. 2010;934:755-761.
3. Bisen S. Effect of calcium nitrate and gibberellic acid application on growth, fruit quality and post-harvest behaviour of guava fruit. Int Q J Environ Sci. 2014;6:55-62.
4. Conway WS, Sams CE, Kelman A. Enhancing the natural resistance of plant tissue to post-harvest diseases through calcium applications. Hort Science. 1994;29:751-61.
5. Gerasopoulos D, Richardson DG. Storage temperature and fruit calcium alter the sequence of ripening events of "de' Anjou" pears. HortScience. 1999;34(2):316318.
6. Ismail SII. Anatomical and physiological studies on Nigella sativa L. plant [PhD thesis]. Mansoura University; 2008. p. 205-11.
7. Kaur M, Singh G, Bakshi M. Post-Harvest Treatment for Improvement of Shelf Life in Guava (Psidium guajava L.) Cultivar 'Allahabad Safeda' Under Ambient Storage Condition. Plant Archives. 2019;19(2):3005-3010.
8. Koul OP, Muthoo AK. Effect of foliar sprays of calcium nitrate, zinc sulphate and ethrel on the fruit characteristics of Florida Sun peach (Prunus persica L.). Adv Plant Sci. 1999;12(2):577-581.
9. Lal D, Tripathi DV, Kumar S, Nayyer M. Effect of preharvest application of gibberellic acid, NAA, and calcium nitrate on fruit drop, maturity and storage quality of kinnow mandarin. J Horticulture. 2015;8(4):561-564.
10. Maksoud MA, Salah MS, El-Shamma, Faud AA. The effect of bio-fertilizers and antioxidants on olive trees under calcareous soil conditions. World J Agric Sci. 2009;5:350-352.
11. Roychaudhary R, Kabir J, Ray S, Dutta K, Dhua RS. Influence of preharvest spray of calcium salts in the improvement of fruit quality in guava cv. L-49. Adv Horticulture Forestry. 1992;2:70-76.
12. Sidhu RS, Singh NP, Singh S, Sharda R. Foliar nutrition with calcium nitrate in strawberries (Fragaria x ananassa Duch.): Effect on fruit quality and yield. Indian J Ecology. 2020;47(1):87-91.
13. Tripathi VK, Shukla HS. Influence of calcium chloride and calcium nitrate on physico-chemical composition of Aonla 'Banarasi'. Acta Horticulturae. 2011;890:371374.