Influence of mulching and fertigation levels on growth, yield, fruit quality and economics of tomato (Solanum lycopersicum L.) cv. ‘Heem Sohna’ under naturally ventilated polyhouse

Introduction

Tomato (Solanum lycopersicum L., 2n = 2x = 24) is among the most widely cultivated and consumed vegetable crops in the world, ranking second only to potato in terms of area and production (Ram, 1991) [27] . Native to Peru in Latin America (Villareal, 1979) [44] , the crop was introduced into India during the seventeenth century, most likely by Portuguese traders (Kalloo, 1991) [16] , and has since become integral to Indian diets, both as a fresh vegetable and in processed forms such as puree, ketchup and sauce. Nearly two-thirds of the global tomato harvest is consumed fresh, with the remainder directed towards processing (Ugonna et al., 2015) [42] . India currently cultivates tomato over roughly 814 thousand hectares, producing about 2,515 thousand tonnes annually, with Himachal Pradesh contributing close to 482 thousand tonnes from about 11.24 thousand hectares (NHB, 2018-19) [23] . Beyond its culinary versatility, tomato is valued as a 'protective food' owing to its rich content of vitamins A and C, dietary fibre and minerals such as potassium, calcium, iron and manganese (Kaur and Kapoor, 2008; Naika et al., 2005) [17,22] . Lycopene, the principal carotenoid responsible for the fruit's characteristic red colour, is widely regarded as one of the most potent naturally occurring antioxidants and has been associated with reduced risk of cardiovascular disease, osteoporosis and certain cancers (Tigist et al., 2013) [38] . Open-field tomato cultivation remains highly susceptible to biotic and abiotic stresses that constrain both yield and quality. Protected cultivation, by moderating the crop microclimate, offers a dependable route to year-round production of high-value, superior-quality fruit (Sirohi, 2002) [35] while enabling more efficient use of shrinking landholdings (Sanwal et al., 2004) [30] .

Within protected systems, mulching and fertigation are two agronomic levers of particular importance. Mulches, whether organic (saw dust, straw) or inorganic (black polythene), moderate soil temperature, conserve moisture, suppress weeds and improve soil structure (Hochmuth et al., 2001; Patil et al., 2013) [13,26] , while black polythene in particular restricts outgoing radiation and thereby enhances moisture retention and weed control relative to organic alternatives (Patil et al., 2013) [26] . Fertigation, the delivery of water-soluble fertilizer through the irrigation system, permits frequent, precise and uniform nutrient application, improving nutrient-use efficiency under protected conditions (Vasanthi et al., 2017) [43] . The rate and scheduling of fertigation is known to strongly influence nutrient uptake and, consequently, crop performance. Despite considerable independent evidence on the benefits of mulching and fertigation, information on their combined or interactive effects on growth, yield, fruit quality and economics of tomato hybrids under mid-hill naturally ventilated polyhouse conditions remains limited. The present investigation was therefore undertaken with the following objectives: (i) to evaluate the effect of different mulch materials on growth, yield and quality of tomato under protected conditions; (ii) to assess the influence of varying fertigation levels on these parameters; (iii) to examine the interaction effects of mulching and fertigation; and (iv) to work out the benefit-cost ratio of the different treatment combinations.

Materials and Methods

Experimental site and climate

The experiment was conducted during Kharif 2021 in a naturally ventilated polyhouse (25 m × 20 m × 15 m) at the Experimental Research Farm, Chhapang, Dr. Khem Singh Gill Akal College of Agriculture, Eternal University, Baru Sahib (173101), Himachal Pradesh, India, situated at 30.73°N, 77.31°E and 898 m above mean sea level, within the sub-temperate, sub-humid mid-hill agro-climatic zone. The site receives an average annual rainfall of 985.8 mm, most of which is received during the south-west monsoon (June-September). The initial soil at 0-15 cm depth was sandy loam in texture, normal in electrical conductivity and pH, high in organic carbon and medium in available nitrogen, phosphorus and potassium.

Experimental design and treatments

The trial was laid out in a Randomized Block Design (RBD) with nine treatment combinations replicated thrice (27 plots; plot size 2 × 1 m; ten plants plot-1 at 60 × 45 cm spacing). Three mulch materials saw dust (M1), straw (M2) and black polythene (M3) were factorially combined with three fertigation levels of water-soluble fertilizer (Polyfeed 19:19:19) 100 kg NPK ha -1 (F1), 150 kg NPK ha -1 (F2) and 200 kg NPK ha -1 (F3) to give nine treatments (T1-T9: M1F1 through M3F3). Nursery seed of the indeterminate hybrid 'Heem Sohna' (Syngenta) was sown on 18 January 2021, and 4-6 leaf-stage seedlings, pre-treated with 0.2% Bavistin, were transplanted onto raised beds on 28 February 2021. Fertigation commenced 15 days after transplanting through drip, and mulches were applied according to treatment; plots were kept weed-free by hand weeding throughout the season.

Observations recorded

Five randomly tagged plants per plot were used to record vegetative parameters (days to flower initiation, plant height, plant spread, leaf area, leaflets per leaf, nodes per plant and internodal distance), yield-attributing and yield parameters (harvest duration, fruit length and breadth, fruit weight, fruits per plant, and fruit yield per plant, per plot and per hectare) and fruit-quality parameters (pericarp thickness, ascorbic acid content estimated by the 2,6-dichlorophenol indophenol dye method, total soluble solids by hand refractometer, and lycopene content by petroleum-ether extraction and spectrophotometry at 503 nm, following Rangana, 1997) [28] . Soil samples were analysed for available N, P and K before planting and after final harvest using standard procedures (Subbiah and Asija, 1956; Olsen et al., 1954; Jackson, 1973) [36,14] . Cost of cultivation, gross and net returns and benefit-cost (B:C) ratio were computed for each treatment on a per-unit-area basis, and incidence of pest and disease was monitored throughout the crop period.

Statistical analysis

Data were subjected to analysis of variance appropriate for a two-factor RBD, following Gomez and Gomez (1984) [11] . Treatment means were compared using critical difference (CD) at the 5% level of significance wherever the F-test was significant.

Results and Discussion

Vegetative growth parameters

Mulching and fertigation level exerted a significant independent influence on all recorded vegetative traits (Table 1). Black polythene mulch (M3) advanced flowering, and produced the tallest, most spreading plants with the greatest leaf area and leaflet number, while saw dust (M1) consistently trailed. Among fertigation levels, the highest dose of 200 kg NPK ha -1 (F3) was significantly superior to the lower levels for every vegetative character measured. Interaction effects were significant for plant spread and leaflet number, where the combination of black polythene mulch with 200 kg NPK ha -1 (M3F3) recorded the best performance (plant spread 87.64 cm; leaflets per leaf 15.67), generally at par with straw mulch at the same fertigation level (M2F3). The superiority of black polythene mulch for early flowering and vigorous vegetative growth can be attributed to the elevated soil and canopy-level temperature it sustains relative to organic mulches, which improves the soil hydrothermal regime and accelerates photosynthate production and floral primordia initiation (Kavitha et [18,33,12] . The response to increasing fertigation level reflects the wellestablished role of nitrogen in stimulating protein synthesis, chlorophyll formation and carbohydrate accumulation, coupled with the contribution of phosphorus to reproductive development (Agrawal et al., 2018; Tegen et al., 2016; Dhiman et al., 2018) [1,37,9] . Enhanced leaf area and plant height under black polythene combined with the highest fertigation level are further consistent with improved nutrient and moisture availability at the root zone through drip-based delivery, which sustains higher rates of cell division and net assimilation (Devi et al., 2020; Wankhede et al., 2018; Kosterna, 2014) [7,45,20] .

Yield and yield-attributing traits

Harvest duration, fruit length and breadth, fruit weight, number of fruits per plant and fruit yield (per plant, per plot and per hectare) were all significantly influenced by mulch type and fertigation level as independent factors, with black polythene mulch and 200 kg NPK ha -1 fertigation producing the best results throughout (Table 2). The interaction of mulch and fertigation level was significant for fruit length, number of fruits per plant, and all three yield expressions, with M3F3 emerging as the single best treatment combination (fruit yield 1715.25 q ha -1 ), generally at par with straw mulch under the same fertigation level (M2F3, 1549.35 q ha -1 ). The yield advantage under black polythene mulch is best explained through its cascading effect on component traits: moisture conservation and a more favourable root-zone microclimate promote greater nutrient influx into developing fruit, translating into longer, broader and heavier fruit with a higher fruit count per plant (Shukla et al., 2009; Kundu et al., 2019; El-Moulla et al., 2018) [32,21,10] . A weed-free environment and reduced nutrient loss through leaching under the impermeable mulch further support a higher number of fruit-bearing nodes (Ogundare et al., 2015; Tipu et al., 2014) [24,39] . The corresponding response to increasing fertigation level is consistent with more efficient translocation of photosynthates from source to sink under a regime of frequent, split nutrient supply, which favours fruit set, fruit size and, ultimately, total yield per unit area (Kavitha et al., 2020; Vasanthi et al., 2017; Ughade et al., 2016) [18,43,41] . The significant mulch × fertigation interaction for yield traits underscores that the full yield benefit of intensive fertigation is best realised only when paired with a mulch, such as black polythene, capable of sustaining the associated microclimatic and moisture advantages (Selvamurugan et al., 2018; Aruna et al., 2007) [31, 4] . .702 M1 = saw dust; M2 = straw mulch; M3 = black polythene mulch; F1 = 100 kg NPK ha -1 ; F2 = 150 kg NPK ha -1 ; F3 = 200 kg NPK ha -1 ; CD = critical difference at 5% level of significance.

Fruit quality parameters

All four quality attributes examined pericarp thickness, ascorbic acid content, total soluble solids (TSS) and lycopene content responded significantly and positively to black polythene mulch and to the highest fertigation level (Table 3). Interaction effects were significant only for ascorbic acid content, where M3F3 again recorded the highest value (26.44 mg 100 g-1), statistically at par with M3F2 and M2F3. Improved pericarp thickness under black polythene mulch parallels the gains already observed in fruit length, breadth and weight, and reflects more efficient nutrient translocation into the pericarp tissue during fruit development (Samui et al., 2020; Dharmatti et al., 1989) [29,8] . The elevated ascorbic acid, TSS and lycopene content under black polythene mulch is consistent with an accentuated metabolic and photosynthetic environment beneath the mulch, including greater canopy-level carbon dioxide concentration, both of which favour sugar translocation to the fruit and support carotenoid biosynthesis during ripening (Samui et al., 2020; Ayyar, 2019; El-Moulla et al., 2018) [29,5,10] . The parallel improvement in these traits with increasing fertigation level is attributable, in particular, to enhanced potassium availability, which plays a central role in sugar translocation, ascorbate metabolism and chloroplast development the very site of lycopene synthesis (Kalanjiyam and Manickam, 2015; Anac and Colcoglu, 1995; Singh et al., 2019) [15,2,34] . [21] , Agrawal et al. (2018) [1] and Vasanthi et al. (2017) [43] , although they contrast with reports of comparatively higher returns from organic mulches under different agro-climatic settings ( [37,6,19] , reflecting the influence of local input costs and market price on the final B:C outcome.

Soil fertility status after final harvest

Residual soil nitrogen was significantly highest under saw dust mulch (340.95 kg ha -1 ), most likely reflecting the immobilisation and gradual release of nitrogen associated with the decomposition of a high carbon-to-nitrogen organic residue and comparatively lower plant offtake (Ogundare et al., 2015) [24] . Available phosphorus was highest under straw mulch (38.28 kg ha -1 ), consistent with the relatively high phosphorus content of decomposing wheat straw (Khan et al., 2005) [19] , while available potassium, though numerically highest under straw mulch, did not differ significantly among mulch treatments. Across all three nutrients, residual availability increased significantly with fertigation level, being highest under 200 kg NPK ha -1 , reflecting a greater unutilised fraction of applied nutrient at the higher dose (Ughade et al., 2016; Tumbare et al., 2004) [41, 40] .

Incidence of pest and disease

No disease incidence was recorded throughout the cropping season, and fruit borer infestation remained well below the economic threshold level in all treatments, consistent with the generally favourable and better-regulated microclimate and improved field sanitation associated with protected cultivation.

Conclusion

Under naturally ventilated polyhouse conditions in the midhills of Himachal Pradesh, black polythene mulch combined with fertigation at 200 kg NPK ha -1 consistently outperformed the other treatment combinations for vegetative growth, yield and fruit quality of tomato cv. 'Heem Sohna', and also returned the highest benefit-cost ratio (2.21). Straw mulch at the same fertigation level offered a comparable, more economical alternative (B:C ratio 2.15) where the cost of plastic mulch is limiting. Saw dust mulch, while agronomically inferior for yield, conserved the greatest residual soil nitrogen and may hold value in nutrient-management rotations. On the basis of overall growth, yield, quality and economic performance, black polythene mulching integrated with fertigation at 200 kg NPK ha -1 can be recommended as the most rewarding management practice for polyhouse tomato cultivation under similar mid-hill agro-climatic conditions.

References

1. Agrawal N, Tanrakar SK, Tiwari RB. Impact of fertigation through drip on the cultivation of tomato. Int J Curr Microbiol Appl Sci. 2018;7:4528-4535.
2. Anac D, Colcoglu H. Response of some major crops to K fertigation. In: Mengel K, Krauss A, editors. K Availability of Soils in West Asia and North Africa: Status and Perspectives. Basel: International Potash Institute; 1995. p. 235-247.
3. Ankush, Sharma SK. Yield, quality, nutrient and water use efficiency of tomato as affected by different fertigation rates through drip irrigation system. Indian J Agric Res. 2017;51:478-482.
4. Aruna P, Sudagar IP, Manivannan MI, Rajangam J, Natarajan S. Effect of fertigation and mulching for yield and quality in tomato cv. PKM-1. Asian J Hortic. 2007;2:50-54.
5. Ayyar S. Mulching and fertigation on the yield and quality of tomato. Int J Chem Stud. 2019;7:2539-2541.
6. Biswas SK, Akanda AR, Rahman MS, Hossain MA. Effect of drip irrigation and mulching on yield, wateruse efficiency and economics of tomato. Plant Soil Environ. 2015;61:97-102.
7. Devi KL, Panda J, Yadav SR, Jhajharia D, Sakharam IN, Sharma APM. Effect of drip and mulch on growth, yield and WUE of tomato under low-cost polyhouse in Sikkim condition. Int J Curr Microbiol Appl Sci. 2020;9:193-198.
8. Dharmatti PR, Madalageri BB, Hosamani RM, Meherwade MN, Babalad HB. Effect of nutrition on the physiological maturity of fruit and seed of tomato. Prog Hortic. 1989;21:268-271.
9. Dhiman JS, Raturi HC, Kachwaya DS, Singh SK. Effect of nitrogen and phosphorus on tomato (Solanum lycopersicum L.) grown under polyhouse condition. Bull Environ Pharmacol Life Sci. 2018;7:25-29.
10. El-Moulla MH, Sadek II, Moursy FS. Effect of plastic colour and organic mulching on the yield of tomato and lettuce. Int J Sci Res Methodol. 2018;9:173-191.
11. Gomez KA, Gomez AA. Statistical Procedures for Agricultural Research. 2nd ed. New York: John Wiley and Sons; 1984.
12. Gudugi IAS, Odofin AJ, Adeboye MKA, Oladiran JA. characteristics of tomato as influenced by irrigation and mulching. Adv Appl Sci Res. 2012;3:2539-2543.
13. Hochmuth G, Chandler C, Stanley C, Legard D, Duval J, Waldo E, et al. Containerized transplants for establishing strawberry crops in Florida. HortScience. 2001;37:443-446.
14. Jackson ML. Soil Chemical Analysis. New Delhi: Prentice Hall of India; 1973.
15. Kalanjiyam S, Manickam K. Fertigation studies in tomato. J Plant Agric Res. 2015;1:1-5.
16. Kalloo G. Genetic Improvement of Tomato: Monographs on Theoretical and Applied Genetics. Vol. 14. Berlin: Springer-Verlag; 1991.
17. Kaur C, Kapoor HC. Antioxidant activity in tomato as a function of genotype. In: Preedy VR, Watson RR, editors. Tomatoes and Tomato Products: Nutritional, Medicinal and Therapeutic Properties. Enfield: Science Publishers; 2008. p. 111-131.
18. Kavitha M, Natarajan S, Pugalendhi L. Effect of shade and fertigation on growth, yield attributes of tomato. Int J Curr Microbiol Appl Sci. 2020;9:2281-2288.
19. Khan MH, Chattha TH, Hayat R. Growth and yield response of tomato (Lycopersicon esculentum L.) to International Journal of Advanced Biochemistry Research https://www.biochemjournal.com organic and inorganic mulches. Asian J Plant Sci. 2005;4:128-131.
20. Kosterna E. The effect of covering and mulching on the soil temperature, growth and yield of tomato. Folia Hortic. 2014;26:91-101.
21. Kundu P, Adhikary NK, Saha M, Ghosal A, Sahu NC. The effect of mulches on tomato (Lycopersicon esculentum L.) in respect of yield attribute in ecosystem of coastal Bengal. Curr J Appl Sci Technol. 2019;35:18.
22. Naika S, van Lidt de Jeude J, de Goffau M, Hilmi M, van Dam B. Cultivation of Tomato. Wageningen: Agromisa Foundation and CTA; 2005.
23. National Horticulture Board. Indian Horticulture Database 2018-19 [Internet]. 2019 [cited 2026 Jul 30]. Available from: http://nhb.gov.in
24. Ogundare SK, Babatunde IJ, Etukudo OO. Response of tomato variety (Roma F) yield to different mulch materials and staking in Kabba, Kogi State, Nigeria. J Agric Stud. 2015;3:61-70.
25. Olsen SR, Cole CV, Watanabe FS, Dean LA. Estimation of Available Phosphorus in Soils by Extraction with Sodium Bicarbonate. USDA Circular No. 939. Washington (DC): United States Department of Agriculture; 1954.
26. Patil SS, Kelkar TS, Bhalerao SA. Mulching: A soil and water conservation practice. Res J Agric For Sci. 2013;1:26-29.
27. Ram HH. Vegetable Breeding: Principles and Practices. New Delhi: Kalyani Publishers; 1991.
28. Rangana S. Manual of Analysis of Fruit and Vegetable Products. 2nd ed. New Delhi: Tata McGraw-Hill; 1997.
29. Samui I, Skalicky M, Sarkar S, Brahmachari K, Sau S, Ray K, et al. Yield response, nutritional quality and water productivity of tomato (Solanum lycopersicum L.) are influenced by drip irrigation and straw mulch in the coastal saline ecosystem of Ganges Delta, India. Sustainability. 2020;12:6779.
30. Sanwal SK, Patel KK, Yadav DS. Vegetable production under protected conditions in NEH region: Problems and prospects. Indian Soc Veg Sci. 2004;3:120-129.
31. Selvamurugan M, Pandian VN, Manikandan M. Effect of drip fertigation and plastic mulching on growth and yield of tomato. J Appl Hortic. 2018;20:75-78.
32. Shukla YR, Thakur AK, Joshi A. Effect of inorganic and bio-fertilizer on yield and horticultural traits in tomato. Indian J Hortic. 2009;66:285-287.
33. Singh H, Sharma P, Kumar P, Dhillon NS, Sekhon BS. Influence of mulching on growth and yield of tomato (Solanum lycopersicum L.) under protected environment. Biol J Int. 2017;19:1-6.
34. Singh P, Raturi HC, Rani S. Effect of different levels of fertigation on the qualitative parameters of tomato (Solanum lycopersicum L.) grown under polyhouse condition. J Pharmacogn Phytochem. 2019;Sp1:695697.
35. Sirohi NS. Growing vegetables under protected cultivation. In: Proceedings of the International Conference on Vegetables; 2002; Bangalore, India. p. 162.
36. Subbiah BV, Asija GL. A rapid procedure for the estimation of available nitrogen in soils. Curr Sci. 1956;25:259-260.
37. Tegen H, Dessalegn Y, Mohammed W. Influence of mulching and varieties on growth and yield of tomato under polyhouse. J Hortic For. 2016;8:1-11.
38. Tigist M, Workneh T, Woldetsadik K. Effects of variety on the quality of tomato stored under ambient conditions. J Food Sci Technol. 2013;50:477-486.
39. Tipu MMH, Amin M, Dhar M, Alam MA. Effects of mulching on yield and quality of tomato varieties. J Agric Sci Technol. 2014;3:12-14.
40. Tumbare AD, Nikam DR, Kasar DV. Effect of planting and fertigation on growth and yield of green chilli (Capsicum annuum L.). Indian J Agric Sci. 2004;74:242-245.
41. Ughade SR, Tumbare AD, Surve US. Response of tomato to different fertigation levels and schedules under polyhouse. Int J Agric Sci. 2016;12:76-80.
42. Ugonna CU, Jolaoso MA, Onwualu AP. Tomato value chain in Nigeria: Issues, challenges and strategies. J Sci Res Rep. 2015;7:501-515.
43. Vasanthi BG, Srinivasap0pa KN, Manjunath B, Padmavathi M. Effect of fertigation levels and schedules on growth, yield and economic returns of tomato (Solanum lycopersicum L.). Int Res J Agric Econ Stat. 2017;8:320-324.
44. Villareal RL. Tomato production in the tropics: Problems and progress. In: Proceedings of the International Symposium on Tropical Tomato. Vol. 23; 1979. p. 6-12.
45. Wankhede PS, Dhaliwalkar SD, Gorantiwar SD, Gaikawad MA. Effect of different irrigation regimes and fertigation levels on yield of tomato under naturally ventilated polyhouse and open field. Int J Agric Sci. 2018;10:5202-5211.