Study on Inorganic Fertilizers and Biofertilizers on Growth and Production of Papaya (Carica Papaya L.) Cv. Red Lady

Introduction

Horticulture occupies a position of immense significance in Indian agriculture, contributing substantially to nutritional security, rural employment, and economic prosperity. Among the various fruit crops that constitute the horticultural wealth of India, papaya (Carica papaya L.) holds a place of exceptional distinction. Belonging to the family Caricaceae, papaya is a fast-growing, soft-wooded, herbaceous, semi-perennial tree that is native to tropical America, with its centre of origin traced to the lowlands of South Mexico and Central America (Purseglove, 1968). It has since spread across all tropical and subtropical regions of the world and today stands as one of the most widely cultivated and commercially important fruit crops globally. Papaya is often referred to as the 'fruit of angels'a term famously attributed to Christopher Columbusowing to its exceptionally pleasant taste, attractive appearance, and remarkable nutritional profile. The fruit is an outstanding source of vitamin A (in the form of carotenoids), vitamin C, folate, potassium, and dietary fibre. It also contains papain and chymopapain, two powerful proteolytic enzymes with wide applications in the pharmaceutical, food processing, textile, leather, and cosmetic industries Badrie and Schauss, 2010 [1] .

Green papaya latex is commercially harvested for papain, which is used as a meat tenderizer, in the brewing industry, and in the preparation of digestive supplements. The seeds, leaves, and roots of the plant also possess well-documented medicinal properties, including antimicrobial, antiinflammatory, and anthelmintic activities. India occupies the foremost position among all papayaproducing nations in the world. According to the National Horticulture Board (NHB, 20232), India contributes approximately 44 per cent of the world's total papaya production, making it the undisputed global leader in this crop. The major papaya-growing states in India include Andhra Pradesh, Gujarat, Karnataka, Maharashtra, Tamil Nadu, Madhya Pradesh, West Bengal, Assam, Kerala, and Orissa. The crop is cultivated across diverse agro-climatic zones and is particularly well-suited to the warm, humid tropical and subtropical conditions that prevail in the Deccan Plateau, the Indo-Gangetic Plain, and the peninsular regions of the country. According to the Final Estimates for 2024-25 and the First Advance Estimates for 2025-26 released by the Department of Agriculture and Farmers Welfare, Government of India (DAFKW, 2026), India's total horticultural production has reached a new high of 370.74 lakh tonnes in 2024-25, up from 354.74 lakh tonnes in 2023-24. Total fruit production in 2024-25 is estimated at 117.65 lakh tonnes, reflecting a growth of 4.13 per cent over the previous year, driven significantly by gains in banana, mango, mandarin, papaya, guava, watermelon, and jackfruit. For the year 2025-26, total horticulture production is projected to reach 370.85 lakh tonnes, with fruit production anticipated at 118.68 lakh tonnes, indicating a sustained upward trajectory. Within fruits, papaya has been specifically identified as one of the key contributors to this national production surge. At the state level, Madhya Pradeshthe state in which the present investigation was conductedis one of the leading producers of papaya in India, contributing significantly to the national basket (Indiastat, 2025). The present investigation was carried out at the Instructional Research Farm of G. H. Raisoni University, Dhoda Borgaon, Village -Saikheda, Tah. Sausar, Dist. Pandhurna, Madhya Pradesh. This region falls within the Satpura hill range belt of central India, characterized by deep black cotton soil (Vertisols), warm semi-arid climate, and well-defined monsoon rainfall patterns. The soil and climatic conditions of this zone are broadly conducive to the cultivation of tropical and subtropical fruit crops including papaya, offering an appropriate environment to study the response of the crop to different nutritional management strategies. Situated in the agrarian landscape of the Chhindwara-Pandhurna corridor, the university farm provides an ideal experimental platform for research aimed at developing economically viable and ecologically sustainable horticulture production systems for the farming communities of the region. Papaya is a remarkably versatile crop that can be grown in a wide range of soils, provided adequate drainage is ensured. It thrives best in deep, well-drained, loamy soils with a pH range of 6.0 to 6.5 and requires a warm temperature between 25°C and 30°C for optimal growth. Being sensitive to waterlogging, frost, and strong winds, careful site selection is essential for successful cultivation. The crop has a relatively short gestation period and begins fruiting within six to nine months of transplanting under favourable conditions, making it one of the quickest-income-generating perennial fruit crops available to farmers. The productive commercial life of a papaya orchard typically spans two to four years. The average yield ranges from 40 to 60 tonnes per hectare under normal management, while modern highyielding varieties and improved cultural practices can push productivity well beyond 100 tonnes per hectare (NHB, 2023). The variety selected for the present study, cv. Red Lady (F 1 hybrid; Taiwan 786), is one of the most commercially successful papaya hybrids in the world. Developed and marketed by Known-You Seed Company, Taiwan, Red Lady is an early-maturing, vigorous, and highyielding F 1 hybrid that exhibits strong tolerance to Papaya Ring Spot Virus (PRSV), the most economically damaging pathogen of papaya worldwide. The plants begin to bear fruits at a height of only 60-80 cm, with over 30 fruits per plant in each fruiting season. Fruits are short-oblong on female plants and elongated on bisexual plants, weighing approximately 1.5 to 2.0 kg each. The flesh is thick, red, and sweet with a total soluble solids (TSS) content of approximately 13 per cent, making it highly preferred in both fresh markets and food processing. The potential yield of cv. Red Lady has been recorded at up to 120 tonnes per hectare over its two-year productive life cycle (TNAU, 2020). Its excellent fruit quality, disease tolerance, and market acceptance make it the most widely recommended variety for commercial papaya cultivation in India, including the central Indian region. Papaya is an exceptionally heavy feeder and has high nutrient demands commensurate with its rapid vegetative growth and prolific fruiting. Adequate and timely supply of nutrientsparticularly nitrogen (N), phosphorus (P), and potassium (K)is critical to achieving optimal growth, maximizing yield, and improving fruit quality attributes. The recommended dose of fertilizers (RDF) for papaya in India generally varies by state and variety but commonly falls in the range of 200-300 g N, 200-250 g P 2 O 5 , and 400-500 g K 2 O per plant per year. Inorganic fertilizersparticularly urea, single superphosphate, and muriate of potashhave traditionally been the primary nutrient sources in papaya cultivation and are known to produce significant improvements in vegetative and reproductive growth when applied at optimal rates and schedules Chandra, 2014 [2] . However, exclusive dependence on chemical fertilizers has raised serious concerns regarding soil health, progressive decline in soil organic matter, longterm reduction in the population and diversity of beneficial soil microflora, and negative environmental externalities including leaching and eutrophication Dahunsi et al., 2021 [3] . In this context, the strategic integration of biofertilizers with reduced doses of inorganic fertilizers has emerged as a scientifically sound and practically viable approach for sustainable intensification of papaya production. Biofertilizers are preparations containing living or latent cells of efficient strains of microorganisms that, when applied to seed, soil, or plant surfaces, colonize the rhizosphere and augment the supply of plant nutrients through biological processes. The major categories of biofertilizers relevant to fruit crops include nitrogen-fixing bacteria such as Azotobacter chroococcum, Phosphate Solubilizing Bacteria (PSB) such as Bacillus and Pseudomonas spp., and Potassium Solubilizing Bacteria (KSB). Azotobacter, being a free-living aerobic nitrogen fixer, is capable of fixing 20 to 30 kg atmospheric nitrogen per hectare per annum and simultaneously produces phytohormones such as gibberellins, auxins, and cytokinins that stimulate root development and shoot growth Bhattacharyya and Jha, 2012 [4] . PSB enhance the availability of soil phosphorus by solubilizing insoluble inorganic phosphates through the production of organic acids, phosphatases, and siderophores, while KSB mobilize fixed potassium in the soil, thus improving multi-nutrient use efficiency (Frontiers in Microbiology, 2021). Combined inoculation of biofertilizers with reduced chemical fertilizers has been consistently reported to improve soil biological activity, crop growth parameters, fruit yield, and fruit quality in papaya and other tropical fruit crops Hari and Binu, 2021 [5] . Several researchers have demonstrated that the substitution of 25 to 50 per cent of the recommended dose of inorganic fertilizers with biofertilizers can sustain or even enhance productivity while simultaneously reducing input costs, improving soil health, and lowering the environmental footprint of crop production. Studies by Chandra 2014 [2] reported that application of recommended dose of NPK combined with FYM and Pseudomonas straita inoculation gave the highest plant height, trunk girth, number of leaves, and fruit yield in papaya. Similar results favouring integrated use of inorganic fertilizers with Azotobacter, PSB, and KSB were documented by Hari and Binu 2021 [5] at Kerala Agricultural University for several growth and yield parameters of papaya. In the present study conducted in Jhalawar (Jhalawar College of Horticulture and Forestry, 2023-24), soil application of 75% RDF combined with Azotobacter, PSB, and KSB was found to be significantly superior for plant height, plant girth, number of leaves, leaf area, and related growth parameters of papaya cv. Red Lady over sole application of inorganic fertilizers, indicating a clear synergism between chemical and biological nutrient sources (Research Gate, 2024). The economic dimension of fertilizer management in papaya is equally important. Papaya cultivation is a capitalintensive enterprise, and input costsparticularly fertilizer costsconstitute a significant proportion of the total cost of cultivation. Integration of biofertilizers offers growers the dual advantage of reducing expenditure on chemical fertilizers while maintaining or improving productivity, thereby enhancing the benefit-cost ratio and net returns from the crop. Cost-benefit analyses of integrated nutrient management in papaya have consistently demonstrated superior economic returns compared to sole application of inorganic fertilizers at full recommended doses. Given the context of rising fertilizer prices and the policy thrust of the Government of India towards balanced and sustainable nutrition management in agriculture, the economic evaluation of bio-intensive nutrient management strategies in papaya assumes considerable relevance and policy significance. Despite the voluminous research literature available on fertilizer management in papaya in various agro-climatic zones of India, comprehensive information specific to the black cotton soil belts of the Satpura plateau region of Madhya Pradeshencompassing growth parameters, yield attributes, and economics simultaneously remains limited. Moreover, the performance of the commercially dominant cv. Red Lady under integrated inorganic-biofertilizer regimes in the central Indian context warrants thorough scientific investigation. The present study was therefore conceptualized and executed at G. H. Raisoni University, Saikheda, Dist. Pandhurna Mdyapradesh

Materials and Methods

The present investigation entitled "Study on Inorganic Fertilizers and Biofertilizers on Growth and Production of Papaya (Carica papaya L.) cv. Red Lady" was conducted at University Research Farm, GHRU, Saikheda in Kharif Season of 2025, are presented and described in this chapter. Data pertaining to various criteria used for treatment evaluation were analyzed statistically to test their significance and analysis of variance for these data has been given in appendices at the end. The research trail was carried on papaya crop cv. Red Lady. The application of Recommended Dose of Fertilizers, Azotobacter,PSB and KSB in different form and combinations, T₁ 100% RDF (Control), T₂ 100% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB,T₃ 100% RDF + 25 g Azotobacter + 25 g PSB + 25 g KSB,T₄ 75% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB, T₅ 75% RDF + 25 g Azotobacter + 25 g PSB + 25 g KSB, T₆ 50% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB, T₇ 50% RDF + 25 g Azotobacter + 25 g PSB + 25 g KSB, T₈ 25% RDF + 25 g Azotobacter + 25 g PSB + 25 g KSB, T₉ 25% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB was used for the experiment for observed the growth, yield, and related parameters from randomly selected tagged plants in each treatment replication. i.e. Days taken to first flowering, Days taken to fruit maturity, Plant height, Plant girth, Number of nodes, Number of leaves per plant, Leaf area, Leaf Area Index (LAI), Fruit weight, Number of fruits per plant, Fruit yield per plant.

Analysis of Variance (ANOVA)

The mean sum of squares (MSS) due to treatments and error, obtained from the analysis of variance for all eleven growth and yield traits of papaya cv. Red Lady, are presented in Table 1. The treatment mean sum of squares were tested against the error mean sum of squares for each trait, and the F-values so obtained were found to be significant at the 1% level of probability (p < 0.01) for all eleven charactersdays to 1st flowering, days to fruit maturity, number of leaves per plant, leaf area, leaf area index, plant girth, number of nodes, plant height, fruit weight, number of fruits per plant, and fruit yield per plant. This confirms that the differences among the nine treatment combinations (inorganic fertilizer levels integrated with varying doses of Azotobacter, phosphate-solubilising bacteria (PSB), and potassium-solubilising bacteria (KSB)) were not due to chance, and that the treatments exerted a highly significant influence on every growth and yield parameter studied. Among the traits, leaf area and fruit weight showed the largest treatment mean sum of squares (59644.7227 and 47431.1056, respectively), reflecting the greatest absolute magnitude of variation induced by the treatments, while leaf area index showed the smallest (0.8049), consistent with its naturally narrow numerical range. Degrees of freedom: Replications (r-1) = 2; Treatments (t-1) = 8; Error (r-1) (t-1) = 18.

Results and Discussion

Plant Girth (cm): Significant differences among treatments were observed for plant girth. Treatment T₄ (75% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB) registered the maximum plant girth of 32.21 cm, followed by T₂ (29.13 cm) and T₆ (28.92 cm). The minimum girth was recorded under T₁ (100% RDF -Control) at 23.04 cm. Treatments T₅, T₆, T₇, and T₉ were statistically at par with each other. The marked increase in stem girth under T₄ relative to T₁ (control) indicates that the 75% inorganic fertilizer dose combined with the maximum biofertilizer consortium dose improved the vasculature and structural biomass of the papaya stem considerably.

Number of Leaves per

Plant: Significant differences were observed among treatments. Treatment T₄ (75% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB) recorded the maximum number of leaves per plant at 62.25, which was significantly superior to all other treatments. It was followed by T₂ (57.66), T₉ (54.78), and T₅ (54.38). The minimum number of leaves was recorded under T₁ (100% RDF -Control) with 41.06 leaves, which was significantly the lowest among all treatments. The trend clearly demonstrated that increasing both the biofertilizer dose and optimizing the inorganic fertilizer percentage together produced the maximum canopy leaf count in papaya.

Leaf Area (cm²): Significant differences were recorded among treatments for leaf area. T₄ (75% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB) produced the highest leaf area of 1912.04 cm², followed by T₂ (1867.08 cm²) and T₆ (1811.54 cm²). These three treatments did not differ significantly from each other but were significantly superior to the remaining treatments. The control treatment T₁ (100% RDF alone) recorded the minimum leaf area of 1453.55 cm², which was significantly the lowest among all treatments. The range of mean leaf area across all treatments was 1453.55 to 1912.04 cm².

Leaf Area Index (LAI): LAI showed highly significant differences among treatments. The highest LAI was recorded in T₂ (100% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB) at 5.00, which was statistically at par with T₄ (75% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB; LAI = 4.96). These were followed by T₆ (4.81) and T₉ (4.70). The minimum LAI was recorded in T₁ (100% RDF -Control) at 3.29, which was significantly lower than all other treatments. The close performance of T₂ and T₄ in LAI -despite T₄ using 25% less inorganic fertilizer than T₂ -is a particularly noteworthy finding, confirming that biofertilizer consortia can offset the reduction in chemical fertilizer dose in terms of leaf area deployment per unit ground area.

Number of Nodes: Significant differences among treatments were observed for number of nodes. T₄ (75% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB) recorded the maximum number of nodes at 71.21, which was significantly superior to all other treatments. It was followed by T₂ (68.00) and T₆ (66.06). The minimum number of nodes was recorded in T₁ (100% RDF -Control) with 61.47 nodes, which was the lowest among all treatments. The number of nodes is a direct function of the rate of node initiation at the shoot apical meristem and internode elongation, both of which are positively influenced by adequate nutrition.

Days to First Flowering: Highly significant differences were observed among treatments for days to first flowering. T₄ (75% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB) recorded the minimum days to first flowering of 140.14 days -the most desirable result. It was followed by T₅ (148.61 days) and T₉ (157.41 days). The maximum (most delayed) days to first flowering was recorded in T₁ (100% RDF -Control) at 169.93 days, which was significantly the highest among all treatments. T₃ (166.79 days) and T₂ (164.21 days) also showed delayed flowering compared to the biofertilizer-supplemented treatments at 75% and 50% RDF.

Days to Fruit Maturity:

The results revealed highly significant differences among treatments. T₄ (75% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB) recorded the minimum days to fruit maturity of 199.37 days, which was significantly the lowest and most desirable among all treatments. It was followed by T₅ (207.83 days) and T₉ (208.55 days). The maximum days to maturity was recorded in T₃ (100% RDF + 25 g biofertilizers) at 215.68 days, followed by T₁ (213.79 days), which was the control treatment. This trend of earlier maturity in optimally integrated treatments mirrored the earlier flowering pattern, confirming that biofertilizer integration accelerates the entire reproductive development cycle in papaya.

Number of Fruits per Plant:

The results revealed highly significant differences among treatments for number of fruits per plant. T₄ (75% RDF + 50 g Azotobacter + 50 g PSB + 50 g KSB) recorded the maximum number of fruits ) of all nine treatmentsa direct consequence of its disproportionately high input cost relative to the yield advantage it produced. The control treatment T₁, while having the lowest cultivation cost, ranked eighth in net return (₹3,69,767/ha), confirming that sole reliance on inorganic fertilizer, although cheap, is not the most remunerative strategy. Thus, two distinct economic leaders emerge from the data: T₄ for the highest absolute net profit per hectare, and T₅ (closely followed by T₇) for the highest return per rupee invested.

References

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