Impact of organic nutrient strategies for improving growth and yield of cauliflower under protected cultivation

Introduction

Cauliflower (Brassica oleracea var. botrytis) is a prominent winter-season cole crop with a diploid chromosome number of 2n = 18. It is believed to have originated from Brassica oleracea var. sylvestris and has evolved through processes such as introgression, mutation and selection. The crop belongs to the family Cruciferae and is cultivated for its edible curd, which is a compact, modified pre-floral apical meristem widely consumed in India (Swarup and Chatterjee, 1972) [10] . Nutritionally, cauliflower is rich in essential nutrients containing about 91.7% water, 4.9 g carbohydrates and 2.4 g protein, along with significant amounts of vitamin C, calcium and phosphorus. It also contains bioactive compounds such as indole-3-carbinol, omega-3 fatty acids and vitamin K, which contribute to its anti-cancer, anti-inflammatory and cardioprotective properties while supporting digestive health (Singh, 1997) [7] . Owing to its mild flavour and versatility, it is widely used in a variety of culinary preparations. In recent years, organic fertilizers have gained importance due to their synergistic effects with mineral and biological fertilizers, improving soil health and plant growth. (Kalalbandi et al., 2007) [5] . Organic manures such as vermicompost, jeevamrutha, poultry manure, lignite and farmyard manure (FYM) play a significant role in sustainable nutrient management (Bopcha and Agarwal, 2024) [3] . Vermicompost improves soil structure, microbial activity and crop productivity while enhancing produce quality. Jeevamrutha is a fermented organic formulation that enhances microbial activity, improves soil biological properties and crop performance whereas poultry manure is rich in essential nutrients that supports better plant growth and enhances yield in cauliflower. Lignite is rich in organic carbon and humic substances which acts as a carrier for biofertilizers. Farmyard manure (FYM) improves soil fertility, structure and water holding capacity while providing a steady nutrient supply, thereby supporting sustained crop growth and long-term soil health (Bhatt, 2023) [2] .

The excessive use of mineral fertilizers in intensive vegetable systems has led to negative impacts on soil and the environment, encouraging the shift toward eco-friendly inputs such as biofertilizers. These improve soil health, reduce costs and enhance sustainability by increasing nitrogen availability and stimulating plant growth through hormone production while also suppressing soilborne pathogens (Asokan et al., 2000). Among them, VAM enhance nutrient and water uptake and improve plant tolerance and productivity, PSB increase phosphorus availability and crop yield whereas Azospirillum promotes root development, nutrient uptake and overall plant growth (Zbar et al., 2021 & Kachari et al., 2009) [1,4,13] . The combined use of organic manures and biofertilizers within a naturally ventilated polyhouse creates a favourable growing environment that supports enhanced cauliflower growth and yield. The relatively stable microclimatic conditions, including moderated temperature, humidity and air movement, facilitate efficient nutrient availability and uptake while minimizing plant stress. This leads to improved vegetative development, expressed through greater plant height, increased leaf production, expanded leaf area, wider canopy spread, and enhanced root growth. In contrast, crops grown under open field conditions are frequently exposed to unpredictable environmental variations that can interfere with nutrient efficiency and restrict growth potential. Consequently, integrating organic nutrient sources with polyhouse cultivation offers a more reliable and efficient system for achieving improved growth, productivity and overall crop performance.

Materials and Methods

The experiment was conducted during the academic year 2025-2026 at the School of Agricultural Sciences, Malla Reddy University, Hyderabad. The materials used and the methodology adopted for the present investigation are described in the following sections.

Experimental Design

The experiment was conducted following a Randomized Block Design (RBD), a widely used experimental layout in agricultural research due to its ability to control field variability. This design was adopted to minimize the influence of inherent variations such as differences in soil fertility, moisture availability, temperature and other microclimatic factors that can affect plant growth. To achieve this, the experimental field was divided into uniform blocks so that each block provided similar growing conditions. Nine treatments (T 1 -T 9 ) were evaluated, with each treatment appearing once in every block and the experiment was replicated three times, resulting in a total of 27 experimental units. The treatments were randomly allocated within each block to eliminate bias and ensure that the observed differences in crop performance were solely due to treatment effects rather than positional variation.

The RBD framework thus facilitated the following outcomes:

• Improved experimental accuracy by minimizing variability and reducing error.

Results and Discussion

Growth parameters, Plant height (cm) The increased plant height under integrated nutrient treatments can be attributed to the combined influence of organic manures and biofertilizers in enhancing nutrient availability, microbial activity and root development. The superior performance of T 6 is likely due to the synergistic effect of poultry manure, which supplies readily available nutrients, along with Azospirillum (nitrogen fixation), PSB (phosphorus solubilization) and VAM (enhanced nutrient and water uptake). This integrated approach improves nutrient use efficiency and overall plant growth, resulting in greater plant height. Similar results were reported by Kachari et al. (2009) and Singh et al. (2023) [4,8] . Vermicompost 50% (2.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 9.31 13.27 19.66 T6 Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 9.63 13.74 19.73 T7 Jeevamrutha 50% (250 l ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 8.98 13.17 18.90 T8 Lignite 50% (0.5 MT ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% A considerable difference was observed in the number of leaves per plant in cauliflower under different organic nutrient management treatments. Significant variation in the number of leaves per plant was observed under different organic nutrient treatments, with observations recorded at 30, 45 and 60 DAT. Among the treatments, T 6 (Poultry manure 50% (7.5 t ha -¹) + VAM (5 kg ha -¹) + Azospirillum (2 kg ha -¹) + PSB (5 kg ha -¹) 50%)) recorded the highest number of leaves (9.63, 13.74, and 19.73) at 30, 45 and 60 DAT, respectively. This treatment was on par with T₅, which recorded 8.98, 13.17 and 18.90 leaves per plant, while the lowest number of leaves was observed in T₄ (Lignite 100%) with 7.70, 11.30 and 16.79 leaves at the respective stages.

Number of leaves per plant

The increased number of leaves per plant in T₆ may be attributed to improved nutrient balance and enhanced physiological activity under integrated nutrient management. The combined application of organic manures and biofertilizers likely created favorable conditions for continuous nutrient supply and efficient utilization, which supported active meristematic growth and leaf initiation. Enhanced metabolic activity and improved photosynthetic efficiency would have further promoted the formation of new leaves and overall vegetative development. In addition, better root growth and nutrient uptake efficiency contributed to sustained plant vigor, resulting in a higher number of leaves per plant (Kachari et al., 2009 & Singh et al., 2023) [4,8] . Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 19.18 24.20 29.54 T7 Jeevamrutha 50% (250 l ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 16.28 23.41 28.35 T8 Lignite 50% (0.5 MT ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% [4,6] . Leaf width (cm) Vermicompost 50% (2.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 17.07 22.34 29.13 T6 Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 17.1 22.82 29.96 T7 Jeevamrutha 50% (250 l ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 16.43 21.95 28.72 T8 Lignite 50% (0.5 MT ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% (2021) [4,13] , who observed enhanced vegetative growth in cauliflower under integrated nutrient management practices. [6,9] , who reported improved plant spread under integrated nutrient management practices. Yield parameters, Fresh weight of curd (g) Vermicompost 50% (2.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 812.38 T6

Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 825.57 T7 Jeevamrutha 50% (250 l ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 764.50 T8 Lignite 50% (0.5 MT ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 347.23 T9 Control -FYM (25 t ha -1 ) 581.55 SEm (±) 2.113 CD (P=0.05) 6.390

Fresh curd weight varied markedly across the different treatments, with T 6 Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% producing the highest curd weight (825.57 g), which was on par with T 5 (812.38 g), followed by T 7 (764.50 g) and the lowest curd weight was recorded in T 4 (Lignite 100%) with 268.85 g. The superior curd weight under T 6 can be attributed to improved nutrient supply and efficient physiological functioning under integrated nutrient management. The sustained availability of nutrients likely enhanced vegetative growth and photosynthetic capacity, leading to greater synthesis of assimilates. These photosynthates were effectively translocated towards the developing curd, acting as a strong sink thereby increasing curd size and weight. Additionally, improved root growth and nutrient uptake efficiency may have supported better partitioning of nutrients towards reproductive development. Enhanced biochemical activities, including carbohydrate metabolism and enzyme action, further contributed to curd formation. The combined influence of organic manures and biofertilizers also improves soil health and ensures a steady nutrient release throughout the growth period. These findings are in agreement with Thakur et al. (2018) [11] . Jeevamrutha 100% (500 l ha -1 ) 9.78 T 4 Lignite 100% (1 t ha -1 ) 9.02 T 5 Vermicompost 50% (2.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 11.16 T 6

Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 11.30 T 7 Jeevamrutha 50% (250 l ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 10.99 T 8

Lignite 50% (0.5 MT ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 9.51 T 9

Control -FYM (25 t ha -1 ) 10.13 SEm (±) 0.046 CD (P=0.05) 0.138

Longitudinal curd length showed considerable variation among the treatments, with T 6 Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% recording the maximum value (11.30 cm) which was statistically on par with T 5 (11.16 cm) followed by T 7 (10.99 cm). The minimum value was observed in T 4 (9.02 cm).

The enhanced curd length under T 6 can be attributed to improved source-sink dynamics and higher physiological efficiency under integrated nutrient management. The balanced and sustained nutrient supply likely promoted vigorous vegetative growth, leading to increased photosynthetic capacity and greater assimilate production. These assimilates were effectively mobilized and partitioned towards the developing curd, which acts as a strong sink organ, thereby contributing to increased curd elongation. Furthermore, improved root architecture and rhizospheric activity would have enhanced nutrient and water uptake, supporting continuous metabolic processes during curd development. In addition, the combined influence of organic manures and biofertilizers may have regulated endogenous growth substances and enzyme activities involved in cell division and elongation, leading to improved curd morphology. Enhanced carbohydrate metabolism, protein synthesis and energy transfer processes also contribute to the development of larger curd structures. The overall improvement in soil health, microbial population and nutrient cycling under integrated nutrient management further supports sustained growth and development. (Kachari et al., 2009) [4] . Vermicompost 50% (2.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 42.33 T6 Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 41.66 T7 Jeevamrutha 50% (250 l ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 43.00 T8 Lignite 50% (0.5 MT ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 46.66 T9 Control -FYM (25 t ha -1 ) 45.33 SEm (±) 0.354 CD (P=0.05)

The number of days to curd initiation varied significantly among the treatments, with T 6 (Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50%) recording the earliest curd initiation (41.66 days) which was statistically on par with T 5 (42.33 days) followed by T 7 (43.00 days). The maximum duration for curd initiation was observed in T₄ (Lignite 100%) with 47.00 days, respectively. The reduced number of days to curd initiation in T 6 may be attributed to improved nutrient dynamics and enhanced physiological efficiency under integrated nutrient management. The continuous and balanced nutrient supply likely promoted rapid vegetative growth and facilitated an earlier transition from the vegetative to reproductive phase. Improved root activity and nutrient uptake efficiency would have supported higher metabolic rates and efficient energy transfer required for curd initiation. In addition, better synthesis of growth regulators and enhanced enzymatic activity may have accelerated meristem differentiation, leading to early curd formation. Improved chlorophyll content and photosynthetic efficiency would have further supported the timely accumulation of assimilates required for initiation (Thadani et al., 2019) [12] . Vermicompost 50% (2.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 72.80 T6 Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 71.76 T7 Jeevamrutha 50% (250 l ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 73.66 T8 Lignite 50% (0.5 MT ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha [11] , who reported reduced crop duration under integrated nutrient management.

Total yield (t ha -1 ) Vermicompost 50% (2.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 32.77 T6 Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 33.12 T7 Jeevamrutha 50% (250 l ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% 27.64 T8 Lignite 50% (0.5 MT ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50% Total curd yield of cauliflower varied markedly among the treatments, with T 6 (Poultry manure 50% (7.5 t ha -1 ) + VAM (5 kg ha -1 ) + Azospirillum (2 kg ha -1 ) + PSB (5 kg ha -1 ) 50%) recording the highest yield of 33.12 t ha -1 , which was statistically on par with T 5 (32.77 t ha -1 ). The lowest yield was obtained in T 4 with 13.31 t ha -1 . The enhanced yield observed in T 6 can be attributed to improved nutrient availability, uptake efficiency and better source-sink relationships under integrated nutrient management. The balanced and sustained nutrient supply likely promoted vigorous vegetative growth, leading to increased photosynthetic capacity and higher assimilate production. These assimilates were efficiently partitioned and translocated towards the curd, which acts as a strong sink, thereby contributing to increased yield.

Improved root architecture and rhizospheric activity would have further facilitated efficient nutrient and water absorption, ensuring continuous growth and development. In addition, enhanced biochemical processes such as carbohydrate metabolism, protein synthesis, and enzyme activity along with improved chlorophyll content, may have contributed to higher productivity. The integration of organic manures with biofertilizers also improves soil physical properties, microbial diversity and nutrient cycling, thereby ensuring sustained nutrient release throughout the crop growth period. These combined effects result in improved curd development, size and weight, ultimately leading to higher total yield. Similar findings were reported by Thakur et al. (2018) and Sharma et al. (2021) [6, 11] .

Conclusion

The present study clearly demonstrated that integrated application of organic manures and biofertilizers significantly improved the growth and yield of cauliflower. Among the treatments, T 6 exhibited superior performance in terms of vegetative growth, curd characteristics and yield attributes across all parameters and was closely followed by T 5 . The enhanced performance of T 6 can be attributed to improved soilplant interactions, increased microbial activity and efficient nutrient cycling under integrated nutrient management. This combination ensured a balanced and sustained nutrient supply, enhanced root architecture and rhizospheric activity and improved nutrient use efficiency. Furthermore, the integration of organic inputs with beneficial microorganisms likely enhanced physiological and biochemical processes, including chlorophyll synthesis, enzyme activity and carbohydrate metabolism, leading to higher photosynthetic efficiency and assimilate production. The effective translocation and partitioning of assimilates towards the developing curd, acting as a strong sink, contributed to improved curd formation, size and quality.

Overall, the synergistic interaction between organic manures and biofertilizers created a favorable soil environment and optimized plant metabolic functions, resulting in enhanced productivity and crop performance under naturally ventilated polyhouse conditions.

References

1. Asokan R, Mohandas S, Nair KM. Biological control of plant diseases using biofertilizers. J Biol Control. 2000;14(2):85-90.
2. Bhatt R. Farm yard manure as a resource for integrated nutrient management. Pharma Innov J. 2023;12(7):15031506.
3. Bopcha R, Agarwal S. Role of farmyard manure in soil fertility and crop productivity. Int J Agric Sci. 2024;16(1):45-52.
4. Kachari S, Das R, Bora GC. Effect of Azospirillum on growth and yield of cauliflower. Hortic J. 2009;22(1):45-48.
5. Kalalbandi BM, Math KK, Patil MB. Effect of organic manures on soil properties and crop yield. Karnataka J Agric Sci. 2007;20(2):257-259.
6. Sharma R, Thakur P, Singh D. Effect of integrated nutrient management on growth, yield and quality of cauliflower. Himachal J Agric Res. 2021;47(1):23-29.
7. Singh B. Nutritional quality and health benefits of cole crops. Indian J Hortic. 1997;54(3):215-222.
8. Singh R, Kumar S, Yadav P. Effect of organic manure on growth, yield and quality of cabbage. Indian J Hortic. 2023;80(2):215-220.
9. Singh V, Kumar R, Singh R. Effect of integrated nutrient management on growth, yield and quality broccoli. Indian J Hortic. 2013;70(3):412-415.
10. Swarup V, Chatterjee SS. Origin and genetic improvement of Indian cauliflower. Econ Bot. 1972;26(4):381-393.
11. Thakur A, Sharma R, Singh S. Effect of integrated nutrient management on growth, yield, quality and economics of cauliflower. Veg Sci. 2018;45(2):220-224.
12. Thadani VN, Patel RK, Desai PM. Effect of PSB and compost on growth and yield of cauliflower. Int J Chem Stud. 2019;7(3):2100-2104.
13. Zbar L, Kaur P, Singh J. Effect of VAM and biofertilizers on growth and yield of cauliflower. Int J Curr Microbiol Appl Sci. 2021;10(5):145-152.