Effect of calcium nitrate and PDKV micro-grade II on growth, yield and quality of gladiolus

Introduction

Gladiolus (Gladiolus grandiflorus L.), popularly known as the "Queen of Bulbous Flower Crops," is one of the most important commercial cut flowers in India. Its attractive spikes, wide colour range, long vase life, and excellent keeping quality make it highly desirable for bouquets, floral arrangements, and landscaping. With increasing domestic and export demand, gladiolus has emerged as a profitable floriculture crop contributing significantly to India's cut flower industry. The production of superior-quality spikes depends on balanced nutrient management. While macronutrients drive vegetative growth, calcium and micronutrients are crucial for enhancing spike strength, floret quality, corm development, and post-harvest longevity. Foliar application of calcium nitrate supplies readily available calcium and nitrate, improving cell wall stability, nutrient uptake, and delaying senescence. Similarly, micronutrients such as iron, zinc, boron, manganese, copper, and molybdenum are indispensable for chlorophyll synthesis, enzyme activation, photosynthesis, pollen germination, and protein metabolism. Deficiencies in these elements directly reduce growth, flowering, and yield. Considering the rising demand for premium gladiolus flowers, foliar nutrition offers an efficient approach to improve nutrient use efficiency and flower quality. The combined application of calcium nitrate and PDKV micro-grade II is expected to enhance growth, spike yield, corm production, and overall quality attributes. Therefore, the present investigation entitled "Effect of calcium nitrate and PDKV micro-grade II on growth, yield and quality of gladiolus" was undertaken to evaluate different concentrations and identify the most suitable combination for achieving superior crop performance.

Materials and Methods

The experiment was conducted during the winter season of 2025-26 at the Satpuda Botanic Garden, College of Agriculture, Nagpur, Maharashtra, to evaluate the effect of calcium nitrate and PDKV Micro-grade II on the growth, flowering, yield and quality of gladiolus (Gladiolus grandiflorus L.) cv. PDKV Satpuda Purple. The trial was laid out in a factorial randomized block design (FRBD) comprising sixteen treatment combinations with three replications. Uniform, healthy corms (4-5 cm diameter) were treated with 0.3% Captan before planting on ridges and furrows at a spacing of 45 cm × 15 cm. The recommended fertilizer dose of 300:200:200 kg N:P₂O₅: K₂O ha -1 was applied and foliar sprays of calcium nitrate (0, 0.5, 1.0 and 1.5%) and PDKV Micro-grade II (0, 0.5, 1.0 and 1.5%) were given twice at the four-leaf and six-leaf stages. Standard agronomic practices, including irrigation, weeding, earthing-up, staking and plant protection, were followed throughout the crop growth period. Five randomly selected plants from each plot were used to record observations on growth, flowering, spike quality, vase life, corm and cormel yield. Statistical analysis of the recorded data was carried out following the methodology proposed by Panse and Sukhatme (1967) [11] . [10] and Nagamani et al. (2017) [8] in gladiolus.

Results and Discussion

b. Flowering parameters

The [10] , Nagamani et al. (2017) [8] in gladiolus and Abood (2017) [2] in Tulipa sp.

c. Corm yield and quality parameters

The highest number of corms per plant (2.73) was recorded under 1.5% concentrations (C 4 ), at par with 1.0% (C 3 , 2.68).

Similarly, maximum cormels per plant were obtained with 1.5% calcium nitrate (C 4 , 21.17), statistically at par with 1.0% (C 3 , 21.03). The improvement in yield attributes is attributed to calcium and nitrogen promoting cell division, cell wall rigidity, biomass distribution, chlorophyll synthesis, and photosynthetic product accumulation. These processes strengthen source-sink relationships, enhance starch synthesis, and support daughter cormel formation.

Comparable results in gladiolus were reported by Qureshi et al. (2015) [12] , Reddy and Sarkar (2016) [13] , and Ahmad and Rab (2020) [3] .

Effect of PDKV micro-grade II a. Growth parameters

Maximum plant height (82.03 cm) was recorded under 1.5% concentration (M 4 ), followed by 1.0% concentration (M 3 , 77.00 cm). Leaf area was also highest in 1.5% concentration (M 4 , 106.73 cm²), statistically at par with M 3 i.e. 1.0% (104.10 cm²). The improvement in growth parameters may be attributed to zinc promoting tryptophan synthesis for auxin production and nitrogen metabolism, along with boron, calcium, and magnesium enhancing cell division, enlargement, and chlorophyll synthesis. Similar findings were reported by Abid Kamal et al. (2022) [1] and Harish et al. (2023) [5] in gladiolus.

b. Flowering parameter

The (2013) [14] , Katiyar et al. (2005) [7] , Fahad et al. (2014) [4] , Naik et al. (2015) [9] , Kashyap and Tikey (2022) [6] , and Harish et al. (2023) [5] in gladiolus.

c. Corm yield and quality parameters

The highest number of corms per plant (2.78) was recorded under 1.5% concentration (M 4 ), followed by 1.0% (M 3 , 2.65). Similarly, maximum cormels per plant were obtained with M 4 i.e. 1.5% concentration (21.33), statistically at par with M 3 i.e. 1.0% concentration (20.70). The observed increase in yield attributes may be attributed to adequate micronutrient supply through foliar application. Zinc plays a key role in enzyme activity, auxin and cytokinin synthesis, and balancing phosphorus and potassium uptake. In association with other micronutrients, zinc improves chlorophyll function, carbohydrate partitioning, and dry matter translocation towards corm and cormel development. These findings were in line with Singh et al. (2012) [15] , Fahad et al. (2014) [4] , and Kashyap and Tikey (2022) [6] .

Interaction effect

The interaction between calcium nitrate and PDKV micrograde II levels was significant for growth and quality traits in gladiolus ( [7] , supporting the present findings.

Conclusion

From the present experimental trial, it is concluded that the maximum vegetative growth, flower yield, quality parameters and corm attributes were recorded under 1.5% concentration of calcium nitrate and 1.5% concentration of PDKV micro-grade II. The treatment combination of 1.0% calcium nitrate + 1.5% PDKV micro-grade II (C 3 M 4 ) was found to be superior in respect plant height, spike length and number of florets spike -1 .

References

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