Tuberose, scientifically known as Agave amica (formerly Polianthes tuberosa) and popularly called rajanigandha, is a high-value tropical and sub tropical bulbous ornamental plant (Mazumder et al., 2022) valued for its highly fragrant white flowers. It belongs to the family Asparagaceae and was first described by Linnaeus (1753). Later morphological and molecular studies revealed that the genus Polianthes is closely related to Agave, leading to its reclassification (Bogler et al., 2006). Among its different types, Double tuberose is a type that is widely grown for its highly attractive and fragrant flowers. It blooms with multiple layers of petals, giving them a fuller and more ornamental appearance. It is popular in the floriculture industry due to its strong spikes, longer vase life and appealing aesthetic value.  The double varieties, such as Suvasini, Vaivab, Hyderabad Double, Calcutta Double and Pearl Double, are highly preferred for commercial uses. Many cultivars have been introduced while some are originated in India. Information pertaining to recommendations of the suitable double tuberose varieties for growth and floral parameters under local climatic scenario of odisha is meager. Suitability and adaptation of diversified tuberose genotypes under humid local climatic scenario of eastern coastal plains of Odisha are to be validated for their superior performance. This particular area is earmarked for its rich biodiversity and soil properties especially suitable for commercial cultivation of tuberose. Screening of high-yielding double tuberose varieties may enable the farmers to know the superiority over local cultivars and to grow newly released and hi-yielding cultivars for better productivity. However, weed infestation and competition with plants is a major limitation in tuberose cultivation, especially during the early growth stages when the crop grows slowly and cannot compete effectively. Plants compete with weeds for moisture, nutrients, space and light ultimately reducing plant growth, delaying flowering and lowering yield. This problem is severe in tropical and humid regions where weed growth is rapid. Mulching helps in regulating soil temperature, weed and insect infestation, moisture content including quality and productivity (Amare and Desta, 2021). Plastic mulch increases soil temperature and higher soil temperatures are beneficial for N mineralization and plant N absorption (Bijalwan et al., 2024). Black and infrared transmissible plastic mulch effectively suppresses weed growth, conserves soil moisture by minimizing evaporation consequently improving the overall crop yield (Bijalwan et al., 2025). Unfortunately, much less research so far has been done on the context of mulching especially in tuberose crop in this region as well as other locations of India to know the exact and extent of mulching efficacy. In this regard, the use of mulch can significantly modify the soil microclimate, offering better opportunities to enhance both the yield and quality of tuberose flowers under various local agro-climatic conditions. Keeping all these facts in view, the current experiment was conducted to access the performances of different double tuberose cultivars and the response of polythene mulching under humid agro climatic conditions of eastern coastal plains of Odisha.

The field experiment was executed at the Agricultural Research Station, Binjhagiri, Khordha, under the Faculty of Agricultural Sciences, Siksha ‘O’ Anusandhan (Deemed to be University), Bhubaneswar, from 4^th September 2022 to 30^th March 2025 for two consecutive years. The experimental site (Fig 1) is situated about 62.9 km from the shore of  Bay of Bengal at an elevation of 25.5 m above mean sea level and is geographically located at 20^o25′ N latitude and 85^o67′  E longitude, representing the central part of eastern coastal plains of Odisha. The experiment was conducted following factorial randomized block design (FRBD) with two factors-Mulching and Varieties with three replications. The mulching treatments included black polythene mulch (M₁) and no mulch as control (M₀). The varietal treatments comprised of seven double tuberose varieties: Calcutta Double (V₁), Pearl Double (V₂), Suvasini (V₃), BR-24(V₄), Vaivab (V₅), BR-19 (V₆) and Hyderabad Double (V₇). Black polythene mulch of 40 µ thickness used and uniform-sized tuberose bulbs (approx 2.5 cm dia) were planted, with each plot measuring 1.2×5 m. Planting material was procured from the Department of Floriculture and Landscaping, OUAT, Bhubaneswar, Odisha and the bulbs were planted in September of both the years, which corresponds to the Late Kharif and Pre Rabi planting season in Odisha. Standard recommended agronomic practices were followed throughout the crop period. Observations were recorded from five randomly selected plants in each plot for vegetative parameters at 135 and 180 DAP (Days after planting) and flowering parameters in winter, summer and rainy seasons in each year excluding flowering duration the spike which was collected only at the peak flowering time. Data were collected on plant height, number of leaves clump^-1, number of tillers clump^-1, leaf width, flowering duration of the Spike , rachis length, floret length, perianth tube length, weight of florets spike^-1, individual spike weight and weight of spikes clump^-1, weight of spikes plot^-1 and weight of the spikes  ha^-1. The yield data ha^-1 was computed by utilizing the yield figure of individual sub plot under each treatment under each replication. The data were statistically analyzed using analysis of variance (ANOVA) (Panse and sukhatme, 1967) and results were interpreted at the 5% level of significance.

Vegetative attributes
 
During both the observations of 135 DAP and 180 DAP, it was observed that mulching with black polythene (M₁) exhibited maximum plant height (45.01 cm and 49.80 cm), number of leaves clump^-1 (94.56 and 111.15) , number of tillers clump^-1 (22.30 and 30.60), width of leaves (2.07 cm  and 2.58 cm),  whereas non mulch (M₀) recorded with minimum plant height (38.55 cm and 44.49 cm), number of leaves clump^-1 (78.35 and 94.31), number of tillers clump^-1 (16.53 and 22.44), width of leaves(1.80 cm and 2.09 cm) throughout the experiment (Table 1 and Fig 2).




       
The variation in the mulching treatments might be due to mulching with black polythene modified the soil properties at a microclimate level prevailing an independent microclimatic conditions and worked as an insulating barrier which reduced evaporation and retained adequate moisture and nutrients, helped maintaining optimum soil temperature, controlled salinity and weeds resulting in better plant growth and other vegetative traits. Increased number of leaf as well as width can be correlated with higher photosynthetic efficiency and improved physiological status of the plant. The enhanced leaf expansion observed under mulched conditions may be ascribed to sustained soil moisture regimes and mitigation of abiotic stress factors. Polythene mulch, being relatively impermeable to gaseous diffusion, facilitates the accumulation of carbon dioxide beneath the mulch layer. The restricted escape of CO₂ except through planting apertures, generates a localized “chimney effect,” leading to elevated CO₂  concentration in the immediate vicinity of the plant canopy. This localized enrichment of carbon dioxide likely augments the rate of photosynthesis, thereby contributing to increased leaf expansion and width. Similar reports was also reported by Deka and Talukdar (2017) in Tuberose, Sarmah et al., (2014) in Gerbera, Kumar et al., (2010) in Rose, Chawla (2008) and Das and Mishra (2005) in Marigold and Arora et al., (2002) in carnation and Sanders (2001) in his studies in plastic mulches.
       
In view of varieties after 135 DAP and 180 DAP variety Calcutta double (V₁) recorded with maximum plant height i.e. 52.17cm and 57.89 cm respectively. Whereas BR-19 (V₆), observed the minimum value in the trend (28.71 cm and 36.21). In the parameters like number of leaves clump^-1 (101.03 and 118.76), number of tillers clump^-1 (31.31 and 41.71) and leaf width (2.17 cm and 2.63 cm), Vaivab (V₅) attained the highest value. In contrast, BR-24 (V₄) produced the lowest number of leaves clump^-1 (60.12 and 74.45), number of tillers clump^-1 (11.62 and 14.59) and BR-19 (V₆) registered with lowest leaf width of 1.48 cm and 2.13 cm respectively during both the observations (Table 1).
       
The differences among the genotypes found may be attributed to difference in genetic constitution and diverse origin of the cultivars which resulted in change in expression of phenotypic under specific geographic and agro-climatic conditions. Also the outcome results on most of the vegetative parameters rely on the environmental factors like, light intensity and relative humidity. Similar findings and trend was also obtained by Hasna and Manjusha (2021); Pal et al., (2017); Sateesha et al. (2011) and Ranchana et al. (2013) in tuberose varieties evaluation programme.
 
Flowering attributes
 
Flowering duration of a spike decides the field life of the particular spike, in that case mulching (M₁) performed well as it obtained maximum days of 20.94 days and minimum resulted with M₀ treatment i.e 17.94 days (Table 2). Mulching treatment (M₁) resulted in the maximum value in flowering traits like rachis length (36.04 cm, 36.86 cm and 44.12 cm), floret length (4.48 cm, 5.03 cm and 5.98 cm), perianth tube length (2.87 cm, 3.23 cm and 4.10 cm), individual spike weight (91.87 g, 96.52 g and 101.04 g), weight of florets spike^-1 (76.92 g, 79.67 g and 84.80 g) while the treatment with no mulch (M₀) registered with minimum values in rachis length (31.53 cm, 29.95 cm and 34.87 cm), floret length (4.16 cm, 4.76 cm and 5.65 cm), perianth tube length (2.59 cm, 2.95 cm  and 3.76 cm), individual spike weight (78.84 g, 80.34 g and 91.64 g), weight of florets spike^-1 (66.31 g, 66.09 g and 76.34 g)  respectively during all the three seasons.


       
These differences may be due to under mulch the movement and leaching of nutrients and moisture were reduced and utilization by bulb was increased, for that reason the plant successfully utilized adequate moisture and nutrients resulting in maximum field life or a longer flowering duration in the mulched environment. Similar findings are in close conformity with the reports of Koppad et al., (2022) in tuberose, Wagan et al., (2022) in marigold, Bohra et al., (2016) in rose. Improvement in flower quality traits like floret length, particularly by black polythene mulch is due to high moisture retention capacity and regulated temperature to the soil that led to vigorous growth as well as maximum flower size. Similar experimental evidence of maximum flower size were observed in black polythene mulch and non mulch produced smaller flower in Gerbera by Sarmah et al., (2014) and Iqbal et al. (2009).  The perianth tube length generally increases with floret length due to integrated floral development. Since the floret length was higher in mulching, the perianth tube length also found maximum in the mulching treatment, also parameters like individual weight of spike and weight of florets spike^-1 was recorded highest in black plastic mulch as black poly mulching provided better favourable environment condition for better floral traits. These results are in close conformity with various mulching and non mulching studies by Vaid et al., (2019) in tuberose and Das and Mishra (2005) in Marigold. 
       
Significant differences also found among the varieties tried during various periods of observations. The variety Suvasini (V₃) recorded with maximum in floral attributes like flowering duration of the spike (30.28 days) (Fig 3), Individual spike weight (115.33 g, 124.73 g and 129.62 g) and weight of florets per spike (101.34 g, 100.54 g and 104.98 g). Whereas the BR-24 (V₄) consistently registered with minimum value in flowering duration of the spike (11.89 days), individual spike weight (52.91 g, 59.69 g and 66.81 g) and weight of florets per spike (31.12 g, 39.60 g, 47.78 g) across all the seasons. Similarly the variety Vaivab (V₅) got the upper hand in terms of rachis length (51.40 cm, 51.70 cm and 55.95 cm), floret length (5.27, 5.83 cm and 6.78 cm) and perianth tube length (3.67 cm, 4.06 cm and 4.88 cm). In contrast, BR-24 (V₄) recorded the lowest values for floret length (3.12, 3.70, and 4.74 cm) and perianth tube length (1.60, 1.88, and 2.84 cm), whereas BR-19 (V₆) recorded the lowest rachis length (22.07, 22.04, and 28.41 cm), respectively (Table 2).


       
The wide variations in the varieties in terms of floral traits like flowering duration of the spike, rachis length and floret length may be due to genotypic variations that attributed to the various inherent characters along with genetic makeup among the varieties, they perform according to their genetically build up depending upon various agro-climatic and environmental conditions. Also the longer length of rachis may be attributed to wider inter-nodal spacing between floret pairs. Same trend and similar results was also obtained by Rao et al., (2015) and Shete et al., (2023) in tuberose. Same trend in which Suvasini(V₃) recorded highest flowering duration has been also obtained by Singh (2017) in tuberose. The perianth tube forms a substantial portion of the floret axis, any enhancement in overall floret size is likely accompanied by a corresponding increase in perianth tube length. This integrated growth pattern implies that genotypes exhibiting larger florets tends to have longer perianth tubes. In the present study, the maximum perianth tube length observed with variety Vaivab(V₅) was thus associated with the longer floret length in the variety Vaivab (V₅). The spike weight mostly depends on the various aspects of floral traits like length of spike, rachis, girth and weight of particular florets along with varietal characteristic diversity among the cultivars prevailing to various climatic factors. Due to the compactness of the petals of the floret, which awarded Suvasini (V₃) as the weightiest floret in the spike among the cultivars tried. The wide variations in these kind of floral traits detected because of genetic diversity in the varieties and climatic factors of the particular geographical location, which also decides the variation among the genotypes. Similar findings of genetically variation and environmental condition among the varieties was also reported by Kumar and Yadav (2005) in gladiolus and Pal et al. (2017); Ranchana et al. (2013) and Patil et al. (2009) in Tuberose evaluation programme in other locations of India. 
 
Yield and yield attributes
 
The data on yield traits described in Table 2 showed significant variation among the treatments. Yield attributes like Weight of Spikes clump^-1 (286.34g) (Fig 4), Weight of Spikes plot^-1 (13.74 kg) and Weight of Spikes ha^-1 (22.91 t) was found superior under black polythene mulch (M₁) as compared to no mulch (M₀) treatments. The higher yield in the mulch environment may be attributed to reduced weed competition, balanced soil temperature, reduced evapo-transpiration, enhanced water use efficiency, lower incidence of soil-borne pathogens and the breakdown of phyto-toxic substances as reported by Shilpa et al., (2025).



Among the varieties tried, Vaivab (V₅) recorded with maximum values of 473.79 g clump^-1 (Fig 5), 22.74 kg yield plot^-1 and (Table 2) and 37.90 tonn in Yield ha^-1 . Whereas BR-24 (V₄) recorded the lowest 104.64 g clump^-1 (Fig 5). 5.02 kg yield plot^-1  and  8.37 tonn ha^-1 . Yield of any particular variety depends on the yield potentially which is aligned with the genetic potentiality with respect to prevailing agro-climatic condition under varied environmental factors. The statement has close resemblance to the findings of Singh (2017) who also found out highest yield in variety Vaivab tried with some other varieties. These findings are also in accordance with the results reported by Ramachandrudu and Thangam (2009) in tuberose.

Vegetative parameters are largely influenced by environmental conditions and mulching with black polythene exhibited a significant effect on both vegetative growth and floral traits of tuberose. Among the different varieties evaluated, Vaivab(V₅) and Suvasini (V₃) exhibited superior performance in terms of most vegetative and flowering attributes. Since Quality and yield is the ultimate objective of crop production, it was observed to be highest in Vaivab (V₅) followed by Suvasini(V₃), particularly under black polythene mulch (M₁). The use of 40 µ black polythene mulch effectively modified the soil microclimate, resulting in a significant increase in all observed parameters. Therefore, it can be concluded that Vaivab (V₅) and Suvasini (V₃) are superior varieties in terms of both yield and quality and their performance can be further enhanced through the use of black polythene mulching under Eastern coastal plains of Odisha.

The present study was supported by Department of Floriculture and Landscaping, Faculty of agricultural Sciences, Siksha ‘O’ Anusandhan (Deemed to be University), Bhubaneswar , India.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.