Original Research Effect of Different Nutrient Applications on Seed Germination of African Marigold ( Tagetes erecta L.)

Global warming and change in climate triggers to combat the feeding need of the population, seed represent the basic requirement for a quality plant material. The present research was carried out in 2021 at Horticulture Garden Sindh Agriculture University Tandojam to assess the effect of different nutrients application on seed germination of marigold (Tagetes erecta L.) The present study was conducted to evaluate effect of different nutrients application on seed germination of marigold ( Tagetes erecta L.) Therefore, the seeds of marigold were emersed in 1% solution of ammonium sulphate ((NH 4 ) 2 SO 4 ), boric acid (H 3 BO 3 ), and potassium nitrate (KNO 3 ) to get the accuracy of seed germination. Results revealed that maximum seed germination percentage (85.27%), germination rate of index (83.84), coefficient of velocity germination (2.96), mean germination time (12.73), mean germination rate (44.45), germination index (1.55), final germination percentage (1.23%), first day of germination percentage (74.61), last day of germination (13.23) and time spread germination (14.40) was observed when 1% potassium nitrate was applied and followed by boric acid {seed germination percentage (59.20%), germination rate of index (54.93), coefficient of velocity germination (24.13), mean germination time (8.84), mean germination rate (36.20), germination index (1.04), final germination percentage (3.10), first day of germination percentage (74.36), last day of germination (15.16) and time spread germination (11.90)} while the minimum results were recorded in control with mineral water seed germination percentage (18.28%), germination rate of index (3.26), coefficient of velocity germination (0.73), mean germination time (2.70), mean germination rate (11.00), germination index (0.32), final germination percentage (10.43), first day of germination percentage (37.35), last day of germination (15.06) and time spread germination (4.83) and Pearson correlation ( r ) exhibited a strong positive correlation observed in MGR with CVG=0.4482, FDP=0.3696, G=0.4554, GI=0.4551, GP=0.4499 and GRI=0.3766-). This study showed that seed is directly related with germination and germination-related traits. It has a great positive impact on crop yield.


INTRODUCTION
Marigold (Tagetes erecta L.) belongs to the family Asteraceae. It is an erect annual plant that can grow up to 180 cm tall but is more likely to be around 35 cm, probably native to Mexico, America. This plant produces yellow to orange flowers and germinates within 5-8 days from seeds at 21 to 24 °C (Kadam et al., 2013).
Seeds is one of the most important factors in existence and proliferation of plants and its quality define plants productivity in agricultural ecosystems. Thus, characterization of decreasing factors of seed quality and applying methods to optimize these characteristics are management strategies that can improve productivity of crops. Germination and seedling establishment are critical stages in the plant life cycle. In crop production, stand establishment determines plant density, uniformity, and management options (Cheng et al., 1999).
Strategies for improving the growth and development of crop species have been investigated for many years. Seed priming is a pre-sowing strategy for influencing seedling development by modulating pre-germination metabolic activity prior to emergence of the radicle and generally enhances germination rate and plant performance (Ashraf et al., 2001;Taylor et al., 1990). During priming, seeds are partially hydrated so that pregermination metabolic activities proceed, while radicle protrusion is prevented, then are dried back to the original moisture level (McDonald, 2000). Various priming treatments have been employed to increase the speed and synchrony of seed germination (Bradford, 1986). Common priming techniques include comprising (soaking seeds in osmotic solutions such as polyethylene glycol), halopriming (soaking seeds in salt solutions) and hydropriming (soaking seeds in water). Comprising contributes to significant improvement in seed germination and seedling growth in different plant species. Seeds of tomato and asparagus (Asparagus offcinalis) osmo conditioned in -0.8 MPa PEG-8000 showed increased germination under saline media (Pill, 1991). Osmotic priming to improve seed germination performance may also enhance general crop performance. Osmo conditioning of Italian ryegrass (Lolium multiflorum) and sorghum (Sorghum bicolor) seeds with 20 % PEG-8000 for 2 d at 10 °C increased the percentage of germination formation of seedling and production of dry matter under conditions of water stress, water logging, cold stress, and saline conditions (Hur, 1991).
In the present scenario, marigold is not only important for social, political, historical occasions, birthdays, wedding and marriage greetings, and religious offerings but are also used in the pharmaceutical industry to cure diseases (Manisha et al., 2013). The extract of the plant has been used against rheumatism, colds and bronchitis, earache, leaves, florets, and decoction used as a diuretic, treatment of eye diseases, skin wash, ulcers, abdominal pain, muscular, bone pain and, ulcers due to, enriched antimalarial, antioxidant, and carminative properties (Manisha et al., 2013;Dixit et al., 2013;Khulbe et al., 2013;Rasoanaivo et al., 1992). Besides medicinal importance, it is also used as a flavouring in food, a popular dye plant, effective repellent i.e., mosquitocidal, insecticidal, and caterpillar repellent (Marcia et al., 2011;Nikkon et al., 2011;Patrick et al., 2011). Seed quality has always been an issue in present day for a quality plant material, and to get vigorous seedlings for high yield per unit area, therefore, to get precise and healthy seedlings, seed quality must be characterized and analysed through various seed quality parameters to confirm its viability and germinating capacity. Therefore, the present study was conducted to analyse the seed germination of as affected by through various quality dimensions.

Imbibition treatment
In present study, seeds of marigold were purchased from The SAU Nursery at Sindh Agriculture University, imbibed in 1% solution of potassium nitrate (KNO3), boric acid (H3BO3), ammonium sulphate ((NH4)2SO4), and (mineral water (H2O). The 36 seeds in each treatment were immersed into the solution for 24 hours, the seedling tray filled with canal silt used for seed sowing. Date of seed sowing was noted and, seed quality attributes were also recorded.

Seed quality based on imbibition
Good quality seed is the feature of good plant yield, therefore, a thorough understanding about seed quality attributes seed germination percentage (SGP), germination rate of index (GRI), coefficient of velocity germination (CVG), mean germination time (MGT), mean germination rate (MGR), germination index (GI), final germination percentage (FGP), first day of germination percentage (FDG), last day of germination (LDG) and time spread germination (TSG) was observed to have a good seed quality. Further, formulas were applied to check its quality index Seed germination represents the base for seed viability and vitality (Table 1).

Statistical analysis
The data were statistically analysed using computer software Statistix 8.1. Significant differences were determined by using ANOVA in combination with the least significance difference (LSD) test. The significance of differences was evaluated at p<0.05. Tables and figures report the means and standard errors means are based on the three replicates per treatment. The Pearson correlation coefficients were used for the dependence between the parameters.

Seed germination percentage
The SGP showed a statistically signification results (Table 2), for all the imbibition treatments. Maximum germination was observed in seeds imbibed with 1% potassium nitrate (85.27%), followed by imbibition in boric acid (59.20%). Whereas less seed germination (18.27%) was noted in seeds imbibed only in mineral water (pH 7.0).

Germination rate of index
The GRI showed a statistically signification (p<0.05) results (Table 2), for all the imbibition treatments, Maximum germination rate of index was observed in seed imbibed with 1% potassium nitrate (83.84), followed by imbibition in ammonium sulphate (4.37). Whereas less germination rate of index (3.26) was noted in seeds imbibed in mineral water (pH 7.0).

Coefficient of velocity germination
The CVG showed a statistically signification results (Table 2), for all the imbibition treatments. Maximum coefficient of velocity germination was observed in seed imbibed with 1% potassium nitrate (2.96), followed by imbibition in boric acid (1.22) Whereas, less coefficient of velocity germination (0.75) was observed in seeds imbibed in mineral water (pH 7.0).

Mean germination time
The MGT showed a statistically signification results (Table 3), for all the imbibition treatments, Maximum mean germination time was observed in seed imbibed with 1% potassium nitrate (12.73), followed by boric acid (8.84). Whereas less mean germination time (2.70) was noted in seeds imbibed in mineral water (pH 7.0).

Mean germination rate
The MGR showed a statistically signification results (Table 3), for all the imbibition treatments, Maximum mean germination rate was observed in seed imbibed with 1% potassium nitrate (44.45), followed by boric acid (36.20). Whereas less mean germination rate (11.00) was noted in seeds imbibed in mineral water (pH 7.0).

Germination index
The GI showed a statistically signification results (Table 3), for all the imbibition treatments, Maximum germination index was observed in seed imbibed with 1% potassium nitrate (1.55), followed by boric acid (1.04). Whereas less germination index (0.32) was noted in seeds imbibed in mineral water (pH 7.0).

Final germination percentage
The FGP showed a statistically signification results (Table 4), for all the imbibition treatments, Maximum germination index was observed in seed imbibed with Control (10.43), followed by ammonium sulphate (4.10). Whereas less final germination percentage (1.32) was noted in seeds imbibed in mineral water (pH 7.0).

First day of germination
The FDG percentage showed a statistically signification results (Table 4), for all the imbibition treatments, Maximum first day of germination was observed in seed imbibed with potassium nitrate (740.61), followed by boric acid (740.36). Whereas less first day of germination (370.14) was noted in seeds imbibed in mineral water (pH 7.0).

Last day of germination
The LDG showed a statistically signification results (Table 4), for   all the imbibition treatments, Maximum last day of germination was observed in seed imbibed with boric acid (15.16), followed by control (15.06). Whereas less last day of germination (13.23) was noted in seeds imbibed in mineral water (pH 7.0).

Time spread germination
The TSG showed a statistically signification results (Table 4), for all the imbibition treatments, Maximum time spread germination was observed in seed imbibed with potassium nitrate (14.40), followed by boric acid (11.90). Whereas less time spread germination (4.83) was noted in seeds imbibed in mineral water (pH 7.0).

Pearson correlation coefficients
Correlation depicts a very deep insights into various positive and negative relationship among various parameters related to seed germination viability and vigour characteristics ( Table 5)

DISCUSSION
The discussion revolves around the seed quality of the marigold to have an extraordinary result by confirming its viability and germination power through germination metamorphosis techniques. The imbibition treatment on seeds were given to have a significant and beneficial result, in this method seeds were imbibed in different solutions and were subsequently tested using ANOVA with combined LSD test, at the end a positive change was observed in germination, germination rate index, coefficient of velocity germination, mean germination time, mean germination rate, germination index, final germination percentage, first day of germination, last day of germination and time spread germination. Which were further analysed by the before and after treatment results. Treatment of seeds with potassium nitrate and boron, had a beneficial effect on seed germination in laboratory conditions. The beneficial effect of seeds on the appearance of seedlings is consistent with the ideas of farmers about their effects on some other medicinal plants, such as cumin and pot marigold (Calendula officinalis L.). Tabrizan KNO3 + B seed priming in this study resulted in an overall germination of 98 %. In station trigger experiments, Harris et al. (1999) reported that soaking seeds in the primer solution for 12 hours reduced germination time by about 50 %. Concentrations above 1.5% NO3 and 1% B in initial solutions adversely affected germination. Ajouri et al. (2004), similarly studying the effects of seed priming on germination, showed that concentrations greater than 0.04 m of boric acid significantly reduced the germination rate of barley. Low germination was also recorded during the processing of sweet pepper when higher doses of micronutrients were used in seed preparation (Diniz et al., 2009). Tabrizian and Osarkh (2007) emphasized the importance of seedling power for creating a rapid vector and early growth of medicinal plants to compete for water, light and nutrients. In this study, it was observed that priming of Face 4 and 3PO3 seeds led to a higher dill SPF. Radpoor and Rimaz (2007), in their study of the preparation of fennel seeds with a solution of iron, molybdenum and boron, came to the same conclusion. In addition, Louzada and Vieira (2005) confirmed that the application of very high doses of micronutrients to bean seeds due to their toxic effects led to an increase in the number of abnormal seedlings and death. Significant differences were observed in dry matter accumulation and sphagnum of the red periwinkle (Catharanthus roseus L.) between primed and nonprimed seeds (Kartikian et al., 2007).

CONCLUSION
The seeds imbibed in 1 % KNO3 induced maximum seed-related attributes as compared to other imbibition treatments. The imbibition really triggered seed germination rapidly and enhanced other seed germination related attributes. The seed germination metamorphic are directly related to seed vigour. The imbibition was directly in correlation to seed improving parameters except final days to germination.

Declaration of competing interests
The authors declare that they have no known competing financial interests or personal relationships that seem to affect the work reported in this article. We declare that we have no human participants, human data, or human tissues.