Introduction
Researchers (Hatano and Asakawa, 1964; Khan, 1977; Nagao and Furutani, 1986; Bhattacharya, 1991; Supari et al., 1993) with decades of their understanding emphasized the need for exogenous application of growth stimulants for improving the germination and vigour status of seeds (Kumaran et al., 1993) as the growth and development of plants are under the control of endogenous level of growth regulating substances within the seed (Pandey and Sinha, 1995). Researchers recommend various growth regulators, inorganic and organic nutrients to invigourate the seeds of agricultural, which vary with their responses, depending on species and the initial quality of the seed lot. In the present study, evaluation were made on Jatropha curcas, the emerging biodiesel crop of the future on standardization of a cost effective pre-sowing seed treatment for production of quality seedling at nursery.

1 Result and Discussion
Nutrients are the other alternatives to growth regulators as they are cost effective and the lethality rate will be lesser at supra optimal conditions. In addition they are also easily available than the growth regulator. The study was formulated to fortify the seeds with micro and macro nutrients in the form of different compounds in two different concentrations of 0.5% and 1% with the soaking durations of 16 h adopting the seed to solution ratio of 1:1 revealed that among the nutrients, seeds fortified with 1% K₂SO₄ enhanced the seed and seedling quality characters at controlled room condition (Table 1) and it was followed by 0.5% KH₂PO₄. The hike due to the soaking treatment with 0.5% K₂SO₄ for 16 h was observed to be 44%, 32.8%, 15.3%, 25% and 54.9% over control seeds, respectively for seedling percent, root length, shoot length, dry matter production and vigour index.
 

Table 1 Influence of inorganic fortification treatment on Jatropha curcas seeds with different concentrations under controlled germination room condition

From the Table 2, the results shows that same as in controlled condition the Jatropha seeds fortified with 0.5% K₂SO₄ were improved the seed and seedling quality characteristics viz., 55%, 24.4%, 48.8%, 24.1% and 69.4% over the control seeds, respectively for seedling percent, root length, shoot length, dry matter production and vigour index. Followed by KNO₃, KH₂PO₄ and ZnSO₄ (0.5%) enhanced the seed and seedling quality characters. Among the treatments, 1% Thiourea, MgSO4 and Na2HPO4 was found to reduce the seed germination as 18% and 31.8% respectively than the control due to the toxic effect on physiological and biochemical processes within the cell (Swartz, 1941). 

Table 2 Influence of inorganic fortification treatment on Jatropha curcas seeds with different concentrations under nursery condition

The increase in seedling per cent obtained with 0.5% K₂SO₄ for 16 h might be due to the action of potash and sulphur which, acted as invigourative agents that maintained a state of swelling on hydration, which would have congenial for the development of plasma colloids and further seedling development (Kamfer and Zehlar, 1967). Sulphur in K₂SO₄ also increased the levels of vitamins, biotins and thiamin and its coenzymes in seeds and enhanced the growth rate of seedling (Renugadevi et al. 2008). 

The influence of the evaluated nutrients and two different concentrations with 16 h durations of soaking were both the positive and negative in enhancing the seedling quality characteristics of Jatropha. Among the nutrients, depending on the response with concentration, the nutrients viz., KNO₃, K₂SO₄, KH₂PO₄, ZnSO₄, MnSO₄ and FeSO₄ (0.5%) at 16 h soaking were better compared to control seeds which, might be due to the beneficial action of various chemicals (Rattan and Goswami, 2003) in improving the physiological function as below. However, the seed quality characters were found to be invigourative even with simple water soaking compared to the control.

Kumaran et al. (1996) in neem also suggested that soaking of seeds in 2% KH₂PO₄ for 24 h improved the germination and vigour of seeds. However, in Jatropha, Kathiravan (2004) reported that 1% ZnSO₄ increased the survival percent of seed at nursery by 16% and in Bambusa bamboo, Krishnaveni et al. (2010) found that one per cent KNO₃ increased 29% seed germination than controlled seeds at nursery condition. In the present study with Jatropha seeds fortified with 0.5% K₂SO₄ for sixteen hours in equal volume found to have invigorative effect on the seed that resulted in production of quality seedling and hence could be advocated as a pre-sowing nursery management technique for production of Jatropha seedling. Similar study has also been reported by Masilamani and Dharmalingam (1995), Singh et al. (1998), Gopikumar et al. (1991), Palani et al. (1996), Agboola (2003), Renugadevi et al. (2008) and Selvakumari et al. (2007), on Grevillea robusta, Commiphora weightii, Cassia fistula, Albizzia lebbeck, Ceiba pentandra, Cyamopsis tetragonoloba and Callistephus chinensis respectively.

2 Conclusion
Thus the present study on seed fortification with inorganic nutrients revealed that seed soaking with 0.5% K₂SO₄ enhanced the seed germination by 44% and 55% than control in both controlled germination room and nursery bed respectively. Hence it could be advocated as a pre-sowing nursery management technique for production of Jatropha seedling. However, when increasing concentration of some inorganic nutrients such as thiourea, MgSO₄ and Na₂HPO₄ that reduced the seed germination.

3 Materials and Method
3.1 Seed source
The bulk seeds obtained from Coimbatore district (11°1’6 N 76°58’21 E), Tamil Nadu, India. Well stored Jatropha seeds were stored in ambient condition in cloth bag in normal room temperature for six months that seeds were used for this seed enhancement study.

3.2 Experimentation and materials
Jatropha seeds were fortified with inorganic nutrients viz., Thiourea, KNO₃ (Potassium Nitrate), K₂SO₄ (Potassium Sulphate), KH₂PO₄, (Potassium dihydrogen phosphate), Na₂HPO₄ (Disodium hydrogen phosphate), ZnSO₄ (Zinc Sulphate), FeSO₄ (Ferrous Sulphate), MgSO₄ (Megnisium sulphate), MnSO₄ (Manganese sulphate), and NaCl (Sodium chloride) in two concentrations viz., 0.5% and 1%. The seeds were removed at 16 h soaking duration in equal volume and were dried back to their original moisture content of 9% and seeds were sown in 100 seeds of 4 replicates in sand media under germination room condition (25℃, 95 ± 2% RH) as well as raised bed nursery along with water soaked and control seeds.

3.3 Observations
After one month they were evaluated for their seed quality characters viz., seedling per cent (%) i.e. number of normal /healthy seedlings produced to the total seeds sown, root length (cm), shoot length (cm) and dry matter production /10 seedlings (g). The vigour index values were computed adopting the formula of Germination (%) × Total seedling length (cm) as per Abdul-Baki and Anderson (1973) as these values could express the seed quality characters inclusive of seed germination and seedling vigour.

3.4 Statistical analysis
The data gathered were statistically scrutinized as per Panse and Sukhathme, (1985) under F test of significance for understanding the level of significance among the seed treatment and seed quality characters.

Acknowledgement
The authors are thankful to the National Oilseeds and Vegetable Oils Development (NOVOD) Board, Gurgaon, Haryana (India) for providing research grant for the project.

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