INFLUENCE OF INCREASED SOURCE SIZE ON SEED SET AND PRODUCTIVITY IN SUNFLOWER (Helianthus annuus L.)

M. GAYITHRI¹, T.K. NAGARATHNA²*, H.G. PRAVEEN^3
1AICRP on Sunflower, University of Agricultural Sciences, GKVK, Bangalore, 560065, India
²AICRP on Sunflower, University of Agricultural Sciences, GKVK, Bangalore, 560065, India
³AICRP on Sunflower, University of Agricultural Sciences, GKVK, Bangalore, 560065, India
* Corresponding Author : nagarathnavijay3033@gmail.com

Received : 15-02-2017     Accepted : 05-03-2017     Published : 12-03-2017
Volume : 9     Issue : 12       Pages : 4045 - 4049
Int J Agr Sci 9.12 (2017):4045-4049

Keywords : Plant growth hormones, Nitrogen, Plant density, Leaf area duration, Harvest index, Productivity
Conflict of Interest : None declared
Acknowledgements/Funding : None declared
Author Contribution : None declared

The study was to increase the source size per unit land area by manipulating plant density (spacing) and nutrient level (mainly nitrogen). The crop was grown with different levels of nitrogen (50 %, 100 % and 200 %) in combination with two different spacing (60 x 30cm2 and 45 x 30cm2) and growth regulator mixture comprising 20 ppm NAA, 10 ppm GA and 20 ppm BA was imposed. Effect of defoliation in two different spacing was also studied. With wider spacing, number of achenes and 100 achene weight per head were higher due to less plant population that produced significantly bold grains which reduced the competition between the plants and also allowed more light interception and availability of nutrients. Among all the treatments, the plants treated with 200 % N along with growth regulator mixture increased absolute growth rate (AGR), seed yield, total dry matter (TDM) and oil content under both plant densities. This treatment enhanced leaf area duration by 15.7%, seed yield was reduced by 32%, due to lesser number of plants/m2. There was no significant difference between the seasons and also between different plant densities in seed yield per plant. In the same treatment, similar observations were recorded for TDM through seed yield/m2 which was more in 60 x 30 cm2 spacing. Whereas biomass/m2 was more in 45 x 30 cm2 spacing up to 30 per cent. Seed yield and TDM were high in rabi compared to kharif. The overall conclusion from this study is, increasing source size by applying 200% N combined with growth regulator mixture by maintaining recommended plant density and productivity can be increased up to 10-15 per cent.

1. Tisdale S.L., Nelson W.L., Beaton J.D. and Havlin J.L. (2003) Soil Fertility and Fertilizers. (5th edition), Prentice-Hall of India. Prt Ltd. New Delhi.
2. Karadogan T. and Akgun I. (2009) Helia., 32(50), 123-134.
3. Gomez K.A. and Gomez A.A. (1984) An International Rice Research Institute Book, A Wiley-Interscience, John-Wiley and Sons Inc. New York, USA.
4. Ozer H., Polat T. and Ozturk E., (2004) Plant soil environment, 50(5), 205–211.
5. Hussein M.A., El-Hattab A.H. and Ahmad A.K. (1980) Journal of Agronomy and Crop Science, 149, 148-156.
6. Srivastava G.C. and Goswami B.K. (1988) Journal of Agronomy and Crop Science, 164(1), 23-29.
7. Johnston A.M., D. Tanaka, P. Miller, S. Brandt, D. Nielsen, P. Lafond and N.R. Riveland (2002) Agronomy Journal, 94, 231–240.
8. Jahangir A. A., Mondal R. K., Katrun Nada, Sadia Afroze R. and Hakim M.A. (2006) Bangladesh Journal on Science and Research, 41(1-2), 33-40.
9. Chetti M.B. and Shirohi G.S. (1995) J. Maharashtra Agril. Univ., 20, 85-87.
10. Alimohammadi R. and Azizov I. (2011) Internat. J. of Agri. Science., 1(7), 316-316.
11. Al-Thabet S.S. (2006) J. King Saud Univ., Agric. Sci., 19(1), 1-11.
12. Kene H. K., Charjan Y. D. (1998) P. K. V. Res. J., 22(1), 139-140.
13. Naganagoud A., Dineshkumar M., and Yelshetty S. (1996) J. Mahara. Agric. Univ., 21(1), 151-152.
14. Muro J., Irigoyen I., Milition A. F. and Lamsfus C. (2001) Agron. J., 93, 634-637.
15. Schneiter A., Jones M. and Hammond J.J. (1987) Agron. J., 79, 431-434.
16. Johnson J.R. (1972) Argon. J., 64, 688-689.