Responses to Water Strees of Sunflower (<I>Helianthus annuus</I> L.)
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Abstract
Growth and yield of Helianthus annuus cv. Hysun 33 was studied under withholding of water at various stages of plant development and irrigation frequencies (every 1, 2, 3 and 4 weeks) at the Faculty of Agriculture, Chiang Mai University during January - April 1987 on paddy soil (clay loam-sady clay loam).
Total dry matter LAI and seed yields were not affected by withholding water treatments when compared with weekly irrigation, but affected by irrigation frequencies. The mean value of seed yield from over all withholding water treatments was 3.37 t/ha. Seed yields and also total dry matter and LAI significantly decreased when irrigation interval increased. The most infrequent irrigation treatment reduced yield by 52%. The reduction in seed yield was due to decreasing in number of seed per capitulum and seed size. Seed oil content was significantly decreased when irrigation interval increased. The oil content of 42.1% was observed from the every 4 weeks irrigation treatment compared with 51.4% observed from the weekly irrigation one. Leaf water potential at predawn, late morning and midday throughout crop cycle are described.
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References
Cox, W.J. and G.D Jolliff. 1986. Growth and yield of sunflower and soybean under soil water deficits. Agron. J. 18: 226-230
Donald, C.M. 1962. In search of yield. J. Aust. Inst. Agric. Sci. September, 171-177.
Kandil, A. 1984. Sunflower head development as affected by irrigation intervals. Ann. Agric. Sci. 22: 3-13.
Kramer, P.J. 1983. Water relations of plants. (ed.) Academic Press Inc. New York.
Robinson, R.G. 1978. Production and culture. In J.F. Cater (ed.). Sunflower science and technology. Am. Soc. of Agron. crop. Sci. of Am., Soil Sci. Soc. of Am., Inc. Wisconsin.
Slatyer R.O. 1969 Physiological significance of internal water relation to crop yield. In J.D. Eastin, F.A. Haskins, C.Y. Sullivan, and C.H.M. Vabarjel. (ed). Physiological Aspects of crop yield. Am. Soc. of Agron., Crop Sci. Soc. of Am., Wisconsin. crop yield. Am. Soc. of Agron., Crop Sci. Soc. of Am., Wisconsin.
Sobrado, W.A. and Rawson. 1984. Leaf expansion as related to plant water availability in a wild and cultivated sunflower. Physiol. Plants, 60: 561-566.
Stegman, E.C. 1983. Corn and sunflower yield vs management of leaf xylem pressures. Transaction of Agric. 26: 1362-1368.
Stegman, E.C. and G.W. Lemert. 1981. Sunflower yield vs water deficit in major growth periods. Transactions of Agric. 24: 1533-1538.
