Salinity Effects on Four Sunflower Hybrids

Autor: L. E. Francois
Rok vydání: 1996
Předmět:
Zdroj: Agronomy Journal. 88:215-219
ISSN: 1435-0645
0002-1962
DOI: 10.2134/agronj1996.00021962008800020016x
Popis: Sunflower (Helianthus annuus L.) is becoming an increasingly important source of edible vegetable oil throughout the world because of its high polyunsaturated fatty acid content and no cholesterol. The increasing demand for this oil may promote increased hectarage of sunflower in the western USA, where some soils are saline or have the potential to become so. Since there is little information concerning the response of sunflower grown under saline conditions, a 2-yr field plot study was conducted. Six salinity treatments were imposed on a Holtville silty clay (clayey over loamy, montmorillonitic [calcareous], hyperthermic Typic Torrifluvent) by irrigating with Colorado River water artificially salinized with NaCl and CaCl2 (1:l by weight). Electrical conductivities of the irrigation waters both years were 1.4 (control), 2.0, 3.0, 4.0, 6.0, and 80 dS m-‘. Seed yield and oil content of the seed were measured. Relative seed yield of four hybrids was unaffected by soil salinity up to 4.8 dS m-’ (electrical conductivity of the saturation extract, EC,). Each unit increase in salinity above 48 dS m-t reduced yield by 5.0%. These results indicate that sunflower is appropriately classified as moderately tolerant to salinity. Yield reduction was attributed primarily to a reduction in seeds per head. Oil concentration in the seed was relatively unaffected by increased soil salinity up to 10.2 dS m-‘. Sunflower appears to be well adapted for growth under moderately saline soil conditions. S UNFLOWER (Helianthus annuus L.), a New World plant, has been developed into a valuable source of edible oil and meal. In 1992, world production of sunflower oil was about 7.8 million tonnes. As an edible vegetable oil, only soybean [Glycine max (L.) Merr.] and rapeseedcanola (Brassica napus L. and B. campestris L.) oil production exceeded that of sunflower (USDA, 1993). In the USA, about 839000 ha of sunflower were harvested in 1992, with oilseed hybrids constituting about 88% of the harvest and nonoilseed hybrids making up the remaining 12%. Most production in the USA is in Minnesota, North Dakota, South Dakota, and Kansas (USDA, 1993). However, with the increasing popularity of edible vegetable oils that, like sunflower, contain high percentages of polyunsaturated fatty acids and low cholesterol, the potential
Databáze: OpenAIRE
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