Growth and Development of Irrigated Sunflower in the Texas High Plains¹

Abstract

Sunflower (Helianthus annuus L.) is widely adapted in the USA. In the southern Great Plains, it has been planted from March to August, but time of planting affected its growth, yield, and quality. Objectives of this study, conducted on Pullman clay loam (Torrertic Paleustolls), were to determine the effect of planting dates and associated environmental factors on sunflower growth, development, yield, quality, and water use. A better understanding of these effects could lead to improved management of this crop. The sunflower was planted from late March to late July in 1980 and 1981. For each planting, sunflower growth, development, yield, and quality were determined and related to environmental factors by simple correlation and multiple regression analyses. Sunflower planted from early April to early June yielded more than earlier‐ or later‐planted sunflower. Values for most other sunflower variables either increased or decreased progressively from the first to the last planting. Early planted sunflower developed slower and used more water than later‐planted sunflower. Planting after early June also resulted in low water use efficiencies because of lower yields. Consequently, early and late plantings are not recommended because they resulted in lower water use efficiency than sunflower planted from April to early June. Oil concentration of seed decreased with later plantings, which resulted in lower total oil production. Based on this study, sunflower in the Texas High Plains should be planted from about mid‐April to early June to use water efficiently and to obtain favorable yields of seed having a high oil concentration.

Yield and quality response of autumn-planted sunflower (Helianthus annuus L.) to sowing dates and planting patterns

“…In both years there was a progressive decline in oleic acid content with each delay in sowing date from D 1 to D 4 . Our study confirmed the findings of Unger (1986) and Ahmad and Hassan (2000), who conducted trials on different sunflower varieties in the Texas High Plains and North West Region of India, respectively. Both studies report that sunflower maturation under higher temperatures generally result in a higher oleic acid concentration in the seed oil.…”

“…Also, sowing date may influence fatty acid oil composition, likely by modifying ontogenesis. Unger (1986) and Cilardi et al (1990) observed a decrease in oleic acid concentration and conversely an increase in linoleic acid as seeding date was delayed while Robertson and Green (1981) found the lowest oleic acid content with late planting. In short, different sowing times might expose the crop to different environmental conditions during grain filling and oil synthesis, resulting in a possible alteration in yield and quality attributes (Connor and Sadras 1992).…”

Effect of water stress on yield and evapotranspiration of sunflower

“…Sunflower is capable of enduring drought but its yield will be lower in that case, because the plants are forced to take up less available forms of water from the soil. Sunflower is the most susceptible to soil water deficiency at flowering, fertilization and grain fill, whereas at the start and end of the growing period the sensitivity is not so evident (Jana et al, 1982;Unger, 1986;Stone et al, 1996;Erdem and Delibas, 2002). The driest months in Vojvodina are July and August, when only 15-20% of the sunflower's potential evapotranspiration (ETP) minimum of 100 mm are provided (Milić, 2008).…”

Effects of irrigation water quantities and seasonal variation on oil content and fatty acid composition of sunflower (Helianthus annuus L.)

“…Generally, the winter oil percentage was greater than that of the summer. 12,13 Higher temperatures during the summer season resulted in higher oleic acid concentration compared with the winter season and the reverse was true for linoleic acid ( Table 2). 3,10 As growth and development advanced, the plants may acclimatize to the alternation of soil moisture deficit and its relief for some time by water application, which might not affect the oil content or may be late water stress on treatments that had sufficient water in the early season, may account for lower oil concentration on the wet treatments.…”