Sunflower Cultivar Performance as Influenced by Soil Water and Plant Population¹

Abstract

Information on the yield performance of sunflower (Helianthus annuus L.) as related to a range of soil water potential in the near‐optimum range has not previously been reported. Previous studies of sunflower plant population density effects on yield have lacked agreement. In this study three sunflower cultivars (‘Peredovic’, ‘894’, and ‘Northrup King 212’) were tested for response to soil water potential at Oakes, North Dakota and for response to population density at Carrington, North Dakota (irrigated) and Fargo, North Dakota (dryland). Yield was higher if the soil water potential in the root zone, as measured by commercial tensiometers, was limited to values of ‐20 cbar and ‐40 cbar and was lowered if the root zone water potential was allowed to drop to ‐75 cbar. There was no significant difference in seed yield between populations at thinning of 49,400, 59,300, and 69,200 plants/ha. A comparison of harvest methods at Oakes indicated that a number‐of‐heads harvest method increased yield estimates by 20% compared to an area harvest method. This comparison also showed that the harvest method used did make a significant difference in yield results obtained from the water potential experiment. It is hypothesized that harvest method may have influenced previous sunflower population density experiments similarly.

Response of sunflower (Helianthus annuus) to planting pattern and population density in a desert climate

“…In contrast, however, Vijayalakshmi et al (1975) found no yield differences at populations between 25000 and 75000 plants/ha in Saskatchewan, Canada. Similarly, Miller & Fick (1978) and Prunty (1981) reported that seed yields were not affected by plant population. Differences in the environment under which these trials were made may be responsible for the inconsistent yield responses reported.…”

Mineral element concentration of six sunflower cultivars in relation to water deficit and aluminum toxicity

“…Sunflower Is an Important oilseed crop which is highly sensitive to both water deficits and excesses (7,8,9,20,23,24) and acid soils (1,2,4,5,6,13,25). Screening experiments conducted since the early 1900's have demonstrated that genotypes differ widely in their sensitivity to Al toxicity (2,10,11,15,20,26,27).…”

“…Screening experiments conducted since the early 1900's have demonstrated that genotypes differ widely in their sensitivity to Al toxicity (2,10,11,15,20,26,27). In 1974, Foy et al (13) found differences in tolerance to Al stress among 13 sunflower genotypes grown on an acid soil with and without Ca.…”

“…Liming the soil or adding Ca to solution culture ameliorates the toxic effects of aluminum and other heavy metals on growth of sunflower (2,3,13,18,20), barley (Hordeum vulgäre L.) (12,16,17), and other crop plants (1,10,11,15,20,26,27). Since plants grown on acid soils frequently experience both Al and water stress, it is likely that injury symptoms generally attributed to Al stress may actually be induced by drought (16,17).…”

EFFECT OF POTASSIUM FERTILIZATION LEVELS ON GROWTH, YIELD AND QUALITY OF SUNFLOWER CULTIVARS (Helianthus annuus L.)

“…Data illustrated in table (4) show generally that Saturn, Gordis and Majak cultivars appeared to be clearly affected by increasing rate of potassium fertilization levels up to 30 kg k ha -1 for the traits of plant height (120cm), stem diameter (2.4cm), leaf area, number of seeds.head -1 , weight of thousand seed, oil percentage (43.7%), oil yield, protein percentage and protein yield only in AL-Rashidia location, while the interaction between cultivars and potassium fertilization levels was significant in number of seeds.head -1 and weight of thousand seed only in AL-Hamdanea location, while they appeared to be little response to 60 kg k ha -1 for those traits. On the other hand, Gordis cultivar reflected the greatest response to potassium fertilization levels up to 30 Kg k ha -1 for these traits, with this regard, Prunty, (1981);Faizani, et al, (1990) ;Sarmah, et al, (1994); Conley and Barta, (2003) and Khan, (1999) found that fertilization with 150 kg k ha -1 produced maximum weight of thousand seed (53.71g) and seed yield (4153 kg ha -1 ). On the other hand, the response rate of Saturn and Majak cultivars to potassium fertilizer was low with increasing potassium fertilization levels more than 60 kg k ha -1 for the most of these traits.…”