EFFECT OF PLANT DENSITY AND ROW SPACING ON AGRONOMIC PERFORMANCE AND ECONOMIC RETURNS OF NONOILSEED SUNFLOWER IN SOUTHEASTERN SASKATCHEWAN

1985 ◽  
Vol 65 (3) ◽  
pp. 501-509 ◽  
Author(s):  
N. W. HOLT ◽  
R. P. ZENTNER

Years, locations and planting density are significant factors that influence the agronomic performance of Sundak nonoilseed sunflower (Helianthus annuus L.) in southeastern Saskatchewan. As plant densities of sunflower were increased from 37 500 to 75 000 plants/ha at Indian Head from 1975 to 1977, achene (seed) yield and test weight increased linearly with density while percentages of roasting and dehulling seed categories decreased. Row spacings of 30–90 cm affected plant height and seed yield and size, but absolute amounts were not large. Based on 1984 prices of four seed-size categories, highest gross economic returns were favored by the higher plant densities. In a second test at Indian Head and Oxbow in 1979 and Areola in 1980, a range of plant densities from 22 900 to 76 400 plants/ha did not significantly affect seed yield or gross economic returns. However, yield and returns tended to be greatest for 50 000-60 000 plants/ha. Percentages of large seed decreased as plant population increased. Because markets generally favor the large-seed size categories and the price differentials among seed size categories tend to increase, plant densities of 40 000 to 50 000 plants/ha might better be recommended to allow for years with greater price differentials.Key words: Nonoilseed sunflower, Helianthus annuus L., plant density, row spacing, seed size, economic returns

1984 ◽  
Vol 64 (3) ◽  
pp. 599-605 ◽  
Author(s):  
N. W. HOLT ◽  
S. J. CAMPBELL

This study investigated the influence of plant density on several agronomic traits of four sunflower (Helianthus annuus L.) cultivars grown at Indian Head and Saskatoon, Saskatchewan in the semiarid prairies. At populations of 40 000–85 000 plants∙ha−1, plant density had no significant effect on seed yield. The increase in percentage oil content with increase in plant density (44.3–45.6%) was small but significant. As plant density was increased, days to flower, height and test weight increased while days to maturity, head diameter and average seed weight decreased. Cultivars × density interactions were generally not significant. Environment (five location-years) had a significant effect on all variables, and environments × cultivar interactions were significant for most of these. Results of this experiment indicated that testing of sunflower lines at several locations in the growing area would be necessary for best assessment but one plant density, suitable to that area, could be used.Key words: Sunflower, plant density, seed, oil, seed size, Helianthus annuus L.


1990 ◽  
Vol 70 (4) ◽  
pp. 1169-1171 ◽  
Author(s):  
G. H. GUBBELS ◽  
W. DEDIO

Two early-maturing sunflower hybrids, Sunwheat 101 and MRS 34, with shorter than normal height and a narrower growth habit were grown at 30- and 60-cm row spacings and three plant densities at each row spacing in the 1986 and 1987 seasons at Morden, Manitoba. There were no differences in achene yield or oil content between row spacings. Plant height and oil content of achenes increased with increase in plant density, while achene weight decreased. Achene yield of both hybrids increased as plant density increased from 55 000 to the 74 000 plants ha−1 density, then remained relatively constant to 148 000 plants ha−1.Key words: Oilseed sunflower, Helianthus annuus L., plant row spacing, plant density


1986 ◽  
Vol 66 (3) ◽  
pp. 801-804
Author(s):  
G. H. GUBBELS ◽  
W. DEDIO

The nonoil sunflower (Helianthus annuus L.) cultivar Sundak was grown at four plant densities and two soil fertility levels for 3 yr in the Morden, Manitoba area. Fertilizer increased achene yield in 2 of the 3 yr and increased achene size in 1 of the 3 yr. Achene size and weight decreased with increase in plant density. Achene yield reached a maximum at approximately 30 000 plants ha−1.Key words: Nonoil sunflower, Helianthus annuus L., plant density, soil fertility


1989 ◽  
Vol 69 (4) ◽  
pp. 1251-1254 ◽  
Author(s):  
G. H. GUBBELS ◽  
W. DEDIO

Field experiments were conducted in 1983, 1984 and 1986 to determine the response of Sun M 20 (early) and 894 (late) sunflower (Helianthus annuus L.) hybrids to three plant densities (30 000, 45 000 and 60 000 plants ha−1) at two seeding dates (18–24 May and 13–16 June). With increase in plant density, achene yields followed the same trends in each seeding date for both hybrids. Yields were similar at the 30 000 and 45 000 plant densities, but lower at the 60 000 density. Plant height and oil content of achenes increased while achene weight decreased with increase in plant density. Plant height was greater but achene weight, oil content and achene yield were lower in the late than the early seeding.Key words: Sunflower, Helianthus annuus L., plant density, seeding date


2002 ◽  
Vol 127 (5) ◽  
pp. 855-859 ◽  
Author(s):  
Haim Nerson

Field experiments were conducted in 1996 and 1997 to examine the effects of plant density on yield and quality of fruit and seeds of muskmelons (Cucumis melo L.). Two open-pollinated cultivars, Noy Yizre'el (Ha'Ogen type) and TopMark (western U.S. shipper type), were grown at plant densities ranging from 0.5 to 16.0 plants/m2 under commercial conditions. The highest marketable fruit yields were achieved with plant densities of 2 to 4 plants/m2. In contrast, the highest seed yields were obtained at 8 to 12 plants/m2. Seed yield index [seed yield (g)/fruit yield (kg)] was used as a parameter to define seed production efficiency. High seed yield was closely related to high value of the seed yield index. High seed yield indexes resulted from high plant densities (up to 12 plants/m2), at which the crops produced many, but relatively small fruit. In all cases, the seed yield per fruit (seed number and seed size) increased with increasing fruit weight. However, the sum of the seed yield of two small fruit was always greater than the seed yield of one, double-sized fruit. There was a clear exception with extremely small fruit (<500 g), which produced both low seed yields and poor seed quality. A positive relationship was found between fruit size and seed size in both cultivars. Nevertheless, relatively small seeds (25 to 30 mg) extracted from relatively small fruit (500 to 1000 g) showed the best performance in terms of germination and emergence percentages and rates, and in the vegetative development vigor of the seedlings.


1986 ◽  
Vol 66 (3) ◽  
pp. 521-527 ◽  
Author(s):  
G. H. GUBBELS ◽  
W. DEDIO

Field experiments were conducted in the 1979 to 1982 seasons to determine the response of sunflower (Helianthus annuus L.) genotypes with different growth habits to different plant densities at two levels of soil fertility in the Morden, Manitoba area. Treatments included hybrids and an open-pollinated cultivar, no fertilizer and 250 kg ha−1 of 27-14-0 and plant densities of 30 000, 45 000, 60 000 and 75 000 plants ha−1. Hybrids and open-pollinated cultivar responded similarly to the fertility and plant density levels. An increase in plant density did not affect yield, but slightly delayed flowering time, increased plant height, test weight and oil concentration and decreased achene weight. A plant density of about 45 000 plants ha−1 was required to ensure optimum yield.Key words: Sunflower, Helianthus annuus L., plant density, soil fertility


2016 ◽  
Vol 96 (1) ◽  
pp. 151-159 ◽  
Author(s):  
Gan Yantai ◽  
K. Neil Harker ◽  
H. Randy Kutcher ◽  
Robert H. Gulden ◽  
Byron Irvine ◽  
...  

Optimal plant density is required to improve plant phenological traits and maximize seed yield in field crops. In this study, we determined the effect of plant density on duration of flowering, post-flowering phase, and seed yield of canola in diverse environments. The field study was conducted at 16 site-years across the major canola growing area of western Canada from 2010 to 2012. The cultivar InVigor® 5440, a glufosinate-resistant hybrid, was grown at five plant densities (20, 40, 60, 80, and 100 plants m−2) in a randomized complete block design with four replicates. Canola seed yield had a linear relationship with plant density at 8 of the 16 site-years, a quadratic relationship at 4 site-years, and there was no correlation between the two variables in the remaining 4 site-years. At site-years with low to medium productivity, canola seed yield increased by 10.2 to 14.7 kg ha−1 for every additional plant per square metre. Averaged across the 16 diverse environments, canola plants spent an average of 22% of their life cycle flowering and another 27% of the time filling seed post-flowering. Canola seed yield had a negative association with duration of flowering and a positive association with the days post-flowering but was not associated with number of days to maturity. The post-flowering period was 12.7, 14.7, and 12.6 d (or 55, 68, and 58%) longer in high-yield experiments than in low-yield experiments in 2010, 2011, and 2012, respectively. We conclude that optimization of plant density for canola seed yield varies with environment and that a longer post-flowering period is critical for increasing canola yield in western Canada.


2003 ◽  
Vol 83 (2) ◽  
pp. 319-326 ◽  
Author(s):  
B. L. Johnson

Growth compensation of dwarf sunflower (Helianthus annuus L.) hybrids to low initial stands, later stand losses, or plant defoliation has not been reported regarding replanting decisions and crop insurance yield loss assessment. Three experiments were conducted to study the affect of stand reduction, defoliation, and row spacing on dwarf sunflower yield and quality when grown in eastern North Dakota. Experiment 1 evaluated stand reduction (0, 25, 50 and 75%) applied at growth stages (V4, R1 and R6) in 15, 45 and 76 cm spaced rows. Row spacing interactions with stand reduction and growth stage were not significant for yield indicating growth stage and stand reduction effects on yield response were independent of row spacing. In exp. 2, significant growth stage (V4, V8, R1, R2, R3, R5 and R6) by stand reduction (0, 12, 25, 37, 50, 62 and 75%) interaction showed stand reduction at vegetative growth stages not influencing yield, but as maturity progressed yield reductions became greater with increased stand reduction. Achene weight increased with increasing stand reduction at vegetative and early reproductive stages. A reciprocal relationship was noted between achene weight and achene oil content where oil content decreased as achene weight increased. Interaction of growth stage (R1 and R6) and defoliation (0, 25, 50, 75 and 100%) in exp. 3 indicated greater reduction in yield, test weight, 1000-achene weight, and achene oil conte nt as defoliatin increased at growth stage R6. Yield compensating ability of dwarf sunflower is dependent on type and level of damage and growth stage of occurrence, with total yield reduction considering all effects. Key words: Sunflower, Helianthus annuus L., row spacing, stand reduction, defoliation


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