EFFECT OF PLANT DENSITY AND SOIL FERTILITY ON OILSEED SUNFLOWER GENOTYPES

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

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


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


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


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


Author(s):  
L. S. Sampaio ◽  
R. Battisti ◽  
M. A. Lana ◽  
K. J. Boote

Abstract Crop models can be used to explain yield variations associated with management practices, environment and genotype. This study aimed to assess the effect of plant densities using CSM-CROPGRO-Soybean for low latitudes. The crop model was calibrated and evaluated using data from field experiments, including plant densities (10, 20, 30 and 40 plants per m2), maturity groups (MG 7.7 and 8.8) and sowing dates (calibration: 06 Jan., 19 Jan., 16 Feb. 2018; and evaluation: 19 Jan. 2019). The model simulated phenology with a bias lower than 2 days for calibration and 7 days for evaluation. Relative root mean square error for the maximum leaf area index varied from 12.2 to 31.3%; while that for grain yield varied between 3 and 32%. The calibrated model was used to simulate different management scenarios across six sites located in the low latitude, considering 33 growing seasons. Simulations showed a higher yield for 40 pl per m2, as expected, but with greater yield gain increments occurring at low plant density going from 10 to 20 pl per m2. In Santarém, Brazil, MG 8.8 sown on 21 Feb. had a median yield of 2658, 3197, 3442 and 3583 kg/ha, respectively, for 10, 20, 30 and 40 pl per m2, resulting in a relative increase of 20, 8 and 4% for each additional 10 pl per m2. Overall, the crop model had adequate performance, indicating a minimum recommended plant density of 20 pl per m2, while sowing dates and maturity groups showed different yield level and pattern across sites in function of the local climate.


2002 ◽  
Vol 50 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Z. Gyenes-Hegyi ◽  
I. Pók ◽  
L. Kizmus ◽  

The plant height and the height of the main ear were studied over two years in twelve single cross maize hybrids sown at three different plant densities (45, 65 and 85 thousand plants/ha) at five locations in Hungary (Keszthely, Gönc, Gyöngyös, Sopronhorpács, Martonvásár). The results revealed that plant height and the height of the main ear are important variety traits and are in close correlation with each other. It was found that the hybrids grew the tallest when the genetic distance between the parental components was greatest (Mv 4, Mv 5). The height of the main ear was also the greatest in these hybrids, and the degree of heterosis was highest (193% for plant height, 194% for the height of the main ear). The shortest hybrids were those developed between related lines (Mv 7, Mv 11). In this case the heterosis effect was the lowest for both plant height (128%) and the height of the main ear (144%). The ratio of the height of the main ear to the plant height was stable, showing little variation between the hybrids (37–44%). As maize is of tropical origin it grows best in a humid, warm, sunny climate. Among the locations tested, the Keszthely site gave the best approximation to these conditions, and it was here that the maize grew tallest. The dry, warm weather in Gyöngyös stunted the development of the plants, which were the shortest at this location. Plant density had an influence on the plant size. The plants were shortest when sown at a plant density of 45,000 plants/ha, and the main ears were situated the lowest in this case. At all the locations the plant and main ear height rose when the plant density was increased to 65,000 plants/ha. At two sites (Gönc and Sopronhorpács) the plants attained their maximum height at the greatest plant density (85,000 plants/ha). In Keszthely there was no significant difference between these two characters at plant densities of 65 and 85 thousand plants/ha, while in Gyöngyös and Martonvásár the greatest plant density led to a decrease in the plant and main ear height. The year had a considerable effect on the characters tested.


Helia ◽  
2001 ◽  
Vol 24 (34) ◽  
pp. 17-24
Author(s):  
K. Manjula ◽  
H.L. Nadaf ◽  
K. Giriraj

SUMMARYGenetic diversity was assessed in 46 non-oilseed sunflower genotypes for 14 characters by adopting D2 analysis. Oil content and plant height exhibited maximum contributions towards genetic divergence. The genotypes were grouped into 11 clusters. The inter-cluster D2 values ranged from 288.17 to 3972.34. The contribution of oil content towards genetic divergence in the 46 genotypes was confirmed when D2 analysis was performed for seed characteristics such as test weight, volume weight, hull content, kernel recovery, oil and protein content.


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 4 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Beverly R. Durgan ◽  
Alan G. Dexter ◽  
Stephen D. Miller

Field experiments were conducted in 1983 and 1984 at two locations to determine the influence of various densities and durations of kochia interference in sunflower. Sunflower achene yield and dry weight were reduced by all densities of kochia, averaged over locations and years. Season-long competition by kochia densities of 0.3, 1, 3, and 6 plants/m of row decreased sunflower achene yield 7, 10, 20, and 27%, respectively. Sunflower achene yield and sunflower dry weight decreased as weeks of kochia competition increased. Only 2 weeks of kochia competition after sunflower emergence decreased sunflower achene yield 6%. Sunflower achene yield loss increased as the duration of kochia competition increased. Sunflower 200 achene weight, oil content, and plant height were not influenced by various densities or durations of kochia competition.


2013 ◽  
Vol 50 (2) ◽  
pp. 62-66
Author(s):  
Jockovic Milan ◽  
Jocic Sinisa ◽  
Marinkovic Radovan ◽  
Prodanovic Slaven ◽  
Canak Petar ◽  
...  

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