scholarly journals Modeling the Influence of Nitrogen Rate and Plant Density on Seed Yield, Yield Components and Seed Quality of Safflower

2013 ◽  
Vol 3 (2) ◽  
pp. 336-360 ◽  
Author(s):  
Ashraf El- Mohsen
1999 ◽  
Vol 79 (4) ◽  
pp. 543-549 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

The population density and spatial arrangement of plants may influence the productive life and performance characteristics of a perennial grass-seed crop. A study was conducted to determine the effects of the initial density (1.6, 3.1, 6.3, 12.5, 25, 50 and 100 plants m−2) and row spacing (20, 40, and 80 cm) of plants on reproductive yield components and seed characteristics of tall fescue (Festuca arundinacea Schreber), over 3 consecutive production years (1991–1993) in the Peace region of Canada. The weight proportion of cleaned-to-uncleaned seed was 85–86% for the three lowest plant densities and then decreased, as density increased, to 82% at 12.5 plants m−2 and 66% at 100 plants m−2. The 1000-seed weight decreased as density increased and ranged from 1.68 to 2.22 g (i.e., 595 000 to 450 000 seeds kg−1). The specific seed weight ranged from 18 to 31 kg hL−1; it differed among years, but the effect of plant density was inconsistent. The germination capacity of the seed was unaffected by plant density, but differed among years; it averaged 87%, 88% and 59% in 1991, 1992 and 1993, respectively. The seed yield/plant, the number of panicles/plant, and the number of seeds/plant decreased exponentially as plant density increased. The number of clean seeds/panicle decreased, as plant density increased, in the first year but was less affected subsequently, particularly with the 20-cm row spacing. The seed yield was correlated closely with the number of panicles m−2 (r = 0.659***). An initial density no greater than 25 plants m−2 in rows spaced 20–40 cm apart enhanced seed quality by producing a greater proportion of clean seed which had a higher 1000-seed weight. Such a plant density, however, is at the low end of the optimum range for maximizing seed yield per unit land area. Key words: Tall fescue, Festuca arundinacea Schreber, population density, plant and row spacing, yield components, seed quality


2010 ◽  
Vol 14 ◽  
pp. 75-83
Author(s):  
C.N. Merfield ◽  
J.G. Hampton ◽  
S.D. Wratten ◽  
P. Prapanoppasin ◽  
P. Yeeransiri

The hypothesis that by increasing carrot (Daucus carota) plant density the contribution to seed yield by the primary umbels would increase, and that therefore both seed yield and seed quality would increase, was examined in two experiments in different years in Canterbury. A radial trial design provided plant densities from 2 to 84 plants/m2 and from 4 to 100 plants/m2 in experiments one and two respectively. Seed yield increased with increasing plant density in both experiments, and at the highest density the primary umbels contributed 90% (experiment one) and 60% (experiment two) of the seed yield. In both experiments seeds from the primary umbels had a greater thousand seed weight and higher germination than those from the other order umbels, and for the second experiment they also had higher seed vigour. The quality of seeds from the primary umbels was consistently higher than that of seeds from the secondary umbels across all plant densities, and for the latter, both germination and seed vigour declined as plant density increased. These results therefore support the hypothesis, and densities higher than the 20 plants/m2 currently used commercially have the potential to increase both seed yield and quality. Keywords: seed production, primary umbels, germination, vigour, plants/m2


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 802C-802
Author(s):  
Sung Eun Lee* ◽  
Sang Gyu Lee ◽  
Chiwon W. Lee

The influence of plant density on yield of three confectionery seed pumpkin accessions was investigated under non-irrigated field conditions. Seeds of Golden Delicious (GD), open-pollinated Chinese snow-white seed (CS), and a selection from Austrian hull-less (HL) pumpkin were planted 30, 60, and 90 cm apart in rows that were 127 cm apart with seedlings thinned to one plant per hill. Plants were grown from 23 May to 18 Sept. One fruit per plant was harvested from five plants for each of the three replications. The number of seeds (and dry weight of seed) per fruit were 242 (59 g), 304 (87 g), and 334 (106 g), respectively, at 30, 60, and 90 cm spacing for GD. The number of seeds (and dry weight of seed) per fruit were 219 (108 g), 266 (108 g), and 258 (106 g), respectively, at 30, 60, and 90 cm spacing for CS. The number of seeds (and dry weight of seed) per fruit were 376 (76 g), 404 (94 g), and 304 (82 g), respectively, at 30, 60, and 90 cm spacing for HL. Highest seed yield was at 60 cm plant spacing for CS and HL, whereas GD produced highest seed yield at 90 cm plant spacing. The differences in total seed yield, seed size, and confectionery seed quality, as influenced by plant density and seed source, were also characterized.


2015 ◽  
Vol 15 (1) ◽  
pp. 85
Author(s):  
Dragoljub Beković ◽  
Rade Stanisavljević ◽  
Milan Biberdžić ◽  
Slaviša Stojković ◽  
Jasmina Knežević

Under agro-environmental conditions of Southern Serbia, the re­search was conducted over a three-year period to evaluate the effect of row spacing on seed yield, yield components and seed quality of alfalfa cv. ’K-23’. The average seed yield of alfalfa was highest at a row spacing of 40 cm (271.7 kg ha-1), followed by row spacing of 20 cm (249.4 kg ha-1) and 60 cm (244.0 kg ha-1). The highest and lowest number of inflo­rescences per stem were obtained in rows spaced 60 cm (13.37 inflo­rescences/stem) and 20 cm apart (8.57 inflorescences/stem), respectively. The widest row spacing of 60 cm (7.15 pods / inflorescence) resulted in the highest number of pods per inflorescence, whereas the lowest number was produced at 20 cm spacing (5.50 pods / inflorescence). Grain number per pod ranged from 3.55 (at 20 cm row spacing) to 4.05 (at 60 cm). The highest quality of alfalfa seed during the three years of the research was obtained at the widest row spacing (60 cm). Thousand-seed weight was highest at 60 cm and lowest at 20 cm (1.97 g and 2.07 g, respectively). The highest average values for seed germination rate were reported for 60 cm row spa­cing (88.00%) and the lowest for 20 cm row spacing (85.76 %).


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1088
Author(s):  
Mohamed Houssemeddine Sellami ◽  
Antonella Lavini ◽  
Davide Calandrelli ◽  
Giuseppe De Mastro ◽  
Cataldo Pulvento

Faba beans (Vicia faba L.), also known as fava beans, like other crops, are influenced by several factors: their genotype, environment, and management, as well as the interaction between these, have an important impact on seed yielding and seed quality traits. This study was conducted at three locations in South Italy between 2017 and 2019 to evaluate the sowing date effect on yield and yield components of three Vicia faba L., originating from cool climates. The results showed that seed yield (SY) and yield components declined with sowing delay. The crop’s environment (year × site) and management (sowing date) were found to explain 34.01% and 42.95% of the total seed yield variation, respectively. The data showed that the tested genotypes were positively influenced by the environment with sandy loam soil and early winter sowing date, resulting in either a greater number of SY and THS than in the other environment. The three faba bean genotypes showed tolerance to winter frost conditions in the two growing seasons.


2003 ◽  
Vol 21 (3) ◽  
pp. 443-447 ◽  
Author(s):  
Márcio S. de Lima ◽  
Antonio I. I. Cardoso ◽  
Marcelo F. Verdial

Squash seeds yield and quality can be improved by proper population plant spacing and the pollen quantity, which influences the pollination quality and fertilization. Nine experiments were conducted as a factorial combination of three spacing between plants (0.8 x 0.3, 0.8 x 0.6 and 0.8 x 0.9 m), two quantities of pollen (50% of an anther and another entire one) and natural insect pollination. Seed and fruit production parameters, and seed quality were evaluated. A randomized complete block design, five replications, with ten plants per plot was adopted. Larger plant spacing increased the average number of mature fruits and seed yield per plant. Seed yield was directly proportional to the amount of pollen used during pollination. Higher amounts of pollen resulted in higher seed yield per area, but the plant spacing did not affect this characteristic. Manual pollination, using a whole anther, did not differ from natural pollination in relation to seed yield and quality.


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