The effect of plant density on the reproductive structure of safflower in the Ord River valley

1966 ◽  
Vol 6 (22) ◽  
pp. 255 ◽  
Author(s):  
DF Beech ◽  
MJT Norman
Keyword(s):  
Plant Density ◽  
Dry Weight ◽  
Plant Size ◽  
Carthamus Tinctorius ◽  
Oil Yield ◽  
Research Station ◽  
Main Effect ◽  
Plant Densities ◽  
Mean Size ◽  
Total Seed

Safflower (Carthamus tinctorius L., variety Gila) was grown under irrigation at the Kimberley Research Station as a row crop at plant densities of 25,000 to 133,000 plants an acre and as a drilled crop at 593,000 plants an acre. The main effect of increasing plant density, within the range examined, was to reduce plant size (dry weight of tops and number of seed heads) ; the mean size of individual heads (number of seeds and their weight) showed little change. Though the relative seed and oil yield per head of primary, secondary, and tertiary heads remained fairly constant with increasing plant density, the increasing proportion of primary heads and the decreasing proportion of tertiary heads brought about corresponding changes in the contribution by primary and tertiary heads to total seed and oil yield. In contrast, the proportion of secondary heads and their contribution to seed and oil yield remained relatively stable.

Plant height and height of the main ear in maize (Zea mays L.) at different locations and different plant densities

2002 ◽  
Vol 50 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Z. Gyenes-Hegyi ◽  
I. Pók ◽  
L. Kizmus ◽  
Keyword(s):  
Plant Height ◽  
Plant Density ◽  
Close Correlation ◽  
Plant Size ◽  
Considerable Effect ◽  
Maximum Height ◽  
The Best Approximation ◽  
Significant Difference ◽  
Plant Densities ◽  
Ear Height

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.

Effect of plant density and spatial arrangement on the yield of Leucaena leucocephala cv. Peru in subcoastal south-eastern Queensland

1988 ◽  
Vol 28 (5) ◽  
pp. 577 ◽  
Author(s):  
DG Cooksley ◽  
EA Goward
Keyword(s):  
Leucaena Leucocephala ◽  
Plant Density ◽  
Spatial Arrangement ◽  
Annual Rainfall ◽  
Panicum Maximum ◽  
Research Station ◽  
Density Maximum ◽  
Plant Densities ◽  
Annual Total ◽  
Establishment Phase

Leucaena (Leucaena leucocephala cv. Peru) was sown at 5 plant densities with 2 spatial arrangements at Brian Pastures Pasture Research Station, Gayndah, to determine the effects of these factors on leucaena and inter-row grass dry matter yield. During the 2 year establishment phase, yields of edible leucaena (leaves, pods, flowers and stems to a diameter of 5 mm) averaged 4400 and 2440 kg/ha respectively. Yields in subsequent years stabilised to an overall mean of 1360 kg/ha, with the amount of edible leucaena increasing with increasing leucaena plant density from 640 to 2260 kg/ha at 6000 and 62 500 leucaena plants/ha respectively. Edible leucaena yield for the mean of the 5 plant densities was increased by 38% when row spacing was doubled. Yields of both total and senesced leucaena were directly related to the annual rainfall. At the end of each growing season in May, edible leucaena yield remained stable between rainfall extremes of 492 and 878 mm while the amount of senesced leucaena litter increased. Edible leucaena yield was directly related to leucaena plant density (R2= 0.86). Annual total leucaena yield (edible leucaena yield plus leucaena litter) was best related to the plant parameters leucaena plant volume (R2 = 0.92), leucaena stem numbers (R2 = 0.90) and leucaena stem diameter (R2 = 0.90). Number of green panic (Panicum maximum var, trichoglume) shoots showed a marked increase at the 3 higher leucaena densities (mean of 28 shoots/m2) compared with the 2 lower leucaena densities (mean of 7 shoots/m2). Total soil nitrogen also increased at the 3 higher leucaena densities (mean of 0.186%) relative to the 2 lower leucaena densities (mean of 0.170%). Inter-row grass and grass litter yields both declined from 4640 and 4010 kg/ha to 31 10 and 2420 kg/ha respectively with increasing leucaena density. Maximum yields of edible leucaena were obtained when leucaena was grown at a density of 62 500 plants per ha in rows 0.8 m apart.

Effect of plant density and detopping following silking on cob growth, fodder and grain yield of maize (Zea mays)

1992 ◽  
Vol 119 (3) ◽  
pp. 297-301 ◽  
Author(s):  
S. K. Roy ◽  
P. K. Biswas
Keyword(s):  
Grain Yield ◽  
Harvest Index ◽  
Plant Density ◽  
Agricultural Research ◽  
Dry Weight ◽  
Research Station ◽  
Maize Crop ◽  
Significant Difference ◽  
Fodder Yield ◽  
Stem Reserves

SUMMARYMaize was grown al the Regional Agricultural Research Station, Hathazari, Bangladesh during 1988/89 and 1989/90 to study fodder yield, cob growth and grain yield together with the contribution of pre-silking stem reserves to grain. Population densities were 33300, 44400 and 66600 plants/ha. Plants were either detopped after silking and pollen shedding, keeping 0, 2 or 3 leaves above the cob, or were left entire.The results showed that the maize crop could successfully be detopped for fodder with little or no adverse effect on grain yield. Fodder yield increased with increased plant density and among the detopping treatments the highest fodder yield was obtained when the plants were detopped just above the cob. Cob growth followed a sigmoid pattern and the highest dry weight per cob was obtained from the lowest plant density and from entire plants. The number of cobs/m2 increased with increased plant density but detopping treatments did not give any significant difference in relation to densities. The number of grains/cob was highest with 33300 plants/ha but, among the detopping treatments, plants detopped just above the cob had the lowest number of grains/cob in both years. Weight of 1000-grain decreased with increasing plant density but it was increased by detopping plants just above the cob during 1988/89, although it was decreased in 1989/90. The highest apparent translocation of pre-silking reserves was obtained using densities of 44400 plants/ha but detopping treatments did not show any consistent effect, although the highest apparent translocation (20%) and harvest index (58%) were obtained from plants detopped just above the cob.

scholarly journals Plant Size Influences Bell Pepper Seed Quality and Yield

HortScience ◽  
1993 ◽  
Vol 28 (8) ◽  
pp. 809-811 ◽  
Author(s):  
Victor M. Sanchez ◽  
F.J. Sundstrom ◽  
N. Suzanne Lang
Keyword(s):  
Seed Quality ◽  
Plant Density ◽  
Cultural Practices ◽  
Plant Size ◽  
Bell Pepper ◽  
Pepper Plant ◽  
Plant Spacing ◽  
Fruit Thinning ◽  
Plant Densities

This study investigated the influence of plant size, as determined by plant density, and fruit load variation on the production and quality of bell pepper (Capsicum annuum L.) seeds. Six-week-old `Resistant Giant no. 4' bell pepper seedlings were transplanted 15, 30, 45, and 60 cm apart. Plants spaced 45 cm apart were not thinned or were thinned to one or three fruit per plant. Pepper plants grown at low plant densities produced larger fruit and seeds that germinated faster and at higher percentages than plants grown at higher densities. Assimilate export rate (AER) increased linearly with plant spacing. At harvest, C exchange rate (CER) and AER of plants with nonthinned fruit loads were ≈ 300% and 500% higher, respectively, than those of plants with one or three fruit. Fruit thinning decreased CER and AER; however, seeds produced by plants with one or three fruit had significantly higher germination percentages than plants with full fruit loads. These observations suggest that the high CERS of smaller plants with nonthinned fruit loads may have been insufficient to compensate completely for the higher sink demands. Therefore, crop cultural practices that increase the ratio of pepper plant size to total fruit count may increase the quality of seeds produced by those plants.

scholarly journals Genotype and plant density effects on oil content and fatty acid composition of safflower

2020 ◽  
Vol 28 (s1) ◽  
pp. 83-101
Author(s):  
O.G. Moatshe ◽  
V.E. Emongor ◽  
T.V. Balole ◽  
S.O. Tshwenyane
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Oil Content ◽  
Plant Density ◽  
Carthamus Tinctorius ◽  
Linoleic Acid Content ◽  
Oilseed Crop ◽  
High Unsaturated Fatty Acid ◽  
Plant Densities

Safflower (Carthamus tinctorius L.) is a multipurpose oilseed crop that is tolerant to drought, saline, heat and cold conditions; and yields high quality edible seed oil. The objective of this study was to evaluate the effect of plant density and genotypes on oil content and fatty acid composition of safflower. A field experiment was conducted in the years 2015 and 2016, during winter and summer seasons. Treatments included five safflower genotypes and six plant densities. Genotype and plant density significantly interacted (P < 0.05) to influence oil content and fatty acid composition of safflower. Increasing plant density from 62,500 to 100,000 plants ha-1 significantly (P < 0.05) increased the oil concentration from 16 to 54%, depending on the interaction between genotype and plant density and genotype by environment (winter and summer seasons). However, as plant density increased from 100,000 to 200,000 plants ha-1, safflower oil content significantly (P < 0.05) decreased in all genotypes. The lowest and highest oil contents was produced by genotype ‘Gila’ planted at density 62,500 or 200,000; and ‘Sina’, ‘Pi 537 636’ at 100 000 or 125, 000 plants ha-1 in winter or summer, respectively. Fatty acid composition was significantly influenced by genotype and plant density interactions during the two growing seasons. The main fatty acids identified included linoleic, oleic, stearic and palmatic. There was a significant (P < 0.05) increase in linoleic acid content and a decrease in oleic, palmatic and stearic as plant density increased from 62,500 to 100,000 plants ha-1, depending on genotype or growing season. Genotype ‘Sina’ at 100,000 plants ha-1 produced the highest oil content and with high unsaturated fatty acid concentrations.

scholarly journals Non-Structural Carbohydrate Metabolism, Growth, and Productivity of Maize by Increasing Plant Density

Agronomy ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 243 ◽  
Author(s):  
Jairo Cazetta ◽  
Marcos Revoredo
Keyword(s):  
Sucrose Synthase ◽  
Plant Density ◽  
Specific Activity ◽  
Sucrose Concentration ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Plant Production ◽  
Crop Density ◽  
Plant Densities ◽  
Narrow Row

Increasing plant density seems to improve the productivity of maize crops, and the understanding of how the metabolism of non-structural carbohydrates is affected in plants under high crop density is critical. Thus, with the objective of further clarifying this issue, maize plants were subjected to densities from 30,000 to 90,000 plants ha−1, and the plant growth, soluble sugars and starch contents, invertase and sucrose synthase activities, and plant production were evaluated. We found that the stalk is more sensitive to the increasing plant density than leaves and kernels. The dry weight of the stalk and leaves per single plant decreased more drastically from low to intermediate plant densities, while grain production was reduced linearly in all plant density ranges, leading to higher values of harvest index in intermediate plant densities. The sucrose concentration did not change in leaves, stalk, or kernels of plants subjected to increasing plant densities at the R4 stage. Also, the specific activity of soluble invertase, bound invertase, and sucrose synthase did not change in leaf, stalk, or kernels of plants subjected to increased plant density. The productivity was increased with the increase in plant density, using narrow row (0.45 m) spacing.

Agronomic Aspects of Broad Beans (Vicia Faba L.) Grown in the Sudan

1968 ◽  
Vol 4 (2) ◽  
pp. 151-159 ◽  
Author(s):  
E. A. K. El Saeed
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Dry Weight ◽  
Factors Affecting ◽  
Growing Seasons ◽  
Broad Beans ◽  
Final Yield ◽  
Total Seed ◽  
Leaf Dry Weight ◽  
Pod Growth

SummaryField experiments in three successive growing seasons (1963–66) studied effects of variety and plant density on yield components of broad beans. In 1963/64 total seed yield of a local variety (Beladi), increased with increasing seed rates from 70 to 280 lb per feddan, but yield increment diminished beyond 140 lb. The same results were obtained with Beladi and Rebaya 34 in 1964/65 and 1965/66, but Rebaya 34, yielded less than Beladi at all seed rates. Growth analysis revealed that Rebaya 34 had greater growth rate at the beginning of the season, due to its relatively large seed size, but eventually Beladi overtook it. Maximum pod growth in both varieties occurred when leaf dry weight was declining. The proportion of dry matter was greater in pods of Beladi than Rebaya 34 because of more sinks in the former variety. The present seed rate of 70 lb per feddan seems to be suboptimal and factors affecting establishment and/or effective leaf area at the time of pod growth are detrimental to the final yield.

Effect of barley plant density on wild oat interference, shoot biomass and seed yield under zero tillage

1999 ◽  
Vol 79 (4) ◽  
pp. 655-662 ◽  
Author(s):  
J. T. O'Donovan ◽  
J. C. Newman ◽  
K. N. Harker ◽  
R. E. Blackshaw ◽  
D. W. McAndrew
Keyword(s):  
Seed Yield ◽  
Yield Loss ◽  
Plant Density ◽  
Interactive Effect ◽  
Dry Weight ◽  
Barley Plant ◽  
Wild Oat ◽  
Zero Tillage ◽  
Shoot Dry Weight ◽  
Plant Densities

There has been little research aimed at developing regression models to describe the effects of barley and wild oat plant density on barley yield loss, or wild oat biomass and seed yield. Such models are an important component of integrated weed management systems, and can help determine when weed control with herbicides is economical. Field experiments were conducted over 4 yr at Vegreville, Alberta, to determine the interactive effects of wild oat and barley plant density on barley and wild oat variables in a zero tillage system. A nonlinear regression model in most cases provided good descriptions of barley yield loss, wild oat shoot dry weight, and wild oat seed yield as functions of wild oat and barley plant densities. The interactive effect of wild oat and barley plant density on percentage barley yield loss did not differ significantly (P = 0.05) among years. A pooled regression model describing barley yield loss accounted for 57% of the variation, and provides a means of estimating yield loss due to wild oat in barley grown under zero tillage. Barley yield loss increased as wild oat density increased but the magnitude of the yield loss diminished with increasing barley plant density. Wild oat economic threshold densities varied among years, and were strongly influenced by barley price and expected wild oat-free yield. Economic thresholds were greater at higher barley plant densities. Barley seed weight decreased with increasing barley plant density, and to a lesser extent with increasing wild oat density. The interactive effect of wild oat and barley plant density on wild oat seed yield varied significantly with year, and appeared to be influenced by climatic conditions. The cooler, wetter spring of 1996 favored wild oat seed production (by several orders of magnitude) compared with the relatively warmer and drier spring of 1995. Each year wild oat seed yield and shoot dry weight decreased as barley plant density increased. The results suggest that seeding barley at relatively high rates may reduce the need for wild oat control with herbicides in zero tillage systems. Key words: Zero tillage, wild oat interference, barley seeding rate, nonlinear regression

Ecological relationships of wild rice, Zizania spp. 10. Effects of sediment and among-population variations on plant density in Zizania palustris

2002 ◽  
Vol 80 (12) ◽  
pp. 1283-1294 ◽  
Author(s):  
P F Lee
Keyword(s):  
Seed Production ◽  
Wild Rice ◽  
Plant Density ◽  
Reproductive Potential ◽  
Resource Depletion ◽  
Dry Weight ◽  
Asymmetric Competition ◽  
Zizania Palustris ◽  
Nutrient Levels ◽  
Plant Densities

The influence of nutrients and intraspecific variations in growth form were examined for their effect on plant density in stands of northern wild rice, Zizania palustris L. In a field situation, densities of a size-restricted wild rice population increased as nutrient levels in the sediment increased. No self-thinning occurred until the population density exceeded 350 plants/m2. A series of controlled experiments examined whether these wild rice densities were determined by resource depletion and (or) intraspecific competition. As nutrient levels increased under constant plant densities, tillering, dry weight, and seed production increased more for populations with the capacity for higher vegetative and reproductive potential. As plant densities increased under constant nutrient levels, height, weight, and seed production declined but inequality of individual plants increased. When both nutrient levels and population densities were increased simultaneously, seed production per panicle declined at higher densities under unfertilized conditions but was unaffected in the treatment with the highest fertilizer level. It was hypothesized that plant densities under field conditions were the result of an integrated mechanism that was influenced by nutrients and the degree of asymmetric competition characteristic of the population. As nutrient levels increase, plant densities would be expected to decrease for populations with high levels of asymmetric competition and increase for populations with low levels of asymmetric competition.Key words: wild rice, density effects, nutrients, intraspecific variation.

scholarly journals Effect of sowing date and plant density on bolting of four sugar beet (Beta vulgaris L.) varieties

2015 ◽  
Vol 4 (2) ◽  
pp. 256-270
Author(s):  
Entessar Al-Jbawi ◽  
Waeel Sabsabi ◽  
Gharibo Gharibo ◽  
Abd El-Muhsien Al-Sayed Omar
Keyword(s):  
Sugar Beet ◽  
Plant Density ◽  
Agricultural Research ◽  
Sowing Date ◽  
The Other ◽  
Research Station ◽  
Sowing Dates ◽  
Plant Densities ◽  
Autumn Sowing ◽  
Plot Design

This experiment was conducted in Homs Agricultural Research Station, Homs, Syria during 2007/2008 and 2008/2009 seasons to study the effect of sowing date and plant density on bolting for four sugar beet varieties, tow are monogerm varieties i.e. Parade and Etna, while the other are multigerm varieties i.e. Nadir and Mammoth. Three sowing dates were applied, began from 15/9 to 15/10, the interval between the sowing dates was 15 days. Three plant densities were executed (133 000, 100 000 and 80 000 plantha-1). Split plot design was used with three replicates. The combined analysis exhibited the significant effect of varieties (V), sowing dates (S), and plant densities (D) on all types of bolting (Early, medium, late and total). Least significant test (L.S.D 0.05) clarified that early autumn sowing (15/9 and 1/10) increased total bolting percent 74.86 and 44.88 % respectively, as compared with date (15/10) 15.57% (control). The plant density (133 000 plant ha-1) decreased total bolting percent 43.56% as compared with the other plant densities (80 000 and 100 000 plant ha-1) 46.35 and 45.40% respectively. The results showed that the monogerm varieties were superior and more resistant to bolting as compared with the multigerm ones. DOI: http://dx.doi.org/10.3126/ije.v4i2.12647 International Journal of Environment Vol.4(2) 2015: 256-270

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