Seed production of Lotus uliginosus cv. Sharnae in response to plant population density

1998 ◽  
Vol 38 (8) ◽  
pp. 837 ◽  
Author(s):  
N. Arango ◽  
B. C. Jacobs ◽  
M. J. Blumenthal
Keyword(s):  
Population Density ◽  
Seed Yield ◽  
Seed Weight ◽  
Dry Matter ◽  
Seed Quality ◽  
Plant Population ◽  
Seed Number ◽  
Pod Development ◽  
Plant Population Density ◽  
Pasture Legume

Summary. An experiment was carried out under irrigation in the field to determine the influence of plant population density (7.5, 15, 30 and 60 plants/m2) on growth, development and yield of the pasture legume Lotus uliginosuscv. Sharnae. Reproductive development (flowering, pod set and stages of pod development) was recorded from 79 days after establishment and harvests were taken on 3 occasions during pod development: 118, 138 and 158 days after establishment. At each harvest, plants were divided into leaf, stem and pods. The pods were further separated into maturity classes on the basis of colour, and seed number and weight measured for each class. Harvesting late (i.e. 158 days after establishment) maximised seed yield (113 g/m2) and seed quality (27% immature, green pods). Seed yield per unit area up to 158 days after establishment was relatively insensitive to plant population up to 60 plants/m2 because the response of individual plants of lotus was highly plastic. At 158 days after establishment, dry matter per plant declined from 985 g at 7.5 plants/m2 to 713 g at 60 plants/m2. At the same time, seed number per plant and seed weight per plant were reduced from 27 400 to 3230 seeds and from 15.5 to 1.65 g, respectively, across the range of population densities. Despite the lack of a clear optimum plant population for maximum seed yield, some aspects of seed quality declined at high population density. For example, single seed weight fell by about 10% from 0.563 mg and the proportion of the harvest contributed by seeds from immature pods rose from 18 to 33%, as population density increased from 7.5 and 60 plants/m2. Seed quality and ease of management, rather than yield, may be the most important considerations when seed growers choose a sowing rate for a L. pedunculatus cv. Sharnae seed crop.

Effect of plant density and row spacing on the yield of chickpea (cv. Tyson) grown on the Darling Downs, south-eastern Queensland

1989 ◽  
Vol 29 (2) ◽  
pp. 241 ◽  
Author(s):  
DF Beech ◽  
GJ Leach
Keyword(s):  
Population Density ◽  
Seed Yield ◽  
Dry Matter ◽  
Plant Population ◽  
Growth And Yield ◽  
Dry Matter Production ◽  
Row Spacing ◽  
South Eastern ◽  
Matter Production ◽  
Plant Population Density

Growth and yield of chickpea, Cicer arietinum cv. Tyson, were studied at 4 row spacings (180, 360, 530 and 710 mm) and 4 plant population densities (14, 28, 42 and 56 plants m-2) in factorial combination in a wet and a dry growing season on a vertisol at Dalby, south-eastern Queensland. In both years, row spacing had only a small effect on above-ground dry matter production and yield, and there were no significant interactions between row spacing and plant population density. Above-ground dry matter production increased significantly with increase in plant population density for about 120 days after sowing. Seed yield increased significantly from 104 to 126 g m-2 in the drier season (106 mm rain, May-October) with increase in plant population density from 14 to 56 plants m-2. In the wetter season (286 mm rain, May- October), the corresponding trend in yield was from 262 to 287 g m-2. The response was attributed chiefly to larger seed size in the wet year, and higher harvest index in the dry year. We conclude that a density of at least 40 plants m-2 is required to attain maximum seed yield in southeastern Queensland. Although row spacing had no significant effect on yield, our earlier research indicated potential benefits from narrow row spacing, particularly for mechanised crop production.

Optimum plant population density for chickpea and dry pea in a semiarid environment

2003 ◽  
Vol 83 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Y. T. Gan ◽  
P. R. Miller ◽  
B. G. McConkey ◽  
R. P. Zentner ◽  
P. H. Liu ◽  
...  
Keyword(s):  
Population Density ◽  
Pisum Sativum ◽  
Cicer Arietinum ◽  
Seed Yield ◽  
Plant Population ◽  
Grain Legume ◽  
Wheat Stubble ◽  
Plant Population Density ◽  
Field Emergence ◽  
Seed Yields

Chickpea (Cicer arietinum L.), an annual grain legume, is being broadly included in cereal-based cropping systems throughout the semiarid Canadian prairies, but information on optimum plant population density (PPD) has not been developed for this region. This study, which was conducted from 1998 to 2000 in southwestern Saskatchewan, determined the effect of PPD on field emergence, seed yield and quality, and harvestability of kabuli and desi chickpea compared with dry pea (Pisum sativum L.). Seed yields of all legumes increased with increasing PPD when the crops were grown on conventional summerfallow. The PPD that produced the highest seed yields ranged from 40 to 45 plants m-2 for kabuli chickpea, from 45 to 50 plants m-2 for desi chickpea, and from 75 to 80 plants m-2 for dry pea. When the legumes were grown on wheat stubble, the PPD that gained optimum seed yield ranged from 35 to 40 plants m-2 for kabuli chickpea, from 40 to 45 plants m-2 for desi chickpea, and from 65 to 70 plants m-2 for dry pea. The proportion of large-sized (>9-mm diameter) seed in the harvested seed was >70% when the kabuli chickpea was grown on summerfallow regardless of PPD, whereas the large-seed proportion decreased with increasing PPD when the crop was grown on wheat stubble. Increases in PPD advanced plant maturity by 1.5 to 3.0 d and increased the height of the lowest pods from the soil surface by 1.4 to 2.0 cm (or 5 to 10%), with desi chickpea receiving the greatest benefits from increased PPD. The percentage of plants established from viable seeds per unit area decreased substantially as PPD increased, with kabuli chickpea emergence decreasing from 90% at PPD = 20 plants m-2 to 72% at PPD = 50 plants m-2, from 81 to 69% for desi type, and from 83 to 59% for dry pea . The reason for the low field emergence with increased PPD is unknown, but methods which lead to improved field emergence represent a great opportunity to increase seed yield and reduce production costs for both chickpea and dry pea in this semiarid region. Key words: seed size, Cicer arietinum, Pisum sativum, seeding rate, summerfallow

Effect of plant population density on dry matter partitioning and yield in a short-duration cultivar of cowpea (Vigna unguiculata) grown in the tropics

1996 ◽  
Vol 127 (1) ◽  
pp. 89-96 ◽  
Author(s):  
P. Q. Craufurd
Keyword(s):  
Population Density ◽  
Leaf Area ◽  
Dry Matter ◽  
Dry Weight ◽  
Incident Radiation ◽  
Plant Population ◽  
Dry Matter Partitioning ◽  
Radiation Interception ◽  
Plant Densities ◽  
Plant Population Density

SUMMARYAn erect, 60-day cultivar of cowpea, IT84S–2246, was grown with adequate soil moisture at two locations in Nigeria in 1990/91, Ibadan (7° N) and Kano (12° N), contrasting in total incident radiation (Q) and at plant population densities of 1·9–7·7 and 5·4–16·3 plants/m2, respectively. Leaf area, radiation interception and dry matter (DM) accumulation and partitioning were measured. Total shoot and seed dry weights were greater at Kano (mean 4·10 and 1·61 t/ha, respectively) than at Ibadan (mean 1·89 and 0·68 t/ha, respectively), and greater athigher plant densities. Relationships between the reciprocal of total shoot (Wt) and seed dry weight (Ws) per plant and plant population density (Np) determined at Kano and Ibadan were linear and parallel; intercepts, however, were significantly different (P < 0·005). The theoretical maximum potential Wt and Ws per unit area (i.e. 1/b) was therefore the same at Kano and at Ibadan, 448 and 170 g/m2, respectively. However, the optimum Np at Kano and Ibadan was markedly different, c. 10 and 40 plants/m2, respectively. These differences in the relations between DM yields and Np at Kano and Ibadan are examined in terms of leaf area, radiation interception and the partitioning coefficient, and the implications for the design of other agronomic investigations in cowpea are discussed.

Effects of Population Density on Yields of Two Soyabean (Glycine max) Varieties in Ghana Forest Zone

1977 ◽  
Vol 13 (3) ◽  
pp. 235-240 ◽  
Author(s):  
D. M. Osafo
Keyword(s):  
Glycine Max ◽  
Population Density ◽  
Seed Yield ◽  
Plant Population ◽  
Main Stem ◽  
Forest Zone ◽  
Plant Population Density ◽  
Crop Stand

SUMMARYSeed yield in two soyabean varieties—one tall (Improved Pelican) and one short (V/1)—was mainly determined by the total number of main stem and branch pods produced when plant population density varied from 5·4 to 16·2 plants/m2. An increasing percentage of the pods was found on the main stems of Improved Pelican as the crop stand became denser.

The potential of maize as a forage crop in Scotland

1979 ◽  
Vol 93 (3) ◽  
pp. 567-580 ◽  
Author(s):  
M. J. Potts ◽  
H. A. Waterson ◽  
J. B. A. Rodger ◽  
I. McMartin
Keyword(s):  
Population Density ◽  
Dry Matter ◽  
Quadratic Function ◽  
Matter Content ◽  
Plant Population ◽  
Dry Matter Content ◽  
Dry Matter Yield ◽  
Maize Varieties ◽  
Final Yield ◽  
Plant Population Density

SUMMARYBetween 1972 and 1976 a series of 15 trials was carried out at various climatically favoured sites throughout Scotland to assess the potential of new hybrid maize varieties of European origin under Scottish conditions. No meaningful differences were found between varieties in respect of dry-matter yield or maturity.Seed rates ranged from 100 to 200 × 103 seeds/ha giving final stands from 40 to 194 × 103 plants/ha. Regression analyses for the variety Dekalb 202 included in 54 treatments indicated that the relationship between plant population density and dry-matter yield was partly linear with an important quadratic function, suggesting an optimum of 179 × 103 (± 80 × 103) plants/ha. Plant population density accounted for 65·9% (P < 0·01) of the variance in dry-matter yield but was not significantly related to dry-matter content.Climatic variation between years had no overriding influence on growth and development. Dry-matter production for the variety Dekalb 202 sown in mid-May ranged from 2·86 (1972) to 14·54 t/ha (1975) with associated dry-matter contents of 15·1 and 24·1% respectively. In a few instances slightly higher dry-matter contents (maximum 28·6%) from mid-May sowings were associated with lower yields.Neither date of sowing nor accumulated temperature to harvest measured as Ontario Heat Units was significantly related to yield but date of sowing accounted for 29·5% (P < 0·01) of the variance in dry-matter content. Accumulated Ontario Units at harvest were not significantly related to dry-matter content.An interesting relationship between dry-matter yield and the date on which the crop had received 1379 Ontario Units was found. This relationship may be useful in selecting sites at which maize may be grown or to predict maximum potential final yield in any given season.

Impact of cultivar, row spacing and seeding rate on ascochyta blight severity and yield of chickpea

2007 ◽  
Vol 87 (2) ◽  
pp. 395-403 ◽  
Author(s):  
K. F. Chang ◽  
H. U. Ahmed ◽  
S. F. Hwang ◽  
B. D. Gossen ◽  
R. J. Howard ◽  
...  
Keyword(s):  
Population Density ◽  
Disease Severity ◽  
Seed Yield ◽  
Plant Density ◽  
Ascochyta Blight ◽  
Plant Population ◽  
Row Spacing ◽  
Seeding Rate ◽  
Plant Population Density ◽  
Wide Row Spacing

Field trials to assess the impact of chickpea type (desi vs. kabuli), row spacing and seeding rate on ascochyta blight of chickpea were conducted over 2 yr at Brooks, Alberta. A compound-leaved desi chickpea cultivar and unifoliate kabuli cultivar were sown at 20, 30 and 40 cm row spacing, and at three seeding rates (20, 40 and 60 seeds per 3 m row). Most of the variation in disease severity was associated with differences between the cultivars. Seeding rate, row spacing and their interactions had substantially smaller effects on ascochyta blight in comparison with cultivar effects. Late in the growing season, blight severity was consistently lower in the desi than the kabuli cultivar. Wide row spacing and low seeding rate reduced ascochyta blight severity and increased seed yield per plant. Wide row spacing in the first year reduced the seed yield per hectare, but row spacing did not significantly affect yield in 2005. Low in-row seeding rates increased yield only in 2004. There was a positive linear relationship between plant density and blight severity, and a negative relationship between yield per plant and both plant density and disease severity. We conclude that reduced plant population density could be one tool in a program to manage ascochyta blight of chickpea. Key words: Cicer arietinum, plant population density, ascochyta blight, yield

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