Optimum plant density of desi chickpea (Cicer arietinum L.) increases with increasing yield potential in south-western Australia

1999 ◽  
Vol 50 (6) ◽  
pp. 1017 ◽  
Author(s):  
R . J. Jettner ◽  
S. P. Loss ◽  
K. H. M. Siddique ◽  
R. J. French

The response of chickpea (cv. Tyson) seed yield to sowing rate (30–180 kg/ha) was examined in 18 field experiments across 3 years in south-western Australia. The economic optimum plant density was estimated at each site by fitting an asymptotic model to the data and calculating the point where the cost of extra seed equalled the return from additional seed yield, allowing a 10% opportunity cost for the extra investment. When averaged across all sites and seasons, plant densities varied from 14 plants/m2 when sown at 30 kg/ha to 84 plants/m2 when sown at 180 kg/ha. Therefore, only about 54% of seeds sown established into viable plants, even though the germination test of the seed was about 80%. The poor establishment rate is thought to be mainly due to physical damage to the seed during transport and sowing, as well as unfavourable seed-bed moisture and temperature conditions. At most experimental sites the seed yield of desi chickpea responded positively to an increase in sowing rate up to about 120 kg/ha. Increased yields at high sowing rate can be directly attributed to large plant populations. Although in many cases the number of pods per plant, seed size, and harvest index were reduced at high plant populations, increased plant density compensated for these effects and seed yield tended to increase. There was a good relationship between economic optimum plant density and yield potential derived in this study (r2 = 0.497, P< 0.001) and this improves the ability of desi chickpea producers to select the most profitable sowing rate, depending upon their yield potential. These results suggest that the optimum plant density is 50 plants/m2 for most chickpea crops in south-western Australia yielding about 1.0 t/ha, whereas in high-yielding situations (>1.5 t/ha), plant densities >70 plants/m2 produce the most profit. Although not observed in these experiments, high plant densities can exacerbate fungal diseases, and hence, reduced plant densities are desirable in disease-prone situations. Differences in sowing rate responses may be expected between Tyson and new large-seeded cultivars such as Heera and Sona, which have longer branches and more open canopy, or kabuli types, and this deserves further investigation.

2003 ◽  
Vol 43 (1) ◽  
pp. 87 ◽  
Author(s):  
K. L. Regan ◽  
K. H. M. Siddique ◽  
L. D. Martin

The effect of sowing rate (60–320 kg/ha) on the growth and seed yield of kabuli chickpea (cv. Kaniva) was assessed at 11 sites for 4 seasons in the cropping regions of south-western Australia. The economic optimum plant density and yield potential were estimated using an asymptotic model fitted to the data and calculating the sowing rate above which the cost of additional seed was equivalent to the revenue that could be achieved from the extra seed yield produced, assuming a 10 and 50% opportunity cost. On average for all sites and seasons, plant densities ranged from 10 plants/m2 when sown at 60 kg/ha to 43�plants/m2 when sown at 320 kg/ha. Assuming a mean seed weight of 400 mg and a germination of 80%, then on average 75% of viable seeds sown (or 60% of sown seeds) established as plants. The poor establishment rates are thought to be associated with reduced viability caused by mechanical damage, storage conditions, fungal infection in the soil, and unfavourable seed bed moisture and temperatures. In general, there was a positive relationship between sowing rate and seed yield. Seed yield increases at higher sowing rates were mainly associated with the greater number of plants per unit area. There were fewer pods per plant at higher sowing rates, but there were more pods per unit area. Changing the sowing rate had little effect on mean seed weight and the number of seeds per pod. The economic optimum plant density varied from 8 to 68 plants/m2, depending on the location, but the mean (27�plants/m2) was within the range currently recommended in southern Australia (25–35 plants/m2). Due to the low establishment rates observed in this study, we estimate a sowing rate greater (160–185 kg/ha) than currently suggested (110–160 kg/ha) to achieve this density. There was a strong relationship between economic optimum plant density and seed yield potential (r2 = 0.66, P<0.01), which allows an estimation of the most profitable sowing rate, depending on the seed yield potential of the site. For most crops yielding about 1.0 t/ha in southern Australia, a plant density of 25 plants/m2 is most profitable, while in higher-yielding situations (>1.5 t/ha) plant densities >35�plants/m2 will produce the most profit.


1998 ◽  
Vol 49 (6) ◽  
pp. 989 ◽  
Author(s):  
R. Jettner ◽  
S. P. Loss ◽  
L. D. Martin ◽  
K. H. M. Siddique

Sowing rate influences plant establishment, growth, seed yield, and the profitability of a crop. However, there is limited published information on the optimum sowing rate and plant density for faba bean in Australia. The response of the growth and seed yield of faba bean (cv. Fiord) to sowing rate (70-270 kg/ha) was examined in 19 field experiments conducted over 3 years in south-western Australia. The economic optimum plant density was estimated at each site by fitting an asymptotic model to the data and calculating the point where the cost of extra seed equalled the return from additional seed yield, allowing a 10% opportunity cost for the extra investment. On average across all sites and seasons, only 71% of the seeds sown emerged. Increasing sowing rate resulted in more dry matter production at first flower and at maturity, and at about half of the sites there was a small trend of reduced harvest index. In general, the mean number of seeds per pod (1·8-2·6) and mean seed weight (32-45 g/100 seeds) were unaffected by sowing rate. As sowing rate increased, the number of pods per plant (5-35) generally decreased, but this was compensated by the large plant population and more pods per unit area. The asymptotic models fitted to the seed yield data accounted for 15-81% of the variance. In 8 experiments, the models indicated that yield was continuing to increase substantially as sowing rate increased at the largest sowing rate treatment. The estimated optimum plant densities in these experiments were beyond the range of the data or had large standard errors and, hence, were excluded from any further consideration. Among the remaining 11 experiments, the estimated optimum plant densities varied from 31 to 63 plants/m2, with a mean of 45 plants/m2. This study demonstrates that targeting sowing rates greater than the current commercial practice for faba bean in southern Australia of 15-30 plants/m2 results in more yield and profit. Additional experiments are required with sowing rates in excess of 270 kg/ha to estimate accurately the optimum plant density for faba bean. Fungal diseases were either absent or controlled with fungicides in these experiments but the interactions between disease, time of sowing, and sowing rates also deserve further attention.


2002 ◽  
Vol 42 (8) ◽  
pp. 1043 ◽  
Author(s):  
M. Seymour ◽  
K. H. M. Siddique ◽  
N. Brandon ◽  
L. Martin ◽  
E. Jackson

The response of Vicia sativa (cvv. Languedoc, Blanchefleur and Morava) and V. benghalensis (cv. Barloo) seed yield to seeding rate was examined in 9 field experiments across 2 years in south-western Australia. There were 2 types of field experiments: seeding rate (20, 40, 60, 100 and 140 kg/ha) × cultivar (Languedoc, Blanchefleur, and Morava or Barloo), and time of sowing (2 times of sowing of either Languedoc or Blanchefleur) × seeding rate (5,�7.5, 10, 15, 20, 30, 40, 50, 75 and 100 kg/ha).A target density of 40 plants/m2 gave 'optimum' seed yield of vetch in south-western Australia. In high yielding situations, with a yield potential above 1.5 t/ha, the 'optimum' plant density for the early flowering cultivar Languedoc (85–97 days to 50% flowering) was increased to 60 plants/m2. The later flowering cultivar Blanchefleur (95–106 days to 50% flowering) had an optimum plant density of 33 plants/m2 at all sites, regardless of fitted maximum seed yield. Plant density in the range 31–38 plants/m2 was found to be adequate for dry matter production at maturity of Languedoc and Blanchefleur. For the remaining cultivars Barloo and Morava we were unable to determine an average optimum density for either dry matter or seed yield due to insufficient and/or inconsistent data.


1989 ◽  
Vol 113 (3) ◽  
pp. 317-323 ◽  
Author(s):  
W. Aufhammer ◽  
I. Götz-Lee

SUMMARYEffects of inflorescence removal under different plant densities and degrees of shading on seed yield of field beans (Vicia faba L.) were investigated. Two indeterminate cultivars were used in field experiments for two seasons (1985 and 1986). The hierarchy within the generative storage system of field bean plants was manipulated by removal of inflorescences at various growth stages and nodes.Removal of the inflorescences of nodes 1–3 (counted from the base upwards) caused about 30% loss of seed yield potential compared with the control but compensatory increases in seed yield were found, differing with plant density and duration of shading. Under favourable growing conditions (no shading, 20 plants/m2), overcompensation occurred, giving a mean seed yield up to 40% more than in controls.Removal of all inflorescences above the ninth flowering node did not significantly reduce seed yield as plants completely compensated for the restriction on yield imposed.


Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 445
Author(s):  
Ning Wang ◽  
Fengxin Wang ◽  
Clinton C. Shock ◽  
Chaobiao Meng ◽  
Lifang Qiao

Quinoa (Chenopodium quinoa Willd.) yield potential needs to be further achieved by good management practices to meet the increasing global demand. Two years of orthogonal field experiments were undertaken to investigate the effects of irrigation onset criteria using soil matric potential (SMP) (−15, −25, and −55 kPa), nitrogen fertilizer rate (80, 160, and 240 kg ha−1), and plant density (20, 30, and 40 plants m−2) on quinoa growth, seed yield, weight, and protein content. Initiating irrigations at an SMP of −15 to −25 kPa achieved significantly (p < 0.05) greater seed yield (37.2 g plant−1), thousand kernel weight (2.25 g), and protein content (21.2%) than −55 kPa (25.2 g plant−1, 2.08 g, and 19.8%, respectively). The 240 kg ha−1 nitrogen rate had significantly (p < 0.05) greater thousand kernel weight (2.26 g) and protein content (21.3%) than 80 (2.07 g and 19.5%, respectively) and 160 kg ha−1 (2.14 g and 20.7%, respectively). The yield under 20 plants m−2 reached 39.5 g plant−1, which was 13.5 g plant−1 higher than 40 plants m−2 (p < 0.05). The quinoa consumed most of the available nitrogen in the soil (410–860 kg ha−1), indicating that quinoa should be part of a sound crop rotation program.


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.


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.


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.


1999 ◽  
Vol 132 (2) ◽  
pp. 173-180 ◽  
Author(s):  
J. E. LEACH ◽  
H. J. STEVENSON ◽  
A. J. RAINBOW ◽  
L. A. MULLEN

The effects of plant density on the growth and yield of winter oilseed rape (Brassica napus) were examined in a series of five multifactorial experiments at Rothamsted Experimental Station between 1984 and 1989. Plant densities, manipulated by changing the seed rate and row spacing, or because of overwinter losses, ranged from 13·5 to 372 plants/m2. Normalized yields for the multifactorial plots increased with densities up to 50–60 plants/m2. In very high density plots in 1987/88, yield decreased as density increased >150 plants/m2. Plants grown at high density had fewer pod-bearing branches per plant but produced more branches/m2. Branch dry matter (DM) per plant was decreased by 42%, the number of fertile pods per plant and pod DM/plant by 37%. There was no effect of density on the number or DM of pods/m2. Over 74% of the fertile pods were carried on the terminal and uppermost branches of plants grown at high density in 1987/88 compared with only 34% in plants grown at low density in 1988/89. Seed DM/plant decreased with increase in density but seed size (1000-seed weight) increased. There was no effect of density on seed glucosinolate or oil contents.


1991 ◽  
Vol 71 (2) ◽  
pp. 481-489 ◽  
Author(s):  
J. R. Moyer ◽  
R. W. Richards ◽  
G. B. Schaalje

Alfalfa was seeded in row spacings of 36, 72 and 108 cm and at broadcast seeding rates of 0.33, 1.0 and 3.0 kg ha−1 on irrigated land at Tilley (1983) and Lethbridge (1984), Alberta to determine the effect of plant density on weed growth and alfalfa seed yield. During the seed-producing years at each location, herbicide treatments were overlaid on seeding treatments in a split-block arrangement to assess the joint effect of herbicides and plant density on alfalfa seed yield. Hexazinone was the main herbicide used for weed control. Alfalfa seed and weeds were harvested for 5 yr following alfalfa establishment. Alfalfa seed yields tended to be maximum with 36-cm row spacings or the 3.0 kg ha−1 broadcast seeding rate, and were similar in row-seeded and broadcast-seeded alfalfa. Dry matter yields of weeds decreased as row spacings decreased or the broadcast seeding rate increased. Hexazinone controlled quackgrass, sow thistle, flixweed and kochia. In the experiment at Tilley with perennial weed infestations, mean alfalfa seed yields from 1984 to 1985 were 20% larger when herbicides were used than in the untreated check. Alfalfa plant densities slightly larger than currently recommended usually produced the largest seed yields and smallest weed infestations. Key words: Medicago sativa, quackgrass, kochia, sow thistle, flixweed, hexazinone


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