Evaluation of row spacing and population density effects on grain sorghum over a range of northern Australian environments

1981 ◽  
Vol 21 (109) ◽  
pp. 210 ◽  
Author(s):  
GA Thomas ◽  
RJK Myers ◽  
MA Foale ◽  
AV French ◽  
B Hall ◽  
...  
Keyword(s):  
Population Density ◽  
Full Range ◽  
Moisture Stress ◽  
Grain Sorghum ◽  
Row Spacing ◽  
Root Pruning ◽  
Population Densities ◽  
Planting Dates ◽  
Wide Range ◽  
Growing Conditions

Fifteen experiments were conducted between 1976 and 1978 to determine the response of grain sorghum to row spacing and population density over a range of soil types, planting dates and seasonal conditions. One experiment was at Kununurra, Western Australia, and the rest were in southern and central Queensland. The trials virtually covered the full range of growing conditions likely to be experienced in the sorghum growing area. Narrow and standard single rows (0.33 m to 1.07 m spacings) yielded as well as or better than more widely spaced (1.50 to 4.27 m) single or twin rows (0.33 or 0.36 m apart) at equivalent population densities over a wide range of yield levels. Only at yield levels below 900 kg ha-l was there a trend for 2.00 or 2.13 m twin rows to outyield the 0.33 or 0.36 m single row spacing. Significant yield reductions resulted in a number of trials, at yield levels above 1600 kg ha-l, from the use of wide row spacings. Where there was severe water stress, grain yields were also reduced by high population densities (>150,000 plants ha-l), particularly at the 0.33 or 0.36 m row spacing. There was no evidence that response to row spacing differed between cultivars. In the one experiment where it was studied, root pruning had no effect on grain yield under conditions of ample moisture supply, but yield was reduced by root pruning of wide row sorghum (1.8 m spacing) under conditions of moisture stress.

EFFECTS OF ROW SPACING AND POPULATION DENSITY ON GRAIN SORGHUM PRODUCTION IN SOUTHERN ALBERTA

1976 ◽  
Vol 56 (1) ◽  
pp. 31-37 ◽  
Author(s):  
B. R. HEGDE ◽  
D. J. MAJOR ◽  
D. B. WILSON ◽  
K. K. KROGMAN
Keyword(s):  
Population Density ◽  
Grain Yield ◽  
Yield Components ◽  
Growing Season ◽  
Grain Sorghum ◽  
Row Spacing ◽  
Population Densities ◽  
Southern Alberta ◽  
Sorghum Production ◽  
Narrow Row

Row spacings of 18–72 cm and population densities of 75,000 to 346,000 plants/ha had no consistent effect on grain yield of two sorghum hybrids (Pride X4004 and Pride X4053) because of compensating variations within yield components. Grain yield per panicle increased as row spacing increased but this was offset by a decrease in panicles per plant and panicles per square meter. Grain yield per panicle, panicles per plant, and panicles per square meter decreased as population density increased. The choice of row spacing and population density in field production will, therefore, depend on convenience factors related to crop management. Evapotranspiration for the growing season was 179 mm in 1973 and 204 mm in 1974. Highest water use efficiencies occurred at the low population densities and narrow row spacings. There were differences between the two hybrids. Grain yield of Pride X4004 was greater than that of Pride X4053 because the former produced a greater number of seed-bearing tillers. Grain yield differences in Pride X4004 among the three experiments were due to differences in grain yield per panicle.

Weed control and row-spacing in dry-land sorghum in northern New South Wales

1982 ◽  
Vol 22 (117) ◽  
pp. 310 ◽  
Author(s):  
JF Holland ◽  
DW McNamara
Keyword(s):  
Weed Control ◽  
New South ◽  
New South Wales ◽  
Grain Sorghum ◽  
Weed Suppression ◽  
Row Spacing ◽  
Dry Land ◽  
Weed Growth ◽  
South Wales ◽  
Growing Conditions

Six experiments were done in northern New South Wales over three seasons to study the effect of weeds on the yield of dry-land grain sorghum and methods of weed control. The relation between crop row spacing and weed control by inter-row cultivation or atrazine (2-chloro-4-ethylamino- 6-isopropylamino-l,3,5-triazine), or both was studied. Where the site yield was high because of favourable growing conditions, an increase in the crop row spacing reduced yield. At low yielding sites, an increase in the row spacing increased yields. At most sites, weed growth was greater with wider row spacings, which resulted in a larger reduction in crop yield where weeds were not removed. Inter-row cultivation reduced weed growth to less than half that of the unweeded controls. Pre-emergent atrazine gave good weed suppression, generally reducing weed growth to less than 10% of the unweeded control when applied at 2.5 kg/ha active ingredient. Post-emergent atrazine was much less effective. Inter-row cultivation combined with a band of pre-emergent atrazine over the crop row was as effective in weed control as an overall spray of pre-emergent atrazine.

Effects of row spacing, seeding rate and nitrogen on yield of barley and wheat under zero-till management

1994 ◽  
Vol 74 (4) ◽  
pp. 703-711 ◽  
Author(s):  
G. P. Lafond
Keyword(s):  
Grain Yield ◽  
Triticum Aestivum L ◽  
Row Spacing ◽  
Continuous Cropping ◽  
Seeding Rate ◽  
Hordeum Vulgare L ◽  
Canadian Prairies ◽  
Tillage Practices ◽  
Wide Range ◽  
Growing Conditions

Adopting water-conserving tillage practices on the Canadian prairies will protect the soil against erosion while conserving soil water. The use of tall-standing stubble to conserve water creates a dilemma for producers because maximum yields can only be obtained with narrow rows, and tall stubble may limit the use of narrow row spacings. A 4-yr study on a thin Black clay soil investigated the effects of three row spacings (10, 20 and 30 cm), six seeding rates (34, 67, 100, 134, 168 and 202 kg ha−1 for wheat and 27, 54, 81, 108, 134 and 161 kg ha−1 for barley) and two rates of N (low and high) in hard red wheat (Triticum aestivum L.), durum (Triticum durum L.) and barley (Hordeum vulgare L.) using a continuous cropping, zero-till production system. The yields of cereals were maintained with 30-cm row spacing over a wide range of growing conditions under zero-till management. Durum had a 5.8% yield advantage and barley a 2.4% advantage for the 30-cm row spacing over the 10-cm row spacing. The number of plants established and the number of spikes produced decreased as row spacing increased for all crops. But wider row spacing resulted in more kernels produced per spike, which, in the case of barley and durum, more than compensated for the lower number of spikes. Increasing seeding rates significantly improved grain yield in all crops and years because more spikes were produced. Grain yield was related to the reciprocal of seeding rate. The few row spacing × seeding rate interactions observed in 2 of 12 cases suggest that seeding rates need not be adjusted for changes in row spacing. The results obtained have important implications for equipment design and the ability to more easily handle high-crop-residue situations. Key words: Yield components, seeding rate, row spacing, yield compensation

Impact of Soybean Planting Date on Soil Population Density of Macrophomina phaseolina

2007 ◽  
Vol 8 (1) ◽  
pp. 13 ◽  
Author(s):  
J. A. Wrather ◽  
J. G. Shannon ◽  
A. Mengistu
Keyword(s):  
Population Density ◽  
Soil Layer ◽  
Macrophomina Phaseolina ◽  
Planting Date ◽  
Soil Samples ◽  
Population Densities ◽  
Maturity Group ◽  
Planting Dates ◽  
Soil Population ◽  
Group 3

A field experiment was conducted during 2000-2003 near Portageville, MO to determine the affects of soybean planting date on the soil population density of Macrophomina phaseolina. The site was planted to cotton the previous 10 years. The planting dates were mid-April, mid-May, and mid-June during 2000-2003, and the cultivars FFR3975 and Asgrow 3834, maturity group 3, were very susceptible to M. phaseolina. Plots were in the same location each year. Soil samples from the top 15-cm soil layer were collected from plots during May 2000-2004 and analyzed for the population density of M. phaseolina. Planting date did not affect the soil population density of M. phaseolina, but the differences in soil population density among years were significant. These results suggest that soybean producers should not be concerned about planting date directly affecting M. phaseolina soil population densities. Accepted for publication 22 May 2007. Published 17 September 2007.

scholarly journals Depth Distribution of Rotylenchulus reniformis Under Different Tillage and Crop Sequence Systems

2003 ◽  
Vol 93 (9) ◽  
pp. 1182-1189 ◽  
Author(s):  
A. Westphal ◽  
J. R. Smart
Keyword(s):  
Population Density ◽  
Conventional Tillage ◽  
Grain Sorghum ◽  
Reduced Tillage ◽  
No Tillage ◽  
Rotylenchulus Reniformis ◽  
Population Densities ◽  
Tillage Systems ◽  
Crop Sequence ◽  
Ridge Tillage

The population density of the reniform nematode, Rotylenchulus reniformis, was monitored at depths of 0 to 30, 30 to 60, 60 to 90, and 90 to 120 cm in a tillage and crop sequence trial in south Texas in 2000 and 2001. Main plots were subjected to three different tillage systems: conventional tillage (moldboard plowing and disking), ridge tillage, and no-tillage. Subplots were planted with three different crop sequences: spring cotton and fall corn every year; spring cotton and fall corn in one year, followed by corn for two years; and cotton followed by corn and then grain sorghum, one spring crop per year. The population density of R. reniformis on corn and grain sorghum was low throughout the soil profile. In plots planted with spring cotton and fall corn every year, fewer nematodes were found at depths of 60 to 120 cm in the no-tillage and ridge tillage systems than in the conventional tillage system. Population densities were lower at depths of 0 to 60 cm than at 60 to 120 cm. Soil moisture and cotton root length did not affect nematode population densities in the field. When soil was placed in pots and planted with cotton in the greenhouse, lower population densities developed in soil taken from depths of 0 to 60 cm than in soil from depths of 60 to 120 cm. Final nematode populations were similar in size in soil from the different tillage systems, but reproductive factors were higher in soil from plots with reduced-tillage systems than in soil from plots with conventional tillage. Reduced-tillage practices lowered the risk of increases in R. reniformis populations and reduced population densities following 2 years of non-hosts throughout soil depths, but population densities resurged to the same high levels as in soil planted with cotton every year during one season of cotton.

EFFECTS OF PLANT POPULATION AND ROW SPACING ON SUNFLOWER AGRONOMY

1975 ◽  
Vol 55 (2) ◽  
pp. 491-499 ◽  
Author(s):  
K. VIJAYALAKSHMI ◽  
N. K. SANGHI ◽  
W. L. PELTON ◽  
C. H. ANDERSON
Keyword(s):  
Helianthus Annuus ◽  
Plant Height ◽  
Moisture Stress ◽  
Plant Population ◽  
Growth Characteristics ◽  
Stem Diameter ◽  
Row Spacing ◽  
Plant Populations ◽  
Helianthus Annuus L ◽  
Wide Range

Studies at Hyderabad, India, and Swift Current, Saskatchewan, Canada, have shown that sunflower (Helianthus annuus L.) can be grown under dryland conditions over a wide range of plant populations and row spacings. At Hyderabad, yield plateaus of approximately 900 and 1,350 kg/ha existed over population ranges of 18,000 to 32,000 and 56,000 to 98,000 plants/ha, respectively. At Swift Current, yields from a 25,000 plants/ha population were 28% higher than those of a 125,000. plants/ha population, but were not significantly different from the mid-range 75,000 plants/ha. Population also influenced growth characteristics such as plant height and stem diameter and the rates of development. The crop showed a remarkable tolerance to drought and the ability to recover after periods of extreme moisture stress. Populations of 60,000 to 75,000 plants/ha at row spacings of 35 to 60 cm are recommended for dryland production.

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