Effect of wheat seeding rate on wild oat competition

1980 ◽  
Vol 20 (102) ◽  
pp. 77 ◽  
Author(s):  
BJ Radford ◽  
BJ Wilson ◽  
O Cartledge ◽  
FB Watkins
Keyword(s):  
Population Density ◽  
Grain Yield ◽  
Dry Weight ◽  
Field Trials ◽  
Wild Oat ◽  
Seeding Rate ◽  
Population Densities ◽  
Wild Oats ◽  
Wheat Population ◽  
A Site

A series of field trials was sown on black earth soils on the Darling Downs, Queensland, with five wheat seeding rates x five levels of wild oat infestation. The lowest seeding rate required to produce optimum grain yield at a site was higher in wild oat infested plots than in weed-free plots. Increase in seeding rate reduced the dry weight of wild oats at maturity and increased the dry weight of wheat at maturity until wheat population density exceeded 150 plants m-2. Increase in seeding rate also reduced wild oat seed production, especially at low wild oat population densities.

Lentil (Lens culinaris) Yield as Influenced by Duration of Wild Oat (Avena fatua) Interference

Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 669-672 ◽  
Author(s):  
William S. Curran ◽  
Larry A. Morrow ◽  
Ralph E. Whitesides
Keyword(s):  
Grain Yield ◽  
Field Data ◽  
Lens Culinaris ◽  
Dry Weight ◽  
Avena Fatua ◽  
Control Measures ◽  
Wild Oat ◽  
Harvest Time ◽  
Wild Oats ◽  
Time Periods

Studies were conducted to evaluate the effect of wild oat (Avena fatua L. # AVEFA) interference in lentils (Lens culinaris Medik). An infestation of 32 and 65 wild oats/m2 maintained up to 5 weeks in the field did not reduce lentil grain yield. However, 32 wild oats/m2 reduced yields 32% when allowed to remain for 7 weeks and 49% if they remained until harvest time (11 weeks). Sixty-five wild oats/m2 reduced grain yield 42 and 61% for the same time periods, respectively. In the growth chamber, 69 wild oats/m2 reduced lentil plant dry weight 29% if allowed to remain for 3 weeks, 61% for 5 weeks, and 72% for 7 weeks (harvest time). The field data suggest that wild oat control measures may be delayed for several weeks after lentil emergence without reducing crop yield.

HARVEST INDEX AS A SELECTION CRITERION FOR GRAIN YIELD IN TWO SPRING WHEAT CROSSES GROWN AT TWO POPULATION DENSITIES

1980 ◽  
Vol 60 (4) ◽  
pp. 1141-1146 ◽  
Author(s):  
H. G. NASS
Keyword(s):  
Population Density ◽  
Grain Yield ◽  
Spring Wheat ◽  
Harvest Index ◽  
Plant Density ◽  
Selection Criterion ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Seeding Rate ◽  
Population Densities

The use of harvest index as a selection criterion for grain yield in F2 populations of spring wheat (Triticum aestivum L.) grown at two population densities was investigated. Harvest index was useful in delineating yield differences between lines for both crosses. The F4 lines selected in F2 for a high harvest index yielded about 9% more per plot in 1978 than F4 lines having a low harvest index in F2. Generally, lines selected at the higher commercial seeding rate yielded more than lines selected at the lower plant density. In 1979, a heavy Fusarium infection reduced the mean grain yield of the F6 lines and suppressed any significant response to selection resulting from population density and harvest index in F2. While selection based on high harvest index at low population density can be used to select higher yielding plants it was not as effective as selection at high population density which more closely approximates commercial crop densities. Additional research is needed before the use of harvest index as a selection tool in wheat breeding programs can be recommended for use in Atlantic Canada.

Management of wild oat (Avena fatua L.) in tame oat (Avena sativa L.) with early seeding dates and high seeding rates

2009 ◽  
Vol 89 (4) ◽  
pp. 763-773 ◽  
Author(s):  
W E May ◽  
S J Shirtliffe ◽  
D W McAndrew ◽  
C B Holzapfel ◽  
G P Lafond
Keyword(s):  
Grain Yield ◽  
Avena Sativa ◽  
Test Weight ◽  
Wild Oat ◽  
Seeding Rate ◽  
Yield And Quality ◽  
Seeding Date ◽  
Grain Yield And Quality ◽  
Oat Biomass ◽  
Density Treatment

Traditionally, farmers have delayed seeding to manage wild oat (Avena fatua L.) in tame oat (Avena sativa L.) crops, but this practice can adversely affect grain yield and quality. The objectives of this study were: (1) to evaluate the effectiveness of using high seeding rates with early-seeded oat to maintain grain yield and quality, and (2) to determine an optimum seeding rate to manage wild oat and maximize grain yield and quality. The factors of interest were wild oat density (low and high density), seeding date (early May, mid May, early June and mid June), and tame oat seeding rate (150, 250, 350 and 450 viable seeds m-2). The study was conducted at Indian Head and Saskatoon, SK, in 2002, 2003 and 2004, at Winnipeg, MB, in 2002, and at Morden, MB, in 2003 and 2004. Wild oat biomass, wild oat panicle density and wild oat seed in the harvested sample decreased as seeding rate increased, while tame oat biomass and grain yield increased. Wild oat density ranged between 0 and 100 plants m-2 with averages of 10 plants m-2 in the low density treatment and 27 plants m-2 in the high density treatment. At low seeding rates, grain yield decreased with increasing wild oat density. The difference in grain yield between the two wild oat densities decreased as the seeding rate increased. There was a curvilinear decrease in grain yield as seeding was delayed. A seeding date × seeding rate interaction was noted for test weight, plump seed, thin seed and groat yield. Seed quality improved as seeding rate increased for only the mid-June seeding date. Even though the mid-June test weight increased as the seeding rate increased it was always lower than the early May test weight at any seeding rate. The results from this study established that in the presence of wild oats, early seeding of tame oat is possible providing high seeding rates, 350 plants m-2 are used.Key words: Wild oat competition, wild oat density, wild oat biomass, grain yield, grain quality

Population dynamics and production of a brine shrimp, Parartemia zietziana Sayce (Crustacea : Anostraca), in two salt lakes in westren Victoria, Australia

1977 ◽  
Vol 28 (4) ◽  
pp. 417 ◽  
Author(s):  
R Marchant ◽  
WD Williams
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Temperature Stress ◽  
Brine Shrimp ◽  
Dry Weight ◽  
Salt Lakes ◽  
Confidence Limits ◽  
Length Frequency ◽  
Population Densities ◽  
The Mean

Quantitative samples of P. zietziana were taken monthly for two years from Pink Lake and Lake Cundare. Shrimps were usually contagiously distributed. To reduce error, samples were stratified resulting in confidence limits of 40-50% for the mean population density. Despite this variability, stable trends emerged, and variation was not so great as to mask significant differences. Length-frequency analyses distinguished cohorts; a regression was established between length and dry weight, enabling growth to be estimated from samples. By combining growth with population densities in Allen curves, production was computed. In Pink Lake and Lake Cundare mean pro- duction was 11.3 and 1.0 g dry weight m-2 year-1 respectively. Generally there were two or three generations per year, but time and extent of recruitment were not predictable. Each generation suffered continuous mortality, the death of young shrimps accounting for most of the production. This mortality remains unexplained; there are no significant predators and salinity and temperature stress would occur only during summer.

Grain Yield Gains and Associated Traits in Tropical X Temperate Maize Germplasm Under High and Low Plant Density

2021 ◽  
Author(s):  
Vince Ndou ◽  
Edmore Gasura ◽  
Pauline Chivenge ◽  
John Derera
Keyword(s):  
Population Density ◽  
Grain Yield ◽  
Plant Density ◽  
Plant Population ◽  
Population Densities ◽  
Genetic Gains ◽  
Maize Germplasm ◽  
High Plant Density ◽  
Number Of Leaves ◽  
Plant Population Density

Abstract Development of ideal breeding and crop management strategies that can improve maize grain yield under tropical environments is crucial. In the temperate regions, such yield improvements were achieved through use of genotypes that adapt high plant population density stress. However, tropical germplasm has poor tolerance to high plant population density stress, and thus it should be improved by temperate maize. The aim of this study was to estimate the genetic gains and identify traits associated with such gains in stable and high yielding temperate x tropical hybrids under low and high plant population densities. A total of 200 hybrids derived from a line x tester mating design of tropical x temperate germplasm were developed. These hybrids were evaluated for grain yield and allied traits under varied plant population densities. High yielding and stable hybrids, such as 15XH214, 15XH215 and 15XH121 were resistant to lodging and had higher number of leaves above the cob. The high genetic gains of 26% and desirable stress tolerance indices of these hybrids made them better performers over check hybrids under high plant population density. At high plant population density yield was correlated to stem lodging and number of leaves above the cob. Future gains in grain yield of these hybrids derived from temperate x tropical maize germplasm can be achieved by exploiting indirect selection for resistance to stem lodging and increased number of leaves above the cob under high plant density conditions.

Integrated Wild Oat (Avena fatua) Management Affects Spring Barley (Hordeum vulgare) Yield and Economics

1992 ◽  
Vol 6 (1) ◽  
pp. 129-135 ◽  
Author(s):  
David L. Barton ◽  
Donald C. Thill ◽  
Bahman Shafii
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Control Strategies ◽  
Integrated Control ◽  
Spring Barley ◽  
Barley Grain ◽  
Row Spacing ◽  
Wild Oat ◽  
Seeding Rate ◽  
Net Return

The effect of barley seeding rate and row spacing, and triallate, diclofop, and difenzoquat herbicide rate on barley grain yield and quality, and wild oat control were evaluated in field experiments near Bonners Ferry, Idaho, in 1989 and 1990. The purpose of the study was to develop integrated control strategies for wild oat in spring barley. Barley row spacing (9 and 18 cm) did not affect barley grain yield. Barley grain yield was greatest when barley was seeded at 134 or 201 kg ha–1compared to 67 kg ha–1. Wild oat control increased as wild oat herbicide rate increased and barley grain yield was greatest when wild oat herbicides were applied. However, barley grain yield was similar when wild oat biomass was reduced by either 65 or 85% by applications of half and full herbicide rates, respectively. Net return was greatest when the half rate of herbicide was applied to 100 wild oat plants per m2and was greatest when half or full herbicide rates were applied to 290 wild oat plants per m2. Net return increased when the seeding rate was increased to 134 or 201 kg ha–1when no herbicide was applied and when 290 wild oat plants per m2were present.

Effect of soybean population density on soybean yield, nitrogen accumulation and residual nitrogen

1988 ◽  
Vol 28 (1) ◽  
pp. 99 ◽  
Author(s):  
MJ Blumenthal ◽  
VP Quach ◽  
PGE Searle
Keyword(s):  
Population Density ◽  
Grain Yield ◽  
Dry Matter ◽  
Nitrogen Accumulation ◽  
Soil N ◽  
Population Densities ◽  
N Accumulation ◽  
Soybean Yield ◽  
Residual Nitrogen ◽  
Residual N

The effect of soybean population density on soybean yield, nitrogen accumulation and residual nitrogen was examined at Camden, N.S.W. (34�S.). In the first experiment, treatments were soybeans (cv. Ransom) at 50, 100, 200 and 400 x 103 plants ha-1; maize (cv. XL66); and a weed-free fallow. Total dry matter yields of tops and grain yields were highest at 200x 103 plants ha-1 (6214 and 3720 kg ha-1, respectively). The yield component most affected by population density was number of branches per plant, with values decreasing with increasing population density. The proportion of unfilled pods was highest at the highest population density. Total nitrogen (N) accumulation in the tops and in the grain was also at a maximum at 200x 103 plants ha-1. The rate of dry matter accumulation declined during pod filling at all population densities. N accumulation continued at high rates throughout the growing season except in the 400x 103 plants ha-1 population. There was a trend for residual dry matter and N in residues to increase with increasing population density. After grain and forage harvest of the first experiment, a crop of wheat (cv. Kite) was sown over the whole area to determine residual N available at anthesis and at maturity (experiment 2). The values of N accumulation in the wheat at maturity were 24 kg N ha-l for the maize treatment, 40-60 kg N ha-l for the soybean treatments and 69 kg N ha-1 for the fallow treatment. Grain yield and grain N followed the pattern of dry matter production and N accumulation at final harvest. The data suggest that soybean depletes soil N to a lesser extent than does maize. For the soybean treatments, there was a trend of increasing residual N at the 3 highest population densities (40-60 kg N ha-1). This was probably a result of an increase in N in leaf fall and in decaying tops and roots at the highest population density. The high value (57 kg N ha-l) at the lowest population density may be due to soybean plants at this density not using as much soil N as the other soybean treatments. No benefit in residual N was gained from planting soybeans at a density beyond the optimum for grain yield when residues were removed by forage harvesting.

PLACEMENT OF DI-ALLATE AND TRI-ALLATE FOR CONTROL OF WILD OATS IN WHEAT

1964 ◽  
Vol 44 (4) ◽  
pp. 351-358 ◽  
Author(s):  
E. S. Molberg ◽  
H. A. Friesen ◽  
E. V. McCurdy ◽  
R. D. Dryden
Keyword(s):  
Weed Control ◽  
Crop Yields ◽  
Field Trials ◽  
Severe Injury ◽  
Western Canada ◽  
Wild Oat ◽  
Wild Oats ◽  
Selective Control ◽  
Seeding Method

Two years of field trials at a number of sites in Western Canada showed that selective control of wild oats in wheat with di-allate or tri-allate was feasible if the seed was planted 3 in. deep and the chemicals incorporated shallowly after seeding. The most reliable and practical means of achieving this placement of the chemical was by harrowing immediately after application. Harrowing twice resulted in slightly better wild oat control than harrowing once, but this did not increase crop yields. At one site, in 1962, under conditions of excessive moisture and late seeding, there was severe injury to wheat. However, even here the injury was less with the post-seeding than with the pre-seeding method. There was some evidence that wheat was more tolerant to tri-allate than di-allate. Pre-seeding incorporation with the disk gave slightly better weed control than post-seeding incorporation with a double harrow, but again differences were not great enough to affect yield.

Response of flax and lentil to seeding rates, depths and spring application of dinitroanaline herbicides

1994 ◽  
Vol 74 (4) ◽  
pp. 875-882 ◽  
Author(s):  
D. A. Wall
Keyword(s):  
Population Density ◽  
Seed Yield ◽  
Linum Usitatissimum ◽  
Field Studies ◽  
Test Weight ◽  
Seeding Rate ◽  
Population Densities ◽  
Herbicide Treatment ◽  
Herbicide Treatments ◽  
One Year

Two field studies were conducted at Morden, Manitoba in 1992 and 1993 to investigate the effect of seeding depth and seeding rate on flax and lentil recovery following spring application of dinitroanaline herbicides. In the first study, the effect of seeding depth on flax and lentil tolerance to ethalfluralin, pendimethalin and trifluralin, applied preplant soil incorporated at 1.1 kg a.i. ha−1 in the spring, was investigated. Deep seeding (6 cm) reduced flax population density by 59%, averaged over 2 yr, when compared with shallow seeding (3 cm). Ethalfluralin, pendimethalin and trifluralin, reduced flax population density, but the effect of herbicide was less when flax was seeded shallow. Trifluralin and ethalfluralin reduced flax yield more when the crop was seeded deep than when seeded shallow. Herbicide treatments had no effect on flax yield when the crop was seeded shallow. Ethalfluralin and trifluralin reduced lentil population density and seed yield in one year only. Pendimethalin did not reduce lentil population density or seed yield. Deep seeding did not affect lentil population density, seed yield or phytotoxicity of dinitroanalines in this crop. In a second study, flax and lentil were seeded at 15, 30, 45, 60 and 90 kg ha−1 at 3 and 6 cm planting depths to assess the effect of seeding depth and seeding rate on crop recovery following spring application of ethalfluralin. In ethalfluralin treated plots, seeding rate had to be increased from 60 to > 90 kg ha−1 to achieve similar population densities as 45 kg ha−1 in untreated plots. Flax yields were unaffected by ethalfluralin when the crop was seeded shallow, but yields were reduced significantly when the crop was seeded deep. Lentil population density increased linearly with seeding rate. Lentil population density was unaffected by seeding depth or herbicide treatment. Ethalfluralin did not reduce lentil yield in either year. Lentil yields increased with seeding rate up to 30 kg ha−1, with little further increase in yield for seeding rates between 30 and 90 kg ha−1. Key words:Lens culinaris, Linum usitatissimum, population density, seeding depth, seeding rate, yield, seed test weight, ethalfluralin, pendimethalin, trifluralin

scholarly journals Drought response of modern and old oat lines in greenhouse and long-term field trials

1997 ◽  
Vol 6 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Pirjo Mäkelä ◽  
Leena Väärälä ◽  
Riikka Rajalahti ◽  
Ari Rajala ◽  
Pirjo Peltonen-Sainio
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Field Trials ◽  
Drought Response ◽  
Wild Oat ◽  
Greenhouse Experiments ◽  
Plant Breeding Institute ◽  
The University ◽  
Term Field

This study compares the response of old and modern oat (Avena sutiva L.) lines to pre-anthesis precipitation in long-term field trials, and to pre- and post-anthesis drought in the greenhouse. Long-term field trials were carried out at the Experimental Farms of Hankkija Plant Breeding Institute and the University of Helsinki between 1965 and 1988. Grain yield of 12 oat lines (released since 1959) was compared with that of the check lines. The effect of differences in May-June precipitation on grain yield was established for different lines. Greenhouse experiments included 19 oat lines (released since 1921) and three wild species of oat (A. barbata L., A. sterilis max. L. and A. fatua L.). The data from greenhouse experiments were analysed using discriminant analysis in groups of old (released before 1970s), modern, and wild oat types. Ranking of the oat lines according to results from long-term field trials and greenhouse experiments was not consistent; contrary to the field experiments, the old lines tended to be the most drought sensitive when tested in the greenhouse. Therefore, the simple and non-laborious methods used in this study for ranking of drought sensitivity of oat lines are not recommended.

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